vol.49 no.2 june 2015 Prva in edina samostojna kemoterapija, ki v primerjavi z ostalimi možnostmi zdravljenja z enim zdravilom, pri bolnicah s predhodno že večkratno zdravljenim metastatskim rakom dojke, dokazano značilno podaljša celokupno preživetje.1,2 NOVA SMER DO PODALJŠANJA CELOKUPNEGA PREŽIVETJA Halaven (eribulin): ne-taksanski zaviralec dinamike mikrotubulov,prvo zdravilo iz noveskupinekemoterapevtikov, imenovanih halihondrini. Zdravilo HALAVEN je indicirano za zdravljenje bolnic z lokalno napredovalim ali metastatskimrakomdojke,kije napredovalpovsaj enemrežimukemoterapije za napredovalo bolezen. Predhodna zdravljenja morajo vključevati antraciklin in taksan, bodisi kot adjuvantno zdravljenje ali za zdravljenje metastatskega raka dojke, razen če to zdravljenje za bolnice ni bilo primerno.1 Priporočeni odmerek1,23mg/m2, intravensko,v obliki2-do 5-minutne infuzije, 1.in8.danvsakega21-dnevnega cikla. Ena2ml vialavsebuje 0,88mg eribulina. Raztopina, pripravljena za uporabo, redčenje ni potrebno. SKRAJŠAN POVZETEK GLAVNIH ZNAČILNOSTI ZDRAVILA HALAVEN 0,44 mg/ml raztopina za injiciranje (eribulin) TERAPEVTSKE INDIKACIJE: Zdravljenje lokalno napredovalega ali metastatskega raka dojke, ki je napredoval po vsaj enem režimu kemoterapije za napredovalo bolezen vključno z antraciklinom in taksanom (adjuvantno zdravljenje ali zdravljenje metastatskega raka dojke), razen če to ni bilo primerno. ODMERJANJE IN NAČIN UPORABE: Halaven se daje v enotah, specializiranih za dajanje citotoksične kemoterapije, in le pod nadzorom usposobljenega zdravnika z izkušnjami v uporabi citotoksičnih zdravil. Odmerjanje: Priporočeni odmerek eribulina v obliki raztopine je 1,23 mg/m2 i.v. v obliki 2- do 5-minutne infuzije 1. in 8. dan vsakega 21-dnevnega cikla. Bolnikom je lahko slabo ali bruhajo. Treba je razmisliti o antiemetični profilaksi, vključno s kortikosteroidi. Preložitev odmerka med zdravljenjem: Dajanje Halavena je treba preložiti, če se pojavi kaj od naslednjega: absolutno število nevtrofilcev (ANC) < 1 x 109/l, trombociti < 75 x 109/l ali nehematološki neželeni učinki 3. ali 4. stopnje. Zmanjšanje odmerka med zdravljenjem: Za priporočila za zmanjšanje odmerka ob pojavu hematoloških ali nehematoloških neželenih učinkov glejte celoten povzetek glavnih značilnosti zdravila. Okvara jeter zaradi zasevkov: Priporočeni odmerek pri blagi okvari jeter (stopnje A po Child-Pughu) je 0,97 mg/m2 v obliki 2- do 5-minutne i.v. infuzije 1. in 8. dan 21-dnevnega cikla. Priporočeni odmerek pri zmerni okvari jeter (stopnje B po Child-Pughu) je 0,62 mg/m2 v obliki 2- do 5-minutne i.v. infuzije 1. in 8. dan 21-dnevnega cikla. Pri hudi okvari jeter (stopnje C po Child-Pughu) se pričakuje, da je treba dati še manjši odmerek eribulina. Okvara jeter zaradi ciroze: Zgornje odmerke se lahko uporabi za blago do zmerno okvaro, vendar se priporoča skrbno nadziranje, saj bo odmerke morda treba ponovno prilagoditi. Okvara ledvic: Pri hudi okvari ledvic (očistek kreatinina < 40 ml/min) bo morda treba odmerek zmanjšati. Priporoča se skrbno nadziranje varnosti. Način uporabe: Odmerek se lahko razredči z do 100 ml 0,9 % raztopine natrijevega klorida (9 mg/ml) za injiciranje. Ne sme se ga redčiti v 5 % infuzijski raztopini glukoze. Pred dajanjem glejte navodila glede redčenja zdravila v celotnem povzetku glavnih značilnosti zdravila ter se prepričajte, da obstaja dober periferni venski dostop ali prehodna centralna linija. Ni znakov, da bi eribulin povzročal mehurje ali dražil. V primeru ekstravazacije mora biti zdravljenje simptomatsko. KONTRAINDIKACIJE: Preobčutljivost na zdravilno učinkovino ali katerokoli pomožno snov. Dojenje. POSEBNA OPOZORILA IN PREVIDNOSTNI UKREPI: Mielosupresija je odvisna od odmerka in se kaže kot nevtropenija. Pred vsakim odmerkom eribulina je treba opraviti pregled celotne krvne slike. Zdravljenje z eribulinom se lahko uvede le pri bolnikih z vrednostmi ANC . 1,5 x 109/l in s trombociti > 100 x 109/l. Bolnike, pri katerih se pojavijo febrilna nevtropenija, huda nevtropenija ali trombocitopenija, je treba zdraviti v skladu s priporočili v celotnem povzetku glavnih značilnosti zdravila. Hudo nevtropenijo se lahko zdravi z uporabo G-CSF ali enakovrednim zdravilom v skladu s smernicami. Bolnike je treba skrbno nadzirati za znake periferne motorične in senzorične nevropatije. Pri razvoju hude periferne nevrotoksičnosti je treba odmerek prestaviti ali zmanjšati. Če začnemo zdravljenje pri bolnikih s kongestivnim srčnim popuščanjem, z bradiaritmijami ali sočasno z zdravili, za katera je znano, da podaljšujejo interval QT, vključno z antiaritmiki razreda Ia in III, in z elektrolitskimi motnjami, je priporočljivo spremljanje EKG. Pred začetkom zdravljenja s Halavenom je treba popraviti hipokaliemijo in hipomagneziemijo in te elektrolite je treba občasno kontrolirati med zdravljenjem. Eribulina ne smemo dajati bolnikom s prirojenim sindromom dolgega intervala QT. To zdravilo vsebuje majhne količine etanola (alkohola), manj kot 100 mg na odmerek. Eribulin je pri podganah embriotoksičen, fetotoksičen in teratogen. Halavena se ne sme uporabljati med nosečnostjo, razen kadar je to nujno potrebno. Ženske v rodni dobi naj ne zanosijo v času, ko same ali njihov moški partner dobivajo Halaven, in naj med zdravljenjem in še do 3 mesece po njem uporabljajo učinkovito kontracepcijo. Moški naj se pred zdravljenjem posvetujejo o shranjevanju sperme zaradi možnosti nepopravljive neplodnosti. INTERAKCIJE: Eribulin se izloča do 70 % prek žolča. Sočasna uporaba učinkovin, ki zavirajo jetrne transportne beljakovine, kot so beljakovine za prenos organskih anionov in beljakovine, odporne na številna zdravila, z eribulinom se ne priporoča (npr. ciklosporin, ritonavir, sakvinavir, lopinavir in nekateri drugi zaviralci proteaze, efavirenz, emtricitabin, verapamil, klaritromicin, kinin, kinidin, dizopiramid itd). Sočasno zdravljenje z indukcijskimi učinkovinami, kot so rifampicin, karbamazepin, fenitoin, šentjanževka, lahko povzroči znižanje koncentracij eribulina v plazmi, zato je ob sočasni uporabi induktorjev potrebna previdnost. Eribulin je blag inhibitor encima CYP3A4. Priporočljiva je previdnost in spremljanje glede neželenih učinkov pri sočasni uporabi snovi, ki imajo ozko terapevtsko okno in se odstranjujejo iz telesa predvsem preko CYP3A4 (npr. alfentanil, ciklosporin, ergotamin, fentanil, pimozid, kinidin, sirolimus, takrolimus). NEŽELENI UČINKI: Povzetek varnostnega profila Neželeni učinek, o katerem najpogosteje poročajo v zvezi s Halavenom, je supresija kostnega mozga, ki se kaže kot nevtropenija, levkopenija, anemija, trombocitopenija s pridruženimi okužbami. Poročali so tudi o novem začetku ali poslabšanju že obstoječe periferne nevropatije. Med neželenimi učinki, o katerih poročajo, je toksičnost za prebavila, ki se kaže kot anoreksija, navzea, bruhanje, driska, zaprtost in stomatitis. Med drugimi neželenimi učinki so utrujenost, alopecija, zvečani jetrni encimi, sepsa in mišičnoskeletni bolečinski sindrom. Seznam neželenih učinkov: Zelo pogosti (. 1/10): nevtropenija (57,0 %) (3./4. stopnje: 49,7 %), levkopenija (29,3 %) (3./4. stopnje: 17,3 %), anemija (20,6 %) (3./4. stopnje: 2,0 %), zmanjšan apetit (21,9 %) (3./4. stopnje: 0,7 %), periferna nevropatija (35,6 %) (3./4. stopnje: 7,6 %), glavobol (17,2 %) (3./4. stopnje: 0,8 %), dispnea (13,9 %) (3./4. stopnje: 3,1 %), kašelj (13,6 %) (3./4. stopnje: 0,6 %), navzea (33,8 %) (3./4. stopnje: 1,1 %), zaprtost (19,6 %) (3./4. stopnje: 0,6 %), driska (17,9 %) (3./4. stopnje: 0,8 %), bruhanje (17,6 %) (3./4. stopnje: 0,9 %), alopecija, artralgija in mialgija (19,4 %) (3./4. stopnje: 1,1 %), bolečina v hrbtu (13,0 %) (3./4. stopnje: 1,5 %), bolečina v udu (10,0 %) (3./4. stopnje: 0,7 %), utrujenost/astenija (47,9 %) (3./4. stopnje: 7,8 %), pireksija (20,4 %) (3./4. stopnje: 0,6 %), zmanjšanje telesne mase (11,3 %) (3./4. stopnje: 0,3 %). Pogosti (. 1/100 do < 1/10): okužba sečil (8 %) (3./4. stopnje: 0,5 %), pljučnica (1,2 %) (3./4. stopnje: 0,8 %), ustna kandidiaza, ustni herpes, okužba zgornjih dihal, nazofaringitis, rinitis, limfopenija (4,9 %) (3./4. stopnje: 1,4 %), febrilna nevtropenija (4,7 %) (3./4. stopnje: 4,5 %), trombocitopenija (4,3 %) (3./4. stopnje: 0,7 %), hipokaliemija (6,1 %) (3./4. stopnje: 1,7 %), hipomagneziemija (2,9 %) (3./4. stopnje: 0,2 %), dehidracija (2,8 %) (3./4. stopnje: 0,5 %), hiperglikemija, hipofosfatemija, nespečnost, depresija, disgevzija, omotičnost (7,9 %) (3./4. stopnje: 0,5 %), hipoestezija, letargija, nevrotoksičnost, obilnejše solzenje (6,0 %) (3./4. stopnje: 0,1 %), konjunktivitis, vrtoglavica, tahikardija, vročinski valovi, orofaringealna bolečina, epistaksa, rinoreja, bolečina v trebuhu, stomatitis (9,3 %) (3./4. stopnje: 0,8 %), suha usta, dispepsija (5,9 %) (3./4. stopnje: 0,2 %), gastroezofagealna refluksna bolezen, razjede v ustih, distenzija trebuha, zvišanje alanin-aminotransferaze (7,6 %) (3./4. stopnje: 2,1 %), zvišanje aspartat-aminotransferaze (7,4 %) (3./4. stopnje: 1,5 %), zvišanje gama-glutamiltransferaze (1,8 %) (3./4. stopnje: 0,9 %), hiperbilirubinemija (1,5 %) (3./4. stopnje: 0,3 %), izpuščaj, pruritus (3,9 %) (3./4. stopnje: 0,1 %), bolezni nohtov, nočno potenje, suha koža, eritem, hiperhidroza, bolečina v kosteh (9,6 %) (3./4. stopnje: 1,7 %), mišični spazmi (5,1 %) (3./4. stopnje: 0,1 %), mišično-skeletna bolečina in mišično­skeletna bolečina v prsih, mišična oslabelost, disurija, vnetje sluznice (8,3 %) (3./4. stopnje: 1,1 %), periferni edem, bolečina, mrzlica, bolečina v prsih, gripi podobna bolezen. Občasni (. 1/1.000 do < 1/100): sepsa (0,5 %) (3./4. stopnje: 0,2 %), nevtropenična sepsa (0,1 %) (3./4. stopnje: 0,1 %), herpes zoster, tinitus, globoka venska tromboza, pljučna embolija, hepatotoksičnost (1,0 %) (3./4. stopnje: 0.6 %), palmarno-plantarna eritrodisestezija, hematurija, proteinurija, odpoved ledvic. Redki (. 1/10.000 do < 1/1.000): diseminirana intravaskularna koagulacija, intersticijska pljučna bolezen, pankreatitis, angioedem. Za popoln opis neželenih učinkov glejte celoten povzetek glavnih značilnosti zdravila. Vrsta ovojnine in vsebina: viala z 2 ml raztopine. Režim izdaje: H Imetnik dovoljenja za promet: Eisai Europe Ltd, European Knowledge Centre, Mosquito Way, Hatfield, Hertfordshire, AL10 9SN, Velika Britanija HAL-270614, julij 2014 Pred predpisovanjem in uporabo zdravila prosimo preberite celoten povzetek glavnih značilnosti zdravila! Viri: (1) Povzetek glavnih značilnosti zdravila Halaven, junij 2014; (2) Cortes J et al. Lancet 2011; 377: 914–23. Odgovoren za trženje v Sloveniji: PharmaSwiss d.o.o., Brodišče 32, 1236 Trzin telefon: +386 1 236 47 00, faks: +386 1 283 38 10 HAL-0714-01, julij 2014 Publisher Association of Radiology and Oncology Affiliated with Slovenian Medical Association – Slovenian Association of Radiology, Nuclear Medicine Society, Slovenian Society for Radiotherapy and Oncology, and Slovenian Cancer Society Croatian Medical Association – Croatian Society of Radiology Societas Radiologorum Hungarorum Friuli-Venezia Giulia regional groups of S.I.R.M. Italian Society of Medical Radiology Aims and scope Radiology and Oncology is a journal devoted to publication of original contributions in diagnostic and interventional radiology, computerized tomography, ultrasound, magnetic resonance, nuclear medicine, radiotherapy, clinical and experimental oncology, radiobiology, radiophysics and radiation protection. Editor-in-Chief Gregor Serša, Institute of Oncology Ljubljana, Department of Experimental Oncology, Ljubljana, Slovenia Executive Editor Viljem Kovač, Institute of Oncology Ljubljana, Department of Radiation Oncology, Ljubljana, Slovenia Editorial Board Sotirios Bisdas, University Clinic Tübingen, Department of Neuroradiology, Tübingen, Germany Karl H. Bohuslavizki, Facharzt für Nuklearmedizin, Hamburg, Germany Serena Bonin, University of Trieste, Department of Medical Sciences, Trieste, Italy Boris Brkljačić, University Hospital “Dubrava”, Department of Diagnostic and Interventional Radiology, Zagreb, Croatia Luca Campana, Veneto Institute of Oncology (IOV-IRCCS), Padova, Italy Christian Dittrich, Kaiser Franz Josef - Spital, Vienna, Austria Metka Filipič, National Institute of Biology, Department of Genetic Toxicology and Cancer Biology, Ljubljana, Slovenia Maria Gődény, National Institute of Oncology, Budapest, Hungary Janko Kos, University of Ljubljana, Faculty of Pharmacy, Ljubljana, Slovenia Robert Jeraj, University of Wisconsin, Carbone Cancer Center, Madison, Wisconsin, USA Advisory Committee Tullio Giraldi, University of Trieste, Faculty of Medicine and Psychology, Trieste, Italy Vassil Hadjidekov, Medical University, Department of Diagnostic Imaging, Sofia, Bulgaria Deputy Editors Andrej Cör, University of Primorska, Faculty of Health Science, Izola, Slovenia Maja Čemažar, Institute of Oncology Ljubljana, Department of Experimental Oncology, Ljubljana, Slovenia Igor Kocijančič, University Medical Centre Ljubljana, Institute of Radiology, Ljubljana, Slovenia Karmen Stanič, Institute of Oncology Ljubljana, Department of Radiation Oncology, Ljubljana, Slovenia Primož Strojan, Institute of Oncology Ljubljana, Department of Radiation Oncology, Ljubljana, Slovenia Tamara Lah Turnšek, National Institute of Biology, Ljubljana, Slovenia Damijan Miklavčič, University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia Luka Milas, UT M. D. Anderson Cancer Center, Houston , USA Damir Miletić, Clinical Hospital Centre Rijeka, Department of Radiology, Rijeka, Croatia Häkan Nyström, Skandionkliniken, Uppsala, Sweden Maja Osmak, Ruder Bošković Institute, Department of Molecular Biology, Zagreb, Croatia Dušan Pavčnik, Dotter Interventional Institute, Oregon Health Science Universityte, Oregon, Portland, USA Geoffrey J. Pilkington, University of Portsmouth, School of Pharmacy and Biomedical Sciences, Portsmouth, UK Ervin B. Podgoršak, McGill University, Montreal, Canada Matthew Podgorsak, Roswell Park Cancer Institute, Departments of Biophysics and Radiation Medicine, Buffalo, NY ,USA Marko Hočevar, Institute of Oncology Ljubljana, Department of Surgical Oncology, Ljubljana, Slovenia Miklós Kásler, National Institute of Oncology, Budapest, Hungary Csaba Polgar, National Institute of Oncology, Budapest, Hungary Dirk Rades, University of Lubeck, Department of Radiation Oncology, Lubeck, Germany , Mirjana Rajer, Institute of Oncology Ljubljana, Department of Radiation Oncology, Ljubljana, Slovenia Luis Souhami, McGill University, Montreal, Canada Borut Štabuc, University Medical Centre Ljubljana, Department of Gastroenterology, Ljubljana, Slovenia Katarina Šurlan Popovič, University Medical Center Ljubljana, Clinical Institute of Radiology, Ljubljana, Slovenia Justin Teissié, CNRS, IPBS, Toulouse, France Gillian M.Tozer, University of Sheffield, Academic Unit of Surgical Oncology, Royal Hallamshire Hospital, Sheffield, UK Andrea Veronesi, Centro di Riferimento Oncologico- Aviano, Division of Medical Oncology, Aviano, Italy Branko Zakotnik, Institute of Oncology Ljubljana, Department of Medical Oncology, Ljubljana, Slovenia Stojan Plesničar, Institute of Oncology Ljubljana, Department of Radiation Oncology, Ljubljana, Slovenia Tomaž Benulič, Institute of Oncology Ljubljana, Department of Radiation Oncology, Ljubljana, Slovenia Radiol Oncol 2015; 49(2): A. Editorial office Radiology and Oncology Zaloška cesta 2 P. O. Box 2217 SI-1000 Ljubljana Slovenia Phone: +386 1 5879 369 Phone/Fax: +386 1 5879 434 E-mail: gsersa@onko-i.si Copyright © Radiology and Oncology. All rights reserved. Reader for English Vida Kološa Secretary Mira Klemenčič Zvezdana Vukmirović Design Monika Fink-Serša, Samo Rovan, Ivana Ljubanović Layout Matjaž Lužar Printed by Tiskarna Ozimek, Slovenia Published quarterly in 400 copies Beneficiary name: DRUŠTVO RADIOLOGIJE IN ONKOLOGIJE Zaloška cesta 2 1000 Ljubljana Slovenia Beneficiary bank account number: SI56 02010-0090006751 IBAN: SI56 0201 0009 0006 751 Our bank name: Nova Ljubljanska banka, d.d., Ljubljana, Trg republike 2, 1520 Ljubljana; Slovenia SWIFT: LJBASI2X Subscription fee for institutions EUR 100, individuals EUR 50 The publication of this journal is subsidized by the Slovenian Research Agency. Indexed and abstracted by: • Celdes • Chemical Abstracts Service (CAS) • Chemical Abstracts Service (CAS) - SciFinder • CNKI Scholar (China National Knowledge Infrastructure) • CNPIEC • DOAJ • EBSCO - Biomedical Reference Collection • EBSCO - Cinahl • EBSCO - TOC Premier • EBSCO Discovery Service • Elsevier - EMBASE • Elsevier - SCOPUS • Google Scholar • J-Gate • JournalTOCs • Naviga (Softweco) • Primo Central (ExLibris) • ProQuest - Advanced Technologies Database with Aerospace • ProQuest - Health & Medical Complete This journal is printed on acid- free paper On the web: ISSN 1581-3207 http://www.degruyter.com/view/j/raon http://www.radioloncol.com • ProQuest - Illustrata: Health Sciences • ProQuest - Illustrata: Technology • ProQuest - Medical Library • ProQuest - Nursing & Allied Health Source • ProQuest - Pharma Collection • ProQuest - Public Health • ProQuest - Science Journals • ProQuest - SciTech Journals • ProQuest - Technology Journals • PubMed • PubsHub • ReadCube • SCImago (SJR) • Summon (Serials Solutions/ProQuest) • TDOne (TDNet) • Thomson Reuters - Journal Citation Reports/Science Edition • Thomson Reuters - Science Citation Index Expanded • Ulrich's Periodicals Directory/ulrichsweb • WorldCat (OCLC) Radiol Oncol 2015; 49(2): B. contents review 107 Blood-brain barrier permeability imaging using perfusion computed tomography Jernej Avsenik, Sotirios Bisdas, Katarina Surlan Popovic nuclear medicine 115 Evaluation of radiographic and metabolic changes in bone metastases in response to systemic therapy with 18FDG-PET/CT Bengul Gunalp, Ali Ozan Oner, Semra Ince, Engin Alagoz, Asli Ayan, Nuri Arslan 121 Thyroid lesion incidentally detected by 18F-FDG PET-CT – a two centre retrospective study Jan Jamsek, Ivana Zagar, Simona Gaberscek, Marko Grmek radiology 128 Primary central nervous system lymphoma: is absence of intratumoral hemorrhage a characteristic finding on MRI Akihiko Sakata, Tomohisa Okada, Akira Yamamoto, Mitsunori Kanagaki, Yasutaka Fushimi, Toshiki Dodo, Yoshiki Arakawa, Jun C. Takahashi, Susumu Miyamoto, Kaori Togashi 135 Doppler ultrasound for diagnosis of soft tissue sarcoma: efficacy of ultrasound-based screening score Satoshi Nagano, Yuhei Yahiro, Masahiro Yokouchi, Takao Setoguchi, Yasuhiro Ishidou, Hiromi Sasaki, Hirofumi Shimada, Ichiro Kawamura, Setsuro Komiya 141 Artery of Percheron infarction: review of literature with a case report Urska Lamot, Ivana Ribaric, Katarina Surlan Popovic experimental oncology 147 Feasibility and safety of electrochemotherapy (ECT) in the pancreas: a pre-clinical investigation Roberto Girelli, Simona Prejano, Ivana Cataldo, Vincenzo Corbo, Lucia Martini, Aldo Scarpa, Bassi Claudio Radiol Oncol 2015; 49(2): C. clinical oncology 155 Efficacy of intensity-modulated radiotherapy with concurrent carboplatin in nasopharyngeal carcinoma Anussara Songthong, Chakkapong Chakkabat, Danita Kannarunimit, Chawalit Lertbutsayanukul 163 Preoperative treatment with radiochemotherapy for locally advanced gastroesophageal junction cancer and unresectable locally advanced gastric cancer Ivica Ratosa, Irena Oblak, Franc Anderluh, Vaneja Velenik, Jasna But-Hadzic, Ajra Secerov Ermenc, Ana Jeromen 173 Febrile neutropenia in chemotherapy treated small-cell lung cancer patients Renata Rezonja Kukec, Iztok Grabnar, Tomaz Vovk, Ales Mrhar, Viljem Kovac, Tanja Cufer 181 Mesenteric ischemia after capecitabine treatment in rectal cancer and resultant short bowel syndrome is not an absolute contraindication for radical oncological treatment Ana Perpar, Erik Brecelj, Nada Rotovnik Kozjek, Franc Anderluh, Irena Oblak, Marija Skoblar Vidmar, Vaneja Velenik 185 Clinical applicability of biologically effective dose calculation for spinal cord in fractionated spine stereotactic body radiation therapy Seung Heon Lee, Kyu Chan Lee, Jinho Choi, So Hyun Ahn, Seok Ho Lee, Ki Hoon Sung, Se Hee Kil radiophysics 192 Dynamic CT angiography for cyberknife radiosurgery planning of intracranial arteriovenous malformations: a technical/feasibility report Anoop Haridass, Jillian Maclean, Santanu Chakraborty, John Sinclair,Janos Szanto, Daniela Iancu, Shawn Malone special communication 200 The cost of systemic therapy for metastatic colorectal carcinoma in Slovenia: discrepancy analysis between cost and reimbursement Tanja Mesti, Biljana Mileva Boshkoska, Mitja Kos, Metka Tekavčič, Janja Ocvirk I slovenian abstracts Radiol Oncol 2015; 49(2): D. 107 review Blood-brain barrier permeability imaging using perfusion computed tomography Jernej Avsenik1, Sotirios Bisdas2, Katarina Surlan Popovic1 1 Institute of Radiology, University Medical Centre Ljubljana, Slovenia 2 Department of Neuroradiology, Eberhard Karls University, Tubingen, Germany Radiol Oncol 2015; 49(2): 107-114. Received 2 December 2013 Accepted 2 March 2014 Correspondence to: Jernej Avsenik, M.D., Institute of Radiology, University Medical Centre Ljubljana, Zaloška cesta 7, SI-1000 Ljubljana, Slovenia. E-mail: jernej.avsenik@gmail.com Disclosure: No potential conflicts of interest were disclosed. Background. The blood-brain barrier represents the selective diffusion barrier at the level of the cerebral microvas­cular endothelium. Other functions of blood-brain barrier include transport, signaling and osmoregulation. Endothelial cells interact with surrounding astrocytes, pericytes and neurons. These interactions are crucial to the development, structural integrity and function of the cerebral microvascular endothelium. Dysfunctional blood-brain barrier has been associated with pathologies such as acute stroke, tumors, inflammatory and neurodegenerative diseases. Conclusions. Blood-brain barrier permeability can be evaluated in vivo by perfusion computed tomography - an efficient diagnostic method that involves the sequential acquisition of tomographic images during the intravenous administration of iodinated contrast material. The major clinical applications of perfusion computed tomography are in acute stroke and in brain tumor imaging. Key words: blood-brain barrier, permeability imaging, computed tomography; perfusion CT Introduction The blood-brain barrier (BBB) is the system of tightly regulated anatomical and biochemical mechanisms that protects the brain from harmful compounds in the peripheral circulation, supplies brain cells with nutrients, functions as a dynamic regulator of ion balance and filters harmful sub­stances from the brain to the bloodstream.1,2 It also restricts the entering of T-lymphocytes, maintain­ing the immune-privileged status of the brain.3 The BBB primarily represents the selective diffusion barrier at the level of the cerebral microvascular endothelium. Capillary lumen is enclosed by a sin­gle endothelial cell, characterized by the presence of tight junctions (TJ), the absence of fenestrations, increased number of mitochondria and minimal pinocytic activity in comparison to peripheral en­dothelium. Pericytes are attached to the abluminal membrane of the endothelium and together they are enclosed by the basal lamina, which is con­tiguous with the plasma membrane of astrocyte end-feet.2 Under physiologic conditions, the BBB is relatively impermeable. However, in pathologic conditions such as neoplasm, inflammatory/infec­tious disease and ischemia, the BBB permeability (BBBP) is increased4 and the diffusion of molecules into the extravascular space is enhanced.5,6 The in­creased BBBP can be evaluated in vivo by means of perfusion computed tomography (PCT) imaging.7,8 Blood-brain barrier cellular structures Brain microvasculature endothelial cells Brain endothelial cells represent the essential com­ponent of the BBB, performing functions such as diffusion barrier, transport, signaling, leukocyte transport and osmoregulation.1 Functional polarity exists between the apical and basolateral surface of the endothelial cell, which is evident by asymmet­rical distribution of various transport-related carri­ers and enzymes present in the luminal and ablu­ 108 minal membranes.9,10 Endothelial cells are connect­ed at the point of junctional complex, comprised predominantly of TJs and adherent junctions. TJs, the critical component of BBB, are complex structures of intracellular and trans-membrane proteins, bound to an active cytoskeleton. This structure enables the tightness, as well as pre­serves the capacity for rapid regulation and func­tional modulation.9 Three major trans-membrane protein components of TJs are occludins11, clau­dins12, and the group of immunoglobulin gene superfamily proteins, namely junctional adhesion molecules (JAMs)13 and the endothelial selective adhesion molecules (ESAMs).14 These molecules are connected to a group of intracellular proteins called membrane-associated guanylate kinases (MAGUK) which function as a cytoplasmic adap­tor proteins.1,9 First order adaptor proteins are zonula occludens (ZO-1, ZO-2 and ZO-3) and Ca2+-dependent protein serine kinase15-17, while the second order adapter proteins include cin­gulin, afadin and function-associated coiled-coil protein (JACOP). Besides providing the structural support, these proteins also interact with a large number of signaling and regulatory molecules, en­abling the regulation of BBB permeability through local chemical signals. In addition to tight junc­tions, endothelial cells are also joined by adherent junctions, composed of transmembrane protein VE-cadherin, connected to cytoskeleton via caten­ins.9 Tightness of the BBB is also provided on the en­zymatic level. Numerous enzymes were found to be present in BBB elements in significantly higher concentrations than in peripheral vessels. These enzymes metabolize neuroactive blood-borne products and include .-glutamyl transpeptidase, alkaline phosphatase, aromatic acid decarboxylase and cytochrome 450 enzymes.9,18 Various transport systems are also crucial for the proper functioning of BBB. For instance, car­rier-mediated transport represents highly specific system that allows the selective transport of small molecules, such as amino-acids, hexoses, nucleo­sides, amines and vitamins.9,18 Intracellular pH of endothelial cells as well as the optimal ion gradient across the membrane are provided by ion transport­ers, namely the sodium pump, sodium-potassium­two chloride co-transporter, chloride-bicarbonate exchanger and the sodium-hydrogen exchanger.18 Active efflux systems such as ATP-binding cas­sette (ABC) transporters, the multidrug resistance transporter P-glycoprotein (P-gp) and the group of multidrug resistance-associated proteins (MDRs) prevent the passage of drugs and toxins across the BBB and facilitate the efflux of neuroactive solutes from brain to blood. The transport across BBB for larger molecules like transferrin, low density lipo­protein, IgG, insulin and insulin like growth factor is provided by receptor mediated transport called transcytosis. Finally, absorptive mediated endo­cytosis represents less selective form of transport, initiated by polycathionic molecules binding to negatively charged plasma membrane.9 Astrocytes, pericytes and neurons Interactions of endothelial cells with surrounding cells as well as the extracellular matrix are crucial to their development, structural integrity1 and function.19,20 Astrocytes are glial cells whose end feet cover over 99% of the outer surface of the BBB endothelium.1,20 Soluble factors released by astro­cytes play important role in enhancing TJs, reduc­ing gap junctional area21 and also regulating water and electrolyte metabolism in the brain.22 Pericytes contribute to the low paracellular per­meability of the BBB, perform a regulatory role in brain homeostasis, participate in vascular devel­opment and maintenance and also represent the source of adult pluripotent stem cells. Moreover, contractile, immune, phagocytic and migratory functions of pericytes have been described.20 Temporally and spatially adjusted blood sup­ply in accordance to metabolic requirements of neurons is provided by intense communication between neurons, astrocytes and BBB. In addition to direct innervation of endothelial cells, neurons can regulate the BBB function through induction of specific enzymes in response to metabolic needs.20 Blood-brain barrier in pathology BBB dysfunction can range from mild and tran­sient TJ opening to chronic barrier breakdown and has been associated with pathologies such as ischemia, tumors, multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, epilepsy, glaucoma and lysosomal storage diseases.23 Hypoxia is the end point in many disorders such as acute stroke, cardiac arrest, carbon monoxide poisoning, respiratory distress and rapid ascent to high altitude and leads to increased BBB perme­ability, edema and tissue damage.3 Early interven­tions to reduce long term disease progression and disability rely on efficient diagnostic methods to identify the site and extent of BBB disturbance.23,24 109 Perfusion computed tomography for the evaluation of blood-brain barrier permeability The advent of fast computed tomography (CT) scanners in the 1990’s, together with the develop­ment of sophisticated post-processing software, has made PCT a powerful tool for investigating pathophysiological processes in the human body.25 In vivo evaluation and quantitative analysis of brain perfusion by means of PCT has had consider­able impact on patient care in the settings of severe head trauma, acute stroke, and cerebral tumors.26-30 The determination of tissue perfusion by PCT in­volves the intravenous injection of tracer and sub-sequential imaging to monitor the concentration of tracer in the tissue and a feeding artery as functions of time.27 One important advantage of CT is that the enhancement is linearly proportional to the con­centration of tracer in the tissue.25 Serial CT scans start before the contrast agent arrives to determine the baseline and repeated scans are acquired un­til the tracer leaves the tissues. Subtraction of the baseline from each of the serial CT scans after the arrival of the contrast agent at the tissue gives the time-density curve (TDC) of the tissue.25,31 All the physiological information is obtained by math­ematical analysis of the tissue TDC. These analyses are based on proposed ‘tracer kinetics’ models that describe the distribution of contrast in blood ves­sels and extravascular space of the tissue.25,31 Permeability imaging: basic concepts BBBP describes how easy it is for a tracer molecule to move between the intravascular and extravascu­lar space across the BBB. It is defined as the bulk flow of a tracer normalized for surface area, con­centration gradient, and time: where P is the permeability (cm/s); S, the surface area per unit mass (cm2/g); M, the tissue mass (g); Cplasma -CEES, the concentration difference between plasma and extravascular extracellular compart­ment (mmol/cm3).6 Blood-brain barrier permeabil­ity (BBBP) can be expressed as the permeability surface area product (PS) or as transendothelial transfer constant (K). PS represents the total diffusional flux across all capillaries and is measured in ml/min/100g of tis­sue. It can be interpreted as following: the unidi­rectional flux of solutes from blood plasma to inter­stitial space is equivalent to the complete transfer of all the solutes in PS ml of blood per minute to interstitial space. Another parameter, frequently used in the set­ting of permeability imaging is called extraction fraction (E). E represents the fraction of solutes in arterial blood, with the potential to diffuse into ex­travascular space that actually becomes transferred from blood to interstitial space during a single pas­sage of blood from the arterial end to the venous end of the capillaries of a tissue.32 Different permeability parameters can be calcu­lated by measuring the leakage of an intravascular tracer into the extravascular space.5,32,33 In the nor­mal brain parenchyma, BBB is intact and tightly regulated. PS is normally 0 for large hydrophilic molecules such as a peripherally injected iodinated contrast agent.5 As mentioned, many pathologic situations such as tumor, inflammatory/infectious disease, and ischemia can alter BBB integrity and allow the diffusion of fluid, blood or contrast mol­ecules into the extravascular space.5,6 Tracer kinetic analysis The analysis of PCT data for the evaluation of BBB can be done by parametric fitting using tracer ki­netic models.27 Compartmental modelling as ex­emplified by the Patlak model33 assumes instanta­neous mixing within the compartments27 and has been used by many authors.5,8,34-36 Alternatively, distributed parameter model (DPM) as first pro­posed by Johnson and Wilson37 describes tracer concentration in the vascular compartment as a function of both time and position along the cap­illary27 and is generally considered more accurate for the assessment of BBBP.7,27,38 Compartmental modelling: Patlak model A compartment is defined as a well-mixed space where the concentration is spatially uniform with­in the volume of distribution. In addition, the out flux at any outlet must be directly proportional to the concentration of tracer.39 The Patlak model is a unidirectional 2-compart­ment model that calculates BBBP via linear regres­sion.5 Following injection into the blood stream, contrast agent will pass into the extravascular space at a rate that is characterized by transen­dothelial transfer constant K.25 The theoretical ba­sis of imaging K is the Patlak graphical analysis33, which assumes that the injected contrast agent is distributed in two well-mixed compartments: the 110 intravascular (blood) and the extravascular com­partment. At any given time, a voxel of tissue will contain both intravascular and extravascular con­trast agent. Assuming that during the time inter­val 0–t there is virtually no return of contrast agent from the extravascular to blood space, the total concentration of contrast agent in the tissue at time t, can be expressed as: where Q(t) is the tissue enhancement at time t; Ca(t) is the arterial enhancement at time t; and Vb is the distribution volume, which is typically considered to be equal to the cerebral blood volume (CBV) in the considered region of interest. In Equation 2, the first term on the right side describes the intravas­cular component of enhancement and the second term describes the extravascular component. The graphical analysis of the Patlak model divides both sides of Equation 2 by Ca(t) to give the following equation, describing the Patlak plot:25,34 In this equation, the ratio of Q(t) to Ca(t) is plotted on the y-axis and is called “apparent distribution volume”. The ratio of the integral of Ca to Ca(t), which is plotted on the x-axis, is called “normal­ized plasma integral”. The slope of a regression line fit to the linear part of the Patlak plot is an approximation of K at that time. This value repre­sents the amount of accumulated tracer in relation to the amount of tracer that has been available in plasma and is a measurement of BBBP expressed in mL /100 g/min. The y-axis intercept is equal to the Vb or CBV.34 Theoretic model of blood-brain exchange, de­scribed by Patlak et al.33,34, is relatively simple and frequently applied model to quantify BBBP from PCT data.5,34 It assumes the unidirectional transfer of a tracer from a reversible (arterial) compartment to an irreversible extravascular space (brain paren­chyma) for a certain period of time.34,40 Transfer of tracer is assumed to be unidirectional when a steady-state phase is reached between reversible compartments (intravascular space and the blood-brain barrier complex). However, such a steady-state phase can only occur after the initial rapid changes in tracer concentration have subsided, so the arterial concentration decreases slowly enough for the tissue compartment to follow. Recent data suggest that only the delayed phase of the PCT acquisition (and not the first-pass) respects the assumptions of the Patlak model and that BBBP measurements extracted from first-pass PCT data overestimate BBBP values obtained from the de­layed phase.34 The assumption that back-flux from extravascu­lar into intravascular can be neglected during early times depends on the relative magnitude of blood flow (F) and the capillary permeability surface area product (PS).25 Permeability (P) is related to the dif­fusion coefficient of contrast agent in the assumed water-filled pores of the capillary endothelium. The diffusion flux of contrast agent across the cap­illary endothelium is dependent on both the dif­fusion coefficient and the total surface area of the pores or the PS product.36 The PS product has the same dimensions as F, and thus the ratio PS/F is dimensionless. PS is re­lated to K by the following: If PS/F < 1, then K ~ PS. In normal cerebral vas­culature, PS is negligible for all contrast agents presently in use.36 The relative magnitude of PS and F also determines E, according to the classic Renkin-Crone equation:25,41 However, in the setting of various pathologic processes, it is doubtful whether the no back flux assumption will be valid in general. Another major drawback of compartmental models is a fact that F and E (PS) cannot be measured separately because they are determined together as K (EF). All infor­mation about the convective transport of solute along the capillaries is lost due to the assumption that intravascular space is a well-mixed compart­ment.32 Distributed parameter model Perfusion parameters can be derived from the im­pulse residue function (IRF). The IRF is a theoreti­cal concept, i.e. a tissue TDC due to an idealized bolus injection of one unit of tracer into the arterial input.31,42 It describes the fraction of tracer that re­mains in the tissue as time evolves.25 Alternatively, it can be seen as the distribution of transit times in the tissue.31 For ease of calculation, the IRF is usu­ally constrained in its shape to comprise a plateau followed by a single exponential decay (Figure 1).42 The duration of the plateau corresponds to the time interval during which all the injected contrast ma­terial remains in the capillary network.28 Contrast agent diffusion appears in the IRF as a residual enhancement that occurs after the initial impulse response and that decreases exponentially with time. The IRF is used to estimate the fraction of the mass of contrast agent arriving at the tissue that leaks into the extravascular space in a single pas­sage through the vasculature, the extraction frac­tion (E).25,36 A mathematical process that uses arterial and tissue TDC to calculate IRF for the considered re­gion of interest is called deconvolution. The height of the flow corrected IRF will give the tissue perfu­sion and the area under the curve (AUC) will de­termine the relative blood volume. This approach can be extended to include a measurement of capil­lary permeability by use of a distributed parameter model.42 In the Patlak model, the tracer concentration gradients within the vasculature are assumed to be zero.32 DPM on the other hand, takes the tracer concentration gradients within the vascular com­partment into account, and may therefore allow more complete analysis of the perfusion param­eters from a single PCT study.25,44 In contrast with compartmental models, it enables the separation of F and E (PS).32 Moreover, with the adiabatic ap­proximation in time domain32,45, the model solution can be computed efficiently to generate functional maps of perfusion parameters.25 For the evaluation of BBBP, two compartment version of DPM has been used7 as it can be math­ematically expressed in a separable form in time domain, each component describing a physiologi­cal process: where R is IRF for vascular (v) and parenchymal (p) phase.7,27 For times, shorter than vascular tran­sit time (duration of the plateau; t < t1), the vascu­lar phase of the equation remains constant and is proportional to the total amount of tracer in the injected bolus.7,44 At t1, the unextracted tracer exits via outflowing blood, and the detector response registers the fraction of extracted tracer, given by E. Beyond the t1, the extracted tracer diffuses back into the blood and is cleared by outflowing blood, giving rise to a gradually decreasing parenchy­mal phase. The parameters that can be directly obtained from fitting experimental curves are F, t1, rate of transfer from intravascular to extravas­cular compartment (k21) and rate of transfer from extravascular to intravascular compartment (k12). With the DPM, E can be formally given by:7,27,44 111 FIgure 1. Impulse residue function (IRF). The IRF can be interpreted as the fraction of contrast medium that remains in the tissue as time evolves, following a bolus injection into arterial input. The duration of the plateau is the vascular transit time (t1). The area under the curve (AUC) is the mean transit time (MTT). As the Central Volume Principle states that the product of flow (F) and MTT is blood volume (CBV), the AUC of the flow corrected IRF (FR(t)) is the CBV. R(t) - the IRF at time t.43 which is a function of the vascular transit time t1. This expression for E implies that, for two capil­laries with the same outflow (extravasation) rate k21, the fraction of extracted tracer in the first-pass would be larger for the capillary with the longer transit time. The rate constant k21 can then be ex­pressed as the ratio of the PS and fractional vas­cular volume (v1): k21 = .PS/v1. Since v1 can be esti­mated by v1 = .Ft1, the PS could then be estimated as PS = k21v1/., and the latter equation reverts to the classic Renkin-Crone equation (Equation 5).7,27 Clinical applications of BBBPimaging The major clinical applications of PCT are in acute stroke and in brain tumor imaging.31 Acute stroke PCT can be used to demonstrate elevated BBBP as an indicator of ischemia-induced vascular dam­age.35 Severe ischemia can alter BBB integrity and allow the diffusion of fluid, blood, or contrast molecules into the interstitium. A nonzero PS rep­resents this diffusion quantitatively, and its func­tional color map can be generated by dedicated software (Figure 2).5 Ischemia or reperfusion in­duced damage to the BBB may lead to hemorrhagic transformation (HT) and poor clinical outcome in­dependent of thrombolytic therapy.7 Symptomatic HT and malignant edema are feared complications in patients with acute ischemic stroke and occur 10 times more frequently in tPA-treated versus pla­cebo-treated patients.35 Permeability analysis by means of PCT with DPM, proved to be an efficient tool for predicting HT in acute ischemic stroke.7 Another study has shown 100% sensitivity and 79 % specificity of admission BBBP imaging (using delayed acquisition PCT and Patlak model) in pre­ 112 FIgure 2. Perfusion computed tomography in acute stroke. Parametric maps show increased blood-brain barrier permeability values (A,B) in the right middle cerebral artery territory. The main advantage of Patlak’s analysis is its conceptual simplicity (A). On the other hand, distributed parameter model takes the tracer concentration gradients within vasculature into account and may allow more complete analysis of kinetic parameters (B). The delineation of ischaemic area is clearly recognized on blood flow (C) and blood volume (D) parametric maps. FIgure 3. Perfusion computed tomography in brain tumours. Tracer kinetic analysis was performed in a patient with a large tumour in left cerebral hemisphere (A), using Patlak model. The tumour tissue presents with significantly higher permeability values, indicating the immature leaky tumour vessels (B). Unlike the blood volume parametric map (C), permeability imaging also shows some local heterogeneity of tumour tissue. dicting symptomatic HT and malignant edema in acute ischemic stroke.35 Brain tumor imaging The development of a tumor blood supply through the process of angiogenesis is essential for the growth of tumors and also determines the ability of tumors to metastasize.31 Hypoxia or hypoglycemia that occurs in rapidly growing tumors increases the expression of vascular endothelial growth fac­tor (VEGF), which is a potent permeability factor.36 Newly formed vessels are immature and have in­creased permeability to macromolecules due to large endothelial cell gaps, incomplete basement membrane, and absent smooth muscle.36,46 Altered permeability of the newly formed tu­mor vessels can be effectively assessed by the PS and E parametric maps, which offer the additional advantage of tumor segmentation and delineation from surrounding healthy tissue (Figure 3).47 Both compartmental and distributed parameter model­ling for contrast transport and exchange have been developed to quantify tissue F, CBV, MTT and per­meability parameters.32 Significant difference in PS was found between low grade (WHO grade II) and high grade (WHO III or IV) glioma.48 Recent data even suggest that perfusion parameters, especial­ly PS, can be used to differentiate grade III from grade IV glioma.36 PCT therefore provides useful information for glioma grading and has the poten­tial to significantly impact clinical management of cerebral gliomas.48 Conclusions The BBB is tightly regulated system, perform­ing functions such as diffusion barrier, transport, signaling and osmoregulation. In the normal brain 113 parenchyma, BBB is intact and impermeable for large molecules such as iodinated contrast agent. In pathologic situations such as neoplasm, inflam­matory/infectious disease, ischemia and some neu­rodegenerative disorders, the BBBP is altered and the diffusion of fluid, blood or contrast molecules into the extravascular space is enhanced. BBBP can be in vivo evaluated by PCT, which uses different mathematical models to calculate physiological in­formation from raw data. An efficient method to identify and quantify the extent of BBB disturbance allows early intervention to reduce the long term disability in some patients. To date, the major clini­cal applications of PCT have been in acute stroke and in brain tumor imaging. references 1. Persidsky Y, Ramirez SH, Haorah J, Kanmogne GD. Blood-brain barrier: structural components and function under physiologic and pathologic con­ditions. J Neuroimmune Pharmacol 2006; 1: 223-36. 2. Hawkins BT, Davis TP. 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Tracer kinetic modelling in MRI: estimating perfu­sion and capillary permeability. Phys Med Biol 2012; 57: R1-33. 40. Schneider T, Hom J, Bredno J, Dankbaar JW, Cheng SC, Wintermark M. Delay correction for the assessment of blood-brain barrier permeability using first-pass dynamic perfusion CT. Am J Neuroradiol 2011; 32: E134-8. 41. Crone C. The Permeability of Capillaries in Various Organs as Determined by Use of the ‘Indicator Diffusion’ Method. Acta Physiol Scand 1963; 58: 292-305. 42. Miles KA. Perfusion CT for the assessment of tumour vascularity: which protocol? Br J Radiol 2003; 76 (Spec No 1): S36-42. 43. Lee TY. Functional CT: physiological models. Trends Biotechnol 2002; 20 (Suppl 8): S3-S10. 44. Larson KB, Markham J, Raichle ME. Tracer-kinetic models for measuring cerebral blood flow using externally detected radiotracers. J Cereb Blood Flow Metab 1987; 7: 443-63. 45. St Lawrence KS, Lee TY. 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Neuroradiol 2006; 48: 773-81. 115 research article Evaluation of radiographic and metabolic changes in bone metastases in response to systemic therapy with 18FDG-PET/CT Bengul Gunalp1, Ali Ozan Oner2, Semra Ince1, Engin Alagoz1, Asli Ayan1, Nuri Arslan1 1 Gulhane Military Medical Academy and Faculty, Department of Nuclear Medicine, Ankara, Turkey 2 Kocatepe University Medical Faculty, Department of Nuclear Medicine, Afyon, Turkey Radiol Oncol 2015; 49(2): 115-120. Received 18 December 2014 Accepted 9 February 2015 Correspondence to: Dr. Bengul Gunalp, Gulhane Military Medical Academy and Faculty, Department of Nuclear Medicine, 06018 Ankara, Turkey. Phone: +90 312 3044806; Fax: +90 312 304 4800; E-mail: bgunalp@yahoo.com Disclosure: No potential conflicts of interest were disclosed. Background. The aim of the study was to retrospectively evaluate radiographic and metabolic changes in bone metastases in response to systemic therapy with 18FDG-PET/CT and determine their roles on the evaluation of therapy response. Patients and methods. We retrospectively evaluated radiographic and metabolic characteristics of bone me­tastases in 30 patients who were referred for the evaluation of response to systemic therapy with 18FDG-PET/CT. All patients underwent integrated 18FDG-PET/CT before and after treatment. Results. The baseline radiographic patterns of the target lesions in responders group were lytic, sclerotic, mixed and CT negative; after treatment the radiographic patterns of all target lesions changed to a sclerotic pattern and attenuation increased (p = 0.012) and metabolic activity decreased (p = 0.012). A correlation was found between decreasing metabolic activity and increasing attenuation of the target lesions (r = -0.55) (p = 0.026). However, in non-responders group, the baseline radiologic patterns of the target lesions were lytic, blastic, mixed and CT negative; after treatment all lytic target lesions remained the same and one CT negative lesion turned to lytic pattern and the attenuation of the target lesions decreased (p ± 0.12) and metabolic activity increased (p = 0.012). A correlation was found between increasing metabolic activity and decreasing attenuation (r = -0.65) (p = 0.032). An exception of this rule was seen in baseline blastic metastases which progressed with increasing in size, metabolic activity and attenu­ation. Conclusions. This study shows that the metabolic activity of lesions is a more reliable parameter than the radio­graphic patterns for the evaluation of therapy response. Key words: bone metastases; therapy response; 18FDG-PET/CT Introduction A significant fraction of patients with known ma­lignancy develop osseous metastases and this usu­ally mandates a radical change to the therapeutic approach. Early detection and evaluation of the treatment response is essential for making correct treatment decisions. Therefore, techniques are re­quired to identify patients with active bone metas­tases and to monitor the treatment response in a timely manner. Bone scintigraphy using technetium-99m­labeled diphosphonates has been the method of choice for the detection of bone metastases for many years but it is considered to be unsuitable for evaluating treatment response, because it has a poor specificity for detecting metastases, and posi­tive lesions on a bone scan tend to remain positive even after effective treatment.1,2 On the basis of radiographic appearance, bone metastases are classified as osteolytic, osteoblas­tic (sclerotic), or mixed pattern. The sclerosis of a lytic component on computed tomography (CT) or plain radiographs is generally considered to sug­gest a response to treatment1-4, but if there are no baseline studies it is not possible to differentiate osteoblastic active metastases from sclerotic unvi­able metastases. 18F-fluorodeoxyglucose positron emission to­mography/CT (18FDG-PET/CT) is widely used for the diagnosis and staging of various malignant tumors and evaluating responses to therapy.5-7 Abnormal bone 18FDG uptake by tumor cells is in proportion to levels of glucose metabolism. 18FDG is transported into tumor cells by glucose trans­porter proteins and phosphorylated by hexokinase to 18FDG-6-phosphate, which is retained in the ma­lignant cells. Because FDG uptake is related to the metabolic activity of the tumor itself, 18FDG may detect metastases before bone destruction on a CT or osteoblastic healing on a bone scan.8-10 In previous investigations, it has been reported that in osteolytic metastases, 18FDG is more likely to be positive, while sclerotic metastases are less likely to be positive11-14, but changes of the radio­graphic and functional characteristics of the met­astatic lesions during the treatment has not been investigated adequately. The clinical significance of 18FDG-positive/CT-negative lesions and CT-positive/18FDG-negative lesions pre and post-ther­apy conditions were unclear. In this retrospective study we tried to elucidate this issue determining functional and anatomic characteristics of bone metastases on pre and post-therapy conditions and their role on the evaluation of response to therapy. Patients and methods Patients We retrospectively evaluated the radiographic and metabolic characteristics of bone metastases in 30 patients (mean age 58 years; age range 27.82) who were referred for the evaluation of response to systemic therapy with 18FDG-PET/CT between January 2013 and April 2014. All patients under­went integrated 18FDG-PET/CT before and after treatment. Two reviewers analyzed the images in consensus. Bone metastases in 15 patients with breast carcinoma, 10 patients with lung cancer, 2 patients with neuroendocrine tumor, 2 patients with lymphoma and 1 patient with sarcoma were included in this study (Table 1). All patients received systemic therapy after baseline 18FDG-PET/CT imaging. Systemic therapy for breast carcinoma patients included the use of TABLE 1. Baseline characteristics of patients Mean age (y) 58 ± 13 (27-82)* Sex Female21 (70)** Male 9 (30) Type of cancer Breast cancer15 (50) Lung cancer10 (33) Neuroendocrine tumor2 (6) Lymphoma2 (6) Sarcoma 1 (3) * Data are mean ± standard deviation. Data in parentheses are range; ** Data are numbers of patients and data in parentheses are percentages endocrine therapy, chemotherapy and/or biologic agents. A choice between them had been made depending on the status of hormone receptors (estrogen, progesterone receptor positive patients received anti-estrogen treatment with tamoxifen or letrazole), status of human epidermal growth factor 2 (HER2) overexpression (HER2 positive patients received biological treatment with trastu­zumab or lapatinib). Chemotherapy was combined if patient hadn’t responded to endocrine or bio­logical treatment. For metastatic lung carcinoma patients systemic therapy generally consisted of cytotoxic chemotherapy using cisplatin or carbopl­atin based doublet. The response assessment was made according to biochemical, radiologic and clinical follow-up and 18FDG-PET/CT findings. Sixteen patients were classified as responders and 14 patients classified as non-responders or progressive disease. The morphologic appearance of the most prominent (target) lesion in each patient was classified as lyt­ic, blastic (sclerotic), mixed or hypermetabolic bone lesion without CT findings (bone marrow) and le­sion attenuation was measured as in Hounsfield units (HU) in axial CT images. The metabolic activ­ity of the same lesion was calculated as the maxi­mum standardized uptake value (SUV Max). The mean follow-up duration of the patients was 7 months, range 3 months to 18 months. The institutional review board approved this study and for this type of study formal consent is not required (No. 50687469-1491-1311-13/1648.4­1472). Imaging 18FDG-PET/CT was performed prior to systemic therapy as a baseline study and after treatment (mean 28 days; range 24.32 days) in all patients. 117 18FDG-PET/CT images were acquired with an inte­grated PET/CT device (GE Discovery 690). Before 18FDG-PET/CT, patients fasted for at least 6 hours. All patients were tested to confirm that their glu­ cose level was within the normal range [80.120 mg/ dL (4.4.6.6 mmol/L)] before 18FDG administration. Before PET, unenhanced CT was performed from vertex to the mid-thigh according to a standard­ized protocol with the following settings: 120 kVp, 85 mA, Pitch 1.375 and slice thickness 3.75 mm. Emission scans were obtained 60 minutes after intravenous administration of 18FDG (mean dose, 370 MBq; range 259.444 MBq). The acquisition time was 3 minutes per bed position in the two di­mensional mode. Images were reconstructed with attenuation –weighted ordered –subset expecta­tion maximization filter. Image interpretation and radiographic analysis PET and CT images obtained in all standard planes were reviewed by two experienced nuclear medi­cine physicians. Images were analyzed visually and quantitatively. Only the lesion that exhibited the most prominent uptake was selected as the tar­get lesion for response evaluation to the treatment. The exact anatomic location of the target lesion was identified on CT images and classified as lytic, blastic (sclerotic), mixed and no CT finding (bone marrow metastases without identifiable bone de­struction on CT). The change in CT attenuation (.Att) (measured in Hounsfield units) in the region of interest (ROI) of the entire lesion before and after treatment was calculated with the following equation: .Att = (Att- Attpre), where Attand Attdenote pre- post pre post and post-treatment attenuation, respectively. The maximum standardized uptake value (SUV) was calculated with the following equation: SUV = A(ID/BW), where A is the decay-corrected mean activity in tissue (measured in millicuries per mil­liliter), ID is the injected dose of FDG (measured in millicuries), and BW is the patient’s body weight (measured in grams). Changes in SUV (.SUV) af­ter treatment were calculated with the following equation: .SUV = (SUV- SUV), where SUV post prepre and SUVpost denote pre and post-treatment SUV, respectively. Therapy response evaluation Patients’ medical records and follow-up 18FDG­PET/CT findings were evaluated retrospectively. FIGURE 1. Baseline lytic lesion is healing with sclerosis. Baseline transaxial (A) 18FDG PET, (B) CT, and 18FDG-PET/CT images 65 years old man with lung carcinoma show lytic bone metastasis in vertebra (arrow). Maximum standardized uptake value (SUV) Max: 14.8, Hounsfield units (HU): 58; (D), (E), (F) 9 months after therapy lesion metabolic activity decreased SUV Max: 1.6, attenuation increased HU: 780; (G), (H), (I) 12 months after therapy. Inactive sclerotic metastasis with no metabolic activity and sclerotic appearance on CT with increased attenuation HU: 934. In patients who were designated as responders, the target lesion showed decreased uptake when com­pared with the same lesion depicted on baseline images and all biochemical, radiologic and clinical follow-up findings confirmed the response to ther­apy. In non-responders, a follow-up examination revealed substantially increased 18FDG uptake in the target lesion or additional new metastatic foci were identified on 18FDG-PET/CT images and all biochemical, radiologic and clinical findings con­firmed a progression of the disease. Statistical analysis Comparison of mean values between groups was performed with the Student t test. Spearman’s rho test was performed to investigate any correlation between attenuation (HU) and metabolic activity (SUV Max) of the lesions. P<0.05 was considered to indicate a significant difference. IBM SPSS statis­tics software (Version 21) was used for the statisti­cal analysis. Results The radiographic pattern of the target lesions on the baseline PET/CT images was classified as lytic 118 FIGURE 2. Baseline CT-negative 18FDG-positive bone marrow metastasis is becoming sclerotic (CT-positive) while decreasing metabolic activity (18FDG-negative) as a response to therapy. Baseline transaxial (A) 18FDG- PET, (B) CT, and 18FDG-PET/ CT images in 45 years old woman with breast carcinoma show bone marrow metastasis in sternum (arrow) without corresponding CT abnormalities. Maximum standardized uptake value (SUV Max): 11, Hounsfield units (HU): 73; (D), (E), (F) 6 months after therapy lesion metabolic activity decreased SUV Max: 2.7, attenuation increased HU: 551; (G), (H), (I) 9 months after therapy. Inactive sclerotic metastasis with no increase metabolic activity and sclerotic appearance on CT with increased attenuation HU: 693. FIGURE 3. Progression of CT-negative 18FDG-positive bone marrow metastasis with becoming lytic lesion on CT. Pre-treatment transaxial (A) 18FDG-PET, (B) CT, and (C) 18FDG-PET/CT images in 67 years old man with lung carcinoma show hypermetabolic bone metastasis in scapula (arrow) without any evidence on CT. Maximum standardized uptake value (SUV Max): 2.6, Hounsfield units (HU): 165; (D), (E), (F) 6 months after therapy bone metastasis did not respond to the therapy and the disease progressed. The lesion became lytic, its attenuation decreased HU: 84 and metabolic activity increased SUV Max: 19.9. in 13 (43%) patients, blastic (sclerotic) in 7 (23%) patients, mixed in 3 (10%) patients and no CT ab­normality on target lesion (bone marrow metasta­ses) in 7 (23%) patients. Responders group There were 16 (53%) patients whose metabolic ac­tivity of the target lesion decreased after treatment TABLE 2. Summary of the results and clinical follow-up confirmed the therapy re­sponse. The baseline radiographic patterns of the target lesions were lytic in 6 (37%) patients, blas­tic (sclerotic) in 5 (31%) patients, mixed in 2 (13%), bone marrow in 3(19%) and the mean attenuation was HU = 190 ± 137; the mean metabolic activity was SUV Max = 8.78 ± 3.09; after treatment the ra­diographic patterns of all target lesions turned to a sclerotic pattern, as shown in Figures 1, 2, attenua­ tion increased (mean HU = 622 ± 273) (p = 0.012) and metabolic activity decreased (SUV Max: 2.92 ± 1.07) (p = 0.012). A negative correlation was found be­tween decreasing metabolic activity (SUV Max) and increasing attenuation (HU) of the target lesions (r = -0.55) (p = 0.026). Three patients with increased metabolic activity on PET and any corresponding radiographic pathologic finding on CT turn to scle­rotic lesion after treatment. Bone metastases of all tumor types with different radiological patterns on baseline CT scan showed sclerotic pattern on post-therapy scan if therapy response was achieved. Non-responders group There were 14 (47%) patients whose metabolic activity of the target lesion increased after thera­py and progression of disease was confirmed by 119 biochemical, radiologic and clinical findings. The baseline radiographic patterns of the target lesions were lytic (n = 7), blastic (n = 2), mixed (n = 1), CT negative (bone marrow) (n = 4), the mean attenua­tion was HU = 349 ± 290 and mean metabolic activ­ity was SUV Max = 7.6 ± 2.95; after treatment radio­graphic patterns of all lytic target lesions remained the same and one bone marrow lesion turned to a lytic pattern and attenuation of the target lesions decreased (HU 168 ± 212) (p = 0.12) and metabolic activity increased (SUV Max:11.0 ± 5.3) (p = 0.012) as shown in Figure 3. A negative correlation was found between increasing metabolic activity and decreasing attenuation (r = -0.65) (p = 0.032). There were 3 (21%) patients with blastic and mixed metastases on their baseline study that pro­gressed with increasing in size, metabolic activity and attenuation as shown in Figure 4. A summary of the results is illustrated in Table 2. Discussion Our results show that an increase in attenuation and a decrease in SUV of bone metastases after systemic treatment are associated with therapy response as reported in previous studies.15,16 All morphologic types of baseline metastatic lesions turned to sclerotic lesions if a therapy response was achieved. On the other hand, if a therapy re­sponse was not achieved different patterns were recognized which were not described in previ­ous studies. If therapy response was not achieved while all baseline lytic lesions remained as lytic and CT-negative bone marrow lesions turned to lytic lesions but blastic lesions remained as blastic with increased metabolic activity, density and size. These findings were found to be highly correlat­ed with the pathophysiology of bone metastases. In osteolytic bone metastases, tumor cells release humoral factors that stimulate osteoclastic activ­ity and osteoclasts start to break down bone. Bone resorption results in the release of growth factors that stimulate tumor cell growth. In osteoblastic bone metastases, tumor cells secrete growth factors that stimulate the activity of osteoblasts. Excessive new bone formation occurs around tumor-cell de­posits. Osteoblastic activation releases unidenti­fied osteoblastic growth factors that also stimulate tumor cell growth.17 Although we had very a few numbers of patients in non-responders group with blastic metastases our findings also confirmed con­tinuing excessive new bone formation if therapy response was not achieved. FIGURE 4. Progression of blastic metastasis with increasing metabolic activity and density. Pre-treatment coronal (A) 18FDG-PET, (B) CT, and (C) 18FDG-PET/CT images in 57 years old woman with breast carcinoma show blastic metastasis in scapula (arrow). Maximum standardized uptake value (SUV Max): 7.5, Hounsfield units (HU): 917; (D), (E), (F) 4 months after therapy bone metastasis did not respond to the therapy and the disease progressed. The lesion metabolic activity increased SUV Max: 11.1 and attenuation increased HU: 1056 Our findings suggest that 18FDG uptake reflects the tumor activity of bone metastases independ­ent of the radiographic characteristics. Since both blastic metastases and sclerotic lesions show in­creased attenuation on CT, it is not possible to dif­ferentiate them based on their CT characteristics. 18FDG-PET/CT enables the clinician to differentiate metabolically active tumor tissue in “blastic metas­tases” from scar tissue in sclerotic lesions. The ra­diographic changes vary greatly among individual patients and do not seem to correlate with the pres­ence of an active tumor. This study also shows that sequential 18FDG-PET/CT can provide vital infor­mation in monitoring the response of bone metas­tases to therapy. In this study we observed “early marrow-based” metastases in 7 (23%) patients with increased met­abolic activity confined to bone marrow without corresponding morphologic changes on CT. This finding is consistent with previous reports which documented that 18FDG-PET/CT detects bone me­tastases earlier than CT when there are a substan­tial number of metabolically active tumor cells pre­sent in bone marrow but still tumor invasion of the bone matrix doesn’t occur.18,19 In the previous studies 18FDG-PET has been found less sensitive than CT and bone scan in the detection of sclerotic metastases, however, most of the patients included in these studies had been 120 treated with a systemic therapy20-24, and it has been suggested that osteolytic bone metastases may be­come sclerotic after effective treatment.25 18FDG­PET/CT combines both metabolic and anatomic information on the same image and provides more accurate assessment of bone metastases than does either PET and CT alone. Hybrid 18FDG-PET/CT provides us with a simul­taneous comparison of functional and morpholog­ic changes in bone metastases during the therapy and our study showed that if therapy response is achieved the most of the FDG positive bone metas­tases on pre-treatment study are becoming 18FDG negative and sclerotic on CT. Our study confirmed that pre-treatment 18FDG positive, post-treatment 18FDG negative sclerotic lesions belong to scar tis­sue which is developing during the healing process of bone metastases. Conclusions This study shows radiographic patterns of bone metastases on CT changing during the therapy and the therapy response cannot be evaluated with the radiographic appearance of the lesion on CT. PET/ CT has been found more sensitive and specific than CT both in detecting and evaluating the therapy re­sponse of bone metastases. References 1. Du Y, Cullum I, Illidge TM, Ell PJ. Fusion of metabolic function and morphol­ogy: sequential [18F]fluorodeoxyglucose positronemission tomography/ computed tomography studies yield new insights into the natural history of bone metastases in breast cancer. J Clin Oncol 2007; 25: 3440-7. 2. Hamaoka T, Madewell JE, Podoloff DA, Hortobagyi GN, Ueno NT. Bone imag­ing in metastatic breast cancer. J Clin Oncol 2004; 22: 2942-53. 3. Tateishi U, Gamez C, Dawood S, Yeung HW, Cristofanilli M, Macapinlac HA. Bone metastases in patients with metastatic breast cancer: morphologic and metabolic monitoring of response to systemic therapy with integrated PET/CT. Radiology 2008; 247: 189-96. 4. Bellamy EA, Nicholas D, Ward M, Coombes RC, Powles TJ, Husband JE. Comparison of computed tomography and conventional radiology in the assessment of treatment response of lytic bony metastases in patients with carcinoma of the breast. Clin Radiol 1987; 38: 351-5. 5. Eisenhauer EA, Therasse P, Bogaerts J, Schwartz LH, Sargent D, Ford R, et al. New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1). Eur J Cancer 2009; 45: 228-47. 6. Wahl RL, Jacene H, Kasamon Y, Lodge MA. From RECIST to PERCIST: evolving considerations for PET response criteria in solid tumors. J Nucl Med 2009; 50: 122S-50S. 7. Juweid ME, Cheson BD. Positron-emission tomography and assessment of cancer therapy. N Engl J Med 2006; 354: 496-507. 8. Evangelista L, Panunzio A, Polverosi R, Ferretti A, Chondrogiannis S, Pomerri F, et al. Early bone marrow metastasis detection: the additional value of FDG-PET/CT vs. CT imaging. Biomed Pharmacother 2012; 66: 448-53. 9. Qu X, Huang X, Yan W, Wu L, Dai K. A meta-analysis of 18FDG-PET-CT, 18FDG­PET, MRI and bone scintigraphy for diagnosis of bone metastases in patients with lung cancer. Eur J Radiol 2012; 81: 1007-15. 10. Yang HL, Liu T, Wang XM, Xu Y, Deng SM. Diagnosis of bone metastases: a meta-analysis comparing 18FDG PET, CT, MRI and bone scintigraphy. Eur Radiol 2011; 21: 2604-17. 11. Ben-Haim S, Israel O. Breast cancer: Role of SPECT and PET in imaging bone metastases. Semin Nucl Med 2009; 39: 408-15. 12. Cook GJ, Houston S, Rubens R, Maisey MN, Fogelman I. Detection of bone metastases in breast cancer by 18FDG PET: Differing metabolic activity in osteoblastic and osteolytic lesions. J Clin Oncol 1998; 16: 3375-9. 13. Schirrmeister H. Detection of bone metastases in breast cancer by positron emission tomography. Radiol Clin North Am 2007; 45: 669-76. 14. Uematsu T, Yuen S, Yukisawa S, Aramaki T, Morimoto N, Endo M. Comparison of FDG PET and SPECT for detection of bone metastases in breast cancer. AJR Am J Roentgenol 2005; 184: 1266-73. 15. Tateishi U, Gamez C, Dawood S, Yeung HW, Cristofanilli M, Macapinlac HA. Bone metastases in patients with metastatic breast cancer: morphologic and metabolic monitoring of response to systemic therapy with integrated PET/CT. Radiology 2008; 247: 189-96. 16. Du Y, Cullum I, Illidge TM, Ell PJ. Fusion of metabolic function and morphol­ogy: sequential [18F]fluorodeoxyglucose positron-emission tomography/ computed tomography studies yield new insights into the natural history of bone metastases in breast cancer. J Clin Oncol 2007; 25: 3440-7. 17. Lipton A. Pathophysiology of bone metastases: How this knowledge may lead to therapeutic intervention. J Support Oncol 2004; 2: 205-22. 18. Basu S,Torigian D, Alavi A. Evolving concept of imaging bone marrow metas­tasis in the twenty-first century: critical role of FDG-PET. Eur J Nucl Med Mol Imaging 2008; 35: 465-71. 19. Ben-Haim S, Israel O. Breast cancer: Role of SPECT and PET in imaging bone metastases. Semin Nucl Med 2009; 39: 408-15. 20. Cook GJ, Houston S, Rubens R, Maisey MN, Fogelman I. Detection of bone metastases in breast cancer by 18FDG PET: Differing metabolic activity in osteoblastic and osteolytic lesions. J Clin Oncol 1998; 16: 3375-9. 21. Uematsu T, Yuen S, Yukisawa S, Aramaki T, Morimoto N, Endo M, et al: Comparison of FDG PET and SPECT for detection of bone metastases in breast cancer. AJR Am J Roentgenol 2005; 184: 1266-73. 22. Nakai T, Okuyama C, Kubota T, Yamada K, Ushijima Y, Taniike K, et al: Pitfalls of FDG-PET for the diagnosis of osteoblastic bone metastases in patients with breast cancer. Eur J Nucl Med Mol Imaging 2005; 32: 1253-8. 23. Abe K, Sasaki M, Kuwabara Y, Koga H, Baba S, Hayashi K, et al: Comparison of 18FDG-PET with 99mTc-HMDP scintigraphy for the detection of bone metastases in patients with breast cancer. Ann Nucl Med 2005; 19: 573-79. 24. An YS, Yoon JK, Lee MH, Joh CW, Yoon SN. False negative F-18 FDG PET/CT in nonsmall cell lung cancer bone metastases. Clin Nucl Med 2005; 30: 203-4. 25. von Schulthess GK, Steinert HC, Hany TF: Integrated PET/CT: Current applica­tions and future directions. Radiology 2006; 238: 405-22. 121 research article Thyroid lesions incidentally detected by 18F-FDG PET-CT . a two centre retrospective study Jan Jamsek1, Ivana Zagar2, Simona Gaberscek1,3, Marko Grmek3 1 Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia 2 Department for Nuclear Medicine, Institute of Oncology Ljubljana, Ljubljana, Slovenia 3 Department for Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia Radiol Oncol 2015; 49(2): 121-127. Received 29 June 2014 Accepted 22 September 2014 Correspondence to: Assist. Prof. Marko Grmek, M.D., Ph.D., Department for Nuclear Medicine, University Medical Centre Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia. E-mail: marko.grmek@kclj.si Disclosure: No potential conflicts of interest were disclosed. Background. Incidental 18F-FDG uptake in the thyroid on PET-CT examinations represents a diagnostic challenge. The maximal standardized uptake value (SUVmax) is one possible parameter that can help in distinguishing between benign and malignant thyroid PET lesions. Patients and methods. We retrospectively evaluated 18F-FDG PET-CT examinations of 5,911 patients performed at two different medical centres from 2010 to 2011. If pathologically increased activity was accidentally detected in the thyroid, the SUVmax of the thyroid lesion was calculated. Patients with incidental 18F-FDG uptake in the thyroid were in­structed to visit a thyroidologist, who performed further investigation including fine needle aspiration cytology (FNAC) if needed. Lesions deemed suspicious after FNAC were referred for surgery. Results. Incidental 18F-FDG uptake in the thyroid was found in 3.89% . in 230 out of 5,911 patients investigated on PET-CT. Malignant thyroid lesions (represented with focal thyroid uptake) were detected in 10 of 66 patients (in 15.2%). In the first medical centre the SUVmax of 36 benign lesions was 5.6 ± 2.8 compared to 15.8 ± 9.2 of 5 malignant lesions (p < 0.001). In the second centre the SUVmax of 20 benign lesions was 3.7 ± 2.2 compared to 5.1 ± 2.3 of 5 malignant lesions (p = 0.217). All 29 further investigated diffuse thyroid lesions were benign. Conclusions. Incidental 18F-FDG uptake in the thyroid was found in 3.89% of patients who had a PET-CT examination. Only focal thyroid uptake represented a malignant lesion in our study . in 15.2% of all focal thyroid lesions. SUVmax should only serve as one of several parameters that alert the clinician on the possibility of thyroid malignancy. Key words: thyroid; 18F-FDG; PET-CT; PET incidentaloma; thyroid cancer Introduction Incidental uptake of 18F-fluorodeoxyglucose (18F-FDG) in the thyroid is sometimes found during positron emission tomography - computed tomography (PET­CT)1-3, which is mostly used in cancer staging and diag­nostics.4-6 Throughout the literature the reported inci­dence of incidental thyroid uptake of 18F-FDG on PET­CT varies between 0.2% and 8.9%.2 Thyroid lesions on PET-CT can be either diffuse or focal (Figure 1). Diffuse 18F-FDG uptake is usually associated with au­toimmune thyroiditis or Graves’ disease7-9, whereas focal 18F-FDG uptake can be either due to a benign or malignant process in the thyroid.10-19 A semi-quantitative parameter that could help in differentiating thyroid lesions on PET-CT is the standardized uptake value (SUV), often expressed as the maximal SUV (SUVmax) or mean SUV (SUVmean).20 However, the discriminating power of this parameter is still unclear, as some studies have reported a statistically significant difference between SUV values of benign and malignant thy­roid lesions13,16,21,22,whilst others have shown no statistically significant difference.17,23-28 Moreover, the SUV of benign and malignant thyroid lesions varied greatly between these studies. We also know that the calculated SUV is highly dependent on the scanner type, reconstruction algorithms and 122 software packages used, which prevents the com­parisons of studies conducted at different centres using different equipment.29-31 This represented a challenge for our study. The aims of this study were to (i) determine the incidence of thyroid lesions incidentally found on 18F-FDG PET-CT, (ii) identify what diffuse and fo­cal thyroid lesions represent, and (iii) what is the optimal SUVmax that can discriminate between benign and malignant focal thyroid lesions inci­dentally found on PET-CT. This study was con­ducted at two PET-CT centres (having different PET-CT scanners) in Slovenia: the Department of nuclear medicine at the University Medical Centre Ljubljana (UMC) and the Institute of Oncology Ljubljana (IO). Patients and methods Subjects and study design We retrospectively evaluated the medical re­cords of 5,911 patients (2,840 patients from UMC and 3,071 patients from IO) who underwent an 18F-FDG PET-CT investigation between January 2010 and December 2011. Only patients (males and non-pregnant females) aged 18 years or more were included in this study. The 18F-FDG PET-CT investigation of patients included in the study was performed for different purposes, mainly because of oncologic indications. The study was approved by the Ethics Committee at the Ministry of Health, Republic of Slovenia (No.: 53/04/12). Methods employed Patients from both centres fasted for at least 6 hours, ideally having a blood glucose level less than 7 mmol/l, before receiving 370 MBq of 18F-FDG. The acquisition on the PET-CT scanner started 60 minutes after the radiotracer adminis­tration. The PET-CT scanners used were differ­ent: at UMC a Siemens Biograph mCT and at IO a Philips Gemini 16 GXL. In all patients, the localisa­tion and attenuation correction CT was first done, followed by the PET scan itself. The CT acquisi­tion parameters in both centres were fairly simi­lar. Also, the PET acquisition parameters did not differ a lot; at UMC a bed position of 2 min with 45% overlap and at IO a bed position of 2 min with 50% overlap was used. The acquired PET-CT data was processed using similar iterative reconstruc­tion algorithms. Nuclear medicine doctors at both centres used visual and semi-quantitative data analysis (SUVmax) for creating a final report. They had access to rel­evant patient history and previous examination reports. Patients with thyroid lesion incidentally found on 18F-FDG PET-CT were referred to a thy­roidologist. Thyroid investigation normally included the pa­tient’s history, clinical examination, relevant labo­ratory workup, ultrasound examination and 99mTc scintigraphy of the thyroid. For a final diagnosis of suspicious thyroid lesions, patients were further investigated using fine needle aspiration cytol­ogy (FNAC). A histological report was obtained for lesions that were surgically removed. All data (PET-CT reports, reports of thyroid examinations, cytological and histological reports) were obtained only from patients treated and followed-up at UMC and IO. Statistical analyses Statistical analysis was performed using IBM SPSS Statistics 22.0 and Microsoft Excel for Mac 14.1. The SUVmax of benign and malignant thyroid lesions were compared using Student’s t-test. Results were deemed statistically significant for p < 0.05. A re­ceiver operating characteristic (ROC) analysis was performed to determine a SUVmax cut-off point that differentiates between suspicious and unsuspi­cious focal thyroid lesions. Results Characteristics of patients The mean age of 2,840 patients who had a PET-CT investigation at UMC was 61.2 ± 12.9 years; the mean age of 3,071 patients at IO was 64.4 ± 12.1 123 years. Fifty per cent of UMC patients were males and 50% females. The percentage of males and females in the IO group was 52.5% and 47.5% re­spectively. Patients at UMC underwent an 18F-FDG PET-CT investigation mainly for cancer-related diagnostics or inflammatory/infection problems. On the other side, patients at IO underwent an 18F-FDG PET-CT investigation almost exclusively because of cancer-related diagnostics. Incidentally detected thyroid lesions Incidental 18F-FDG uptake in the thyroid was found in 230 out of 5,911 investigated patients (in 3.89%). Focal thyroid uptake represented 64.3% and diffuse thyroid uptake 35.7% of detected thy­roid lesions. 56.1% of all focal lesions and 81.7% of all diffuse lesions were detected in female patients. More detailed information about patients with in­cidentally found thyroid lesions on 18F-FDG PET­CT is presented in Table 1. Data of further treatment were found for 58 out of 82 patients (in 70.7%) with increased 18F-FDG uptake in the thyroid investigated at UMC and for 46 out of 148 patients (in 31.1%) investigated at IO. Diffuse thyroid lesions in 14/58 patients (24.1%) from UMC (SUVmax range from 3.5 to 10.3) and in 15/46 (32.6%) patients from IO (SUVmax range from 1.9 to 9.2) were all benign. Hashimoto’s thyroiditis was diagnosed in 92.9% and 73.3% respectively. At UMC, 44 patients with focal 18F-FDG uptake in the thyroid (SUVmax range from 2.3 to 31.9) were further investigated. Thyroid nodules were found in 30 patients (in 68.2%). Autoimmune thyroid dis­ease was diagnosed in 29.5% – in 12 patients with Hashimoto’s thyroiditis and in one patient with Graves’ disease. One patient was diagnosed to have benign diffuse goitre. FNAC was performed in 28 of 44 patients (63.6%). Results of FNAC are presented in Table 2. Out of 31 focal thyroid lesions diagnosed on PET-CT in patients from IO (SUVmax range from 1.5 to 8.7) thyroid nodules were found in 28 cases (in 90.3%). In two patients the focal lesion was caused TABLE 1. Patients and characteristics of incidental 18F-FDG uptake in the thyroid detected by PET-CT UMC 61 (24/37) 2.15 63.6 ± 12.1 Focal 6.6 ± 4.4 21 (4/17) 0.74 57.5 ± 14.4 Diffuse 7.9 ± 4.0 (all) 82 (28/54) 2.89 62 ± 12.9 6.9 ± 4.3 IO 87 (41/46) 2.83 64.2 ± 12.3 Focal 4.2 ± 2.1 61 (11/50) 1.99 64.9 ± 11.2 Diffuse 4.3 ± 2.7 (all) 148 (52/96) 4.82 64.5 ± 11.8 4.2 ± 2.3 UMC = University Medical Centre Ljubljana; IO = Institute of Oncology Ljubljana; SUVmax = maximal standardised uptake value FIGURE 2. SUVmax of malignant and benign focal thyroid lesions (median, IQR and MIN/MAX values). by Hashimoto’s thyroiditis and in one by Graves’ disease. FNAC diagnostics were performed in 24 of 31 patients (77.4%) (Table 2). The optimal SUVmax cut-off point for differenti­ating between suspicious and unsuspicious focal thyroid lesions incidentally detected on PET-CT, calculated using ROC analysis, was 5.4 for patients investigated at UMC (sensitivity 76.9%, specificity 61.3%, AUC = 0.785); the optimal differentiating SUVmax for patients investigated at IO was 4.0 (sen­sitivity 66.7%, specificity 73.7%, AUC = 0.754). TABLE 2. Results of fine needle aspiration cytology for focal thyroid lesions, classified according to the Bethesda classification UMC 28 2 (7.1) 17 (60.8) 2 (7.1) 5 (17.9) 0 2 (7.1) IO 24 5 (20.8) 7 (29.2) 1 (4.2) 3 (12.5) 3 (12.5) 5 (20.8) All 52 7 (13.4) 24 (46.2) 3 (5.8) 8 (15.4) 3 (5.8) 7 (13.4) FNAC = fine needle aspiration cytology, ND or UnS = non-diagnostic or unsatisfactory; BEN = benign; AUS or FLUS = atypia of undetermined significance or follicular lesion of undetermined significance; FN = follicular neoplasms and oncocytic tumours; SM = suspicious for malignancy; M = malignant 124 Surgically removed focal thyroid lesions Malignant thyroid disease was found in 10 out of 18 patients (55.6%) who underwent surgery. Malignant thyroid disease was more common in males (8 cases) than in females (2 cases). Nine pa­tients with focal thyroid lesions who were referred for surgery were lost to follow-up. Therefore in 10 out of 66 patients (15.2%) with focal thyroid lesion incidentally detected on 18F-FDG PET-CT malig­nant thyroid disease was confirmed. Detailed char­acteristics of all surgically removed thyroid lesions are presented in Table 3. SUVmax of malignant and benign focal thyroid lesions SUVmax of malignant focal lesions (histologically confirmed) was compared to SUVmax of benign fo­cal lesions (the benign nature of a lesion was es­tablished either after a thorough thyroid examina­tion with ultrasound, FNAC or surgical treatment) (Figure 2). A statistically significant (p < 0.001) dif­ference was observed between 36 benign (SUVmax from 2.3 to 13.2) and 5 malignant (SUVmax from 10 to 31.9) focal thyroid lesions incidentally detected on PET-CT in patients from UMC. No statistical­ly significant difference (p = 0.217) was observed between 20 benign (SUVmax from 1.5 to 8.8) and 5 malignant (SUVmax from 2.7 to 7.8) focal thyroid le­sions in patients from IO. Discussion Incidental 18F-FDG uptake in the thyroid was ob­served in 3.89% of 5,911 patients investigated; in 2.89% of patients investigated at UMC and in 4.82% of patients investigated at IO. This is in ac­cordance with the present literature, where the incidence of such lesions varied from 0.2 to 8.9%, with most studies reporting a incidence between 2 and 3%.2,3,11-13,16,17,19,21-28,32-36 In a review article by Bertagna et al.2, the authors postulated that this variability in incidence could be attributed to pop­ulation characteristics and background risk of thy­roid disease related to specific geographic areas. Slovenia, although not an endemic goitre region, still has a significant incidence of thyroid nodules in the general population.37 This could in part ex­plain the slightly higher incidence of thyroid le­sions incidentally found on PET-CT compared to some studies, where authors found a smaller inci­dence of thyroid lesions.11,12,17 According to the American Thyroid Association Guidelines Taskforce38 further investigation of inci­dentally found thyroid nodules is recommended. Adhering to these guidelines, all patients from our practices with an incidentally detected thyroid le­sion on PET-CT were referred to a thyroidologist. Due to different reasons, not all patients had a consultation, mainly because of the management of their primary illness. In our study, 71% of pa­tients from UMC and only 31% of patients from IO received additional thyroid diagnostics. Our explanation for this difference is that PET-CT ex­aminations in patients at IO were done almost ex­clusively for staging of known primary malignant diseases – many of these patients had more severe primary malignancies that required more prompt treatment than potential thyroid neoplasms. In comparison at UMC, approximately one third of PET-CT examinations were done for non-oncologic indications in which cases additional thyroid diag­nostics were more likely than in oncologic patients with more severe primary disease. Other studies also reported a similar percentage of patients with incidentally discovered thyroid PET lesions who were further investigated, with follow-up rates in the ranks of 50%.11-13,16-18,23-25,28 Experts agree that diffuse thyroid uptake of 18F-FDG on PET-CT is associated with Hashimoto’s thyroiditis.9 This was also confirmed by our re­sults, where most diffuse lesions were caused by Hashimoto’s thyroiditis and no malignancy was found in patients with diffuse thyroid PET lesions. According to the literature, the rate of focal le­sions ranges from 14% to 73% of all thyroid PET lesions8,16,24,32 with a risk of malignancy in further investigated lesions of about 33%.2,38 In our study, focal thyroid lesions were present in 64.3% of all cases with incidental thyroid uptake. These lesions represented a thyroid nodule in 68.2% (UMC pa­tients) and in 90.3% (IO patients). We histologically confirmed thyroid malignancy in 5 of 10 surgically treated patients from UMC and in 5 of 8 patients from IO. Altogether, malignant disease was ob­served in 10 of 66 patients (in 15.2%) with a focal 18F-FDG uptake in the thyroid. In comparison to other reports, the incidence of thyroid malignancy in our study was somewhat lower.2,12,13,16,17,21-28,34 This is, in our opinion, mainly due to higher goitre prevalence in our population.37 Autoimmune thyroid disease was present in 29.5% of focal thyroid lesions from UMC patients. This finding is quite different from data published in the literature.18,23 Our explanation for this dis­crepancy is in the different diagnostic process 125 TABLE 3. Characteristics of surgically removed thyroid lesions UMC Gastric carcinoma f 71 5.5 10 Oncocytic cells Hürthle adenoma Suspicious lesion in the right lungs m 68 4.8 12 Unsatisfactory Nodular goitre Tumour of the cardia f 48 8.9 9 Oncocytic cells Hürthle adenoma Erythema nodosum and pharyngitis f 40 7.5 22 Unsatisfactory Hürthle adenoma Pelvic inflammatory disease f 61 6.4 10 Oncocytic cells Nodular goitre Lung carcinoma m 70 15.2 30 Oncocytic cells Follicular carcinoma Origo ignota malignant disease m 48 11 21 Atypia of undetermined significance Medullary carcinoma Histiocytosis m 41 11 10 Papillary carcinoma Papillary carcinoma GIT malignancy f 64 31.9 52 Atypia of undetermined significance Papillary carcinoma Metastatic lesion on the left side of the neck m 74 10 30 Planocelluar metastasis Planocellular subglottic carcinoma — metastasis IO Hodgkin’s lymphoma f 64 3.2 15 Suspicious for malignancy (follicular or Hürthle) Hyperplastic follicular benign nodule Malignant melanoma m 71 2 23 Suspicious for malignancy (follicular or papillary) Multinodular colloid goitre Tumour of the GE junction f 62 8.7 35 Oncocytic cells Hürthle adenoma Tumour mass in the thigh m 22 7.8 9 Papillary carcinoma Follicular carcinoma Rectal carcinoma m 71 2.7 40 Suspicious for follicular malignancy Follicular carcinoma Malignant melanoma f 55 6 10 Papillary carcinoma Thyroid malignancy with elements of follicular, papillary and Hürthle carcinoma Rectal carcinoma m 59 6.4 10 Papillary carcinoma Papillary carcinoma Rectal carcinoma m 58 2.8 15 Oncocytic cells Papillary carcinoma UMC = University Medical Centre Ljubljana; IO = Institute of Oncology Ljubljana; SUVmax = maximal standardised uptake value; GE = gastro-oesophageal; GIT = gastro-intestinal tract that was used in different institutions. At UMC, a 31 focal PET lesions proved to be of autoimmune thorough thyroid examination with relevant labo-origin. ratory workup and an ultrasound examination of According to the literature, Graves’ disease the thyroid, irrespective of the use of FNAC, was is demonstrated most commonly by diffuse-in most patients enough to make a final diagnosis ly increased 18F-FDG uptake in the thyroid.39,40 of thyroid disease. The decision regarding FNAC However, in our study, we found two cases of examination was undertaken by the consulting Graves’ disease with focal 18F-FDG uptake. thyroidologist on a patient by patient basis. Most One of the main goals of our study was to de-studies, like the one conducted by Chu et al.12, were termine whether it would be possible to differen­more in line with the IO group, where only 3 of tiate between benign and malignant thyroid le­ 126 sions using SUVmax. The literature is quite divided on this topic, with studies claiming to being able to differentiate between benign and malignant le­sions13,21,22,41 and others whose conclusions were the exact opposite.17,23-28 This was also the case in our study, where the UMC group presented a statistically significant difference between benign and malignant lesions, whereas no such differ­ence was found in the IO group. Even though the mean SUVmax of malignant lesions were on average higher than benign lesions, the overlap between both sets of lesions was considerable. For example, a Hürthle adenoma had a relatively high SUVmax of 8.9 while on the other side; a papillary thyroid carcinoma had a SUVmax of only 2.8. It should also be noted, that calculated SUVmax is highly dependent on the type of PET-CT scanner, reconstruction algorithms and software packages used20,29-31, as was the case in our study, which in­cluded two centres with different equipment. The newer Siemens Biograph® mCT used at UMC had a better detector system and time of flight technol­ogy compared to the older Philips Gemini 16 GXL. These might be some of the factors resulting in dif­ferent SUVmax readings at both centres. Therefore, the SUVmax of a thyroid lesion should only serve as one of several parameters that alert the clinician on the possibility of thyroid malignancy. The cor­rect protocol in this situation is, as recommended by the American Thyroid Association Guidelines, to promptly investigate all focal thyroid PET lesions with additional diagnostics.38 Conclusions Incidental 18F-FDG uptake in the thyroid on PET­CT was found in 3.89%. Only focal thyroid uptake represented a malignant lesion in our study – in 15.2% of all focal thyroid lesions. SUVmax should only serve as one of several parameters that alert the clinician on the possibility of thyroid malig­nancy and as such must be used with caution in the interpretation of PET-CT studies. References 1. 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Nucl Med Biol 2000; 27: 643-6. 21. Kang BJ, O JH, Baik JH, Jung SL, Park YH, Chung SK. Incidental thyroid uptake on F-18 FDG PET/CT: correlation with ultrasonography and pathology. Ann Nucl Med 2009; 23: 729-37. 22. Kim BH, Na MA, Kim IJ, Kim S-J, Kim Y-K. Risk stratification and prediction of cancer of focal thyroid fluorodeoxyglucose uptake during cancer evaluation. Ann Nucl Med 2010; 24: 721-8. 23. Kim TY, Kim WB, Ryu JS, Gong G, Hong SJ, Shong YK. 18F-fluorodeoxyglucose uptake in thyroid from positron emission tomogram (PET) for evaluation in cancer patients: high prevalence of malignancy in thyroid PET inciden­taloma. Laryngoscope 2005; 115: 1074-8. 24. Are C, Hsu JF, Ghossein RA, Schöder H, Shah JP, Shaha AR. Histological aggressiveness of fluorodeoxyglucose positron-emission tomogram (FDG­PET)-detected incidental thyroid carcinomas. Ann Surg Oncol 2007; 14: 3210-5. 127 25. Bogsrud TV, Karantanis D, Nathan MA, Mullan BP, Wiseman GA, Collins DA, et al. The value of quantifying 18F-FDG uptake in thyroid nodules found incidentally on whole-body PET–CT. Nucl Med Comun 2007; 28: 373-81. 26. Kwak JY, Kim E-K, Yun M, Cho A, Kim MJ, Son EJ, et al. Thyroid incidentalo­mas identified by 18F-FDG PET: sonographic correlation. Am J Roentgenol 2008; 91: 598-603. 27. Chen W, Parsons M, Torigian DA, Zhuang H, Alavi A. Evaluation of thyroid FDG uptake incidentally identified on FDG-PET/CT imaging. Nucl Med Commun 2009; 30: 240-4. 28. Pampaloni MH, Win AZ. Prevalence and Characteristics of Incidentalomas Discovered by Whole Body FDG PETCT. Int J Mol Imaging 2012; 18: 1-6. 29. Nguyen NC, Kaushik A, Wolverson MK, Osman MM. Is there a common SUV threshold in oncological FDG PET/CT, at least for some common indications? A retrospective study. Acta Oncol 2011; 50: 670-7. 30. de Langen AJ, Vincent A, Velasquez LM, van Tinteren H, Boellaard R, Shankar LK, et al. Repeatability of 18F-FDG uptake measurements in tumors: a metaanalysis. J Nucl Med 2012; 53: 701-8. 31. Makris NE, Huisman MC, Kinahan PE, Lammertsma AA, Boellaard R. Evaluation of strategies towards harmonization of FDG PET/CT studies in multicentre trials: comparison of scanner validation phantoms and data analysis procedures. Eur J Nucl Med Mol Imaging 2013; 40: 1507-15. 32. King D, Stack B, Spring P, Walker R, Bodenner D. Incidence of thyroid carci­noma in fluorodeoxyglucose positron emission tomography-positive thyroid incidentalomas. Otolaryngol Head Neck Surg 2007; 137: 400-4. 33. Bertagna F, Giubbini R. F18-FDG-PET/CT thyroid incidentalomas and their benign or malignant nature: a critical and debated issue. Ann Nucl Med 2010; 25: 151–2. 34. Ohba K, Nishizawa S, Matsushita A, Inubushi M, Nagayama K, Iwaki H, et al. High incidence of thyroid cancer in focal thyroid incidentaloma detected by 18F-fluorodeoxyglucose [corrected] positron emission tomography in relatively young healthy subjects: results of 3-year follow-up. 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Glucose metabolism of the thyroid in Graves’ disease measured by F-18-fluoro­deoxyglucose positron emission tomography. Thyroid 1998; 8: 765-72. 40. Liu Y. Clinical significance of thyroid uptake on F18-fluorodeoxyglucose positron emission tomography. Ann Nucl Med 2009; 23: 17-23. 41. Ho T-Y, Liou M-J, Lin K-J, Yen T-C. Prevalence and significance of thyroid uptake detected by 18F-FDG PET. Endocrine 2011; 40: 297-302. 128 research article Primary central nervous system lymphoma: is absence of intratumoral hemorrhage a characteristic finding on MRI? Akihiko Sakata1, Tomohisa Okada1, Akira Yamamoto1, Mitsunori Kanagaki1, Yasutaka Fushimi1, Toshiki Dodo1, Yoshiki Arakawa2, Jun C Takahashi2, Susumu Miyamoto2, Kaori Togashi1 1 Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan 2 Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto, Japan Radiol Oncol 2015; 49(2): 128-134. Received 12 August 2014 Accepted 6 January 2015 Correspondence to: Tomohisa Okada, M.D., Ph.D., Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawaharacho, Sakyo-ku, Kyoto, 606–8507, Japan. Phone: +81 75 751 4215; Fax: +81 75 751 4216; E-mail: tomokada@ kuhp.kyoto-u.ac.jp Disclosure: No potential conflicts of interest were disclosed. Background. Previous studies have shown that intratumoral hemorrhage is a common finding in glioblastoma multi­forme, but is rarely observed in primary central nervous system lymphoma. Our aim was to reevaluate whether intra­tumoral hemorrhage observed on T2-weighted imaging (T2WI) as gross intratumoral hemorrhage and on susceptibility-weighted imaging as intratumoral susceptibility signal can differentiate primary central nervous system lymphoma from glioblastoma multiforme. Patients and methods. A retrospective cohort of brain tumors from August 2008 to March 2013 was searched, and 58 patients (19 with primary central nervous system lymphoma, 39 with glioblastoma multiforme) satisfied the inclu­sion criteria. Absence of gross intratumoral hemorrhage was examined on T2WI, and an intratumoral susceptibility signal was graded using a 3-point scale on susceptibility-weighted imaging. Results were compared between primary central nervous system lymphoma and glioblastoma multiforme, and values of P < 0.05 were considered significant. Results. Gross intratumoral hemorrhage on T2WI was absent in 15 patients (79%) with primary central nervous system lymphoma and 23 patients (59%) with glioblastoma multiforme. Absence of gross intratumoral hemorrhage could not differentiate between the two disorders (P = 0.20). However, intratumoral susceptibility signal grade 1 or 2 was diag­nostic of primary central nervous system lymphoma with 78.9% sensitivity and 66.7% specificity (P < 0.001), irrespective of gross intratumoral hemorrhage. Conclusions. Low intratumoral susceptibility signal grades can differentiate primary central nervous system lym­phoma from glioblastoma multiforme. However, specificity in this study was relatively low, and primary central nervous system lymphoma cannot be excluded based solely on the presence of an intratumoral susceptibility signal. Key words: glioblastoma multiforme; primary central nervous system lymphoma; magnetic resonance imaging Introduction Primary central nervous system lymphoma (PCNSL) represents approximately 2.6% of all brain tumors and 1.2% of all non-Hodgkin lym­phomas.1,2 The vast majority of PCNSLs are diffuse large B-cell lymphomas, regardless of the patient’s immunological state, and primary T-cell lympho­ mas are uncommon in the central nervous system (CNS).3 The incidence of this pathology has recent­ly been on the rise among both immunocompetent and immunocompromised populations.4 Histology is required for a definitive diagnosis, but radical surgical excision of PCNSL is not war­ranted; even partial tumor resection seems to be a negative prognostic factor.2 Glioblastoma mul­tiforme (GBM), on the other hand, requires maxi­mal excision. Because symptomatic patients with 129 PCNSL often present with lesions of considerable size, steroid administration is sometime clinically indicated before pathological confirmation, result­ing in low diagnostic yields for histological exami­nation.5 Accurate diagnosis of PCNSL by initial im­aging is thus crucial to avoid steroid treatment and facilitate biopsy, rather than resection that does not improve prognosis. PCNSL has many documented imaging fea­tures1,6-10, but may mimic other diseases or show atypical findings, making preoperative diagnosis of PCNSL imperfect even with current advanced imaging techniques.11,12 As another imaging meth­od, susceptibility-weighted imaging (SWI) has re­cently been reported to differentiate PCNSL from GBM, as the most common malignant primary brain tumor, nearly perfectly when intratumoral susceptibility signal (ITSS) that reflects hemor­rhage is used.13-15 However, some reports have described PCNSL with cerebral hemorrhage even in non-HIV pa­tients16-18 and hemorrhage may not be particular­ly rare even among immunocompetent patients. Moreover, the relationship between ITSS and in­tratumoral hemorrhage observed on conventional imaging modalities such as computed tomography (CT) or T2-weighted imaging (T2WI) in PCNSL cases has not been clarified in detail.13-15 Given these considerations, we have retrospec­tively reviewed all patients with PCNSL and GBM encountered within a fixed period in our hospital to investigate the differential capabilities of gross intratumoral hemorrhage (GITH) on T2WI and ITSS grading on SWI. Patients and methods Patients A retrospective cohort of brain tumors in the pathol­ogy archives of our institution from August 2008 to March 2013 was searched for cases of PCNSL and GBM. From the database, we included all patients with pathologically diagnosed PCNSL and GBM who had preoperative CT and MRI studies includ­ing T2WI and SWI. From the database, we found 65 patients with pathologically diagnosed PCNSL and GBM who had undergone preoperative CT and MRI studies, including T2WI and SWI. Exclusion criteria were a history of organ transplantation (n = 1) or surgical intervention (i.e. biopsy or drain­age) before initial MRI (n = 6). In total, 58 patients satisfied these criteria: 19 patients with PCNSL (10 men, 9 women; mean age, 65.1 years; range, 26.83 years) and 39 patients with GBM (24 men, 15 wom­en; mean age, 59.7 years; age range, 16.87 years). Among PCNSL patients, all were diagnosed with B-cell lymphoma (diffuse large B-cell lymphoma, n = 17; precursor B cell lymphoma, n = 1), except 1 case of T-cell lymphoma. No patient had history of acquired immunodeficiency syndrome or other immunodeficiency disorders. One patient with B-cell lymphoma had Sjögren syndrome and was treated with disease-modifying anti-rheumatic drugs. Another patient was treated for multiple sclerosis with steroid pulse therapy for 1 month prior to admission to our hospital. One patient with T-cell lymphoma showed positive results for human T-lymphotropic virus type 1 infection post­operatively, but the lesion was limited to the CNS. Five patients with PCNSL had received steroids prior to MRI to diminish edema. This study was approved by the institutional review board. Given the retrospective design, the requirement for in­formed consent was waived. Image acquisition Patients were imaged using a 3T MRI system (Magnetom Trio Tim or Skyra; Siemens Healthcare, Erlangen, Germany) with a 32-channel head coil. T2WI was acquired using a fast spin-echo sequence under the following conditions: repetition time (TR), 3200 ms; echo time (TE), 79 ms; matrix, 420 × 448; field of view, 206×220 mm; matrix size, 0.49 × 0.49 mm; 35 slices of 3 mm thickness with a 1 mm gap. SWI was acquired with a three-dimensional fully flow-compensated gradient echo sequence using the following parameters: TR, 28 ms; TE, 20 ms; flip angle, 15°; matrix, 320 × 230; field of view, 230 × 179 mm; matrix size, 0.72 × 0.78 mm. Slab size was 76.8 mm or 128 mm, partitioned into 64 slices of 1.2 or 2 mm (n = 28 and 30, respectively). SWI se­quences were acquired before contrast administra­tion. Diffusion-weighted imaging (DWI), pre- and post-contrast enhanced T1-weighted images were also routinely acquired. DWI was performed using a single-shot spin-echo (SE) echo planar sequence with following parameters: TR 5000ms, TE 84 ms, flip angle 90°, matrix 160 × 160, field of view 220 × 220 mm, matrix size, 0.49 × 0.49 mm; 35 slices of 3 mm thickness with a 1 mm gap. Diffusion-sensitizing gradients were applied in 3 directions with b factors of 0 and 1000 s/mm2. Apparent dif­fusion coefficients (ADCs) were automatically cal­culated by the operating console of the MR scanner and displayed as corresponding ADC maps. All patients underwent unenhanced CT with an in­ 130 plane resolution of 0.41 × 0.41 mm and slice thick­nesses of 4.8 mm in conventional scans and 5 mm in helical acquisitions using 16- or 64-detector-row CT scanners (Aquilion 16 or Aquilion 64; Toshiba Medical Systems, Ohtawara, Japan). Image analysis Qualitative analysis including T2WI and contrast-enhanced T1-weighted images (CE-T1WI) as well as SWI was conducted on a clinical picture archiv­ing and communication system (Centricity, PACS workstation version 3.2; GE Medical Systems, Milwaukee, WI) by two board-certified neuroradi­ologists (A.S. and T.D.; both with 5 years of expe­rience in diagnostic radiology) who were blinded to the final diagnosis. First, they evaluated the ab­sence of GITH. GITH was defined as nodular or lin­ear hypo-intense foci observed on T2WI (Figure 1). Second, ITSS grading on SWI was conducted inde­pendently by the same two neuroradiologists at 1 month after GITH evaluation. As described by Kim et al.12, ITSS was defined as a dot-like or fine lin­ear low signal within a tumor, and graded using a 131 3-point scale: grade 1, no ITSS (Figure 2A); grade 2, 1.10 ITSSs (Figure 2B); and grade 3, . 11 ITSSs (Figure 2C) within a tumor. Corresponding con­trast-enhanced T1-weighted images are presented as tumor references (Figure 2D-F). Enhancement patterns on contrast-enhanced T1-weighted image were evaluated as necrotic or non-necrotic: necrotic was defined as solid enhancement with any loss of contrast enhancement.19 When absence of GITH, ITSS grading or enhancement patterns were dis­cordant between evaluators, the final results were reached by consensus. To exclude low signal inten­sity caused by calcification (defined as a CT attenu­ation value >100 Hounsfield units), unenhanced CT was also referred to. The same neuroradiologists (A.S. and T.D.) eval­uated ADC maps using software (Image J version 1.49a; NIH, Bethesda). Firstly, we selected all slices that included tumor. One round- or oval-shaped region of interest (area, approximately 0.3 cm2) was carefully placed on each slice of the ADC map of the whole tumor to include the area with the low­est ADC value determined by visual inspection. Cystic, necrotic or hemorrhagic areas were care­fully avoided by referencing to conventional MR images. Finally, the value of a region of interest with the lowest average ADC value was selected as a minimum ADC (ADCmin) value of the tumor in each case.20 Statistical analysis Patient groups of PCNSL and GBM were com­pared for age, sex and parameters using a t-test and a Pearson’s .2 test, respectively. Inter-observer variability of GITH and ITSS grading was evalu­ated using . statistics. Inter-observer variability of the readers for ADC analysis was evaluated by intraclass correlation (ICC) coefficient (0.00–0.20 poor, 0.21–0.40 fair, 0.41–0.60 moderate, 0.61–0.80 good and 0.81–1.00 excellent correlation). ADCs were averaged between the two observers for fur­ther analysis. ADCmin Receiver-operating char­acteristic (ROC) curve analysis was conducted for GITH, ITSS, enhancement pattern and ADCmin, and sensitivity , specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for differentiating PCNSL from GBM.21 Areas under the curve (AUCs) were sta­tistically compared using a method by Delong et al.22 To analyze whether ADCmin were affected by microhemorrhage, ADCmin values of the groups defined by ITSS were compared using ANOVA in both GBM and PCNSL patients. A value of P < 0.05 TABLE 1. Gross intratumoral hemorrhage (GITH) frequency in primary central nervous system lymphoma (PCNSL) and glioblastoma multiforme (GBM) PCNSL 15 (79) 4 (21) GBM 23 (59) 16 (41) TABLE 2. Intratumoral susceptibility signal (ITSS) grading of primary central nervous system lymphoma (PCNSL) and glioblastoma multiforme (GBM) PCNSL 9 (47) 6 (32) 4 (21) GBM 4 (10) 9 (23) 26 (67) TABLE 3. Enhancement patterns of primary central nervous system lymphoma (PCNSL) and glioblastoma multiforme (GBM) Non-necrotic 15 2 Necrotic 3 37 was considered significant. All statistical analy­ses were conducted using MedCalc for Windows (version 12.5.0.0; MedCalc Software, Mariakerke, Belgium). Results No significant differences in age (P = 0.39) or sex (P = 0.72) were found between patient groups. Inter-observer agreement between the two evaluators was substantial for GITH (. = 0.75, 95% confidence interval (CI) = 0.58.0.92) and almost perfect for ITSS (. = 0.88, 95% CI = 0.81.0.96). ICC of ADCmin was 0.693 (95% CI = 0.48.0.82). CT showed no calcification in any cases. GITH was not observed in 15 patients (79%) with PCNSL and in 23 patients (59%) with GBM (Table 1), and ROC analysis thus failed to reveal any significant difference (P = 0.20). ITSS grades 1, 2 and 3 were found in 9, 6 and 4 PCNSL patients, respective­ly, and in 4, 9 and 26 GBM patients, respectively (Table 2). GITHs were associated with grade 3 ITSS in almost all cases, except for 1 patient with GBM and 1 patient with PCNSL; both of these patients showed grade 2 ITSS. ITSS was not observed (i.e., grade 1) in 9 PCNSL patients (47.4%) and 4 GBM 132 FIGURE 3. Receiver-operating charac­teristic curve analysis of intratumoral susceptibility signal (ITSS) grading to differentiate primary central nervous system lymphoma from glioblastoma multiforme. ITSS grades. 2 is diagnostic of primary central nervous system lym­phoma with 78.9% sensitivity and 66.7% specificity, not as high as in previous studies. FIGURE 4. Receiver-operating charac­teristic curve analysis of minimum ap­parent diffusion coefficient (ADCmin) and intratumoral susceptibility signal (ITSS) grading to differentiate prima­ry central nervous system lymphoma from glioblastoma multiforme. ADCmin . 0.629 mm2/s is diagnostic of primary central nervous system lymphoma with 100% sensitivity and 53.8% specificity. patients (10.3%). When ITSS grade 1 was used as the criterion of PCNSL, sensitivity, specificity, PPV, and NPV was 47.4%, 89.7%, 69.2%, and 77.8% re­spectively, whereas ITSS grade 1 or 2 was diagnos­tic of PCNSL with 78.9% , 66.7% , 53.6% and 86.7%. The AUC values were 0.686 and 0.728, respectively (p values were 0.0036 and 0.0002, Figure 3). There was not statistically significant difference between the two curves. Enhancement patterns of GBM and PCNSL were summarized in Table 3: one patient with no con­trast-enhancement was excluded from this analy­sis. Most GBMs showed necrotic pattern, while most PCNSL showed non-necrotic enhancement. Sensitivity, specificity PPV and NPV were 83.3%, 94.9%, 88.2% and 92.5%, respectively. ADCmin was significantly lower for lymphoma than for GBM (0.487 ± 0.09 × 10-3 mm2/s and 0.645 ± 0.15 × 10-3 mm2/s, respectively; p = 0.001 with stu­dent t-test). ROC curve analysis of ADCmin found the optimal cutoff value to be 0.629 mm2/s (sensi­tivity: 100%, specificity: 53.8%, PPV: 51.4%. and NPV: 100%). There was not statistically significant differences between AUCs of ITSS and ADCmin (p value = 0.68) (Figure 4). Discussion Our results demonstrated that ITSS on SWI can aid to differentiate PCNSL from GBM compared with GITH on T2WI. However, in this study cohort, more than half of PCNSL patients showed positive ITSS (i.e., . 2), including 4 patients with ITSS grade 3. The frequency of positive ITSS in PCNSL was much higher than in previous reports, resulting in the lower specificity of 66.7%. Conventional imaging technique, especially CE-T1WI, is useful for differentiating PCNSL and GBM. Most GBMs show heterogeneous enhance­ment with variable size of necrotic foci, while PCNSL typically shows homogenous enhancement because of paucity of intratumoral necrosis, espe­cially in immunocompetent patients. However, up to 10% of patients show atypical enhancement pat­terns in GBM and PCNSL.1,19 Therefore, further im­aging technique is warranted for more appropriate evaluation. Hemorrhagic and necrotic foci are commonly observed in GBM.23 Previous studies have also showed that ITSS on T2*-weighted imaging or SWI is more frequently detected in high-grade glio­ma.24,25 Conversely, in immunocompetent PCNSL patients, intratumoral hemorrhage before therapy has rarely been observed. On CT and conventional MRI, tumor-associated hemorrhage was reported in 0.8% of PCNSL cases.1,6,8,10 Based on this rarity, the presence of hemorrhage or calcification is used to exclude PCNSL from the differential diagnosis. Previous reports on SWI have confirmed non-SWI results.13-15,21,26 Kim et al., first demonstrated the presence of ITSS, particularly grade 3, could distinguish high-grade glioma from PCNSL with 100% specificity, although their study included only 7 patients with PCNSL.13 Radbruch et al., also recently reported that ITSS was not observed in any of 14 patients with B-cell PCNSL, with the ex­ception of 1 case of T-cell lymphoma.14 Peters et al., also showed that SWI is useful for differentiating PCNSL from GBM, although 1 in 4 patients with PCNSL showed grade 2 ITSS.15 Previous studies have suggested nearly complete absence of ITSS in PCNSL.13-15,21,26 However, on pathological examination, necro­sis and hemorrhage are occasionally observed in PCNSL.27 Some case reports have described PCNSL presenting with intracerebral hemorrhage in both immunocompetent and immunocompromised pa­tients.16-18 In a study of 10 immunocompetent PCNSL patients, small hemorrhage was found on MRI in 4 of 19 lesions (21%).9 Moreover, Kickingereder et al., have recently reported presence of the ITSS in 6 out of 19 PCNSL patients on 3T MRI.19 These findings are comparable to our result. SWI is much more sen­sitive to susceptibility difference than conventional 133 MRI, including T2*-weighted imaging24,28,29, and is considered to identify more small hemorrhagic lesions within the tumors. Actually, in the present study, patients with positive ITSS were twice as common as those with GITH in both groups. This is in accordance with the recent report by Ding et al., demonstrating the significant difference in the de­tecting rate of intra-tumoral hemorrhage in patients with GBM and brain metastasis between the con­ventional MR imaging and SWI.21 Therefore, con­ventional MR including T2*WI seems insensitive to hemorrhagic change, and unsuitable for differenti­ating GBM from PCNSL based on the absence of intratumoral hemorrhage. This study showed much higher frequency of positive ITSS in PCNSL patients compared with previous studies. Several factors may contribute to this result. One possible explanation is that SWI in this study used thinner slices than previous studies. Nandigum et al., demonstrated that SWI acquired with thinner slices in a higher magnetic field de­tected significantly more cerebral microbleeds.30 Previous SWI studies on PCNSL have reported almost no ITSS13,14, but used 2.5- or 3-mm slice thicknesses, thicker than used in this study (i.e., 1.2 or 2 mm). Peters et al., used 1-mm slice thick­ness and found grade 2 ITSS in 1 of 4 patients with PCNSL (diffuse large B-cell lymphoma).15 Thinner slice thickness thus appears more sensitive to small foci of hemorrhage and may have contributed to higher ITSS grades in our PCNSL cases compared to previous reports. The other technical factor is the difference in head coils used in studies. Previous studies used 8- to 12-channel head coils13-15, where­as the present study used a 32-channel brain coil, which improves the signal-to-noise ratio (SNR).31 SWI was acquired at high resolution, but there is a trade-off between resolution and SNR. With lower SNR, lesion detectability is impaired32,33, which may also have contributed to the differences with previous studies. Several authors investigate the role of other advanced techniques, especially DWI, in evalu­ation of differentiation of PCNSL and GBM.12,34,35 Generally, the ADC values of PCNSL are low, re­flecting the high degree of cellularity. However, according to several earlier investigations, the dif­ferences in ADC between patients with PCNSL and those with glioblastoma were not always statisti­cally significant.35 Our results showed there were significant differences between both groups, but its specificity was relatively low, which is consistent with previous studies. We also tested if the pres­ence of ITSS effects ADC values, but the ADC val­ue of the tumor did not differ depending on the amount of microhemorrhage. Our results showed the diagnostic capability of ITSS for differentiating PCNSL from GBM were comparable to that of ADCmin, however, as a sin­gle parameter, both of them were not so specific as previously described.13-15,21,26 Kickingereder et al., showed that ITSS as an additional imaging param­eter allowed correct classification of the atypical GBM (i.e. GBM showing homogenous enhance­ment) and PCNSL.19 Therefore, considering with the limited diagnostic capability of ITSS, combined analysis of several parameters obtained by other imaging technique, such as PWI12, ASL26 and MRS19 should be considered in the clinical practice. Some limitations in this study must be con­sidered. The sample size was relatively small. However, the case number is more than or com­parable to former studies. Another limitation was that we included patients who were treated with steroids before imaging. Steroid therapy is well known to disrupt cellular morphology, which may affect imaging appearance.5,36 However, no patients with steroid administration prior to MRI showed positive ITSS, and steroid use had minimal effect on our results. We also included one human T-lymphotropic virus type 1-positive case that may potentially have arisen in an im­munocompromised patient. PCNSL in an immu­nocompromised host with primary CNS T-cell lymphoma is known to have a relatively high in­cidence of intratumoral hemorrhage11,37, but the patient in this study showed no GITH or ITSS. Finally, Epstein-Barr virus infection is another important factor that must be considered. Lee et al., recently demonstrated that Epstein-Barr virus -positive PCNSL cases showed intratumoral ne­crosis or hemorrhage more frequently than cases with Epstein-Barr virus -negative PCNSL, even in the absence of HIV infection.38 No description of Epstein-Barr virus infection status has been avail­able in previous studies on ITSS13-15, and this was also the case for this study. PCNSL with GITH or ITSS could potentially be related to Epstein-Barr virus infection, but no conclusion can be drawn within this study. In conclusion, low ITSS grades can differenti­ate PCNSL from GBM. However, specificity in this study was relatively low, and PCNSL cannot be excluded based solely on the presence of an ITSS. Careful evaluation using several imaging tech­nique is important. 134 References 1. Haldorsen IS, Krakenes J, Krossnes BK, Mella O, Espeland A. CT and MR imaging features of primary central nervous system lymphoma in Norway, 1989-2003. AJNR Am J Neuroradiol 2009; 30: 744-51. 2. 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Differentiation of primary central nerv­ous system lymphoma from high-grade glioma and brain metastases using susceptibility-weighted imaging. Brain and Behavior 2014; 4: 841-9. 22. DeLong ER, DeLong DM, Clarke-Pearson DL. Comparing the areas under two or more correlated receiver operating characteristic curves: a nonparamet­ric approach. Biometrics 1988; 44: 837-45 23. Kondziolka D, Bernstein M, Resch L, Tator CH, Fleming JF, Vanderlinden RG, et al. Significance of hemorrhage into brain tumors: clinicopathological study. J Neurosurg 1987; 67: 852-7. 24. Bagley LJ, Grossman RI, Judy KD, Curtis M, Loevner LA, Polansky M, et al. Gliomas: correlation of magnetic susceptibility artifact with histologic grade. Radiology 1997; 202: 511-6. 25. Li C, Ai B, Li Y, Qi H, Wu L. Susceptibility-weighted imaging in grading brain astrocytomas. Eur J Radiol 2010; 75: e81-5. 26. Furtner J, Schöpf V, Preusser M, Asenbaum U, Woitek R, Wöhrer A, et al. 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AJNR Am J Neuroradiol 2013; 34: 1562-7. 135 research article Doppler ultrasound for diagnosis of soft tissue sarcoma: efficacy of ultrasound-based screening score Satoshi Nagano1*, Yuhei Yahiro1*, Masahiro Yokouchi1, Takao Setoguchi2, Yasuhiro Ishidou3, Hiromi Sasaki1, Hirofumi Shimada1, Ichiro Kawamura3, Setsuro Komiya1,2 1 Department of Orthopaedic Surgery, 2 The Near-Future Locomotor Organ Medicine Creation Course (Kusunoki Kai) and 3 Department of Medical Joint Materials, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan Radiol Oncol 2015; 49(2): 135-140. Received 25 November 2014 Accepted 9 February 2015 Correspondence to: Satoshi Nagano, M.D., Ph.D., Department of Orthopaedic Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima City, Kagoshima 890-8520, Japan. Phone: +81 99 275 5381; Fax: +81 99 265 4699; E-mail: naga@m2.kufm.kagoshima-u.ac.jp * These authors contributed equally to this work. Disclosure: No potential conflicts of interest were disclosed. Background. The utility of ultrasound imaging in the screening of soft-part tumours (SPTs) has been reported. We clas­sified SPTs according to their blood flow pattern on Doppler ultrasound and re-evaluated the efficacy of this imaging modality as a screening method. Additionally, we combined Doppler ultrasound with several values to improve the diagnostic efficacy and to establish a new diagnostic tool. Patients and methods. This study included 189 cases of pathologically confirmed SPTs (122 cases of benign disease including SPTs and tumour-like lesions and 67 cases of malignant SPTs). Ultrasound imaging included evaluation of vas­cularity by colour Doppler. We established a scoring system to more effectively differentiate malignant from benign SPTs (ultrasound-based sarcoma screening [USS] score). Results. The mean scores in the benign and malignant groups were 1.47 ± 0.93 and 3.42 ± 1.30, respectively. Patients with malignant masses showed significantly higher USS scores than did those with benign masses (p < 1 × 10-10). The area under the curve was 0.88 by receiver operating characteristic (ROC) analysis. Based on the cut-off value (3 points) calculated by ROC curve analysis, the sensitivity and specificity for a diagnosis of malignant SPT was 85.1% and 86.9%, respectively. Conclusions. Assessment of vascularity by Doppler ultrasound alone is insufficient for differentiation between benign and malignant SPTs. Preoperative diagnosis of most SPTs is possible by combining our USS score with characteristic clinical and magnetic resonance imaging findings. Key words: Doppler ultrasound; soft-part tumours; differential diagnosis; ultrasound-based sarcoma screening score Introduction The diagnosis of soft-part tumours (SPTs) in ortho­paedic primary care is not easy because of the rar­ity of the disease, few characteristic findings, and lack of simple diagnostic tools. Ultrasonography is a noninvasive imaging tool that is gaining popu­larity in orthopaedic clinics. It has already been used in daily clinics for evaluation of muscle in­jury1, rotator cuff tears2, entrapment neuropathy3, and many other conditions.4 The utility of ultra­sound imaging in the screening of SPTs has been discussed in the past by several authors with some modifications.5-9 To improve the diagnostic accura­cy of malignant tumours, more defined and com­plex methods of ultrasound imaging for SPTs have 136 Table 1. USS score of benign tumors. PNST 34 1.59 0.36 lipoma et 29 1.41 0.33 Cystic lesion 20 1.20 0.23 PVS/GCT 10 1.60 0.43 Vascular tumor 10 2.30 0.78 Fibroma et 8 1.13 0.42 Other tumor / mass 11 1.09 0.43 Total 122 1.47 0.16 PNST = Peripheral nerve sheath tumor; PVS = Pigmented villonodular synovitis; GCT = Giant cell tumor Table 2. USS score of malignant tumors UPS/MFH 23 3.87 0.45 Liposarcoma 15 3.13 0.58 WDL 14 2.15 0.5 Synovial sarcoma 3 4.67 0.65 Leiomyosarcoma 3 2.67 0.65 Other sarcoma 9 4.44 0.74 Total 67 3.42 0.31 PS = Unclassified pleomorphic sarcoma; MFH = Malignant fibrous histiocytoma; WDL = Well-differentiated liposarcoma been reported. For instance, contrast-enhanced ultrasound is reportedly useful for differentiation between malignant and benign SPTs by analysis of contrast-enhancement kinetics10 or in combina­tion with three-dimensional power Doppler.11 On the other hand, Chiou et al. used a computer-aided diagnosis (CAD) system to improve the diagnosis of malignant SPT.12 They analysed five features (namely area, boundary transition ratio, circular­ity, high-intensity spots, and uniformity) with the CAD system and achieved a sensitivity of 88.2% and specificity of 87.5%. Although this new method might be more accurate, it is not feasible for outpa­tient screening. An accelerated diagnostic process and appropriate treatment of patients with SPTs could be expected with the use of a simple, easy screening method using ultrasound without the re­quirement for a special technique. Ultrasound may also reduce the performance of unnecessary imag­ing studies, thus decreasing medical care costs. Previous reports on diagnostic ultrasound im­aging of SPTs describe several methods with which to judge malignancy according to the amount of blood flow seen on Doppler ultrasonography.8,13,14 Giovagnorio et al.13 classified the blood flow pat­terns of 51 superficial SPTs into 4 types. By defining hypervascular type III and IV blood flow as malig­nant criteria, they reported a sensitivity and speci­ficity of 90% and 100%, respectively. Their method is recognised as one of the most useful screening techniques for SPTs.15 In the present study, we classified the blood flow pattern of SPTs according to the Doppler ultra­sound findings and re-evaluated these previously described results.13 We also sought to establish new diagnostic criteria, and thus improve the diagnos­tic efficacy by combining Doppler ultrasound find­ings with other factors. Patients and methods This study included 189 patients with SPTs who un­derwent surgery in our department and obtained a pathological diagnosis. Ultrasound imaging stud­ies were performed at the initial visit to the ortho­paedic outpatient clinic. The patients comprised 87 men and 102 women with an average age of 54 years. In total, 122 patients had benign diseases including SPTs and tumour-like lesions, while 67 patients had malignant SPTs (Table 1). This study was conducted according to the principles of the Declaration of Helsinki and approved by the insti­tutional ethical committee. A musculoskeletal oncologist performed the ultrasonography examinations using a 12L-RS lin­ear-type probe of 5.0 to 13.0 MHz (Logic e series; General Electric, Fairfield, CT). According to a re­port by Giovagnorio et al.13, we classified the in­tratumoural blood flow patterns shown on colour Doppler into four groups: avascular (type I), hypo-vascular with a single vascular pole (type II), hyper-vascular with multiple peripheral poles (type III), and hypervascular with internal vessels (type IV). We also established a scoring system to improve the sensitivity of differential diagnosis of benign and malignant SPTs (ultrasound-based sarcoma screening [USS] score). In addition to three ultra­sound findings (echoic intensity, uniformity of in­ternal structure, and Doppler blood flow classifi­cation), the tumour diameter was included in the USS score (Table 2). We evaluated all cases using the USS score and analysed its utility in the differ­ential diagnosis of SPTs. 137 A p value of < 0.05 was considered to indicate a statistically significant difference between two groups using the chi-squared test or Student’s t test. Additionally, we established the cut-off value by receiver operating characteristic (ROC) curve analysis (Microsoft Excel; Microsoft Corporation, Redmond, WA). Results The rates of malignant tumours were 18% among type I, 63% among type II, 65% among type III, and 79% among type IV using the classification de­scribed by Giovagnorio et al.13 (Figure 1A). Using type III and IV vascularity as markers of malignan­cy, the sensitivity and specificity were 41.8% and 91.0%, respectively. ROC analysis demonstrated that the area under the curve was 0.77 (Figure 1B). We re-evaluated all cases using the USS score, which comprised four values, to determine wheth­er we could improve the diagnostic accuracy (Figure 2A). The mean scores in the benign and ma­lignant groups were 1.47 ± 0.93 and 3.42 ± 1.30, re­spectively. Malignant tumours showed significant­ly higher USS scores than did benign tumours (p < 1×10-10) (Figure 2B). The ratio of malignant tumours to all cases at each USS score (0–6 points) was 0% at 0 points and 8% at 1 point; this increased to 93% and 100% at 5 and 6 points, respectively (Figure 2C). The area under the curve was 0.88 by ROC analy­sis, suggesting that USS scoring is diagnostically superior to the Doppler classification described by Giovagnorio et al.13 (Figure 2D). Based on the cut-off value (3 points) calculated by ROC curve analysis, the sensitivity and specificity for a diagnosis of ma­lignant SPT was 85.1% and 86.9%, respectively. Finally, we examined the average score of each pathological tumour type (Table 1,2). Among be­nign tumours, vascular tumours (haemangioma, angioleiomyoma, etc.) showed significantly higher scores than did all other benign lesions (p = 0.003) (Table 1). Among malignant tumours, well-differ­entiated liposarcoma (WDL) showed significantly lower scores than did all other malignant tumours (p = 0.0004) (Table 2). However, the score for WDL (2.15 ± 0.95) was significantly higher than that for lipomatous benign lesions (1.41 ± 0.91; p = 0.02). Discussion Advances in imaging technology have provided clinicians multiple diagnostic choices for each indi- AB FIGURe 1.Validation of categorisation by Doppler ultrasound pattern.(a) All cases were categorised by their vascular pattern using Doppler ultrasound according to the classification described by Giovagnorio et al. The type I group included 101 benign tumours and 22 malignant tumours. In contrast, type IV comprised 4 and 15 benign and malignant tumours, respectively. (b) Receiver-operating curve analysis of the Doppler ultrasound classification described by Giovagnorio et al. The efficacy of the type III and IV pattern for diagnosis of malignant tumours was evaluated. The area under the curve was 0.77. AB CD FIGURe 2. Evaluation of new scoring system for soft tissue tumours with ultrasound.(a) The new scoring system for differentiation between benign and malignant soft tissue tumours was established by combining four parameters (tumour size, echogenicity, internal structure, and Doppler pattern). The score was designated the ultrasound-based sarcoma screening (USS) score. (b)All cases in this study were analysed using the USS score. The average scores of benign and malignant tumours were 1.47 ± 0.90 and 3.71 ± 1.30, respectively. (C) Distribution of benign and malignant tumours for each score. As the score increased, the incidence of malignant tumours increased. (D)Receiver-operating curve analysis of the USS score revealed a cut-off value of 3 points. TPF = true-positive fraction; FPF = false-positive fraction 138 FIGURe 3. Intramuscular haemangioma of gastrocnemius. A 19-year-old woman presented with a swelling and mild pain in her right lower leg. She experienced increased swelling and pain after exercise or long walks. (a) Ultrasound revealed an ill-defined mass with a mixed inner texture in the calf muscle. Colour Doppler examination showed multiple vessels within the tumour, corresponding to type IV in the classification described by Giovagnorio et al. (b) MRI showed a mass with an irregular border in the soleus muscle. (C) CT angiography revealed multiple vessels branching from the tibial artery. (D) Pathological analysis of a biopsy specimen demonstrated multiple vessels between the skeletal muscles with no atypia. vidual patient. Among several imaging modalities, ultrasound is the most feasible method with which to screen for SPTs if the evaluation method is estab­lished. Our analysis, which was based on a higher number and greater variety of cases than that by Giovagnorio et al.13, revealed that the specificity for malignant SPT was relatively good (0.91) by Doppler ultrasound alone, but that the sensitivity was poor (0.42). Therefore, we established a novel scoring system (USS score) that can be easily used in orthopaedic outpatient clinics and evaluated whether it can improve the diagnostic sensitivity and specificity without using special equipment. Generally, the probability of malignancy increases as the tumour diameter increases. Grimer16 report­ed that a diameter of 5 cm was a significant prog­nostic factor in patients with soft tissue sarcoma, and recommended that patients should undergo a medical examination if their mass is golf ball-sized or larger (. 4.2 cm). We therefore included the tu­mour size (cut-off of 5 cm) as a simple value in­corporated into the USS score. Although a highly significant difference was shown in the USS score between the benign and malignant groups, there were several exceptions. We thus analysed benign cases with USS scores of . 3 points. Among vascu­lar tumours, 40% showed high USS scores (. 3), fol­lowed by peripheral nerve sheath tumours (PNSTs) (20.6%). This result suggests that these benign tu­mours require other factors or imaging studies for an accurate diagnosis. Fortunately, these two tumour types exhibit characteristic clinical pres­entations; i.e., changeable size and symptoms for vascular tumours (Figure 3) and a Tinel-like sign for PNSTs. On the other hand, WDL, known as a low-grade malignancy without metastatic poten­tial17, exhibited a low USS score (. 2 points) in 9 of 13 cases (64.3%) in the present study. Preoperative differential diagnosis between benign lipomatous tumours and WDL is not easy, even with magnetic resonance imaging (MRI). Although the average USS score w as significantly higher in WDL than in benign lipomatous tumours, differential diagnosis between the two groups was not possible. As men­tioned above, because WDL does not metastasise and rarely de-differentiates into high-grade lipo­sarcoma, we and others treat such cases by mar­ginal resection, as for benign lipomatous tumours (Figure 4).17 Adjuvant radiotherapy following re­section of WDL was recently shown to reduce local recurrence.18 Therefore, differentiation of a WDL from a benign tumour is not clinically critical, but differentiation between a high-grade sarcoma 139 FIGURe 5. Myxofibrosarcoma of the thigh. A 52-year-old woman presented with a firm mass in her popliteal region. (a) Ultrasound imaging demonstrated a mixed-echoic mass with an irregular inner texture. Power Doppler revealed a relatively large vessel accompanying multiple small vessels (type IV). (b) MRI revealed a mass of both high and low intensity on T2-weighted imaging. (C) Positron-emission tomography with fluorodeoxyglucose isotope revealed a tumour with high accumulation and no distant metastases. (D) Pathological examination of the biopsy specimen demonstrated abundant atypical tumour cells with nuclear pleomorphism. FIGURe 6. Flowchart of diagnosis of soft-part tumours based on ultrasound scoring. This flowchart proposes a screening procedure for soft-part tumours (SPTs). The screening procedure is mainly based on stratification by the ultrasound-based sarcoma screening (USS) score. The USS score is evaluated at the initial visit (0–6 points). If the score is low (0–2 points), the patient can be observed periodically over several months. If the score increases or the tumour size rapidly increases on the second visit or later, the physician may consider performing MRI (*). If the score is high at the initial visit (3–6 points), MRI may be recommended. In this group, peripheral nerve sheath tumours and vascular tumours may be diagnosed based on characteristic clinical symptoms without MRI. MRI can usually be used to diagnose typical fibrous tumours, lipomas, and pigmented villonodular synovitis (PVS) / giant cell tumour of the tendon sheath (GCT-TS). When malignant SPT is suspected, biopsy should be performed to obtain a pathological diagnosis. UPS = Undifferentiated pleomorphic sarcoma; WDL = Well-differentiated liposarcoma (Figure 5) and a benign tumour should be achieved with high accuracy. The patient’s medical history and tumour-relat­ed symptoms should be routinely obtained by the physician. We recommend using the USS score in combination with such information to improve the differential diagnostic process. Figure 6 shows a flowchart of the diagnostic process of SPTs based on our analysis. The USS score was used to stratify the cases into high- and low-score groups, which mainly contained malignant and benign cases, respectively. Characteristic symptoms should be combined with ultrasound findings; this will lead to a diagnosis of vascular tumours or PNSTs. If the diagnosis is not conclusive, MRI should be performed. Among benign tumours, MRI can dif­ferentiate between fibrous tumours, pigmented vil­lonodular synovitis and histologically related giant cell tumours of the tendon sheath, and lipomatous tumours. Other rare tumours or tumour-like le­sions (nodular fasciitis, organising haematoma, or soft tissue chondroma) should be diagnosed by multiple modalities or resectional biopsy. Because the majority of tumours with high USS scores may be malignant, procedures should be chosen care­fully for those cases. In the present study, 49 of 73 cases (67%) in the high USS score group were high-grade sarcomas. After careful preoperative assessment, we usually perform a biopsy to ob­tain a pathological diagnosis for possible cases of malignant SPT. Ultrasound-guided fine-needle aspiration is reportedly useful for soft tissue sar­coma.19,20 However, because of the shortage of spe­cialised cytologists and the difficulty in obtaining sufficient material, we have not used this method. We are planning to start a prospective study to evaluate the efficacy of fine-needle aspiration as a diagnostic test for SPTs. 140 In conclusion, our USS score achieved high sen­sitivity as a screening test for SPT without compro­mising specificity. Preoperative diagnosis of most SPTs would be possible by combining the USS score with characteristic clinical symptoms and MRI findings. References 1. Wilson DJ, Parada SA, Slevin JM, Arrington ED. Intrasubstance ruptures of the biceps brachii: diagnosis and management. Orthopedics 2011; 34: 890­ 6. 2. Murphy RJ, Daines MT, Carr AJ, Rees JL. An independent learning method for orthopaedic surgeons performing shoulder ultrasound to identify full-thickness tears of the rotator cuff. J Bone Joint Surg Am 2013; 95: 266-72. 3. Fowler JR, Maltenfort MG, Ilyas AM. Ultrasound as a first-line test in the di­agnosis of carpal tunnel syndrome: a cost-effectiveness analysis. Clin Orthop Relat Res 2013; 471: 932-7. 4. Blankstein A. Ultrasound in the diagnosis of clinical orthopedics: The ortho­pedic stethoscope. World J Orthop 2011; 2: 13-24. 5. Van der Woude HJ, Vanderschueren G. Ultrasound in musculoskeletal tumors with emphasis on its role in tumor follow-up. Radiol Clin North Am 1999; 37: 753-66. 6. AbiEzzi SS, Miller LS. The use of ultrasound for the diagnosis of soft-tissue masses in children. J Pediatr Orthop 1995; 15: 566-73. 7. Latifi HR, Siegel MJ. Color Doppler flow imaging of pediatric soft tissue masses. J Ultrasound Med 1994; 13: 165-9. 8. Sintzoff SA, Jr., Gillard I, Van Gansbeke D, Gevenois PA, Salmon I, Struyven J. Ultrasound evaluation of soft tissue tumors. J Belge Radiol 1992; 75: 276-80. 9. Griffith JF, Chan DP, Kumta SM, Chow LT, Ahuja AT. Does Doppler analysis of musculoskeletal soft-tissue tumours help predict tumour malignancy? Clin Radiol 2004; 59: 369-75. 10. Stramare R, Gazzola M, Coran A, Sommavilla M, Beltrame V, Gerardi M, et al. Contrast-enhanced ultrasound findings in soft-tissue lesions: preliminary results. J Ultrasound 2013; 16: 21-7. 11. Chiou HJ, Chou YH, Chen WM, Chen W, Wang HK, Chang CY. Soft-tissue tumor differentiation using 3D power Doppler ultrasonography with echo-contrast medium injection. J Chin Med Assoc 2010; 73: 628-33. 12. Chen CY, Chiou HJ, Chou SY, Chiou SY, Wang HK, Chou YH, et al. Computer-aided diagnosis of soft-tissue tumors using sonographic morphologic and texture features. Acad Radiol 2009; 16: 1531-8. 13. Giovagnorio F, Andreoli C, De Cicco ML. Color Doppler sonography of focal lesions of the skin and subcutaneous tissue. J Ultrasound Med 1999; 18: 89-93. 14. Lakkaraju A, Sinha R, Garikipati R, Edward S, Robinson P. Ultrasound for initial evaluation and triage of clinically suspicious soft-tissue masses. Clin Radiol 2009; 64: 615-21. 15. Bianchi S, Martinoli C. Ultrasound of the musculoskeletal system. Berlin, New York: Springer; 2007. 16. Grimer RJ. Size matters for sarcomas! Ann R Coll Surg Engl 2006; 88: 519-24. 17. Laurino L, Furlanetto A, Orvieto E, Dei Tos AP. Well-differentiated liposar­coma (atypical lipomatous tumors). Semin Diagn Pathol 2001; 18: 258-62. 18. Cassier PA, Kantor G, Bonvalot S, Lavergne E, Stoeckle E, Le Pechoux C, et al. Adjuvant radiotherapy for extremity and trunk wall atypical lipomatous tumor/well-differentiated LPS (ALT/WD-LPS): a French Sarcoma Group (GSF­GETO) study. Ann Oncol 2104; 25: 1854-60. 19. Trovik CS, Bauer HC, Brosjo O, Skoog L, Soderlund V. Fine needle aspira­tion (FNA) cytology in the diagnosis of recurrent soft tissue sarcoma. Cytopathology 1998; 9: 320-8. 20. Ayala AG, Ro JY, Fanning CV, Flores JP, Yasko AW. Core needle biopsy and fine-needle aspiration in the diagnosis of bone and soft-tissue lesions. Hematol Oncol Clin North Am 1995; 9: 633-51. 141 case report Artery of Percheron infarction: review of literature with a case report Urska Lamot1, Ivana Ribaric2, Katarina Surlan Popovic1 1 Clinical Institute of Radiology, University Medical Centre Ljubljana, Ljubljana, Slovenia 2 Department of Vascular Neurology and Intensive Therapy, Neurology Clinic, University Medical Centre Ljubljana, Ljubljana, Slovenia Radiol Oncol 2015; 49(2): 141-146. Received 21 January 2014 Accepted 20 August 2014 Correspondence to: Asisst. Prof. Katarina Šurlan Popovič, M.D., Ph.D., Clinical Institute of Radiology, University Medical Centre Ljubljana, Zaloška cesta 7, 1525 Ljubljana, Slovenia. E-mail: katarina.surlan@gmail.com Disclosure: No potential conflicts of interest were disclosed. Background. Clinical features indicating an ischemic infarction in the territory of posterior cerebral circulation require a comprehensive radiologic examination, which is best achieved by a multi-modality imaging approach (computed tomography [CT], CT-perfusion, computed tomography angiography [CTA], magnetic resonance imaging [MRI] and diffusion weighted imaging [DWI]). The diagnosis of an acute ischemic infarction, where the damage of brain tissue may still be reversible, enables selection of appropriate treatment and contributes to a more favourable outcome. For these reasons it is essential to recognize common neurovascular variants in the territory of the posterior cerebral circulation, one of which is the artery of Percheron. Case report. A 69 year-old woman, last seen awake 10 hours earlier, presented with two typical clinical features of the artery of Percheron infarction, which were vertical gaze palsy and coma. Brain CT and CTA of neck and in­tracranial arteries upon arrival were interpreted as normal. A new brain CT scan performed 24 hours later revealed hypodensity in the medial parts of thalami. Other imaging modalities were not performed, due to the presumption that the window for the application of effective therapy was over. The diagnosis of an artery of Percheron infarction was therefore made retrospectively with the re-examination of the CTA of neck and intracranial arteries. Conclusions. A multi-modality imaging approach is necessary in every patient with suspicion of the posterior circu­lation infarction immediately after the onset of symptoms, especially in cases where primary imaging modalities are unremarkable and clinical features are severe, where follow-up examinations are indicated. Key words: Percheron; infarction; imaging Introduction The thalami and midbrain have a complex blood supply with a large number of feeding arteries.1,2 The arterial supply is provided by perforating branches from the posterior cerebral artery and the posterior communicating artery.3 Although there are significant variations and overlaps, the thalam­ic vascular supply is classically categorized into 4 territories: anterior, paramedian, inferolateral and posterior.4-6 In addition to the paramedian thalami, the paramedian thalamic arteries supply the medial areas of the upper brainstem: the interpeduncular nucleus, the decussation of the superior cerebellar peduncles, the medial part of the red nucleus, the third and fourth cranial nerve nuclei and the ante­rior portion of the periaqueductual grey matter.3,7 Consequently, occlusion of the artery of Percheron causes a bilateral paramedian thalamic infarction with or without midbrain infarction.2,4,5 Additional involvement of the anterior thala­mus is uncommon.5 The prevalence of arteries of Percheron is unknown. Since strokes in these ter­ritories are infrequently diagnosed, it is not known whether they are really rare or highly underdiag­nosed.1 142 Due to a large number of blood supply variants of the posterior cerebral circulation, an ischemic in­farction in this territory presents variable and un­specific clinical symptoms, which requires a com­prehensive radiologic examination. This approach enables a diagnosis of an ischemic infarction in the early stage, when treatment with thrombolysis and/or mechanical recanalization is still possible and therefore reversibly damaged brain tissue can be salvaged with prompt revascularization. The goal of this paper is to report a case where the diag­nosis of an artery of Percheron infarction was made retrospectively, due to an unspecific clinical pres­entation and a deficient multi-modality approach. Clinical presentation The complex anatomy and function of the hu­man thalamus and its variable vascular supply are responsible for the extremely variable clinical features when this structure is damaged by an is­chemic infarction; in addition, the vascular overlap with the underlying midbrain extends the spec­trum of these clinical features to include midbrain signs.5,9 An ischemic stroke in the territory of an ar­tery of Percheron usually presents with three main symptoms, which are found in patients with bilat­eral paramedian thalamic strokes. These are verti­cal gaze palsy (65%), memory impairment (58%) and coma (42%).4,6 Bilateral paramedian thalamic lesions are often accompanied by rostral midbrain lesions, producing a “mesencephalothalamic” or “thalamopeduncular” syndrome.6,10 In addition to the mentioned triad, the syndrome is characterized by other oculomotor disturbances, hemiplegia, cer­ebellar ataxia and movement disorders.6 Imaging and treatment Diagnosing an artery of Percheron infarction is critical for directing the appropriate time sensitive management and preventing additional unneces­sary procedures.6,11 Different treatment methods, such as intravenous thrombolysis and endovas­cular treatment are available. They can be per­formed if a diagnosis of acute stroke is made.4 As in our case, the diagnosis is often made in the late stage, when therapy is ineffective and dangerous. Magnetic resonance imaging (MRI) usually allows visualization of the initial infarct in cases of acute cerebral ischemia and is used in stroke centres as the primary or early secondary imaging modality.4 Infarction of the artery of Percheron presents as an abnormal signal intensity on MRI and/or hy­poattenuation on CT, involving the bilateral para-median thalami with or without rostral midbrain involvement.6 Early diagnosis is best made by a diffusion weighted imaging (DWI) sequence using MRI.11 Lazzaro et al., identified four patterns of ischemic infarctions when the Percheron artery is occluded.6 Approximately 43% of their patients demonstrated damage to both paramedian thalami and midbrain, while 38% had ischemic damage to paramedian thalami only, without midbrain involvement. In around 14% of patients, the damage involved the anterior thalamic nuclei in addition to paramedian thalami and upper midbrain. The least common pattern (5%) was ischemic damage of the bilateral paramedian and anterior thalami; the midbrain was spared in these cases. They also found that a previously unreported finding (a “V” sign) on fluid attenuated inversion recovery (FLAIR) and DWI sequences was identified in 67% of cases of artery of Percheron infarction with midbrain in­volvement and this sign supports the diagnosis when present.5,6 The “V” sign appears as a distinct pattern of V-shaped hyperintensity on axial FLAIR and/or DWI along the pial surface of the midbrain adjacent to the interpeduncular fossa.6 The artery of Percheron is rarely visualized with conventional angiography and, to the best of our knowledge, only four authors have successfully demonstrated this variant5,6; it is too small to be visualized by computed tomography angiogra­phy (CTA) or magnetic resonance angiography (MRA).11 Case presentation A 68 year-old Caucasian woman, last seen awake 10 hours earlier, was found unresponsive in front of her apartment. The patient had a history of hy­pertension, but, it is unclear if she had used any long-term medication. On physical examination in our Neurological Emergency Room, she was coma­tose with Glasgow Coma Scale 4 and the follow­ing initial vital signs: pulse 60 beats/min, respira­tory rate 16 breaths/min and blood pressure 110/53 mmHg. Pupillary light reflex in the right eye was non-reactive and the left eye poorly reactive. The right pupil was dilatated. Passive examination of the ocular movements showed complete vertical gaze palsy. The patient was afebrile and no me­ningeal signs were present. She flexed the right arm and extended the left leg on painful stimulus. Babinski could not be provoked on the left and 143 was in flexion on the right. No other pathological signs were present. The following laboratory tests were all unremarkable: complete blood cell count, glycaemia, electrolytes, liver enzymes, creatinine, ammonia, arterial blood gas values, ethanol, ben­zodiazepine and opioid levels. The international normalized ratio (INR) was 1.15. In this case the neurological examination was misleading due to unspecific clinical signs and symptoms which were unhelpful in the process of achieving the correct working diagnosis. The initial CT performed 60 minutes after find­ing the patient (and an unknown time after loss of consciousness) showed no acute haemorrhage or early signs of ischemia, only an old lacunar infarction in the left thalamus (Figure 1). CTA of neck and intracranial arteries was interpreted as normal. A new head CT was performed 24 hours later. It revealed areas of hypodensity (16x 10 mm) in the medial thalami, which were not present on the previous CT examination (Figure 2). The right hypodense area extended into the anterior part of the mesencephalon and cerebral peduncle. The left hypodense area extended only into the anterior part of the mesencephalon. The chronic ischemic change in the posterior part of the left thalamus re­mained unchanged. Due to our findings on the second CT, we de­cided to perform another reading of the CTA ex­amination performed at the time of the patients’ admission, which revealed a duplication of the right superior cerebellar artery and a filling defect of the P1 segment of the right posterior cerebral ar­tery (Figure 3). There was no improvement in the patients’ neu­rological status in the following days and she was included in our palliative care program. On day 5, the patient became febrile with raised inflammatory parameters. Although we applied an antibiotic, the patient’s clinical status deteriorated and she died of cardiopulmonary failure on the 13th day of hospi­talization. This study was conducted according to the principles of the Declaration of Helsinki and ap­proved by the institutional ethical committee. Discussion The large number of variants of the blood supply in the posterior cranial fossa, especially the high variability of presence and size of P1 segments, which give rise to the paramedian arteries, may be a clue that the artery of Percheron is not such an infrequent variant and may be underdiagnosed.1,6 FIGURE 3. Computed tomography angiography (CTA) of the neck and intracranial arteries. The basilar artery and the left posterior cerebral artery (PCA) (black arrow) were both transient (A). At first glance, the right PCA appears to be fully opacified. Detailed examination of the CTA images revealed a filling defect of the P1 segment of the right PCA (white arrow) and another rare anatomic variant: duplication of the right superior cerebellar artery (black arrow), which could have been mistaken for a transient right PCA (B). 144 FIGURE 4. Anatomic variations of the arterial supply to the paramedian thalamic-mesencephalic region as described by Percheron: Variant I (A), variant IIa (B), variant IIb (C) – the artery of Percheron, variant III (D). Vessels marked by initials: thalamic perforators (TP), midbrain perforators (MP), posterior cerebral artery (PCA), superior cerebellar artery (SCA), basilar artery (BA), anterior inferior cerebellar artery (AICA) and artery of Percheron (AOP). The characteristic artery of Percheron infarct pat­tern has been estimated in different studies to oc­cur in 0.1 to 2%5,7 of all ischemic strokes and in 4% to 18% of all thalamic strokes.6 According to Percheron, there are four normal variants of the neurovascular anatomy of the thal­ami and midbrain.4,8 Variant I is most common, in which each perforating artery arises from each left and right posterior cerebral artery (Figure 4A).4,5 Variant IIa is a less common, asymmetrical vari­ant, in which perforating arteries arise directly from the proximal segment of one of the posterior cerebral arteries (Figure 4B).3-5 In variant IIb, the bilateral perforating thalamic arteries arise from a single arterial trunk called the artery of Percheron, which arises from the P1 segment of one posterior cerebral artery. It supplies the paramedian thalami and the rostral midbrain bilaterally (Figure 4C).2-5 Variant III is an arcade variant, with several small perforating branches arising from a single arterial arc that bridges the P1 segments of both posterior cerebral arteries (Figure 4D).3,5 It is difficult to suspect bithalamic paramedian infarcts because of the complex anatomy, which causes large clinical variability.4 They are typically characterized by a triad of altered mental status, vertical gaze palsy and memory impairment.6 Our patient presented with two of the three typical fea­tures of this stroke syndrome; that is, vertical gaze palsy and altered mental status. A head CT was performed on admission to ex­clude haemorrhage, tumours, other obvious brain lesions and early signs of brain ischemia. A re­examination of the CTA revealed an overlooked anatomical variant, a duplication of the right su­perior cerebellar artery and a filling defect of the P1 segment of the right posterior cerebral artery. In our previous reading, we had mistaken one of the duplicated right superior cerebellar arteries for a transient P1 segment of the right posterior cer­ebral artery. Due to the aforementioned findings, we assume that right and left paramedian thalamic arteries aroused from a common trunk, since the P1 segment of the left posterior cerebral artery was transient. A falsely negative CTA of neck and in­tracranial arteries omitted the consideration of me­chanical revascularization, for the possibly effected vessels were not visualized. In such cases where clinical findings are severe we suggest prompt fur­ther examination using other imaging modalities. On the basis of clinical, neuroimaging and neuro­vascular findings, the only possible diagnosis was an ischemic stroke in the territory of the artery of Percheron and this diagnosis was therefore made retrospectively. These findings demonstrate that when an artery of Percheron is suspected, the pos­sibility that other rare anatomic variants of the posterior circulation may be present should also be considered. In a patient with an acute onset of a neurologi­cal deficit and changes in the described locations, a diagnosis of a stroke of an artery of Percheron must be considered.1 The prognosis of artery of Percheron infarction may be ameliorated by treat­ment of acute stroke. Patients with acute ischemic stroke are thrombolysed intravenously (applica­ 145 tion of alteplase) unless there are contraindications. Endovascular revascularization applies thrombo­lytic agents directly into the thrombus or mechani­cally extracts the cloth.12 Mechanical trombectomy is considered in patients with a diagnosis of acute stroke, who have an occlusion of a treatable intrac­ranial artery and are within 10.5 hours of onset of posterior circulation symptoms, to allow recanali­zation within 12 hours.4,12 The most applicable sites for interventional exploration are carotid T occlu­sion, M1 and M2 segments of the medial cerebral artery occlusion and vertebra-basilar thrombo­sis.12 As in our case, the diagnosis is often made many hours or even days after the clinical onset. At this stage therapy is ineffective and dangerous. Endovascular treatment is only seldom an option in these cases, for these arteries are often too small for visualization during the procedure. MRI normally allows visualization of the ini­tial infarct in cases of acute cerebral ischemia and is usually used in stroke centres as the primary or early secondary imaging modality. When brain MRI shows an acute stroke, thrombolysis can be performed if the deadline for achieving it is not over.4 Early diagnosis is best made using a DWI se­quence.1 As in other locations in the brain, the com­bination of pathologic DWI and normal findings on T2-weighted or FLAIR images suggest an acute stroke. If the lesions are already visible on T2 or FLAIR images, the time window for thrombolysis is over.1,4 In our case, early MRI and CT perfusion were not performed because, on the basis of the pa­tients’ medical history, we presumed the window for thrombolysis was over. Considering our find­ings, we should perhaps have performed MRI or CT perfusion, since they could have helped in the decision-making process. To the best of our knowledge, there is only a single report in the literature of a symptomatic patient presenting an acute Percheron stroke with normal early brain MRI.4 On the basis of this one case, Cassourret4 et al. concluded that a normal ini­tial MRI cannot formally eliminate the diagnosis of acute stroke of the artery of Percheron, although they state that the MRI was of inferior quality be­cause the technical conditions were not optimal. The article suggests that, on the presentation of acute rostral brain stem stroke, accompanied by an inconclusive brain MRI, new brain imaging by MRI should be performed within therapeutic times or interventional explorations focused on the verte­brobasilar territory4 should be considered. To the best of our knowledge, the value of CT perfusion in acute Percheron stroke has not been evaluated. The advantage of CT perfusion is that it is able to delineate areas of the brain that may be salvaged by intervention (e.g., thrombolysis or clot retrieval), known as the penumbra, from the parts that are irrevocably destined to go into infarct regardless of therapy, known as the infarct core. What is more, identification of infracted areas is easier than with non-contrast head CT. The weak­ness of CT perfusion at the level of the midbrain is that we often come across artefacts that reduce the quality of the examination. It must be born in mind that the artery of Percheron is rarely visualized with conventional angiography6, since these vessels are too small1, and to our knowledge only 4 authors have suc­cessfully demonstrated this variant.6 Performing conventional angiography may not be indicated, because lack of visualization of the artery does not exclude its presence (because it is occluded).2 Although in our case it is unlikely that we would have visualized the artery of Percheron, we should perhaps have performed conventional angiogra­phy, since it could have shown the filling defect of the P1 segment of the right posterior cerebral artery, which would have influenced our decision regarding treatment. Conventional cerebral angi­ography should therefore not be used routinely to diagnose Percheron artery occlusion.5 When an ischemic infarction in the territory of the posterior circulation is suspected we firstly perform a native head CT to exclude haemorrhage and enable treatment with intravenous thrombol­ysis. In the case of negative imaging findings we continue the examination by performing a brain CT-perfusion and CTA of neck and intracranial ar­teries for the detection of ischemic infarctions not visible on native CT. When regardless the severe clinical picture all the mentioned imaging methods fail to depict the causative pathology for the dete­rioration of the patient’s state, we suggest perform­ing MRI with T1-, T2- and FLAIR sequences and DWI for an exclusion of ischemic infarction in early stages. We estimate the time to perform a comprehen­sive multi-modality examination in the evaluation of posterior circulation ischemic infarctions to 45 to 90 minutes, depending on the time from the insult to imaging, size of infarction and technical difficul­ties, for patients with posterior circulation infarcts usually require mechanical life support devices which make examination with MRI difficult. The imaging differential of bithalamic lesions is broad and includes arterial and venous occlusion, infiltrative neoplasm, infectious and inflammatory 146 lesions, and a single large embolus at the basilar tip could result in a similar infarct pattern. However, this would typically manifest as the “top of the basilar” syndrome with additional characteristic posterior circulation infarcts.6 The final diagnosis is based on the combination of clinical picture, labo­ratory tests and imaging findings. Considering all the given information, we sug­gest that in emergency settings, in which the sever­ity of the clinical features (coma and vertical gaze palsy) does not correlate with the imaging findings, the possibility of an artery of Percheron infarction must be taken into consideration and CT perfusion or MRI performed within therapeutic times, in or­der to make the correct diagnosis when treatment is still possible. References 1. Krampla W, Schmidbauer B, Hruby W. Iscmaemic stroke of the artery of Percheron. Eur Radiol 2008; 18: 192-4. 2. Matheus MG, Castillo M. Imaging of acute bilateral paramedian thalamic and mesencephalic infarcts. AJNR Am J Neuroradiol 2003; 24: 2005-8. 3. Godani M, Auci A, Torri T, Jensen S, Sette DM. Coma with vertical gaze palsy: Relevance of angio-CT in acute percheron artery syndrome. Case Rep Neurol 2010; 2: 74-9. 4. Cassourret G, Prunet B, Sbardella F, Bordes J, Maurin O, Boret H. Ishemic stroke of the artery of Percheron with normal initial MRI: a case report. Case Rep Med 2010; 2010: 425734. doi:10.1155/2010/425734. 5. Amin OSM, Shwani SS, Zangana HM, Hussein EMH, Ameen NA. Bilateral infarction of paramedian thalami: a report of two cases of artery of Percheron occlusion and review of the literature. BMJ Case Rep 2011; 2011: bcr0920103304. doi: 10.1136/bcr.09.2010.3304. 6. Lazzaro NA, Wright B, Castillo M, Fischbein NJ, Glastonbury CM, Hildenbrand PG, et al. Artery of Percheron infarction: imaging patterns and clinical spec­trum. AJNR Am J Neuroradiol 2010; 31: 1283-9. 7. Carrera E, Michael P, Bogousslavsky J. Anteromedian, central, and poste­rolateral infarcts of the thalamus: three variant types. Stroke 2004; 35: 2826-31. 8. Kraft P, Waschbisch A, Wendel F, Muellges W, Classen J. Why it’s important to know Percheron’s artery: solitary carotid stenosis as a unique cause of anterior, posterior and bithalamic ischemia. J Neurol 2009; 256: 1558-60. 9. Slamia LB, Jemaa HB, Benammou S, Tlili-Graiess K. Occlusion of the artery of percheron: clinical and neuroimaging correlation. J Neuroradiol 2008; 35: 244-5. 10. Perren F, Clarke S, Bogousslavsky J. The syndrome of combined polar and paramedian thalamic infarction. Arch Neurol 2005; 62: 1212-6. 11. Shea YF, Lin OY, Chang RSK, Luk JKH. Artery of Percheron infarction. Hong Kong Med J 2012; 18: 446. e1-2. 12. Ahmad N, Nayak S, Jadun C, Natarajan I, Jain P, Roffe C. Mechanical thrombectomy for ischaemic stroke: the first UK case series. PLoS One 2013; 8: 1-10. 147 research article Feasibility and safety of electrochemotherapy (ECT) in the pancreas: a pre-clinical investigation Roberto Girelli1*, Simona Prejano2*, Ivana Cataldo2, Vincenzo Corbo2, Lucia Martini3, Aldo Scarpa2, Bassi Claudio4 1 Pancreatic Unit – Casa di Cura Pederzoli, Peschiera del Garda (VR), Italy 2 ARC-NET Research Centre and Department of Pathology and Diagnostics, University and Hospital Trust of Verona, Verona, Italy 3 Laboratory of Preclinical and Surgical Studies and Laboratory of Biocompatibility, Innovative Technologies and Advanced Therapies, Rizzoli Orthopedic Institute Bologna, Italy 4 Department of Surgery and Oncology, Pancreas Institute, University and Hospital Trust of Verona, Verona, Italy Radiol Oncol 2015; 49(2): 147-154. Received 27 December 2014 Accepted 12 February 2015 Correspondence to: Roberto Girelli, M.D., Pancreatic Unit – Casa di Cura Pederzoli, Via Monte Baldo 24–37019 Peschiera del Garda, Verona, Italy. Phone: + 045 644 91 10; Fax: + 045 644 91 15; E-mail: r.girelli@cdcpederzoli.it Disclosure: No potential conflicts of interest were disclosed. * These authors contributed equally to this work. Supported by: FIMP-Italian Ministry of Health (CUP_J33G13000210001) Background. Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease generally refractory to standard chemotherapeutic agents; therefore improvements in anticancer therapies are mandatory. A major determinant of therapeutic resistance in PDAC is the poor drug delivery to neoplastic cells, mainly due to an extensive fibrotic reaction. Electroporation can be used in vivo to increase cancer cells’ local uptake of chemotherapeutics (elec­trochemotherapy, ECT), thus leading to an enhanced tumour response rate. In the present study, we evaluated the in vivo effects of reversible electroporation in normal pancreas in a rabbit experimental model. We also tested the effect of electroporation on pancreatic cancer cell lines in order to evaluate their increased sensitivity to chemo­therapeutic agents. Materials and methods. The application in vivo of the European Standard Operating Procedure of Electrochemotherapy (ESOPE) pulse protocol (1000 V/cm, 8 pulses, 100 µs, 5 KHz) was tested on the pancreas of normal New Zealand White Rabbits and short and long-term toxicity were assessed. PANC1 and MiaPaCa2 cell lines were tested for in vitro electrochemotherapy experiments with and without electroporation. Levels of cell permea­bilization were determined by flow cytometry, whereas cell viability and drug (cisplatin and bleomycin) sensitivity of pulsed cells were measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazo­lium (MTS) assay. Results. In healthy rabbits, neither systemic nor local toxic effects due to the electroporation procedure were ob­served, demonstrating the safety of the optimized electric parameters in the treatment of the pancreas in vivo. In parallel, we established an optimized protocol for ECT in vitro that determined an enhanced anti-cancer effect of bleomycin and cisplatin with respect to treatment without electroporation. Conclusions. Our data suggest that electroporation is a safe procedure in the treatment of PDAC because it does not affect normal pancreatic parenchyma, but has a potentiating effect on cytotoxicity of bleomycin in pancreatic tumour cell lines. Therefore, ECT could be considered as a valid alternative for the local control of non-resectable pancreatic cancer. Key words: electroporation; bleomycin; cisplatin; electrochemotherapy; preclinical study; safety; pancreatic ad­enocarcinoma 148 Introduction Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with a poor 5-year sur­vival, resulting in the fifth leading cause of cancer-related death in Europe.1-3 PDAC is usually diag­nosed in advanced stage, with loco-regional inva­sion and distant metastasis, and usually results largely drug-resistant. Surgical resection, although is currently the only “curative” chance to prolong survival, is suitable only for a minority of patients (< 20%). Standardized protocols of treatment in resectable patients provide a 6-month-course adju­vant chemotherapy following resection4, although the survival is still poor. The optimal treatment for patients with lo­cally advanced pancreatic cancer (LAPC) with no evidence of metastases remains to be defined. The standard treatment for LAPC is based on Chemotherapy (CT)5-9 and combination of CT and Radiotherapy (RT) with a median overall survival of 10.15 months.10-12 Because of the poor results achieved, some new ablative techniques have been considered for local treatment: radiofrequency ablation (RFA), laser ab­lation, microwave, ethanol injection and irrevers­ible electroporation (IRE).13 Particularly, RFA has been used in the clinical setting with promising preliminary results.14-17 Patients with metastatic disease undergo sys­temic palliative chemotherapy. Treatment out­comes are typically poor and resistance to standard chemotherapeutic agents remains the major prob­ lem.18-24 Based on recent preclinical data in mouse mod­els, it has been hypothesised that currently avail­able anticancer drugs cannot access tumour cells at an effective concentration due to the presence of an extensive hypo-vascular fibrotic stroma that acts as a barrier shielding tumour cells from the ac­tion of systemic therapeutic agents.25 Therefore, the improvement of anticancer drug delivery enhances tumour cells sensitivity and hence would provide a better response and a potential prolongation of survival. Electroporation is a physical method that em­ploys microsecond length electric pulses to alter temporarily the permeability of cell membranes in order to facilitate chemicals and large molecules delivery to the cells.26-28 Electroporation can be used in all types of isolated cells as well as in tis­sues. Target cells have to be exposed to an electric .eld of suf.cient strength and for a suf.cient time. The magnitude of the electric .eld depends on cell type, size, orientation and density, pulse duration and number of pulses.29 Electrochemotherapy (ECT) combines the ad­ministration of non-permeant or low-permeant cytotoxic drugs (bleomycin or cisplatin) with the application to the tumour of permeabilizing elec­tric pulses, to increase local drug uptake and hence its effectiveness.30, 31 This combination treatment has proven to be very effective in local control of skin metastatic tu­mour nodules independently of the histotype32-39 and it is now routinely employed for this purpose in a number of European countries, in about 140 cancer treatment centres; recently this technique has been developed for the treatment of deep-seat­ed tumours.40,41 Electrochemotherapy has been used in pre­vious preliminary studies for the treatment of rats and mice bearing subcutaneous implants of melanoma30,41-44, sarcoma30,43-45, and pancreatic tu­mours46 with encouraging results. Furthermore, liver tumours of rats and rabbits resulted highly responsive to ECT without impairment of the sur­rounding normal tissue functionality.47-48 The effec­tiveness of intraoperative ECT was demonstrated in hamster pancreatic adenocarcinoma cell line (PC-1) model.49 We hypothesize that ECT could be used for the treatment of primary non-resectable pancreatic cancer. The aim of the present study was to investi­gate the feasibility and safety of electroporation in an experimental rabbit model. In vivo local and sys­temic effects of electric pulses applied to the pan­creas were evaluated. Furthermore, we tested ECT in vitro on highly drug resistant pancreatic cancer cell lines in order to prove its efficacy in this subset as well. Materials and methods Electroporation apparatus Electroporation was performed using the Cliniporator™ (IGEA S.p.A., Carpi, Modena, Italy). Different protocols of 100 µs square-wave electric pulses were tested in vitro; one sequences of 8 elec­trical pulses, 100 µs of duration, at 1000 V/cm were used for in vivo experiments. Animals and anaesthesia The experiments were conducted according to the EU Directive 2010/63/EU and to the Guidelines for the welfare and use of animals in cancer research 149 (Br J Cancer 2010; 102:1555–77). The protocol was approved by the Ethical Committee of the Rizzoli Orthopaedic Institute (ELETTRO-RAB 03/25/2009 prot.10499), and submitted to the Italian Ministry of Health (28/04/2009 prot.10771). We used 9 male Hybrid New Zealand rabbits weighing 2.1 ± 0.5 kg, housed under controlled conditions. General anaesthesia was induced with an intramuscular injection of 44 mg/kg ketamine (Imalgene 1000, Merial Italia S.p.a., Milano), 3 mg/kg xylazine (Rompun: Bayer S.p.a. Milano) and maintained by means of facial mask in spontaneous ventila­tion (O2: 1 L/min, N2O: 0.4 L/min, isoflurane: 2.5% to 3%). Postoperatively, antibiotic and analgesic therapy was administered (Flumequine - Flumexil Fatro, Italy and metamizole Farmolisina Vetem, Italy). General physiological status of rabbits, in­cluding potential onset of anorexia and intestinal blocking, was monitored daily by technician and in charge veterinarian during all the period of the study. Animal electroporation and sample collection Animals underwent pancreas and duodenum (gut) electroporation in open surgery according to the standard operating procedure: 8 pulses at 1000 V/ cm of amplitude over distance ratio, 100 µs of dura­tion were delivered at 5 KHz using linear N-20-4B electrodes. The electroporated area ranged between 12.15 mm in length. The animals were euthanized 24 hours (n = 2), 72 hours (n = 1), 15 days (n = 3), 30 days (n = 3) after surgery with i.v. injection of 2 ml Tanax (Tanax, Intervet International AN Baxmeer NL) under deep general anaesthesia. The pancreas was removed and treated for the morphological and histological analysis. All the specimens were formalin fixed and paraffin embedded. Four mm tissue sections were stained with Haematoxylin and Eosin (H&E) for histopathological evaluation. Post mortem bowel was visually explored for in­tegrity. No histological evaluation was performed on the bowel. Biochemical analysis Peripheral blood was collected before surgery (T0) and at each experimental time: 7 days, 15 days and 30 days following electroporation. After blood col­lection, serum was separated by centrifugation and parameters of hepatic function such as alanine transaminase (ALT), aspartate transaminase (AST), and pancreatic enzymes, such as amylase, were an­alysed. The animals did not receive any pharmaco­logical prophylaxis for pancreatitis such as octreo­tide and Gabesato mesylate. Since the in vivo study is limited to tissue electroporation and no drug was administered to the animals, for ethical reasons, we did not include control groups. Cell line and drugs PANC1 and MiaPaCa2 human pancreatic cancer cell lines were obtained from the American Type Culture Collection (ATCC). Various molecular mechanisms have been taken in account to play a role in drug-resistance development in these spe­cific cell lines. One of these mechanisms is medi­ated by the overexpression of BRG1, a chromatin modulator responsible for gemcitabine resistance also in locally advanced and metastatic pancreatic cancer.50 The two cell lines were cultured in RPMI 1640 medium supplemented with 10% of heat-inacti­vated foetal calf serum (Gibson, Milan, Italy). Cells were maintained as monolayer in 75 cm2 tissue culture flasks at 37°C in a humidified atmosphere of 5% CO2. The cell lines were Mycoplasma free as assessed by MycoAlert assay (Lonza, Milan, Italy). Cells used for experimental purposes were de­tached using trypsin-EDTA (0.05% trypsin, Lonza) and collected by centrifugation at 300 rpm. Cell di­ameter for PANC1 and MiaPaCa2 was 16.8 µm and 12.2 µm respectively, as measured by FACS analy­sis. The following anticancer drugs were used: ble­omycin and cisplatin (Sigma, Milan, Italy). Drugs were dissolved in 0.9% bacteriostatic saline and used at indicated concentrations. Cell viability and permeabilization Three aliquots of 1x105 cells (in 100µl of RPMI medium) were placed in separate 2 mm gap elec­troporation cuvettes (Bio-Rad laboratories). Each cuvette was exposed to electric field strength of 0.5 or 1 kV/cm (8 pulses, 100 µs of duration, 5 KHz). After 30 minutes of incubation, pulsed cells were diluted by a factor 100 in RPMI medium and seed­ed into 96- well tissue culture plates. Unpulsed cells were subjected to same procedure. The acute effect of electroporation on cell viability was de­termined using MTS assay (Promega) and the Countess Cell Counter (Invitrogen, Milan, Italy). Cell permeabilization was determined at indicated field strength by uptake of fluorescent dye Lucifer yellow (Sigma, Milan, Italy). Briefly, cells incubat­ 150 FIGURE 2. Photomicrographs of rabbit pancreata at different times after electroporation. (A) 24 hours: necrosis in the treated areas surrounded by significant hyperaemia and oedema. Acinar degranulation and vacuolation with granulocytes and lymphocytes infiltration (inset). (B) 72 hours: necrosis is still evident while acinar to ductal metaplasia appears along with intraductal protein plugs (inset). (C) 15 days: fibrotic areas are evident; chronic inflammatory cells are present while pancreatic acini are normal (inset). (D) 30 days: calcium deposition is detectable in fibrotic areas; pancreatic parenchyma is normal (inset). ed in the presence of Lucifer yellow at a final con­centration of 1 mM were exposed to electric pulses and then incubated at 37°C for 5 min. Cells were then chilled on ice, washed in phosphate-buffered saline (PBS) buffer and examined for fluores­cence emission in a FACScalibur flow cytometer (Beckton Dickinson). Median fluorescence emis­sion was determined and percent of permeabilized cells was calculated. In vitro electrochemotherapy (ECT) Cell sensitivity of PANC1 and MiaPaCa2 to cis­platin and bleomycin was preliminary tested in order to define an appropriate range of drug con­centrations to be used for electrochemotherapy ex­periments (data not shown). For ECT, cells (1x105 suspended in 100µl of RPMI medium) were placed between 2 plate electrodes in 2 mm gap cuvette (Bio-Rad laboratories) in the presence of a range of concentration of drugs or isotonic saline and ex­posed to a defined electric field strength of 1 kV/ cm (8 pulses, 100 µs of duration). Aliquots of cells were left unpulsed in presence of drugs or vehicle. Seven concentrations of cisplatin ranging from 1.6 to 26 µM were used for PANC1, whereas 7 concen­trations ranging from 1.6 to 40 µM were tested for MiaPaCa2. For bleomycin, 5 concentrations rang­ing from 0.1 to 6.6 µM were used for MiaPaCa2, whereas 7 concentrations ranging from 0.3 to 130 µM were tested for PANC1. Pulsed and unpulsed cuvettes were incubated in humidified atmosphere at 37°C for 30 min after electric exposure. Then cells were diluted by a factor of 100 in RPMI me­dium and three aliquots of 100 µl (1x104 cells) from each cuvette were seeded in 96-well tissue culture plates. Plates were incubated for 72 h and then survival was evaluated by MTS assay (Promega) and the Countess Cell Counter (Invitrogen, Milan, Italy). Data from the plate reader were analysed using GraphPad Prism version 6. The data were first nor­malized to the vehicle control and then analysed using the nonlinear regression feature. The curves shown in the figures and the calculated IC50 values were the result of three technical replicates for each cell lines. Statistical analysis Comparisons between groups were performed us­ing Student’s T test and p < 0.05 level was consid­ered significant. 151 TABlE 1. IC50 of bleomycin and cisplatin for PANC1 and MiaPaCa-2 unpulsed (-) or pulsed (+) with electroporation (EP) Cell - EP + EP P value - EP + EP P value PANC1 100 µM 0.59 µM <0.0001 23 µM 8 µM <0.0001 MiaPaCa2 3.5 µM 0.2 µM <0.0001 30 µM 23 µM 0.001 Results In vivo electroporation of non-pathological rabbit pancreata; general toxicity and histological evaluation General physiological status of the rabbits was checked daily and no functional deficits as anorex­ia, intestinal blockage or other clinical status altera­tions were detected; all the rabbits recovered from general anaesthesia after 1 hour. Transaminase and amylase levels were not statistically modified (p > 0.05) over 30 days of the electroporation procedure (day 0, day 7, day 15, day 30) (Figure 1). Histological evaluation The results of hystopathological analysis are shown in Figure 2A.D. At short term, 24 h post­ electroporation, non-pathological rabbit pancreas showed necrosis in the treated areas surrounded by important hyperaemia and oedema in addition to aspects of acute distress of acinar cells (degranu­lation and vacuolation). An acute inflammatory reaction was also present (Figure 2A). Acinar to ductal metaplasia appeared after 72 h. Elevation of serum amylase is often, but not always, associated with acute pancreatitis. In our study, we found that the ductal metaplasia is not associated with an in­crease in the serum level of amylase. It is possible that the ductal metaplasia is the consequence of the transient inflammatory response to the insertion of the needle rather than the inflammatory response of the entire organ. Moreover, the evidence of intraductal protein plugs, containing degenerating cells, was due to proteins hypersecretion by acinar cells (Figure 2B). After 15 days, fibrotic areas surrounded by normal pancreatic acinar cells were detected. Fat substitu­tion of about 20% of pancreatic parenchyma was also present (Figure 2C). After 30 days, calcium deposition was evident in fibrotic areas (Figure 2D) as a result of mild and transient modification. When electrical pulses were directly applied to the gut, its integrity was maintained without in-fection on further clinical complications (data not shown). Cells survival and permeabilization Before testing the toxicity of anticancer drugs on electropermeabilized cells, we defined the opti­mal parameters for electrical treatment in order to obtain high cell survival and effective permea­bilization. Therefore, both PANC1 and MiaPaCa2 cells were subjected to 8 pulses of 100 µs at two different electric field strength of 0.5 or 1 kV/cm. Percent of viable cells was calculated with respect to untreated cells. Field strength of 0.5 kV/cm did not affect cell viability, whereas a slight reduction of about 4% was observed when both cell lines were exposed to field strength of 1 kV/cm (data not shown). Cell permeabilization was assessed by flow cytometry at 1 kV/cm showing that about 90% and about 75% of cells were permeabilized, for PANC1 and MiaPaCa2 respectively (Figure 3). The optimal electric condition was defined as 1 kV/cm, 8 pulses of 100µs duration. In these conditions, the mean value of viability of the pulsed controls was 95% (range 93.97%) of that of the unpulsed con­ 152 trols, with a permeabilization level of at least 75% of pulsed cells. Cell viability following electrochemotherapy After establishing the optimized parameters for electroporation, 8 pulses of 100µs duration at 1 kV/cm, we investigated the cytotoxicity of two chemotherapeutic agents, bleomycin and cispl­atin, against PDAC cell lines. Pulsed PANC1 and MiaPaCa2 cell lines showed enhanced sensitivity to both bleomycin and cisplatin compared to un­pulsed cells. Specifically, the IC50 of bleomycin for PANC1 and MiaPaCa2 was reduced by a factor 166 and 18 respectively, after electroporation. Whereas the IC50 of cisplatin was reduced by a factor 2.8 for PANC1 and 1.3 for MiaPaCa2 (Table 1). The cells viability after bleomycin and cisplatin treat­ment pulsed with electroporation and unpulsed (Figure 4,5). Discussion In this study, we demonstrated that a well-defined electroporation protocol does not induce evident signs of local and systemic toxicity when applied to normal pancreas in a pre-clinical model. In ad­dition, the effect of ECT with cisplatin and bleomy­cin was evaluated in human pancreatic cancer cells lines after. ECT refers to the combined administra­tion of chemotherapy with the local application of electric pulses to the tumour cells in order to in­crease drug delivery and local cytotoxicity. ECT has been proven effective in the treatment of skin or subcutaneous metastases from solid tumours of different origin. Subsequently to several reports of clinical studies35-38 assessing the use and the effica­cy of ECT in the treatment of various primary skin cancers, head and neck cancer, and skin metastasis of different primary tumours, clinicians and re­searchers are trying to develop novel approaches to extend ECT to the treatment of deep-seated and visceral tumours.39-41 Edhemovic et al., have recently reported for the first time, the feasibility and safety of the procedure highlighting the effec­tiveness of ECT in the treatment of patients with liver metastases from primary colorectal cancer. The lack of side effect during and after the proce­dure, demonstrates the safety of the treatment.41 Furthermore, Granata et al. reported a preliminary experience of feasibility and safety of intraopera­tive electrochemotherapy in locally advanced pan­creatic tumour. Twelve patients with tumours of the head or the body of the pancreas underwent ECT. No side effects or major complications have been recorded. No acute intraoperative or postop­erative serious adverse effects were related to ECT, showing that electrochemotherapy is a feasible and safe treatment for patients with locally advanced pancreatic adenocarcinoma.51 According to the results reported in further stud­ies, the viability of human tumoural pancreatic cell lines was not modified by electrical pulse alone, while it decreased after exposure to bleomycin and cisplatin. Bleomycin and cisplatin result cytotoxic only at high concentrations. Nevertheless, when 153 the cells were exposed to both the chemothera­peutic agent and the electric pulses, the cytotoxic effect was achieved at lower drug concentration. Specifically, the potentiating effect of electric pulse was more pronounced for bleomycin than cispl­atin, confirming previous observations.35,41,49,52-54 Todorovic et al.55 observed a similar sensitization effect in murine colon carcinoma cell-line CMT3 and reported the referral range of IC50 value of different murine and human cell lines treated with bleomycin and cisplatin, with and without electroporation. The pancreatic cell lines PANC1 and MiaPaCa2 tested in the present study, dem­onstrate IC50 values within the range indicated by Todorovic et al. The delivery of electric pulses through needles inserted into the pancreas of rabbits elicits a lo­cal inflammatory response in the early days after ECT and completely resolves in 30-days. The blood values of pancreatic amylase and transaminases (ALT and AST) were not significantly increased over the whole observational period. Our data agree with previous results reported by Ramirez LH et al., which demonstrate that tissues submit­ted to electroporation alone, present an immediate inflammatory reaction restricted to electropulsed areas. No diffuse damage of adjacent organs was observed.48 Similarly, Cemazar M et al. analysed in vivo the ECT antitumour efficacy in a number of animal models.56 Our data confirmed that elec­troporation is a safe procedure in the treatment of pancreatic tumours and ECT could be effective for local control of non-resectable pancreatic cancer. The development of new electrodes and specific software for the assessment of proper preoperative strategies could increase both the safety of ECT and extend its application field. References 1. Ferlay J, Parkin DM, Steliarova-Foucher E. Estimates of cancer incidence and mortality in Europe in 2008. Eur J Cancer 2010; 46: 765-81. 2. Jemal A, Bray F, Center MM, Ferlay J, Ward E, et al. Global cancer statistics. 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A meta-analysis of 20 phase 3 trials. Cancer 2007; 110: 525-33. 25. Olson P, Hanahan D. Cancer. Breaching the cancer fortress. Science 2009; 324: 1400-1. 26. Neumann E, Schaefer-Ridder M, Wang Y, Hofschneider PH. Gene transfer into mouse lyoma cells by electroporation in high electric field. EMBO J 1982; 1: 841-5. 27. Neumann E, Kakorin S, Toesing K. Fundamentals of electroporative delivery of drugs and genes. Bioelectrochem Bioenerg 1999; 48: 3-16. 154 28. Orlowski S, Mir LM. Cell electropermeabilization: a new tool for biochemi­cal and pharmacological studies. Biochim Biophys Acta 1993; 1154: 51-63. 29. Gehl J. Electroporation: theory and methods, perspectives for drug delivery, gene therapy and research. Acta Physiol Scand 2003; 177: 437-47. 30. Mir LM, Orlowski S, Belehradek M and Paoletti C. Electrochemotherapy: potentiation of antitumor effect of bleomycin by local electric pulses. Eur J Cancer 1991; 1: 68-72. 31. Belehradek M, Domenge C, Luboinski B, Orlowski S, Belehradek Jr. J, Mir LM. Electrochemotherapy, a new antitumor treatment - first clinical phase I.II trial. Cancer 1993; 72: 3694-700. 32. Marty M, Sersa G, Garbay JR, Gehl J, Collins CG, Snoj M, et al: Electrochemotherapy – an easy, highly effective and safe treatment of cuta­neous and subcutaneous metastases. Results of ESOPE (European Standard Operating Procedures of Electrochemotherapy) study. Eur J Cancer 2006; S4: 3-13. 33. Sersa G, Stabuc B, Cemazar M, Jancar B, Miklavcic D, Rudolf Z. Electrochemotherapy with CDDP: potentiation of local CDDP antitumor ef­fectiveness by application of electric pulses in cancer patients. Eur J Cancer 1998; 34: 1213-8. 34. Sersa G, Stabuc B, Cemazar M, Miklavcic D, Rudolf Z. Electrochemotherapy with cisplatin: clinical experience in malignant melanoma patients. Clin Cancer Res 2000; 6: 863-7. 35. Matthiessen LW, Johannesen HH, Hendel HW, Moss T, Kamby C, Gehl J. Electrochemotherapy for large cutaneous recurrence of breast cancer: A phase II clinical trial. Acta Oncol 2012; 51: 713-21. 36. Mevio N, Bertino G, Occhini A, Scelsi D, Tagliabue M, Mura F, et al. Electrochemotherapy for the treatment of recurrent head and neck can­cers: preliminary results. Tumori 2012; 98: 308-13. 37. Curatolo P, Quaglino P, Marenco F, Mancini M, Nardo T, Mortera C, et al. Electrochemotherapy in the treatment of kaposi sarcoma cutaneous lesions: A two-center prospective phase II trial. Ann Surg Oncol 2012; 1: 192-8. 38. Campana LG, Valpione S, Mocellin S, Sundararajan R, Granziera E, Sartore L, et al. Electrochemotherapy for disseminated superficial metastases from malignant melanoma. Br J Surg 2012; 99: 821-30. 39. Fini M, Salamanna F, Parrilli A, Martini L, Cadossi M, Maglio M, et al. Electrochemotherapy is effective in the treatment of rat bone metastases. Clin Exp Met 2013; 30: 1033-45. 40. Edhemovic I, Gadzijev EM, Brecelj E, Miklavcic D, Kos B, Zupanic A, et al. Electrochemotherapy: a new technological approach in treatment of metas­tases in the liver. Technol Cancer Res Treat 2011; 10: 475-85. 41. Edhemovic I, Brecelj E, Gasljevic G, Marolt Music M, Gorjup V, Mali B et al. Intraoperative electrochemotherapy of colorectal liver metastases. J Surg Oncol 2014; 110: 320-7. 42. Heller R, Jaroszeski M, Perrot R, Messina J and Gilbert R: Effective treatment of B16 melanoma by direct delivery of bleomycin using electrochemo­therapy. Melanoma Res 1997; 7: 10-8. 43. Sersa G., Cemazar M, Miklavcic D, Mir LM. Electrochemotherapy: variable anti-tumor effect on different tumor models. Bioelectrochem Bioenerg 1994; 35: 23-7. 44. Pendez S, Jaroszeski MJ, Gilbert R Hyacinthe M, Dang V, Hickey J, et al. Direct delivery of chemotherapeutic agents for the treatment of hepatoma and sarcoma in rat models. Radiol Oncol 1998; 21: 53-64. 45. Sersa G, Novakovic S, Miklavcic D: Potentiation of bleomycin antitumor ef­fectiveness by electrochemotherapy. Cancer Lett 1993; 69: 81-4. 46. Nanda GS, Sun FX, Hofmann GA, Hofmann RM, Dev SB. Electroporation enhances therapeutic efficacy of anticancer drugs: treatment of human pancreatic tumor in animal model. Anticancer Res 1988; 18: 1361-6. 47. Jaroszeski MJ, Gilbert RA, Heller R. In vivo antitumor effects of electro­chemotherapy in a hepatoma model. Bioch Biophis Acta 1997; 1334: 15-8. 48. Ramirez LH, Orlowski S, An D, Gindoula G, Dzodic R, Ardouin P, et al. Electrochemotherapy on liver tumours in rabbit. Br. J Cancer 1998; 77: 2104-11. 49. Jaroszeski MJ, Illingworth P, Pottinger C, Hyacinthe M, Miller R. Electrically mediated drug delivery for treating subcutaneous and orthotopic pancre­atic adenocarcinoma in a hamster model. Anticancer Res 1999; 19: 989-94. 50. Liu X, Tian X, Wang F, Ma Y, Kornmann M, Yang Y. BRG1 promotes chemore­sistance of pancreatic cancer cells through crosstalking with Akt signalling. Eur J Cancer 2014; 50: 2251-62. 51. Granata V, Fusco R, Piccirillo M. Palaia R, Lastoria A, Petrillo A, et al. Feasibility and safety of intraoperative electrochemotherapy in locally pan­creatic tumor: A preliminary experience. Eur J Inflamm 2014; 12: 467-77. 52. Allegretti JP, Panje WR. Electroporation therapy for head and neck cancer including carotid artery involvement. Laryngoscope 2001; 111: 52-6. 53. Bloom DC, Goldfarb PM. The role of intratumour therapy with electropora­tion and bleomycin in the management of advanced squamous cell carci­noma of the head and neck. Eur J Surg Oncol 2005; 31: 1029-35. 54. Miklavcic D, Sersa G, Brecelj E, Gehl J, Soden D, Bianchi G, Ruggieri P, Rossi CR, Campana LG, Jarm T. Electrochemotherapy: technological advance­ments for efficient electroporation-based treatment of internal tumors. Med Biol Eng Comput 2012; 50: 1213-25. 55. Todorovic V, Sersa G, Flisar K, Cemazar M. Enhanced cytotoxicity of bleomy­cin and cisplatin after electroporation in murine colorectal carcinoma cells. Radiol Oncol 2009; 43: 264-73. 56. Cemazar M, Tamzali Y, Sersa G, Tozon N, Mir LM, Miklavcic D, et al. Electrochemotherapy in veterinary oncology. J Vet Inter Med 2008; 22: 826-31. 155 research article Efficacy of intensity-modulated radiotherapy with concurrent carboplatin in nasopharyngeal carcinoma Anussara Songthong, Chakkapong Chakkabat, Danita Kannarunimit, Chawalit Lertbutsayanukul1 Division of Radiation Oncology, Department of Radiology, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Pathumwan, Bangkok, Thailand Radiol Oncol 2015; 49(2): 155-162. Received 30 June 2014 Accepted 1 October 2014 Correspondence to: Anussara Songthong, M.D., Division of Radiation Oncology, Department of Radiology, King Chulalongkorn Memorial Hospital, 1873 Rama IV Rd. Pathumwan, Bangkok 10330, Thailand. Phone: +662 256 4334; Fax: +662 256 4590; E-mail: anussara_pr@yahoo.com Disclosure: No potential conflicts of interest were disclosed. Background. The aim of the prospective phase II study was to evaluate the efficacy and toxicities of concurrent carboplatin with intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma (NPC). Patients and methods. Between October 2005 and November 2011, 73 stage II.IVB NPC patients received IMRT 70 Gy concurrently with three cycles of carboplatin (AUC 5) every three weeks, followed by three cycles of adjuvant carboplatin (AUC 5) and 5-FU (1,000 mg/m2/day for four days) every four weeks. All patients were evaluated for tu­mour response using response evaluation criteria in solid tumour (RECIST) criteria, survival analysis using Kaplan-Meier methods, and toxicities according to common terminology criteria for adverse events (CTCAE) version 4.0. Results. At three months after chemoradiation, 82.2% and 17.8% of patients achieved complete and partial re­sponse, respectively. With a median follow-up of 48.1 months (1.3.97.8 months), 9.6% and 17.8% had local recurrence and distant metastasis, respectively. The median survival was not reached. A three-year overall survival was 83.6% and a progression-free survival was 65.3%. Regarding treatment compliance, 97.2%, 68.5% and 69.8% completed radiation treatment, concurrent carboplatin and adjuvant chemotherapy, respectively. Grade 3.4 acute toxicities were oral mucositis (16.4%), dysphagia (16.4%), xerostomia (15.1%) and haematotoxicity (6.8%). Conclusions. Carboplatin concurrently with IMRT provided excellent tumour response, manageable toxicities and good compliance. This should be considered as an alternative treatment for NPC patients. Key words: intensity-modulated radiotherapy (IMRT); carboplatin; nasopharyngeal carcinoma Introduction Nasopharyngeal carcinoma (NPC) is one of the most common head and neck neoplasms among Asian people. The overall incidence of NPC in Southeast Asia is 6.5 and 2.6 per 100,000 person-years in males and females, respectively.1 In Thailand, the age-standardized incidence rates of NPC are approximately 3.7 and 1.2 per 100,000 in males and females, respectively.2 Meta-analysis showed that chemotherapy plays an important role in the treatment of this disease.3 Al Saraff et al. (Intergroup 0099) demonstrated sig­nificant benefits of additional cisplatin in terms of both disease free survival and overall survival, when used concurrently with radiation followed by a combination of cisplatin and 5-fluorouracil chemotherapy for three cycles.4 Thus, this regi­men has become standard of care for nasopharyn­geal carcinoma despite the low compliance rate (55.63%) in this trial. Significant side effects of cis­platin include nausea and vomiting, renal, neuro­logical and ototoxicity. Additionally, during high-dose cisplatin administration, adequate hydration and volume monitoring are needed and require hospital admission. Recently, Chan et al. proposed 156 a low-dose weekly cisplatin that could be admin­istered in an outpatient setting and provides good patient compliance.5 Based on similar radiosensitizing properties of carboplatin and cisplatin along with pre-clinical data that demonstrated an enhanced radiation ef­fect from concurrent carboplatin in tumour cells, some physicians use carboplatin as an alternative regimen to avoid serious cisplatin toxicities, espe­cially renal, gastrointestinal and neurotoxicity.6-10 Many studies have shown comparable response rates and survival outcomes with acceptable tox­icities and better compliance from carboplatin.11-14 However, the radiation technique in those studies was the conventional technique. More recently, in­tensity-modulated radiotherapy (IMRT) has been proven in NPC treatment for its efficacy and its advantages over conventional techniques and has been considered as a standard radiation technique for NPC.15-17 The objectives of this study are to evaluate ef­ficacy and toxicities using IMRT concurrently with carboplatin, followed by adjuvant carboplatin and 5-fluorouracil (5-FU) chemotherapy for the treat­ment of NPC. Patients and methods Patients and methods Between October 2005 and November 2011, new­ly diagnosed NPC patients were accrued for this prospective phase II study after obtaining the in­stitutional review board approval (RA 13/49). The eligibility criteria included those aged 18 years old and above; histologically confirmed non-metastatic nasopharyngeal carcinoma stage II.IVB according to the 7th edition of the American Joint Committee on Cancer Staging System (AJCC 2010); Eastern Cooperative Oncology Group (ECOG) perfor­ mance status 0.2; adequate hematologic and renal function, defined by with blood cells (WBC) . 4,000/ mL, platelet count . 100,000/mL, serum creatinine . 1.5 mg/dL or calculated creatinine clearance . 60 ml/min. Patients with distant metastasis; previous radiation and/or chemotherapy treatment less than six months prior to the study entry; other malig­nancy except non-melanoma skin cancer or a car­cinoma of non-head and neck origin, controlled for at least five years; active infection; major medical or psychiatric condition or pregnancy were excluded. All eligible patients received a pre-treatment evaluation including complete history and physi­cal examination, endoscopic biopsy, routine labo­ratory tests for hematologic, renal and hepatic function as well as a dental and nutritional evalu­ation before the treatment. Radiological investi­gations consisted of computed tomography (CT) scan or magnetic resonance imaging (MRI) of the nasopharynx, chest radiography, ultrasound of upper abdomen and bone scintigraphy. Positron emission tomography (PET) scan was optional. A pathologic confirmation of NPC was performed and re-classified according to WHO subtype.18 Treatment protocol Each patient underwent contrast-enhanced CT simulation with a long thermoplastic mask. The GTVs and CTVs were contoured according to RTOG guidelines. There were two planning target volumes (PTVs): PTV-high risk (PTV-HR), defined as primary tumour and gross lymphadenopathy with appropriate margin, and PTV-low risk (PTV­LR), defined as PTV-HR plus elective lymph node region. The prescription dose was 50 Gy in 25 frac­ tions to PTV-LR followed by a boost of 20 Gy in 10 fractions, called sequential IMRT (SEQ). Recently, a simultaneous integrated boost (SIB) technique was developed and applied in last few patients with total dose of 70 Gy and 56 Gy in 33 fractions for PTV-HR and PTV-LR, respectively. Normal tis­sue constraints were used according to our institu­tional protocol (adopted from RTOG 0225 and 0615 study protocols) and are described in Table 1. All patients received IMRT concurrently with three cycles of carboplatin (AUC 5) every three weeks, followed by three cycles of adjuvant carbo­platin (AUC 5) and 5-FU (1,000 mg/m2 /day for four days) every four weeks. During the concurrent and the adjuvant treat­ment, patients were assessed weekly. Dose modi­fication and proper management were performed according to patients’ toxicity grading. The re­sponse of the primary tumour and lymph node was evaluated at three months after the last fraction of radiotherapy by endoscopic examination and CT scan. Other imaging was performed if indicated. Statistical analysis Data collection consisted of patient characteristics including age, sex and ECOG performance status; disease characteristics including pathologic WHO subtype and TNM staging; and treatment modali­ties including radiation treatment technique, radia­tion dose, duration of radiation treatment as well as compliance with radiation and chemotherapy. 157 TABLE 1. Dose volume constraints of normal tissue TABLE 2. Patients and disease characteristics Spinal cord 50 45 1 cc Brain stem 60 54 1 cc One parotid gland 26 50% Optic nerve 54 Cochlear 46 50% Eyes 24 50% Lens 6 Mandible 70 53 50% Oral cavity 60 40 50% Vocal cord 58 45 50% Maximum dose (Dmax) defined as radiation dose encompasses 1% of each organ-at-risk volume All patients were evaluated for tumour response using response evaluation criteria in solid tu­mour (RECIST) criteria, survival outcomes using Kaplan-Meier methods, and acute and late toxici­ties according to common terminology criteria for adverse events (CTCAE) version 4.0. Primary endpoints were progression-free sur­vival (PFS) and overall survival (OS). PFS was de­fined as the time period since the initial treatment of NPC until disease recurrence or progression or death. OS was defined as the time period between the initial treatment of NPC and any cause of death. Survival analyses were computed using the Kaplan-Meier method and log-rank test. P-value of 0.05 or less was applied to define significance. Statistical Packages for Social Sciences (SPSS) soft­ware version 17.0 was used for the statistical analy­sis. Secondary endpoints were disease control and treatment-related toxicities. The sample size calculation was based on the proportion of expected death (mortality rate) with 95% confidence interval. We employed 18.1% mor­tality rate for concurrent radiation with carboplatin according to the results of a randomized study of Chitapanarux et al.13 Allowing 20% dropout p-val­ue of 0.05, 69 participants were planned to be en­rolled in the study. Results Patient and disease characteristics A total of 73 patients diagnosed with NPC and treated between October 2005 and November Age, years Mean (range) Sex Male Female Performance status ECOG 0 ECOG 1 WHO classification Type II (Non-keratinizing SCCA) T stage 1 2 3 4 N stage 0 1 2 3a 3b M stage 0 Stage grouping II III IV A IV B 54.4 (24.76) 49 24 67 6 73 15 26 23 9 5 19 41 5 3 73 16 42 12 3 67.1% 32.9% 91.8% 8.2% 100.0% 20.6% 35.6% 31.5% 12.3% 6.8% 26.0% 56.2% 6.9% 4.1% 100.0% 22.0% 57.5% 16.4% 4.1% SCCA = Squamous cell carcinoma 2011 were accrued. Patient and disease character­istics are listed in Table 2. The mean age was 54.4 years (range 24.76 years). The majority of patients (67.1%) were males. All were in good performance status and had non-serious comorbidities. The histological subtype, according to WHO classifi­cation, was non-keratinizing squamous cell carci­noma (NK-SCCA) in every patient, which could be further identified as undifferentiated NK-SCCA in most patients (83.6%). Approximately half of pa­tients had stage III disease. Radiation treatment Whole-neck IMRT was planned using the Eclipse treatment planning system. The majority of pa­ tients (91.8%) was treated with the SEQ-IMRT technique. The rest were treated with the SIB­ IMRT technique. Seventy-two patients (98.6%) completed a course of radiation. One patient could not complete the course of radiation and the treat­ment interruption of 38 days occurred in another patient; both resulted from intolerable toxicity. The average PTV-HR and PTV-LR dose were 69.95 Gy (range 58.76 Gy) and 50.82 Gy (range 42.62 Gy), respectively. The median duration of the radiation treatment was 55 days (range 14.93 days). 158 Chemotherapy Seventy-two patients (98.6%) received concurrent carboplatin and radiation; 50 patients (68.5%) re­ceived all three cycles of chemotherapy as planned. The compliance of chemotherapy treatment is de­tailed in Table 3. Clinical outcome The median follow-up time was 48.1 months (6.1.97.8 months). At three months after comple­tion of radiotherapy, a complete response (CR) was achieved in 60 patients (82.2%) while 13 patients (17.8%) achieved a partial response (PR). Regarding the site of the tumour response, 94.5% of patients achieved CR at the primary (nasopharyngeal) site while 83.6% achieved CR at regional lymph node TABLE 3. Compliance of chemotherapy treatment 0 1 (1.4%) 4 (5.5%) 1 2 (2.7%) 8 (11%) 2 20 (27.4%) 10 (13.7%) 3 50 (68.5%) 51 (69.8%) Total 73 (100%) 73 (100%) sites. Patients who achieved PR received a further treatment: a radiotherapy boost of 30 Gy in 10 frac­tions to any residual disease at the primary site. Patients with small residual lymph node(s) had a radiation boost of 15 Gy in 5 fractions while those with a larger residual disease in the neck under­went a salvage neck dissection. No additional sys­temic therapy was given after the patients complet­ed three chemotherapy cycles. During the follow-up period, seven patients (9.6%) and 13 patients (17.8%) experienced local and distant failure, respectively. None of the pa­tients had regional recurrence or both, local/re­gional and distant failure. The median time to local and distant recurrence was 20.3 months and 22.2 months, respectively. The most common sites of metastasis were bone (8.2%), liver (6.8%) and lung (4.1%). At the last follow-up, 45 patients (61.6%) were alive without disease while eight patients (10.9%) had disease recurrence. There were 20 deaths (27.4%); 14 patients died from the progression of the disease. Survival outcome Median OS was not reached. Median PFS was 71 months. Three-year OS and PFS were 83.6% and 65.3%, respectively and at 5 years they were 72.7% and 58.9%, respectively, as shown in Figure 1. Toxicities The toxicities were classified as acute and late tox­icities using a 90-day cut-off point after the comple­tion of chemoradiation. Acute toxicity consisted of symptoms developing during the concurrent and the adjuvant treatment. During concurrent chemo­radiation, all patients experienced some degrees of acute toxicities, most of which were mild (grade 1.2). The most common grade 3.4 toxicities were 159 mucositis (16.4%), dysphagia (16.4%) and xerosto­mia (15.1%). Only two patients (2.7%) had severe nausea and vomiting. Twelve patients (16.4%) needed nasogastric tube insertion. Weight loss of more than 20% (grade 3) occurred in 5 patients (6.8%) during concurrent chemoradiation and in 24 patients (32.9%) during the adjuvant period. During adjuvant chemotherapy, most patients re­covered from mucositis, xerostomia and dyspha­gia. Grade 3 or more hematologic toxicities devel­oped in 6 patients (8.2%). Three (4.1%) and two pa­tients (2.7%) developed grade 3.4 neutropenia and thrombocytopenia, respectively. A renal function impairment was not found. No patient developed grade 5 toxicity during the concurrent and the ad­juvant treatment. The incidence of acute toxicities is described in Table 4. Eighteen patients (28.6%) had grade 3 weight loss at one year after chemoradiation. Most patients regained their weight within two years. Grade 2 xerostomia was found in 10 patients (13.7%) and three patients (4.1%) at 6-month and 12-month fol­low-up, while no patient had grade 2 xerostomia at the 24-month point. None of the patients experi­enced grade 3.4 gastrointestinal and dermatologic toxicities during follow-up. There was no renal tox­icity among these patients. Discussion Nasopharyngeal carcinoma is one of the most com­mon head and neck cancer in Southeast Asia and has a different natural history and prognosis from other cancers in this region. The current standard treatment of locally advanced NPC is concurrent chemoradiation followed by adjuvant chemother­apy.3-5 According to a meta-analysis from eight trials involving 1,753 patients, chemotherapy re­ sulted in an absolute survival benefit of 6% (from 56% to 62%) and an event-free survival benefit of 10% (from 42% to 52%) at five years. This study also concluded that the concurrent trials showed significant survival benefit with hazard ratio (HR) of 0.60 (95% CI, 0.48.0.76).3 Another meta-analysis from 10 randomized clinical studies with a total of 2,450 patients supported that concurrent chemo­ radiation improved survival by 20% at five years with a pooled HR of 0.48 (95% CI, 0.32.0.72).19 The landmark study by Al Saraff et al. (INT 0099)4 sup­ported the standard treatment of nasopharyngeal carcinoma using concurrent radiation with cispl­atin followed by cisplatin and 5FU with 5-year OS and DFS of 67% and 58%, respectively. Although TABLE 4. Acute toxicity during treatment Constitutional symptoms Fatigue Anorexia Weight loss Gastrointestinal Oral mucositis Xerostomia Dysphagia Nausea Vomiting Diarrhea Dermatitis Hematologic Anaemia Neutropenia Thrombocytopenia Creatinine Total 72 (98.6%) 71(97.3%) 68(93.2%) 61(83.6%) 62(84.9%) 61(83.6%) 71(97.3%) 71(97.3%) 73(100%) 73(100%) 73(100%) 68(93.2%) 72(98.6%) 73(100%) 73(100%) 1(1.4%) 2(2.7%) 5(6.8%) 12(16.4%) 11(15.1%) 12(16.4%) 2(2.7%) 2(2.7%) 0 0 0 5(6.8%) 1(1.4%) 0 0 71(97.3%) 73(100%) 49(67.1%) 73(100%) 73(100%) 73(100%) 73(100%) 73(100%) 73(100%) 73(100%) 72(98.6%) 70(95.9%) 71(97.3%) 73(100%) 73(100%) cisplatin is a widely accepted regimen, its toxicity, including nausea, vomiting, ototoxicity, neurotox­icity and nephrotoxicity, may lead to poor compli­ance; only 63% and 55% of patients completed con­current and adjuvant chemotherapy in INT 0099.4 Carboplatin has come into interest due to its lesser side effects, especially gastrointestinal and nephrogenic side effects. The advantages of car­boplatin are tolerable toxicity leading to better compliance and its capability of out-patient ad­ministration, thus reducing hospitalization, cost of the treatment and workload of medical person­nel. Eisenberger indicated that 100 mg/m2/week of carboplatin was well tolerated when given con­currently with radiation in locally advanced head and neck cancers.20 Unfortunately for NPC, a pro­spective phase I/II study from Canada of concur­rent carboplatin in 47 patients reported probably inferior OS and PFS with acceptable toxicity com­pared to INT 0099. With the median follow-up of 23.1 months, 3-year OS and PFS were 56% and 58%, respectively.11 Nevertheless, different WHO histo­logical subtypes may result in different natural his­tory of disease and response between Caucasian and Asian people. The randomized controlled trial from Thailand, comparing carboplatin-based chemotherapy with an INT 0099 regimen in 220 patients demonstrated a non-inferior survival out­come. Three-year OS and DFS in the carboplatin arm were 79.2% and 60.9% compared with 77.7% and 63.4% in the cisplatin arm. They also showed better compliance to treatment in carboplatin arm, 73% versus 59%.13 Another report from Thailand 2(2.7%) 0 24(32.9%) 0 0 0 0 0 0 0 1(1.4%) 3(4.1%) 2(2.7%) 0 0 160 TABLE 5. Comparison of treatment schedule, compliance and outcome between studies on concurrent chemoradiation with carboplatin in NPC patients and INT 0099 trial; and RTOG 0225 using IMRT technique INT 00994 RCT 147 III 9% IV 91% NA Conventional 66.70 Gy Cis 100 mg/m2 q 3 wk x 3 cycles Cis 80 mg/m2 +5FU 4000 mg/m2 q 4 wk x 3 cycles 63% 55% 58%(5Y) 67%(5Y) Parliament11 Prospective phase I/II (AJCC 2002) 47 I/II 10.7% III 14.9% IV 74.5% 23.1 mo Conventional 70 Gy Carbo 100mg/m2 q 1 wk x 6 cycles - 95.7% - 58%(3Y) 56%(3Y) Chitapanarux13 RCT (AJCC 1997) 206 III 36% IVA 25% IVB 40% III 31% IVA 23% IVB 46% 26.3 mo Conventional 70 Gy Cis 100 mg/m2 q 3 wk x 3 cycles Carbo 100mg/m2 q 1 wk x 6 cycles Cis 80 mg/m2 +5FU 4000 mg/m2 q 4 wk x 3 cycles Carbo AUC 5 +5FU 4000 mg/m2 q 4 wk x 3 cycles 59% 77% 42% 72% 63.4%(3Y) 60.9%(3Y) 77.7%(3Y) 79.2%(3Y) Dechaphunkul14 Prospective (AJCC 2002) 50 IIB 8% III 36% IVA 38% IVB 18% 37.3 mo Conventional 66.70 Gy Carbo AUC 6 q 3 wk x 3 cycles Carbo AUC 5 +5FU 4000 mg/m2 q 3 wk x 2 cycles 98% (total 5 cycles) 89.7%(3Y) 72.7%(3Y) I 13.2% RTOG 022521 Prospective Phase II (AJCC 1997) 68 IIA 2.9% IIB 25.0% III 30.9% IVA 16.2% 31.2 mo IMRT 70 Gy Cis 100 mg/m2 q 3 wk x 3 cycles Cis 80 mg/m2 +5FU 4000 mg/m2 q 4 wk x 3 cycles 87% 45.6% 72.7% (2Y) 80.2% (2Y) IVB 11.8% MSKCC22 Prospective Phase II (AJCC 1997) 74 I 7% IIB 16% III 30% IVA/B 47% 35 mo IMRT 70 Gy (AF and SIB) Cis 100 mg/m2 q 3 wk x 2 cycles Cis 80 mg/m2 +5FU 4000 mg/m2 q 4 wk x 3 cycles 92% NA 67% (3Y) 83% (3Y) This study Prospective Phase II (AJCC 2010) 73 II 22.0% III 57.5% IVA 16.4% IVB 4.1% 48.1 mo IMRT 70 Gy (Seq and SIB) Carbo AUC 5 q 3 wk x 3 cycles Carbo AUC 5 +5FU 4000 mg/m2 q 4 wk x 3 cycles 68.5% 69.8% Median=71m 65.3% (3Y) 58.9% (5Y) MS=not reached 83.6% (3Y) 72.7% (5Y) AF = Accelerated fractionation (here, hyperfractionated concomitant boost); AJCC = American Joint Committee on Cancer Staging; Carbo = Carboplatin; Cis = Cisplatin; CMT = Chemotherapy; DFS = Disease-free survival; F/U = Follow-up time; 5FU = 5-fluorouracil; mo = months; NA = Not available; OS = Overall survival; PFS = Progression-free survival; RCT = randomized-controlled trial; RT = Radiation treatment; SIB = simultaneous integrated boost; wk = week that included 50 patients using concurrent chemo­radiation with carboplatin followed by carboplatin and 5FU in NPC showed good results and toler­ ability. The 3-year OS and PFS were 72.7% and 89.7%, respectively.14 Although the efficacy of concurrent carbopl­atin with radiation in NPC was demonstrated, these studies used a conventional radiation tech­nique11,13,14 whereas in current practice, the stand­ard radiation technique for NPC is IMRT, which has demonstrated significantly better salivary flow rate and quality of life in NPC patients compared with conventional techniques.15-17 Additionally, the recent RTOG phase II trial 0225 and a prospec­tive study from Memorial Sloan Kettering Cancer Center (MSKCC) reported promising results of tumour control and toxicities by using IMRT and concurrent cisplatin.21,22 In RTOG 0225 with 68 patients, 2-year OS and PFS were 80.2% and 72.7%, respectively. In the MSKCC study with 74 patients, 3-year OS and PFS were 83% and 67%, respectively. In this study, using concurrent car­boplatin with IMRT, our 3-year OS and PFS were 83.6% and 65.3%, which were comparable with those previous studies. Moreover, approximately 70% of patients completed three cycles of adjuvant chemotherapy. Distant metastasis is the major reason of fail­ure in nasopharyngeal carcinoma. The rate of distant metastasis reported in many series was 14.7%.22% in cisplatin-based chemotherapy series compared with 14.3%.29.8% in carboplatin-based series.4,11-14,18,21,22 In our study, the crude distant metastasis rate was 17.8%, which was comparable with the results from studies using either of the two chemotherapy regimens. The most common sites of metastasis were bone (8.2%), liver (6.8%) and lung (4.1%), giving the 3- and 5-year distant 161 metastasis-free survival (DMFS) of 82% and 77.1%, respectively. With regards to toxicity, because different crite­ria were used for evaluation, comparing the toxic­ity among several published trials including our study might not be appropriate. Compared with RTOG 0225, which used similar toxicity evalua­tion criteria, Common Terminology Criteria for Adverse Events (CTCAE), overall acute grade 3 toxicity was 61.8%21, while it was 24.7% in our study. Acute grade 3 mucositis, defined as con­fluent pseudomembranous reaction (contiguous patches generally > 1.5 cm in diameter) in CTCAE version 2.0 and as severe pain or interference with oral intake in CTCAE version 4.03, was 29.4% in the RTOG study compared to 16.4% in our study. There was no patient who experienced acute grade 5 mucositis in this trial but one patient (1.3%) did in the RTOG study. According to Dechapunkul, us­ing conventional radiation and RTOG acute toxic­ity criteria in which grade 3 mucositis was defined as confluent fibrinous mucositis or severe pain re­quiring narcotics, grade 3.4 mucositis was report­ed in 42% of total 50 patients.14 In contrast, in the Chitapanarux study, using conventional radiation technique and RTOG acute toxicity criteria, the rate of mucous membrane toxicity was very low: 0% in the cisplatin arm and 5% in the carboplatin arm. However, the rate of nasogastric tube insertion was as high as 48% and 22% in the cisplatin and carbo­platin arm, respectively, compared with 16.4% in our study. Grade 3 or higher nausea and vomiting rates dur­ing chemoradiation in our study were comparable to those of carboplatin studies and was less than cisplatin studies, for example, 2.7% in our study, 0% in Chitapanarux study, 8% in Dechapunkul study versus 19.2% in INT 0099 study. The rate of grade 3 dermatitis, which was de­ fined as confluent moist desquamation . 1.5 cm diameter and not confined to skin folds or pitting oedema in CTCAE version 2.0 and RTOG toxicity criteria and as moist desquamation other than skin folds and creases or bleeding induced by minor trauma or abrasion in CTCAE 4.03, was 13.2% in the RTOG 0225 study, 3% and 6% in the cisplatin and carboplatin arm in the Chitapanarux study, and none in our study. Late grade 2 xerostomia at 12-month period in our study was 4.1% compared with 13.5% reported in RTOG 0225 and 24% in the Chitapanarux study. The treatment schedule, compliance and out­come in each study are demonstrated in Table 5. One of the major concerns of carboplatin ad­ministration is hematologic toxicity. In our study, 8.2% experienced grade 3.4 hematologic toxicity, mainly neutropenia (6.8%) and thrombocytopenia (1.4%), which was comparable to the Chitapanarux study in which 10% and 2% of patients experienced grade 3 neutropenia and thrombocytopenia in the carboplatin arm. This is the first study to our knowledge that demonstrated the efficacy and feasibility of car­boplatin concurrently with IMRT in NPC and that this treatment can be applied as an alternative chemotherapy regimen, especially in vulnerable patients or those not suitable for standard cisplatin regimen. Conclusions Carboplatin concurrently with IMRT provided ex­cellent tumour response, manageable toxicities and good compliance. This should be considered as al­ternative to standard treatment with cisplatin for NPC patients. References 1. International Agency for Research on Cancer, World Health Organisation, International Association of Cancer Registries. Nasopharyngeal carcinoma. In: Curado MP, Edwards B, Shin HR, Storm H, Ferlay J, Heanue M, et al, editors. Cancer in five continents, vol IX. IARC Scientific Publication No. 160. Lyon: IARC; 2007. 2. Nasopharyngeal carcinoma. In: Khuhaprema T, Srivatanakul P, Attsara A, Sriplung H, Wiangnon H, Sumitsawan Y, editors. Cancer in Thailand. Bangkok: Ministry of health; 2010. p. 16-17. 3. Baujet B, Audry H, Bourhis J, Chan AT, Onat H, Chua DT, et al. Chemotherapy in locally advanced nasopharyngeal carcinoma: an individual patient data meta-analysis of eight randomized trials and 1753 patients. Int J Radiat Oncol Biol Pys 2006; 64: 47-56. 4. Al-Sarraf M, LeBlanc M, Giri PG, Fu KK, Cooper J, Vuong T, et al. Chemoradiotherapy versus radiotherapy in patients with advanced naso­pharygeal cancer: Phase III randomized Intergroup study 0099. J Clin Oncol 1998; 16: 1310-7. 5. Chan AT, Leung SF, Ngan RK, Teo PM, Lau WH, Kwan WH, et al. Overall sur­vival after concurrent cisplatin-radiotherapy compared with radiotherapy alone in locoregionally advanced nasopharyngeal carcinoma. J Natl Cancer Inst 2005; 97: 536-9. 6. Douple EB, Richmond RC, O’Hara JA, Coughlin CT. Carboplatin as a potentia­tor of radiation therapy. Cancer Treat Rev 1985; 12(Suppl A): 111-24. 7. Coughlin CT, Richmond RC. Biologic and clinical developments of cisplatin combined with radiation: Concepts, utility, projections for new trials, and the emergence of carboplatin. Semin Oncol 1989; 16: 31-43. 8. Calais G1, Alfonsi M, Bardet E, Sire C, Germain T, Bergerot P, et al. Randomized trial of radiation therapy versus concomitant chemotherapy and radiation therapy for advanced-stage oropharynx carcinoma. J Natl Cancer Inst 1999; 91: 2081-6. 9. Calais G, Le Floch O. Concomitant radiotherapy and chemotherapy in the treatment of cancer of the upper respiratory and digestive tracts. Bull Cancer Radiother 1996; 83: 321-9. 162 10. Muggia FM. Overview of carboplatin: Replacing complementing and ex­tending the therapeutic horizons of cisplatin. Semin Oncol 1989; 16(Suppl 5): 7-13. 11. Paliament M, Jha N, Rapp E, Smith C, MacKinnon J, Nabholtz JM, et al. Concurrent weekly carboplatin and radiotherapy for nasopharyngeal car­cinoma: report of a joint phase II study. Radiother Oncol 2001; 58: 131-6. 12. Okita J, Hatta C, Terada T, Saeki N, Ogasawara H, Kakibuchi M, et al. Concurrent chemo-radiotherapy for nasopharyngeal carcinoma. Auris Nasus Larynx 2004; 31: 43-7. 13. Chitapanarux I, Lorvidhaya V, Kamnerdsupaphon P, Sumitsawan Y, Tharavichitkul E, Sukthomya V, et al. Chemoradiation comparing cisplatin versus carboplatin in locally advanced nasopharyngeal cancer: Randomised, non-inferiority, open trial. Euro J of Cancer 2007; 43: 1399-406. 14. Dechaphunkul T, Pruegsanusak K, Sangthawan D, Sanpaeravong P. Concurrent chemoradiotherapy with carboplatin followed by carboplatin and 5- fluorouracil in locally advanced nasopharyngeal carcinoma. Head Neck Oncol 2011; 3: 30. 15. Pow EH, Kwong DL, McMillan AS, Wong MC, Sham JS, Leung LH, et al. Xerostomia and quality of life after intensity-modulated radiotherapy vs conventional radiotherapy for early-stage nasopharyngeal carcinoma: initial report on a randomized controlled clinical trial. Int Radiat Oncol Biol Phys 2006; 66: 981-91. 16. Kam MK, Leung SF, Zee B, Chau RM, Suen JJ, Mo F, et al. Prospective randomized study of intensity- modulated radiotherapy on salivary gland function in early-stage nasopharyngeal carcinoma patients. J Clin Oncol 2007; 25: 4873-9. 17. Peng G, Wang T, Yank KY, Zhang S, Zhang T, Li Q, et al. A prospective, ran­domized study comparing outcomes and toxicities of intensity-modulated radiotherapy vs. conventional two-dimensional radiotherapy for the treat­ment of nasopharyngeal carcinoma. Radiother Oncol 2012; 104: 286-93. 18. Chan J, Bray F, McCarron P, Foo W, Lee AWM, Yip T, et al. Nasopharyngeal carcinoma. In: Barnes EL, Eveson JW, Reichart P, Sidransky D, editors. Pathology and genetics of head and neck tumor. World Health Organization classification of tumours. Lyon: IARC Press; 2005. p. 85. 19. Langendijk JA, Leemans CR, Buter J, Berkhof J, Slotman BJ. The additional value of chemotherapy to radiotherapy in locally advanced nasopharyngeal carcinoma: a meta-analysis of the published literature. J Clin Oncol 2004; 22: 4604-12. 20. Eisenberger M, Jacobs M. Simultaneous treatment with single-agent chemotherapy and radiation for locally advanced cancer of head and neck. Semin Oncol 1992; 4(Suppl11): 41-6. 21. Lee N1, Harris J, Garden AS, Straube W, Glisson B, Xia P, et al. Intensity-modulated radiation therapy with or without chemotherapy for naso­pharyngeal carcinoma: radiation therapy oncology group phase II trial 0225. J Clin Oncol 2009; 27: 3684-90. 22. Wolden SL, Chen WC, Pfister DG, Kraus DS, Berry SL, Zelefsky MJ. Intensity-modulated radiation therapy (IMRT) for nasopharyngeal cancer. Update of the Memorial Sloan-Kettering experience. Int J Radiat Oncol Biol Phys 2006; 64: 57-62. 163 research article Preoperative treatment with radiochemotherapy for locally advanced gastroesophageal junction cancer and unresectable locally advanced gastric cancer Ivica Ratosa, Irena Oblak, Franc Anderluh, Vaneja Velenik, Jasna But-Hadzic, Ajra Secerov Ermenc, Ana Jeromen Department of Radiotherapy, Institute of Oncology Ljubljana, Ljubljana, Slovenia Radiol Oncol 2015; 49(2): 163-172. Received: 14 April, 2014 Accepted: 19 May, 2014 Correspondence to: Assist. Prof. Irena Oblak, M.D., Ph.D., Institute of Oncology Ljubljana, Zaloška c. 2, SI-1000 Ljubljana, Slovenia. Phone: +386 1 5879 661; Fax: +386 1 5879 304; E-mail: ioblak@onko-i.si Disclosure: No potential conflicts of interest were disclosed. Background. To purpose of the study was to analyze the results of preoperative radiochemotherapy in patients with unresectable gastric or locoregionally advanced gastroesophageal junction (GEJ) cancer treated at a single institution. Patients and methods. Between 1/2004 and 6/2012, 90 patients with locoregionally advanced GEJ or unresectable gastric cancer were treated with preoperative radiochemotherapy at the Institute of Oncology Ljubljana. Planned treatment schedule consisted of induction chemotherapy with 5-fluorouracil and cisplatin, followed by concomitant radiochemotherapy four weeks later. Three-dimensional conformal external beam radiotherapy was delivered by dual energy (6 and 15 MV) linear accelerator in 25 daily fractions of 1.8 Gy in 5 weeks with two additional cycles of chemotherapy repeated every 28 days. Surgery was performed 4–6 weeks after completing radiochemotherapy. Following the surgery, multidisciplinary advisory team reassessed patients for the need of adjuvant chemotherapy. The primary endpoints were histopathological R0 resection rate and pathological response rate. The secondary endpoints were toxicity of preoperative radiochemotherapy and survival. Results. Treatment with preoperative radiochemotherapy was completed according to the protocol in 84 of 90 patients (93.3%). Twenty patients (22.2%) did not undergo the surgery because of the disease progression, serious co­morbidity, poor performance status or still unresectable tumour. In 13 patients (14.4%) only exploration was performed because the tumour was assessed as unresectable or diffuse peritoneal carcinomatosis was established. Fifty-seven patients (63.4%) underwent surgery with the aim of complete removal of the tumour. Radical resection was achieved in 50 (55.6%) patients and the remaining seven (7.8%) patients underwent non-radical surgery (R1 in five and R2 in two pa­tients). In this group of patients (n = 57), pathological complete response of tumour was achieved in five patients (5.6% of all treated patients or 8.8% of all operated patients). Down-staging was recorded in 49 patients (86%), in one patient (1.8%) the stage after radiochemotherapy was unchanged while in seven patients (12.3%) the pathological stage was higher than clinical, mainly due to higher pN stage. No death was recorded during preoperative radiochemotherapy. Most grade 3 and 4 toxicities were due to vomiting, nausea and bone marrow suppression (granulocytopenia). Twenty-six (45.6%) patients died due to GEJ or gastric carcinoma, one died because of septic shock following the surgery and a reason for two deaths was unknown. Twenty-eight patients (49.1%) were disease free at the time of analysis, while 29 patients (50.9%) developed the recurrence, mostly as distant metastases. At two years, locoregional control, disease-free survival, disease-specific survival and overall survival were 82.9%, 43.9%, 56.9% and 53.9%, respectively. Conclusions. Preoperative radiochemotherapy was feasible in our group of patients and had acceptable toxicity. Majority of patients achieved down-staging, allowing greater proportion of radical resections (R0), which are essential for patients’ cure. Key words: unresectable gastric cancer; gastroesophageal junction cancer; preoperative radiochemotherapy; sur­gery; toxicity 164 Introduction Gastric and gastroesophageal junction (GEJ) cancer are two groups of tumours with different patho­genesis, epidemiology and clinicopathological characteristics.1,2 In the past years changes in clas­sification based mainly on anatomical localization of the tumour were made, and today GEJ cancer that arises within first 5 cm of the stomach and also extends to the oesophagus, is classified as oesopha­geal cancer (Siewert type I, II or III).3 Not all of the authors agree with new staging principles, as new classification does not represent the molecular ori­gin of carcinoma. An appropriate interpretation of results from past therapeutic trials also became dif­ficult, as GEJ carcinomas were formerly classified and treated as gastric carcinomas.4-6 Surgery is without doubt the main part of cu­rative treatment of primarily advanced (. cT3N+) gastric and GEJ cancer. The best surgical approach for both groups is still a subject of a debate, espe­cially regarding the extension of lymphadenecto­my. Panel of experts agree that gastrectomy with D2 lymph node dissection (without resection of the pancreatic tail and without routine splenectomy) is advised as the standard approach in Europe and Asia for gastric and Siewert type III GEJ cancers, while Siewert type I and II should be treated by oesophagectomy (or by extended transhiatal gas­trectomy for type II tumours, if needed) with dis­section of mediastinal lymph nodes. Although surgical techniques have been im­proved, local recurrence rate after complete re­section of gastric and GEJ adenocarcinoma is still high.7-9 Suboptimal surgery and high rates of dis­tant metastases - especially to liver, bone, brain and lung - have led to search for additional therapeutic approaches. The results of INT-0116 and MAGIC trials suggest a survival benefit of postoperative ra­diochemotherapy or perioperative chemotherapy and subsequently they were accepted as standards of care.10,11 Recent evidence shows an important role of ra­diotherapy in addition to preoperative chemother­apy regimens in GEJ and in gastric cancers as well as in others gastrointestinal cancers.12 According to the results of the CROSS trial, in which 368 patients with T1N1 or T2-3N0-1 tumours without clinical evidence of metastatic spread (M0) were included, preoperative radiochemotherapy followed by sur­gery significantly improves disease-free survival (DFS) and overall survival (OS) as compared with surgery alone in patients with distant oesophageal or GEJ squamous-cell carcinoma, adenocarcinoma, or large-cell undifferentiated carcinoma. A patho­logical complete response (pCR) and radical resec­tion (R0) was achieved in 29% and 92% of patients who underwent resection after radiochemotherapy, compared to the 69% of R0 resections in the group where the patients were treated with surgery only.13 In ACCORD07 phase III trial patients treated with preoperative chemotherapy had better survival compared to the patients treated with surgery alone (5-year OS 38% vs. 24%). Survival rates from CROSS trial where preoperative radiochemotherapy was used seem to be superior then in ACCORD07 trial where preoperative chemotherapy was used (5-year OS 47% vs. 34% in control arm).14 Results, published by Stahl et al., also pointed to a survival advantage for preoperative radiochemotherapy compared with preoperative chemotherapy in GEJ carcino­ mas (3-year OS rate 47.4% and 27.7%, respectively). The patients treated with preoperative radiochemo­therapy also had lower rate of non-radical resections (4.1% and 14.4%, respectively) and higher rate of pCRs (15.6% and 2%, respectively). Another inter­esting observation in that study is that the patients who achieved pCR had 100% 3-year OS rate, where­as in other patients the 3-year OS was 47.4%.15 In gastric cancer, data demonstrating survival benefits of preoperative radiochemotherapy are less clear. Only several retrospective or prospec­tive, randomized or non-randomized trials (in general with small number of included patients), investigating the role of preoperative radiochemo­therapy for gastric cancer have been published. Rates of R0 resection and pCR in resectable gastric cancer patients were as high as 70–78% and 20– 30%, respectively.16-25 Authors concluded that mor­bidity and mortality were not significantly higher in preoperative radiochemotherapy treatment.15,26 Valenti et al. randomized 72 patients with operable locally advanced gastric cancer (cT3–4/N+) in two groups. The first group was treated with preopera­tive chemotherapy, the second one with preopera­tive radiochemotherapy. They did not find differ­ences in the incidence of complications between groups (30.9% vs. 33.3%, respectively). A major pathological response was detected in 33.3% of pa­tients and it was more frequent in the radiochemo­therapy group (47.6% vs. 13.3%, p = 0.0024).26 A randomized phase II/III trial (TOPGEAR) is cur­rently recruiting patients with resectable adenocar­cinoma of the stomach or GEJ to answer whether preoperative radiochemotherapy is superior to perioperative chemotherapy alone.27 Arguments for using the combination of chemo­therapy and radiotherapy have a biological expla­ 165 nation: chemotherapy - by acting cytotoxically - re­duces the number of cells in tumours and makes them more susceptible to radiotherapy by inhib­iting cellular repair mechanisms. Radiotherapy triggered accelerated repopulation of tumour cells reduced by chemotherapy is another example of cooperation of the two modalities. Tumour shrink­age allows enhanced reoxygenation.28,29 Intact tu­mour vasculature in the preoperative setting helps in better chemotherapy delivery. The aim of such treatment is also to eradicate subclinical metastatic disease and to sterilize the surgical fields - poten­tially reducing the risk of local tumour dissemina­tion at resection.19,21,30 Preoperative radiotherapy treatment fields can be smaller and the radiation delivery itself more accurate.21 It seems that pre­operative treatment with chemotherapy or radio-chemotherapy for locally advanced gastric or GEJ cancer can be performed safely, with high compli­ance, and acceptable toxicity profiles and low peri­operative morbidity and mortality rates.13,26 Several authors reported benefits of preopera­tive radiochemotherapy also in unresectable gas­tric cancer patients showing that tumour down-staging can be achieved, enabling radical resec­tions, in 25.50% of these patients with consequent benefit on their survival.31-40 The purpose of this study was to analyze the ef­fectiveness and safety of preoperative radiochemo­therapy in patients with unresectable gastric and locoregionally advanced GEJ adenocarcinoma treated at the Institute of Oncology Ljubljana. Methods Patient characteristics Patients with unresectable gastric or locoregionally advanced GEJ adenocarcinoma treated in Slovenia with preoperative radiochemotherapy between January 2004 and July 2012 were included in this retrospective study. According to surgeon’s opinion gastric tumours were estimated as unresectable by endoluminal ultrasound (EUS) and/or computer to­mography (CT) imaging, and GEJ tumours were esti­mated as locoregionally advanced by EUS and/or CT. Patients were presented to a multidisciplinary advisory team, consisting of a surgeon, radiation oncologist and medical oncologist and were con­sidered for preoperative treatment if the following criteria were met: histologically confirmed unre­sectable gastric or locoregionally advanced GEJ ad­enocarcinoma, age greater than 18 years and below 80 years, no prior radiotherapy and/or chemother­apy, a performance status of 2 or lower according to World Health Organization (WHO), adequate function of major organs (including cardiac, bone marrow, renal and hepatic function) and adequate collaboration during treatment. All patients under­went a general clinical examination, blood tests, endoscopy of upper gastrointestinal tract with bi­ opsy of the tumour and EUS and/or radiographic imaging (CT of abdomen and/or thorax) to define the extent of the disease. If there was a suspicion of distant metastases (high level of tumour mark­ ers or any suspicious lesion on CT scan), positron emission tomography-computed tomography (PET-CT) was performed. During therapy the patients were clinically ex­amined and referred to haematology and biochem­istry blood tests once a week. The therapy-related local and systemic toxicity was assessed according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 4.0.41 The performance status of patients was determined and their body weight was measured on a weekly basis. All pa­tients received intensive supportive care, including intensive nutrition support. For the purpose of this study patients’ disease stage was classified using medical records, accord­ing to the new, 7th edition of the AJCC cancer-stag­ing manual.3 Ninety patients with stages IIIA–IV of gastric carcinoma (including Siewert III) and IIB– IV of GEJ adenocarcinoma (Siewert I and II) were included in the study (Table 1). Treatment All patients were treated preoperatively at the Institute of Oncology Ljubljana. The treatment schedule consisted of induction chemotherapy (one cycle) with 5-fluorouracil (1000 mg/m2) in 96 h con­tinuous infusion and cisplatin (75 mg/m2) in a bolus on day 2, followed by concomitant radiochemother­apy four weeks later. Concomitant radiochemother­apy included two cycles of the same type of chemo­ therapy repeated every 28 days. Chemotherapy administration required hospitalization for appro­priate monitoring, hydration, antiemetic therapy and other supportive treatment that included also nutrition support. In case of severe therapy-related toxicity, irradiation and/or chemotherapy doses were modified and adapted to the patient’s physi­cal condition or laboratory tests. When necessary, chemotherapy application was delayed, or radio­therapy was temporarily interrupted or terminated. Radiotherapy started at the beginning of the sec­ond cycle. Three-dimensional conformal radiother­ 166 TABLE 1. Patients and tumour characteristics (n = 90) Gender Male 24 26.7 Female 66 73.3 PS (WHO) 0 62 68.9 1 26 28.9 2 2 2.2 Weightloss before therapy Yes No 67 23 74.4 25.6 Primary tumour localization Stomach (including GEJ Siewert III) 55 61.1 GEJ (Siewert I+II) 35 38.9 Clinical T 1 0 0 stage 2 2 2.2 3 20 22.2 4a 35 38.9 4b 33 36.7 Clinical N 0 6 6.7 stage 1 16 17.8 2 29 32.2 3 39 43.3 Clinical M 0 86 95.6 stage 1* 4 4.4 Stagegrouping atpresentation IIA IIB 2 5 2.2 5.6 IIIA 12 13.3 IIIB 11 12.3 IIIC 56 62.2 IV 4 4.4 GEJ = gastroesophageal junction; PS = Performance status at presentation according to WHO scoring system; * Clinical M1 stage includes only tumours with local peritoneal carcinomatosis TABLE 2. Surgery characteristics No surgery 20 22.2 Only exploratory operation 13 14.4 Subtotal gastrectomy 15 16.7 Total gastrectomy 32 35.6 Multivisceral resection 7 7.8 Transthoracic oesophagectomy 3 3.3 R0 50 55.6 Type of resection R1 5 5.6 R2 2 2.2 apy was delivered by dual energy (6 and 15 MV) linear accelerator in 25 daily fractions of 1.8 Gy in 5 weeks. Planning target volume (PTV) received 45 Gy and encompassed the entire stomach or all tumour extension (if present) and draining lymph nodes (perigastric, coeliac, porta hepatis, gastroduodenal, splenic hilar, suprapancreatic, pancreaticoduode­ nal and paraaortic to the level of L3/L4) (Figure 1). For GEJ tumours and tumours which originated in the upper third of the stomach the upper margin of at least 3.5 cm was used in the distal oesophagus, and for distal lesions (at or near the gastroduode­nal junction), a 5 cm lower margin in the part of duodenum was used. The dose was prescribed to cover the PTV with a 95% reference isodose (95% of the International Commission on Radiation Unit reference point dose). Custom shielding with mul­tileaf collimator was applied to reduce the dose to kidneys (70% of one kidney volume < 20 Gy and 30% of second kidney volume < 20Gy), liver (30% of liver volume < 30Gy) and spinal cord (Dmax < 45 Gy). Dose-volume histogram parameters were used for plan verification regarding target coverage and normal structures sparing. Treatment was verified using a weekly portal imaging. During the radiochemotherapy treatment, the patients were followed up on weekly basis by clinical examination and laboratory blood tests. Patients’ performance status, weight loss and tox­icity profiles according to CTCAE v4.0 were reg­istered.41 Surgery was performed 4–6 weeks after radiochemotherapy in two University Clinical Centers in Slovenia -Ljubljana and Maribor. Following the surgery patients were reassessed by multidisciplinary advisory team for the need of ad­juvant chemotherapy. After the treatment, patients were followed up every 3 months for 2 years and later on every 6 months until 5 years or death. The study was approved by the institutional review board com­mittee and it was carried out according to the Declaration of Helsinki. Statistical analysis Statistical analysis was performed using statistical package SPSS, version 20 (SPSS Inc., USA). The primary endpoints were histopathological R0 resection rate and pathological response rate. The effect of preoperative radiochemotherapy on tumour down-staging was assessed by comparing the pretreatment clinical TNM stage with the post­operative pathologic TNM stage. The secondary endpoints of this study were as follows: toxicity of 167 FIGURE 1. Planning target volume and dose–volume histogram for patient with locoregionally advanced gastric cancer. preoperative radiochemotherapy, early postopera­ tive mortality and locoregional control (LRC, the event was local and/or regional recurrence), DFS (the event was local, regional or systemic recur­rence), disease-specific survival (DSS, the event was death due to gastric adenocarcinoma) and OS (the event was death from any cause). Survival data was calculated from the beginning of preoperative treatment to the November 1st 2013 (close-out date). Survival probability was calcu­lated using Kaplan-Meier estimate42, and log rank test43 was used to evaluate the differences between individual groups of patients. Independent prog­nostic values of variables that appeared as statisti­cally significant on univariate analysis were tested by multivariate Cox regression analysis model. Two-sided tests were used and the differences at p < 0.05 were considered as statistically significant. Results Eighty-four patients (93.3%) completed preopera­tive treatment with radiochemotherapy according to the protocol. In six patients (6.7%) RT was in­terrupted before 45 Gy and none of those patients received the last (third) cycle of chemotherapy. In one patient treatment was interrupted at 12.6 Gy due to pulmonary abscess (as a result of commu­nication between tumour and pulmonary system), in one patient at 14.4 Gy because of febrile neutro­penia, in one patient at 33.6 Gy because of progres­sion into the liver and in three patients at 41.4 Gy due to serious side effects of treatment and deterio­ration of performance status. Resection rate Twenty patients (22.2%) did not undergo the sur­gery. In 8 patients the reason was progression of the disease with the occurrence of distant metasta­ses during or after preoperative treatment, one pa­tient developed ileus of small intestine and one pa­tient died due to the rupture of colon transversum caused by direct tumour infiltration. In six patients tumour was estimated as unresectable and other four patients were not operated on due to poor performance status or serious comorbidity. In 13 patients (14.4%) only exploration was performed because the tumour was assessed as unresectable in 6 and diffuse peritoneal carcinomatosis estab­ lished in 7 patients (three of them had M1 stage at diagnosis). Fifty-seven patients (63.4%) underwent sur­gery with the aim of complete removal of the tu­mour. Except for one patient (whose surgery was performed in regional hospital) all the operations were performed in two major surgical centres in 168 TABLE 3. Pathological response rate any statistical differences in survival between the groups of patients with tumour/nodes down-stag­ing versus patients with no response to preopera­tive treatment. pCR* 58.8× × 58.8 p-stage < c-stage 42 73.7 37 64.9 49 86 Toxicity of preoperative radiochemotherapy p-stage = c-stage 14 24.6 13 22.8 1 1.8 p-stage > c-stage 1 1.8 7 12.3 7 12.3 Five patients (5.6%) did not complete the treatment as planned. Reasons were lung abscess in one pa- c = clinical; p = pathologic; pCR = pathologic complete response tient and serious side effects of the treatment (such as fatigue, neutropenic fever and serious deteriora­tion of performance status) in other four patients. TABLE 4. Toxicity of preoperative radiochemotherapy Consequently none of them received the last (third) cycle of chemotherapy. No death was recorded during preoperative radiochemotherapy. Most grade 3 and 4 toxicities Radiomucositis 53.4 30 13.3 2.2 1.1 0 (Table 4) were due to vomiting, nausea and bone Radiodermatitis 0 0 0 0 0 0 marrow suppression. In total, 58% of patients lost Diarhoea 90 6.7 2.2 1.1 0 0 their weight during radiochemotherapy, but more Dysphagia 44.4 37.8 8.9 5.6 3.3 0 than 10% of weight loss was seen in only 13.9% of Vomiting, nausea 38.8 16.7 18.9 20 5.6 0 patients. Infection 53.4 18.9 11.1 13.3 3.3 0 Weight loss 41.7 44.4 11.1 2.8 × × Outcome of the disease for patients who Granulocytopenia 17.8 15.6 37.8 23.3 5.5 0 underwent surgery Anemia 13.3 41.1 41.1 3.3 1.1 0 The median follow up for all patients was 18 Trombocytopenia 31.1 47.8 10 5.6 5.6 0 months (range 4–77 months), but for the subgroup of survivors the median follow up was 20 months NCI = National Cancer Institute Common Toxicity Criteria for Adverse Events version 4.0 (CTCAE v4.0) 41 (range 5–77 months). Twenty-six (45.6%) patients died due to GEJ or gastric carcinoma, one died because of septic shock following the surgery and Slovenia - University Medical Centre Ljubljana and a reason for two deaths was unknown. Twenty-Maribor. Distal subtotal resection of the stomach eight patients (49.1%) were disease free, while 29 was performed in 15 (16.7%) patients, total resec-patients (50.9%) developed the recurrence: one tion of the stomach in 32 (35.6%) patients, mul-patient (1.8%) only local, one patient (1.8%) locore­tivisceral resection in seven (7.8%) patients and gional, 24 patients (42.1%) only distant metastases transthoracic oesophageal resection in three (3.3%) and other three patients (5.4%) locoregional re-patients. R0 resection was achieved in 50 (55.6%) currence in combination with distant metastases. of all patients and the remaining seven (7.8%) pa-At two years, LRC, DFS, DSS and OS were 82.9%, tients underwent non-radical surgery (R1 in five 43.9%, 56.9% and 53.9%, respectively. and R2 in two patients) (Table 2). The GEJ cancer patients (Siewert I + II) Pathological response rate who underwent surgery Among the patients that underwent surgery with In the group of the GEJ cancer patients (Siewert the aim of complete tumour removal (n = 57), pCR I + II) 21 patients completed preoperative treat-was achieved in five patients (5.6% of all treated ment and were operated on for the removal of the patients or 8.8% of all operated patients). Down-tumour. R0 resection of the tumour was achieved staging was recorded in 44 patients (86%), in one in 19 patients (90.5%) and the remaining 2 patients patient (1.8%) the stage after radiochemotherapy (9.6%) underwent non-radical surgery. pCR was was unchanged while in seven patients (12.3%) the achieved in four patients (19%). Down-staging was pathological stage was higher than clinical, mainly altogether achieved in 17 patients (81%) (Table 5). due to higher pN stage (Table 3). We did not find 169 Seven patients (33.3%) died due to GEJ carcino­ma, one died because of septic shock after surgery and a reason for one death is unknown. Twelve patients (57.1%) were disease free, in one patient (4.8%) only locoregional recurrence developed and eight patients (38.1%) presented with distant me­tastases. At 2 years, LRC, DFS, DSS and OS were 82.3%, 47%, 56% and 50.6% respectively. The initially unresectable gastric cancer patients who underwent surgery After preoperative radiochemotherapy the surgery for tumour removal was performed in 36 patients with initially unresectable cancer. R0 resection of the tumour was achieved in 31 (86.1%) patients and the remaining 5 (13.9%) patients underwent non-radical surgery. pCR of the tumour was achieved in 1 patient (2.8%) and downstaging was recorded in 32 patients (88.9%) (Table 6). Nineteen patients (52.8%) died due to gastric cancer; in one patient (2.8%) the reason for death was unknown. Sixteen patients (44.4%) were with­out any signs of disease, in one patient (2.8%) only locoregional recurrence developed, sixteen pa­tients (44.4%) developed distant metastases only and other three patients (8.4%) developed combi­nation of locoregional recurrence and distant me­tastases. At 2 years, LRC, DFS, DSS and OS were 79.9%, 43.5%, 58.8% and 57.1%, respectively. Discussion In the 7th edition of the AJCC cancer staging manual, GEJ carcinomas have been classified as oesophageal carcinomas. However, for various reasons, some of the experts believe that their clas­sification should remain under gastric carcinoma. Furthermore, the published literature in this area is not uniform and often deals with both localizations together. Based on various research findings GEJ cancer is currently treated with different modali­ties: postoperative radiochemotherapy9,11, perio­perative chemotherapy with epirubicin, cisplatin and 5-fluorouracil8,10 and in few past years preop­erative radiochemotherapy is being used increas­ingly.14,15 The current approach to the treatment of unresectable gastric cancer patients is based mainly on the preference of the oncologist and periopera­tive chemotherapy10, systemic therapy with trastu­zumab for tumours with HER2 overexpression44 or preoperative radiochemotherapy is used.31-40 It has been shown that preoperative radiochemotherapy TABLE 5. The GEJ cancer patients (Siewert I + II) who underwent surgery Gender Male Female Age PS (WHO) 0 1 2 Resectability R0 R1 R2 Response pCR pT-stage < cT-stage pT-stage = cT-stage p-Tstage > cT-stage pN-stage < cN-stage pN-stage = cN-stage pN-stage > cN-stage p-stage < c-stage p-stage = c-stage p-stage > c-stage 17 81 4 19 Median 62 years (44–80 years) 17 81 2 9.5 2 9.5 19 90.5 1 4.8 1 4.8 4 19 14 66.7 6 28.6 1 4.8 12 57.2 5 23.8 4 19 17 81 0 0 4 19 pCR = Pathological complete response; PS = Performance status according to WHO scoring system in GEJ carcinoma is superior to preoperative chem­otherapy.15 In resectable gastric carcinoma the role of preoperative radiochemotherapy is not so de­fined, since there are currently no data to clarify the differences of both treatment modalities and results from TOPGEAR study are eagerly await­ed.27 In patients with unresectable gastric cancer, who were offered only palliative treatment in the past, it is even more meaningful to use the combi­nation of radiotherapy and chemotherapy in order to increase the effectiveness of the treatment and hopefully change the unresectable disease into the resectable one with R0 resection. At our institution the same preoperative treat­ment for GEJ and gastric carcinomas is used. Radiation therapy is delivered daily in 1.8 Gy per fraction to the total dose of 45 Gy with concomitant chemotherapy using 5-fluorouracil and cisplatin. Surgery for both tumours follows in 4.6 weeks after the completion of preoperative radiochemo­therapy. Patients in our study had advanced dis­ease with tumours staged as cT4 and cN+ disease in 75.6% and 93.3% of patients, respectively. Four patients with unresectable gastric carcinoma (4.4%) 170 TABLE 6. The unresectable gastric cancer patients who underwent surgery Gender Male 25 69.4 Female 11 30.6 Age Median 62 years (43–78 years) PS (WHO) 0 28 77.8 1 8 22.2 Resectability R0 31 86.1 R1 4 11.1 R2 1 2.8 Response pCR 1 2.8 pT-stage < cT­ 28 77.8 stage pT-stage = cT­ 8 22.2 stage p-Tstage > cT­ 0 0 stage pN-stage < cN- 25 69.4 stage pN-stage = cN­ 8 22.2 stage pN-stage > cN- 3 8.3 stage p-stage < 32 88.9 c-stage p-stage = 1 2.8 c-stage p-stage > 3 8.3 c-stage pCR = Pathological complete response; PS = Performance status according to WHO scoring system had localized peritoneal carcinomatosis diagnosed by laparoscopy or exploratory operation prior to treatment. Despite M1 disease multidisciplinary advisory team indicated preoperative treatment because of excellent general condition of these patients and hope for achieving radical resection. Two patients were later operated on, with R1 resec­tion in first and only exploratory operation in the second patient. All 4 patients died due to gastric cancer within one year from completing the preop­ erative treatment (median: 4 months, range: 3.12 months). Eighty-four patients (93.3%) finished preopera­tive treatment with radiochemotherapy according to the protocol. Only in four patients the treatment was stopped prematurely due to toxic side effects, which did not allow the continuation of therapy (neutropenic fever in one patient and serious de­terioration of performance status in other three patients). No death was recorded during preopera­tive radiochemotherapy. Most grade 3 and 4 toxici­ ties were due to nausea and vomiting (in 25.6% of patients) and bone marrow suppression with gran­ulocytopenia (in 16.9% of patients). Similar tox­icities were noted in other studies.16,22,35 Altogether 58% patients lost their weight during radiochem­otherapy, but more than 10% of weight loss was seen in only 13.9% of patients, which we believe is the result of excellent team work between radiation oncologists, nutritionists and intensive supportive therapy that was provided to our patients. Several studies have demonstrated that preop­erative radiochemotherapy does not increase early postoperative mortality.15,35,45 In our study only one patient (1.8%) died due to septic shock early after the surgery and there were no reports of anasto­motic leak or any other complications after surgery. Only 57 patients (63.4%) in our study underwent surgery for tumour removal. In 50 patients (55.6% of all included or 87.7% of operated patients) R0 re­section was obtained. Ajani et al. reported that 85% of all included patients underwent surgery and in 70% R0 resection was obtained, but in this study only initially resectable, non-cT4 tumours were in­cluded.17 There is a general belief that all such patients should be operated in large, multidisciplinary cen­tres, by experienced surgeons in order to achieve better treatment outcome. In our study only one patient was not operated in a large volume surgery centre, which reflects that gastric surgery in our country is centralized. In 49 (86%) of operated patients tumour and/or nodes down-staging was achieved (when compar­ing clinical stage and pathological stage), which we believe is a very good result. Ajani et al. noted re­sponse on preoperative radiochemotherapy in 64% of patients with resectable gastric cancer who were operated and in 55% of all assessable patients.17 In our study pCR was achieved in only five patients (5.6% of all assessable patients) in comparison with Ajani et al. who reported pCR in 30% of all pa­tients.17 As expected, more pCRs in our study were achieved in patients with GEJ tumour (four) com­paring to only one patient with unresectable gas­tric cancer, as GEJ tumours were less advanced and mostly resectable. The 2-years OS of our patients was 53.9%, which is similar to the results that Ajani et al. reported in their study.16 If we consider GEJ tumours and gastric tumours separately, we can notice that patients with gastric cancer had worse 2-years LRC than patients with GEJ cancer (79.9% and 82.3%, respectively). This is somehow expected because gastric cancer patients in our study had more advanced disease consid­ 171 ered as unresectable before the start of any treat­ ment. On the other hand, there were no significant differences between GEJ and gastric tumours in DFS, DSS and OS at 2-years. It seems that the well- known worse outcome for GEJ tumours was not so obvious, as GEJ tumours in our study were less advanced. The biggest limitation of our study is the ret­rospective data collection. For more accurate con­clusions we would need longer follow-up and a larger number of enrolled patients. Maybe patients with GEJ and gastric cancer should be separated (although TOPGEAR study includes both tumour sites, without Siewert I). Furthermore, we need to develop more effective systemic drugs in order to decrease the incidence of distant metastases, which are the most common site of the disease recurrence. 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Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesopha­geal junction cancer (ToGA): a phase 3, open-label, randomised controlled trial. Lancet 2010; 376(9742): 687-97. 45. Burmeister BH, Thomas JM, Burmeister EA, Walpole ET, Harvey JA, Thomson DB, et al. Is concurrent radiation therapy required in patients receiving preoperative chemotherapy for adenocarcinoma of the oesophagus? A randomised phase II trial. Eur J Cancer 2011; 47: 354-60. 173 research article Febrile neutropenia in chemotherapy treated small-cell lung cancer patients Renata Rezonja Kukec1, Iztok Grabnar2, Tomaz Vovk2, Ales Mrhar2, Viljem Kovac3, Tanja Cufer4 1 Krka, d.d., Novo mesto, Slovenia 2 University of Ljubljana, Faculty of Pharmacy, Ljubljana, Slovenia 3 Institute of Oncology Ljubljana, Ljubljana, Slovenia 4 University Clinic Golnik, Golnik, Slovenia Radiol Oncol 2015; 49(2): 173-180. Received: 24 September 2014 Accepted: 15 October 2014 Correspondence to: Prof. Aleš Mrhar, Ph.D., Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana. E-mail: ales.mrhar@ffa.uni-lj.si Disclosure: No potential conflicts of interest were disclosed. Background. Chemotherapy with platinum agent and etoposide for small-cell lung cancer (SCLC) is supposed to be associated with intermediate risk (10–20%) of febrile neutropenia. Primary prophylaxis with granulocyte colony-stimulating factors (G-CSFs) is not routinely recommended by the treatment guidelines. However, in clinical practice febrile neutropenia is often observed with standard etoposide/platinum regimen. The aim of this analysis was to evalu­ate the frequency of neutropenia and febrile neutropenia in advanced SCLC patients in the first cycle of standard chemotherapy. Furthermore, we explored the association between severe neutropenia and etoposide peak plasma levels in the same patients. Methods. The case series based analysis of 17 patients with advanced SCLC treated with standard platinum/etopo­side chemotherapy, already included in the pharmacokinetics study with etoposide, was performed. Grade 3/4 neu­tropenia and febrile neutropenia, observed after the first cycle are reported. The neutrophil counts were determined on day one of the second cycle unless symptoms potentially related to neutropenia occurred. Adverse events were classified according to Common Toxicity Criteria 4.0. Additionally, association between severe neutropenia and etoposide peak plasma concentrations, which were measured in the scope of pharmacokinetic study, was explored. Results. Two out of 17 patients received primary GCS-F prophylaxis. In 15 patient who did not receive primary prophy­laxis the rates of both grade 3/4 neutropenia and febrile neutropenia were high (8/15 (53.3%) and 2/15 (13.3%), respec­tively), already in the first cycle of chemotherapy. One patient died due to febrile neutropenia related pneumonia. Neutropenic events are assumed to be related to increased etoposide plasma concentrations after a standard etoposide and cisplatin dose. While the mean etoposide peak plasma concentration in the first cycle of chemothera­py was 17.6 mg/l, the highest levels of 27.07 and 27.49 mg/l were determined in two patients with febrile neutropenia. Conclusions. Our study indicates that there is a need to reduce the risk of neutropenic events in chemotherapy treated advanced SCLC, starting in the first cycle. Mandatory use of primary G-CSF prophylaxis might be considered. Alternatively, use of improved risk models for identification of patients with increased risk for neutropenia and individu­alization of primary prophylaxis based on not only clinical characteristics but also on etoposide plasma concentration measurement, could be a new, promising options that deserves further evaluation. Key words: small cell lung cancer; platinum-etoposide chemotherapy; etoposide; febrile neutropenia; plasma drug concentration Introduction aggressive, growing rapidly and spreading early. Seventy percent of SCLC patients have extensive Small cell lung cancer (SCLC) accounts for approx-disease at the time of diagnosis. The standard ther­imately 13% of all lung cancer diagnoses. It is very apeutic approach for extensive disease is chemo­ 174 TABLE 1. Factors associated with FN risk according to EORTC, ASCO, NCCN and ESMO guidelines Older age (. 65 years) ¦ ¦ ¦ ¦ Comorbidities Liver, renal or cardiovascular diseases ¦ Liver dysfunction, poor renal function History of prior FN ¦ ¦ ¦ Poor performance status ¦ ¦ ¦ Reduced marrow Extensive prior treatment including large radiation ports ¦ ¦ reserve (e.g. ANC < 1.5 × 109/l) due to radiotherapy of > 20% marrow Poor nutritional status ¦ ¦ Advanced stage of disease ¦ ¦ Cytopenias due to bone marrow involvement by tumour ¦ ¦ The presence of open wounds or active infections ¦ ¦ Lack of antibiotic prophylaxis ¦ Lack of G-CSF use ¦ Female gender ¦ Haemoglobin < 12 g/dl ¦ Administration of combined chemoradiotherapy ¦ Previous chemotherapy ¦ Pre-existing neutropenia ¦ Recent surgery ¦ Further infections in the next treatment cycle considered life-threatening ¦ Dose reduction below treshold ¦ Delay of chemotherapy ¦ Lack of protocol adherence if compromising cure rate, overall or disease-free survival ¦ Human immunodeficiency virus ¦ ANC = absolute neutrophil count; ASCO = American Society of Clinical Oncology; EORTC = European Organisation for Research and Treatment of Cancer; ESMO = European Society for Medical oncology; FN = febrile neutropenia; G-CSF = granulocyte colony-stimulating factor; NCCN = National Comprehensive Cancer Network therapy with platinum agent and topoisomerase II inhibitor etoposide.1 Chemotherapy causes haematological as well as non-haematological adverse drug reactions. The most serious haematological toxicity is neutrope­nia, which can cause fatal septicaemia by suppress­ing the production of neutrophils and by cytotoxic effects on the cells that line the gastrointestinal tract allowing bacterial multiplication and invasion.2 Febrile neutropenia (FN) is a serious adverse event of chemotherapy characterized as an oral tempera­ture > 38.5 °C or two consecutive readings of > 38 °C for 2 h and an absolute neutrophil count (ANC) < 0.5 × 109/l, or expected to fall below 0.5 × 109/l.3 It is associated with high morbidity, mortality, costs, and an increase of the risk for chemotherapy dose delays and/or reductions, or even discontinuation of chemotherapy.4,5 Primary prophylaxis with granulocyte colony-stimulating factors (G-CSFs), i.e. use with first cycle of chemotherapy, has been shown to significantly reduce the risk of FN; however, its use in all pa­tients is not considered cost-effective.2,4 According to recommendations of the European Organisation for Research and Treatment of Cancer (EORTC)6, American Society of Clinical Oncology (ASCO)7, National Comprehensive Cancer Network (NCCN)8, and European Society for Medical Oncology (ESMO) clinical practice guidelines9, the prophylactic G-CSF is recommended when the risk of FN is high (. 20%). Treatment-related risk factors classify chemotherapy regimens to high (. 175 20%), intermediate (10.20%), or low risk (< 10%) for developing FN.4,6 When using a chemotherapy regimen associated with an intermediate (10.20%) risk of FN other factors that may increase the over­all risk of FN should be considered in making the decision to use prophylactic G-CSF. Guidelines indicate various risk factors, with an older age in­cluded in all four guidelines. Additional factors are history of prior FN, poor performance status (PS) and comorbidities7,8; for further details see Table 1. Recently, genetic factors which are not mentioned in the guidelines have also been associated with the risk of FN.4 According to EORTC and NCCN guidelines etoposide/platinum regimen for SCLC is associ­ated with an intermediate risk of FN, while in the ESMO guidelines which provide only the list of regimens with high risk of FN, etoposide/platinum is not listed. ASCO guidelines do not indicate FN risk for any particular chemotherapeutic regimen. Based on the guidelines, primary prophylaxis with G-CSF in SCLC patients treated with etoposide/ platinum regimen is not recommended without a prior identification of a high risk of FN in each indi­vidual patient. However, in routine clinical practice FN seems to be frequent in advanced SCLC patients treated with standard etoposide/platinum regimen, who are not entitled to G-CSF prophylaxis. To get additional information on febrile neu­tropenia in a first cycle of standard chemotherapy with etoposide/platinum, a post-planned analysis of the frequency of neutropenia and FN in a case series of patients with advanced SCLC, already in­cluded in a clinical trial of etoposide pharmacoki­netics, was performed. Furthermore, analysis of association of severe neutropenia with previously measured levels of etoposide peak plasma concen­tration in the same patients during the first cycle of etoposide/cisplatin has been conducted. Patients and methods Clinical observation The post-planned analysis of the frequency and grade of neutropenia and FN was conducted in a case series of patients in the first cycle of standard chemotherapy with etoposide/platinum. These pa­tients were already included in a clinical trial of etoposide pharmacokinetics. Furthermore, asso­ciation between severe neutropenia and etoposide peak plasma levels was explored. Eligible patients were at least 18 years old receiv­ing first-line chemotherapy with etoposide/plati­num for advanced SCLC confirmed by cytology or histology. Other entry criteria included World Health Organization PS 0.2, adequate haematolog­ical parameters and medical conditions allowing chemotherapy, satisfactory liver and renal func­tion. The main exclusion criteria were Gilbert syn­drome, Criegler-Najjar syndrome, active gastroin­testinal disorders, and concomitant drugs entering the clinically important pharmacokinetic interac­tions. The Charlson comorbidity index was not as­sessed; however, patients with some comorbidities, such as liver or kidney dysfunction were excluded by the criteria of pharmacokinetic study. Patients gave written informed consent to participate in the pharmacokinetic study, which was approved by the Slovenian Ethics Committee for Research in Medicine (approval ref. no. 02/11/11) and was car­ried out according to the Helsinki Declaration. Patients received a standard myelosuppressive chemotherapeutic regimen of etoposide and cis­platin or carboplatin without any concurrent ir­radiation. G-CSF prophylaxis was administered according to current guidelines. Planned dose of etoposide was of 100 mg/m2 intravenously on day 1 through 3. Cisplatin or carboplatin were admin­istered intravenously on day 2 at a planned dose of 80 mg/m2 or at a target area under the curve (AUC) 5.6 mg min/ml (maximally 350 mg/m2), respec­tively. Patients were followed according to routine practice guidelines valid at that period at our uni­versity clinic. Neutrophil count was determined on day one of the next 3-week cycle, or earlier in case of clinical symptoms associated with neutropenia. If indicated, patients with severe neutropenia and/ or FN were hospitalized at our clinic. Grade 3/4 neutropenia and FN were classified according to Common Toxicity Criteria (NCI-CTC, version 4.0). The reason for including only the first chemo­therapy cycle in our post-planned analysis was rel­atively high rate of observed neutropenia grade 3/4 or FN in the first cycle while using primary G-CSF prophylaxis according to current guidelines. The following cycles were not included into our analy­sis due to the fact that G-CSF prophylaxis had been used in the majority of patients in consecutive cy­cles. In addition, some patients in consecutive cy­cles received decreased etoposide dose or adminis­tration of chemotherapy was delayed. Pharmacokinetic sampling and drug assay in the scope of pharmacokinetic study Blood sampling was performed on days 1, 2 and 3 in the first cycle of chemotherapy. Blood samples 176 TABLE 2. Patients and treatment characteristics with the data on grade 3/4 and febrile neutropenia in the first cycle 1 60 F 1 100 2 No No 16.27 2 62 M 0 100 4 No No 14.43 3 65 M 1 100 1 No No 16.17 4 60 M 1 100 4 Yes, death No 27.07 5 64 F 0 100 4 Yes No 27.49 6 78 M 1 75 0 No No 15.09 7 51 M 1 100 0 No Yes 14.73 8 73 M 1 100 1 No No 17.04 9 63 M 1 100 1 No No 17.88 10 78 M 1 75 0 No No 11.93 11 62 M 1 75 0 No Yes 10.59 12 54 M 0 75 3 No No 15.14 13 63 F 1 100 3 No No 17.65 14 64 M 1 100 4 No No 16.73 15 65 F 0 100 0 No No 20.25 16 66 M 0 100 4 No No 23.71 17 62 M 1 100 3 No No 16.74 Grade 3/4: 8/17(47.1%)Grade 3/4 2/17(no G-CSF): 8/15 (11.8%) 64.1 (53.3%)17.6 No G-CSF (51-78) Grade 1/2 or 0: (range 10.59-27.49) 2/159/17 (52.9%) (13.3%) Grade 1/2 or 0(no G-CSF): 7/15 (46.7%) FN = febrile neutropenia; G-CSF = granulocyte colony-stimulating factor; PS = performance status; M = male; F = female (6 ml) were collected at the end of etoposide 60-min infusion. Samples were immediately placed on ice. Plasma was separated by centrifugation at 3000 × g and 4 °C for 10 min and stored at -80 °C until the analysis. Etoposide plasma concentration was determined by high-performance liquid chroma­tography with fluorimetric detection using a modi­fied method of Krogh-Madsen et al.10 Linearity of the method was 0.125.30 mg/l with a lower limit of quantification of 0.125 mg/l. The method was accurate (all deviations . 10.3%) and reproducible (coefficient of variability . 7.22% intra-day and . 7.33% inter-day). Results According to patients baseline characteristics pre­sented in Table 2 our group of 17 patients repre­sents a typical population of advanced SCLC pa­tients treated with chemotherapy, with a mean age of 64.1 years (range, 51.78 years), mostly males (76.5%) and PS . 2. In the first cycle etoposide was administered in a full dose in 13 of all patients (76.5%). Primary G-CSF prophylaxis was adminis­tered in only 2 patients (11.8%). Two out of 17 cases (11.8%) of FN have been ob­served in the first cycle, one of these two patients died due to FN related pneumonia. Taken into ac­count only 15 patients without primary prophylax­is with G-CSF the rate of FN was even higher, i.e. 13.3% (2/15). The whole rate of neutropenia grade 3/4 after the first cycle was also quite high, it was recorded in 8 out of 15 patients not receiving pri­mary G-CSF prophylaxis (53.3%). Of note, in our study neutrophil count has only been determined on day one of the second cycle, unless symptoms potentially related to neutropenia occurred. 177 TABLE 3. A summary of studies reporting risk of FN by ASCO, EORTC and NCCN guidelines Roth et al.11, 1992 159 Etoposide 80 mg/m2/d i.v. for 5 days, Cisplatin 20 mg/m2/d i.v. for 5 days, every 3 weeks, 4 cycles 70 (granulocytopenia) NR Yes (patients with brain metastases). No. Skarlos et al.12, 1994 Regimen A: 73 Regimen B: 74 Regimen A: Etoposide 100 mg/m2/d i.v. days 1-3, Cisplatin 50 mg/m2/d day 1 to 2 Regimen B: Etoposide 100 mg/m2/d i.v. days 1-3, Carboplatin 300 mg/m2/d i.v. day 1, every 3 weeks, 6 cycles NR NR Yes (responding limited disease patients and complete responders with extensive disease) No. Kosmidis et al.13, 1994 Regimen A: 73 Regimen B: 74 Regimen A: Etoposide 100 mg/m2/d i.v. days 1-3, Cisplatin 50 mg/m2/d day 1 to 2 Regimen B: Etoposide 100 mg/m2/d i.v. days 1-3, Carboplatin 300 mg/m2/d i.v. day 1, every 3 weeks, 6 cycles NR NR Yes (limited disease patients) No. ASCO = American Society of Clinical Oncology; EORTC = European Organisation for Research and Treatment of Cancer; FN = febrile neutropenia; NCCN=National Comprehensive Cancer Network; G-CSF = granulocyte colony-stimulating factor; i.v. = intravenous administration; NR = not reported; pts = patients In addition, mild grade 1/2 neutropenia or nor­mal neutrophil blood count have been observed in 7/15 (46.7%) of patients without G-CSF prophylaxis on the scheduled day of the second cycle. Mean etoposide peak plasma concentration in the first cycle of chemotherapy was 17.6 mg/l (from 10.59 to 27.49 mg/l) (Table 2). Of note, the highest levels 27.07 and 27.49 mg/l were determined in two patients with FN. Patients with grade 3/4 neutrope­nia not experiencing FN had also high mean peak plasma concentrations of 17.4 mg/l (from 14.43 to 23.71 mg/l). Mean etoposide peak plasma con­centration in patients with grade 1/2 neutropenia was 16.84 (from 16.17 to 17.88 mg/l), while patients who did not experience neutropenia had etoposide plasma level of 14.5 mg/l (from 10.59 to 20.25 mg/l). Discussion According to the guidelines, G-CSF primary proph­ylaxis is mandatory when the overall risk of FN due to chemotherapy regimen and other factors is . 20%. Etoposide/platinum regimen for SCLC treatment is considered to be associated with 10.20% risk of FN and G-CSF primary prophylaxis is not unambigu­ously recommended by current guidelines.6-9 We reviewed studies on the basis of which guidelines classified etoposide/platinum regimen for SCLC treatment into the intermediate risk group for FN. Taken together, according to EORTC, ASCO, NCCN and ESMO guidelines, information on FN rates in SCLC patients treated with etoposide/ platinum regimen is scarce. Only three published studies related to the risk of FN in SCLC patients treated by etoposide/cisplatin are cited11-13, two of them12,13 are even very likely the same study. Roth et al.11 reported grade 3/4 granulocytopenia in 70% of patients, while in other two studies12,13 grade 3/4 neutropenia was not even reported. FN was not re­ported in any of these studies.11-13 Of note, in all of these trials concomitant irradiation has been per­formed in selected patients (Table 3). Therefore, we performed a comprehensive PubMed literature search to find additional data on grade 3/4 neutropenia and FN rates in SCLC pa­tients treated with first-line intravenous etoposide/ platinum regimen (etoposide dosage 240 to 420 mg/m2 per cycle) without concurrent radiotherapy and G-CSF primary prophylaxis. In addition to the above 3 mentioned articles11-13, our literature search found nine studies14-22 (Table 4). In fact, our search confirmed a substantially high rate of grade 3/4 neutropenia (51-91%) observed in SCLC patients treated with etoposide/platinum chemotherapy given the fact that G-CSF use has been allowed in 3 out of nine trials. In addition, FN rates reported in five of these nine articles14-22 were in the range of 10.20% referred in the guidelines.6,8 The reported rates of FN during all, not only the first cycle of the chemotherapy, were in the range from 9.5% to 17%, with the highest rate observed in the trial us­ing relatively high daily dose of etoposide, i.e. 140 mg/m2 for 3 days.16,18,19,21,22 Of note, data on neutro­penia rates were based on all chemotherapy cycles and not just the first cycle. In our limited series of patients, severe neutro­penia G3/4 and FN were observed in unexpect­ 178 TABLE 4. A summary of comprehensive literature search of studies on FN and grade 3/4 neutropenia Miller et al.14, 156 1995 Pujol et al.15, 109 2001 Quoix et al.16, 38 2001 Schiller et al.17, 4022001 Hanna et al.18, 1062006 Schmittel et al.19, 35 2006 Heigener et al.20, 372009 Lara et al.21, 324 2009 Zatloukal et al.22, 2032010 Etoposide 130 mg/m2/d i.v. for 3 days, cisplatin 25 mg/m2/d i.v. for 3 days, every 3 weeks, up to 8 cycles Etoposide 100 mg/m2 i.v. days 1-3, cisplatin 100 mg/m2 i.v. day 1, every 4 weeks, up to 6 cycles Etoposide 100 mg/m2 i.v. days 1-3, carboplatin AUC 5 mg/ml/min day 1, every 4 weeks, up to 6 cycles Etoposide 120 mg/m2 i.v. days 1-3, cisplatin 60 mg/m2 i.v. day 1, every 3 weeks, 4 cycles Etoposide 120 mg/m2 i.v. days 1-3, cisplatin 60 mg/m2 i.v. day 1, every 3 weeks, at least 4 cycles Etoposide 140 mg/m2 i.v. days 1-3, carboplatin AUC 5 mg min/ml day 1, up to 6 cycles Etoposide 140 mg/m2 i.v. days 1-3, carboplatin AUC 5 i.v. day 1, every 4, up to 6 cycles Etoposide 100 mg/m2 i.v. days 1-3, cisplatin 80 mg/m2 i.v. day 1, every 3 weeks, 4 cycles Etoposide 100 mg/m2 i.v. days 1-3, cisplatin 80 mg/m2 i.v. day 1, every 3 weeks, 6 cycles 85.0 91.0 57.0% cycles (NR per patient) 67.0 86.5 51.0 69.4 68.0 59.6 Grade 3/4(range):51.0-91.0 NR NR 13.2 NR 10.4 17.0 NR 9.5 9.9 FN (range): 9.5-17.0 No No No Used at the discretion of the treating physician. (no data on use) Used in accordance with their package inserts or the 1999 guidelines from the ASCO. (no data on use) No No Use of G-CSF was allowed per investigator discretion. (no data on use) No ASCO=American Society of Clinical Oncology; d = day; FN = febrile neutropenia; G-CSF = granulocyte colony-stimulating factor; i.v. = intravenous administration; NR = not reported; pts = patients; edly high portion of patients not receiving primary G-CSF prophylaxis already in the first cycle of platinum/etoposide chemotherapy; neutropenia G 3/4 developed in more than half patients (53.3%) and FN developed in 2 out of 15 patients. Of note, neutropenia and FN were recorded after the first cycle of the chemotherapy based on the neutro­phil count determined only on day one of the sec­ond cycle, unless symptoms potentially related to neutropenia occurred. In addition, only 12 out of these 15 patients without G-CSF prophylaxis re­ceived the full dose of etoposide. Patient 4 was on long-term treatment with corticosteroids. This pa­tient developed FN with lung infection and died. Taken together, more than half of our patients not receiving primary G-CSF prophylaxis developed at least grade 3/4 neutropenia already in the first cycle, with FN representing a quarter of these eight patients. None of the patients on primary G-CSF prophylaxis developed grade 3/4 neutropenia. Based on this observation most of our consecutive patients included into the prospective etoposide pharmacokinetic study received primary GCS-F prophylaxis and are not included in this analysis. Compared to the literature search data showing the rate of grade 3/4 neutropenia between 51 and 91% and FN rate between 9.5 and 17% after all cycles in the population of patients not receiving primary prophylaxis with G-CSF the 53.3% rate of grade 3/4 neutropenia and 13.3% rate of FN observed in our patients already in the first cycle without G-CSF prophylaxis is rather high. Taking into account 4 additional patients with grade 1/2 neutropenia re­corded on the day one of the second cycle (includ­ing one patient taking corticosteroids chronically), the number of grade 3/4 neutropenia in the first cy­cle might be even higher, if the ANC was measured in the middle of the first chemotherapy cycle. Despite the fact that the majority of our patients did not classify to high risk FN due to first-line chemotherapy, no concurrent palliative irradiation, good PS, no major comorbidities and normal kid­ney, liver and bone marrow function, which were all prerequisites for patients to be included into 179 the pharmacokinetic trial, the rate of FN and 3/4 neutropenia observed after first cycle of the chemo­therapy was substantially high. The reason for this might be in the fact that half of our patients were older than 65 years and all of them had advanced disease. Age more than 65 years has not been taken as high-risk criteria per se in our selected popula­tion of patients without comorbidities and with a good PS included into the pharmacokinetic trial. Obviously in elderly, fragile population the use of comprehensive geriatric assessment might im­prove our efforts to better identify patients with an increased risk of cytotoxic drugs complications.23 However, so far there are no reported prognostic validation studies using comprehensive geriatric assessment for decision on prophylactic use of G-CSF. In addition, we have still not found a score that would help us select these patients in a more comprehensive fashion. EORTC, ASCO, NCCN and ESMO guidelines indicate various risk factors that predispose to increased risk of FN. Older age is the only factor included in all four guidelines. EORTC guidelines define older age even as patient-related risk fac­tor most consistently associated with an increased FN risk.6 However, Crawford et al. tested various patient’s baseline characteristics as possible risk factors for . 1 event of FN, including age, body weight, body surface area, sex, PS, disease stage, and neoplastic disease involvement in the marrow. Surprisingly, only sex was marginally predictive in their study, while patient age was not found to be a risk factor for FN.24 The association between neutropenic events and etoposide peak plasma concentration has been well perceived by our analysis. According to the litera­ture etoposide therapeutic trough serum concen­tration range in cancer patients is 2 to 6 mg/l and peak, 8 to 14 mg/l.25 In all our groups of patients, i.e. patients with FN, grade 3/4 neutropenia, grade 1/2 neutropenia and without neutropenia, mean peak plasma concentration of etoposide was above ther­apeutic level (i.e. 14 mg/l). However, relatedness of mean peak plasma concentration height with se­verity of neutropenia was observed; concentrations were the highest in patients with FN and declined to the lowest levels observed in patients without neutropenia. Based on the fact that the mean etopo­side peak plasma concentration was above thera­peutic level also in patients without neutropenia could be anticipated that the frequency of (high­grade) neutropenia would be even higher if neu­trophils were measured at the time of the largest expected neutrophil nadir. On another point, peak plasma etoposide con­centrations in two patients (one of them did not re­ceive G-CSF prophylaxis) not experiencing neutro­penia were within therapeutic range. Interestingly enough, in patient 7 etoposide plasma concentra­tion was increased (14.73 mg/l) after dosage of etoposide; however, primary G-CSF prophylaxis was received and neutropenia did not develop. These data raised the question of whether high plasma concentrations measured immediately af­ter the first application of etoposide on day one of the three day application course could help in se­lection of patients for primary G-CSF prophylaxis. Our analysis is limited by the biases of se­lected patient population with good PS, without major comorbidities, treated in a controlled situa­tion in the frame of the prospective clinical study. Additionally, the number of the patients is low and neutrophil counts were routinely measured only on the day one of the second cycle and not at the time of the largest expected neutrophil nadir in the middle of the cycle. But, all these limitations do not compromise our conclusion that the risk of FN in advanced SCLC population of patients treated with etoposide/platinum is substantially high. In a real world scenario the probability of FN in these patients might be even higher. The goal is to develop a comprehensive risk models for FN which can be used as a guide wheth­er or not to incorporate primary G-CSF prophy­laxis for each individual patient.26,27 Some predic­tive models for neutropenia in the first cycle have already been proposed. However, a prospective study is needed for their validation. On the other hand, individualization of etoposide dosage taking into account pharmacokinetic parameters as well as genetic factors such as genetic polymorphisms, which can also affect drug plasma concentrations, is another option that has to be considered.28 Conclusions According to the guidelines etoposide/platinum regimen for SCLC treatment is not associated with high . 20% risk of FN and primary G-CSF prophy­laxis is therefore not mandatory. However, in our case series analysis of selected advanced SCLC pa­tients included in a prospective pharmacokinetic trial, the rate of neutropenic complications in pa­tients not receiving primary G-CSF prophylaxis was substantially high, already in the first cycle. Advanced SCLC patients treated with a standard dose of etoposide in combination with platinum 180 may have increased plasma etoposide concentra­tions as reported in our patients and may therefore be at increased risk for high grade neutropenia and FN. There is a need of greater effort to reduce the risk of neutropenic events starting in the first cycle. To avoid overuse of G-CSF a better prediction of post-chemotherapy neutropenic events, based on etoposide peak plasma concentration, might be of great value. An option could be the development and validation of risk models for severe neutrope­nia, based on etoposide plasma concentration on day one of the first cycle, a strategy that deserves further evaluation. References 1. 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Heigener DF, Manegold C, Jäger E, Saal JG, Zuna I, Gatzemeier U. Multicenter randomized open-label phase III study comparing efficacy, safety, and toler­ability of conventional carboplatin plus etoposide versus dose-intensified carboplatin plus etoposide plus lenograstim in small-cell lung cancer in “extensive disease” stage. Am J Clin Oncol 2009; 32: 61-4. 21. Lara PN Jr, Natale R, Crowley J, Lenz HJ, Redman MW, Carleton JE, et al. Phase III trial of irinotecan/cisplatin compared with etoposide/cisplatin in extensive-stage small-cell lung cancer: clinical and pharmacogenomic results from SWOG S0124. J Clin Oncol 2009; 27: 2530-5. 22. Zatloukal P, Cardenal F, Szczesna A, Gorbunova V, Moiseyenko V, Zhang X, et al. A multicenter international randomized phase III study comparing cis­platin in combination with irinotecan or etoposide in previously untreated small-cell lung cancer patients with extensive disease. Ann Oncol 2010; 21: 1810-6. 23. Maas HAAM, Janssen-Heijnen MLG, Olde Rikkert MGM, Machteld Wymenga AN. Comprehensive Geriatric assessment and its clinical impact in oncology. Eur J Cancer 2007; 43: 2161-9. 24. Crawford J, Glaspy JA, Stoller RG, Tomita DK, Vincent ME, McGuire BW, et al. Final results of a placebo-controlled study of filgrastim in small-cell lung cancer: exploration of risk factors for febrile neutropenia. Support Cancer Ther 2005; 3: 36-46. 25. Clarke’s analysis of drugs and poisons. Moffat AC, Osselton MD, Widdop B, Watts J, editors. Available from: http://www.medicinescomplete.com/mc/ clarke/current/CLK0691.htm?q=etoposide&t=search&ss=text&p=1#_hit. Accessed 19 September 2013. 26. López-Pousa A, Rifa J, Casas de Tejerina A, González-Larriba JL, Iglesias C, Gasquet JA, et al. Risk assessment model for first-cycle chemotherapy-induced neutropenia in patients with solid tumors. Eur J Cancer Care 2010; 19: 648-55. 27. Lyman GH, Lyman CH, Agboola O. Risk models for predicting chemotherapy-induced neutropenia. Oncologist 2005; 10: 427-37. 28. Režonja R, Knez L, Čufer T, Mrhar A. Oral treatment with etoposide in small cell lung cancer – dilemmas and solutions. Radiol Oncol 2013; 47: 1-13. 181 case report Mesenteric ischemia after capecitabine treatment in rectal cancer and resultant short bowel syndrome is not an absolute contraindication for radical oncological treatment Ana Perpar1, Erik Brecelj2, Nada Rotovnik Kozjek3, Franc Anderluh1, Irena Oblak1, Marija Skoblar Vidmar1, Vaneja Velenik1 1 Department of Radiotherapy, 2 Department of Oncological Surgery, 3 Clinical Nutrition Unit, Institute of Oncology Ljubljana, Ljubljana, Slovenia Radiol Oncol 2015; 49(2): 181-184. Received 10 December 2013 Accepted 23 January 2014 Correspondence to: Assist. Prof. Vaneja Velenik, M.D., Ph.D., Department of Radiotherapy, Institute of Oncology Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia. Phone: +386 1 5879 661; Fax: +386 1 5879 304; E-mail: vvelenik@onko-i.si Disclosure: No potential conflicts of interest were disclosed. Background. Thrombotic events, arterial or venous in origin, still remain a source of substantial morbidity and mortality in cancer patients. The propensity for their development in oncology patients is partially a consequence of the disease itself and partially a result of our attempts to treat it. One of the rarest and deadliest thromboembolic complications is arterial mesenteric ischemia. The high mortality rate is caused by its rarity and by its non-specific clinical presentation, both of which make early diagnosis and treatment difficult. Hence, most diagnoses and treatments occur late in the course of the disease. The issue survivors of arterial mesenteric ischemia may face is short bowel syndrome, which has become a chronic condition after the introduction of parenteral nutrition at home. Case report. We present a 73-year-old rectal cancer patient who developed acute arterial mesenteric thrombosis at the beginning of the pre-operative radiochemotherapy. Almost the entire length of his small intestine, except for the proximal 50 cm of it, and the ascending colon had to be resected. After multi-organ failure his condition im­proved, and he was able to successfully complete radical treatment (preoperative radiotherapy and surgery) for the rectal carcinoma, despite developing short bowel syndrome (SBS) and being dependent upon home-based paren­teral nutrition to fully cover his nutritional needs. Conclusions. Mesenteric ischemia and resultant short bowel syndrome are not absolute contraindications for radical oncological treatment since such patients can still achieve long-term remission. Key words: rectal cancer; capecitabine; acute mesenteric ischemia; multiorgan failure; short bowel syndrome Introduction Standard treatment for locally advanced and/or node positive rectal cancer is neoadjuvant con­comitant radiochemotherapy, surgery and adjuvant chemotherapy. All systemic therapy is 5-FU based.1,2 During treatment patients experience side ef­fects, the most common of which are leukopenia, diarrhoea and proctitis, fatigue, nausea and vom­iting, dermatitis, paraesthesia and hand-foot syn­drome.3 Most patients require supportive measures and symptomatic therapy to complete treatment. Severe toxicity, e.g. thrombotic events or coronary vasospasm, is rare.3 We present a patient with locally advanced rectal cancer who developed severe and life-threatening 182 complications during neoadjuvant treatment with mesenteric thrombosis and short bowel synrome. Good interdepartmental cooperation and multi­disciplinary treatment played a key role in the suc­cessful treatment first for mesenteric ischemia and then for rectal cancer as well. To our knowledge, ours is the first case de­scribed wherein a patient with acute mesenteric is­chemia was able to complete specific treatment for a malignant disease. Case report A 73-year-old man presented with a 4-month his­tory of bloody stools and weight loss. He had no previous relevant medical history. Magnetic reso­nance imaging (MRI) of the pelvis showed a T3N1 tumour of the rectum, 5 cm above the proximal margin of the anal sphincter. Endoscopic biopsy confirmed a moderately differentiated adenocarcinoma. Abdominal ultra­sound and chest x-ray excluded the presence of distant metastases, setting the stage at IIIB. The patient was referred to an oncology multi­disciplinary team, who made the decision to start pre-operative chemoradiotherapy after one cycle of induction chemotherapy with 2,500 mg/12h capecit­abine within the framework of a national study. Written informed consent of patients was obtained for the treatments and for the scientific use of the clinical data according to Declarations of Helsinki. After 10 days of chemotherapy the patient devel­oped severe nausea, headaches, flushing and gen­eral weakness. Physical examination showed only tenderness in the upper abdomen. Laboratory tests showed leukocytosis with relative neutrophilia and hypophosphatemia; other results were normal. Capecitabine was discontinued. Despite symp­tomatic therapy (with proton pump inhibitors, antiemetics, parenteral nutrition, analgesia and empiric antibiotics) his clinical condition and labo­ratory results worsened on the fifth day. Computed tomography (CT) scan showed a thrombus in the superior mesenteric artery ap­proximately 5 cm distal of the aorta; dilated jeju­nal, ileal and colonic loops with absence of contrast enhancement in the intestinal wall. The patient was admitted to the intensive care unit, where he received fluid infusion, vasoactive support with noradrenaline, repeated transfusions of thrombocytes, and fresh frozen plasma; the met­abolic acidosis was corrected. After the patient had been declared stable enough for surgery, a laparotomy was performed and the small bowel, except for the proximal 50 cm of it, along with the right colon were resected despite the rectal tumour. A jejunal-transverse anastomo­sis was constructed. An attempt at revasculariza­tion was not considered due to the clearly necrotic appearance of the affected intestine. Histological examination of the resected gut showed gangrene and multiple thrombi in the vessel walls. In the intensive care unit he developed sepsis, multi-organ failure (with hemodynamic instabil­ity, respiratory insufficiency, hepatic and renal failure, coagulopathy) and fistulae as enteric con­tents started to leak from the laparotomy wound and through two surgical drains. The decision was made not to operate but to manage the patient conservatively. The patient’s condition improved; he was hemodynamically sta­ble, he no longer needed oxygen, his organ func­tion was restored and his fever subsided. On the nineteenth post-operative day, the pa­tient was extubated and he began physiotherapy. Additional imaging showed enterocutaneous fis­tulae among the jejunal loops, skin and enterocolic anastomosis, as well as a pancreatic pseudocyst. The multidisciplinary team composed of radia­tion therapists, an oncologic surgeon and an anaes­ 183 thesist specializing in artificial nutrition decided to continue specific oncologic treatment and simulta­neously treat gastrointestinal failure with paren­teral nutrition. The rectal carcinoma was treated with short-course pre-operative radiotherapy (5 x 5 Gy) and surgery, during which the fistulae were excised and jejuno-colic re-anastomosis was done. Rectal cancer was treated with total mesorectal excision and permanent colostomy. Post-operatively, the patient developed a paracolic hematoma and a presacral abscess which was drained when he was well enough to be transferred to the regular ward. The patient remained on home parenteral nutri­tion (HPN) because of short bowel syndrome. No complications arose during oncologic treatment and the patient is to date in good health and with­out any signs of recurrence. Discussion Cancer patients face an increased risk of throm­bosis as a consequence of their disease and/or its treatment. While the majority of thrombotic events occurring in cancer patients are of venous origin, arterial thrombosis is a well-documented, albeit rarer, entity. Chemotherapy has been identified as a risk factor for thrombosis and may, depending on the agent, damage the endothelium, induce cytokine release, activate platelets and disrupt the balance between the pro- and anti-thrombotic molecules.4 The toxic effects of fluorouracil on the endothe­lium and the serum concentration of anti-throm­botic molecules have been studied4 and most likely apply to capecitabine, a pro-drug of fluorouracil, as well. Acute mesenteric ischemia (AMI) is an uncom­mon entity, affecting less than 0.1% of hospitalised patients.5 It is most commonly caused by superior mesenteric artery embolism (40.50%) and throm­bosis (15.30%).6,7 With its high sensitivity (96.100%) and speci­ficity (89.92%), CT angiography remains the gold standard for the diagnosis of mesenteric ischemia. 6,7 Treatment decisions are affected by the intraop­erative appearance of the bowel. Evidently necrotic bowel loops should be resected, while in any other case, treatment is guided by the principle of arte­rial reperfusion before intestinal resection is con­sidered, which has in a recent series of three cases proven to be a safe and effective method.5 There exists no data about the outcome of in­testinal resection in patients with untreated rectal cancer. Our patient’s surgery resulted in short bowel syndrome (SBS), which is a consequence of a mas­sive anatomical and/or functional loss of intestine, where a reduced small-bowel surface area leads to malabsorption and dehydration. SBS may occur as a consequence of surgery (25%), irradiation/cancer (24.46%), mesenteric vascular disease (15.22%), Crohn’s disease (16.19%) and other benign causes (13.20%).8,9 The early management of a patient with SBS is that of a critically ill surgical patient, while later, the primary objective is artificial nutritional sup­port at the patient’s home. Enteral intake should be encouraged to minimise dependence on parenteral nutrition.10 The patient had type II SBS with a jejunal-colon­ic anastomosis and from the beginning it was clear that he will remain dependent upon the parenteral supply of adequate energy and nutrients. Despite that the specific oncologic treatment went well with no major complications. There are three types of intestinal anatomy in SBS, depending on the presence of the colon and ileocecal valve.11 Presence of the distal ileum/il­eocecal valve is essential to slowing the transit and preventing bacterial overgrowth, while the colon is able to absorb water, electrolytes and fatty acids; both functions serve as a deterrent to the develop­ment of diarrhoea, an important cause of malnutri­tion.11 Patients with SBS on parenteral nutrition are at risk of many complications: catheter occlusion and breakage; catheter infections and thrombosis of the central venous access, metabolic disturbances and small bowel bacterial overgrowth.11 Conclusions Cancer patients face an increased risk of thrombo­sis as a result of their disease and its treatment. The risks and benefits of aggressive oncological treat­ment should always be carefully weighed, espe­cially in patients with a good prognosis. However, with adequate parenteral nutrition and medical support, SBS is not an absolute con­traindication for specific oncologic treatment, espe­cially if said treatment is expected to result in cure and/or long-term remission. Even though the prognosis of patients with bow­el necrosis and systemic inflammatory response is 184 dismal, long-term survival is still possible with ad­equate treatment and management. References 1. Glimelius B, Tiret E, Cervantes A, Arnold D. Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol 2013; 24(Suppl 6): vi81-8. 2. Oblak I, Velenik V, Anderluh F, Mozina B, Ocvirk J. The correlation between the levels of tissue inhibitor of metalloproteinases 1 in plasma and tumour response and survival after preoperative radiochemotherapy in patients with rectal cancer. Radiol Oncol 2013; 47: 138-44. 3. Walko CM, Lindley C. Capecitabine: a review. Clin Ther 2005; 27: 23-44. 4. Haddad TC, Greeno EW. Chemotherapy-induced thrombosis. Thromb Res 2006; 118: 555-68. 5. Kuhelj D, Kavcic P, Popovic P. Percutaneous mechanical thrombectomy of superior mesenteric artery embolism. Radiol Oncol 2013; 47: 239-43. 6. Wyers MC. Acute mesenteric ischemia: diagnostic approach and surgical treatment. Semin Vasc Surg 2010; 23: 9-20. 7. Dewitte A, Biais M, Coquin J, Fleureau C, Cassinotto C, Ouattara A, et al. Diagnosis and management of acute mesenteric ischemia. Ann Fr Anesth Reanim 2011; 30: 410-20. 8. Thompson JS, DiBaise JK, Iyer KR, Yeats M, Sudan DL. Postoperative short bowel syndrome. J Am Coll Surg 2005; 201: 85-9. 9. Bakker H, Bozzetti F, Staun M, Leon-Sanz M, Hebuterne X Pertkiewicz M. Home parenteral nutrition in adults: a european multicentre survey in 1997. ESPEN-Home Artificial Nutrition Working Group. Clin Nutr 1999; 18: 135-40. 10. DiBaise JK, Young RJ, Vanderhoof JA. Intestinal rehabilitation and the short bowel syndrome: part 2. Am J Gastroenterol 2004; 99: 1823-32. 11. DiBaise JK, Young RJ, Vanderhoof JA. Intestinal rehabilitation and the short bowel syndrome: part 1. Am J Gastroenterol 2004; 99: 1386-95. 185 research article Clinical applicability of biologically effective dose calculation for spinal cord in fractionated spine stereotactic body radiation therapy Seung Heon Lee1, Kyu Chan Lee1, Jinho Choi1, So Hyun Ahn1, Seok Ho Lee1, Ki Hoon Sung1, Se Hee Kil2 1 Department of Radiation Oncology; 2 Gachon Medical Research Institute, Gachon University Gil Medical Center, Republic of Korea Radiol Oncol 2015; 49(2): 185-191. Received 7 November 2014 Accepted 5 January 2015 Correspondence to: Kyu Chan Lee, M.D., Ph.D., Department of Radiation Oncology, Gachon University Gil Medical Center 21, 774 beon-gil, Namdong-daero, Namdong-gu, Incheon, 405-460, Republic of Korea. Phone: +82 32 460 8050; Fax: +82 32 460 3009; E-mail: kyu22@gilhospital.com Disclosure: No potential conflicts of interest were disclosed. Background. The aim of the study was to investigate whether biologically effective dose (BED) based on linear-quadratic model can be used to estimate spinal cord tolerance dose in spine stereotactic body radiation therapy (SBRT) delivered in 4 or more fractions. Patients and methods. Sixty-three metastatic spinal lesions in 47 patients were retrospectively evaluated. The most frequently prescribed dose was 36 Gy in 4 fractions. In planning, we tried to limit the maximum dose to the spinal cord or cauda equina less than 50% of prescription or 45 Gy2/2. BED was calculated using maximum point dose of spinal cord. Results. Maximum spinal cord dose per fraction ranged from 2.6 to 6.0 Gy (median 4.3 Gy). Except 4 patients with 52.7, 56.4, 62.4, and 67.9 Gy2/2, equivalent total dose in 2-Gy fraction of the patients was not more than 50 Gy2/2 (12.1– 67.9, median 32.0). The ratio of maximum spinal cord dose to prescription dose increased up to 82.2% of prescription dose as epidural spinal cord compression grade increased. No patient developed grade 2 or higher radiation-induced spinal cord toxicity during follow-up period of 0.5 to 53.9 months. Conclusions. In fractionated spine SBRT, BED can be used to estimate spinal cord tolerance dose, provided that the dose per fraction to the spinal cord is moderate, e.g. < 6.0 Gy. It appears that a maximum dose of up to 45–50 Gy2/2 to the spinal cord is tolerable in 4 or more fractionation regimen. Key words: biologically effective dose; spine stereotactic body radiation therapy; spinal cord; tolerance dose; linear quadratic model Introduction Stereotactic body radiation therapy (SBRT) has been increasingly applied to the management of spinal metastases with encouraging clinical results of rapid and durable pain relief.1,2 SBRT is also ef­fective for treating radio-resistant metastatic tu­mours, such as, renal cell carcinoma or malignant melanoma.3,4 The spinal cord is the major dose-limiting tis­sue in spine SBRT. In conventionally fractionated radiation therapy, the tolerance dose for the spi­nal cord has been reported to be 50 Gy for cord lengths of 5 and 10 cm, and 47 Gy for 20 cm, given a probability of myelopathy of less than 5% within 5 years.5 Schultheiss reported that the probabili­ties of myelopathy were 0.03% and 0.2% at 45 Gy and 50 Gy, respectively.6 For single fraction SBRT, Ryu et al. reported a partial volume tolerance of the human spinal cord of at least 10 Gy to 10% of the spinal cord volume when spinal cord volume was defined from 6 mm above and to 6 mm below the 186 TABLE 1. Patient and tumour characteristics Age (year, median) Histology (person) Lung Colorectal Breast Pancreas Hepatocellular Stomach Cholangiocarcinoma Prostate Renal cell Other Spine level (lesion) Cervical Cervicothoracic Thoracic Thoracolumbar Lumbar 33–86 (56) 13 11 6 3 3 2 2 2 1 4 3 4 37 5 14 Number of involved spine segments per PTV (lesion) 1 2 3 4 5 Tumour volume (cc, median) PTV volume (cc, median) Number of treated sites per patient (person) 1 2 3 ESCC grade20 (lesion) 0 1a 1b 1c 2 3 24 17 16 3 3 1.0–176.7 (21.0) 17.9–340.8 (59.1) 35 8 4 14 15 9 5 18 2 ESCC = epidural spinal cord compression; PTV = planning target volume treatment target.7 Sahgal et al. suggested 10 Gy as a maximum safe threshold for single fraction SBRT to the thecal sac.8 In fractionated spine SBRT, however, variable dose schedules are applied and no reliable dose comparison method has been established for the target or the spinal cord. Since Fowler first pro­posed the term ‘biologically effective dose’ based on linear-quadratic (LQ) cell survival model in 1989, BED has been used to compare the bio­logic effects of various radiotherapy schedules.9 However, because prescription doses in fraction­ated spine SBRT are usually between 6 and 10 Gy per fraction, several authors have argued that the simple application of BED based on LQ model is not appropriate in SBRT. 10-18 The extrapolations us­ing the LQ model beyond 5.6 Gy per fraction are likely to lack clinically useful precision.19 Modern linear accelerator based stereotactic ra­diotherapy technology using a fine multileaf col­limator of 2.5 mm thickness could deliver highly conformal radiation to the target while sparing the spinal cord with the merit of a steep dose gradi­ent just outside the target. The irradiated dose to the spinal cord can be more strictly limited and is usually much lower than the prescription dose in fractionated spine SBRT. We hypothesized that if maximum doses per fraction to the spinal cord are less than 6 Gy, BED based on LQ model could be used to estimate spinal cord tolerance dose in fractionated spine SBRT. We usually implemented fractionated spine SBRT in 4 or 5 fractions to avoid complications such as radiation-induced myelopa­thy and vertebral compression fracture. To determine if BED based on LQ model can be used to estimate spinal cord tolerance dose in frac­tionated spine SBRT of 4 or more fractionation regi­men, the plans used for actual fractionated SBRT at our institution were analysed retrospectively and clinical outcomes, including complications, were investigated. Patients and methods Sixty-three metastatic spinal lesions in 47 patients were treated by spine SBRT between January 2010 and March 2014. Median patient age was 56 (range 33.86) and 27 patients (57.4%) were male. The tho­racic spine was the most frequent site for treatment. Of the 63 lesions, 41 lesions involved single or two contiguous spine segments. When categorized with the epidural spinal cord compression (ESCC) grading system, 43.5% of the lesions belonged to 187 grade 1c (deformation of the thecal sac with spinal cord abutment), 2 (spinal cord compression, but with cerebrospinal fluid [CSF] visible around the cord) or 3 (spinal cord compression, no CSF visible around the cord) (Table 1).20 No patients received surgical intervention, vertebroplasty or kyphop­lasty, prior to spine SBRT. All patients underwent CT simulation with an appropriate immobilization technique to obtain SBRT planning images. To delineate targets and spinal cords, T2-weighted and gadolinium con­trast T1-weighted MRI sequences with a 3 mm slice thickness including at least one vertebral body above and below the target were obtained and fused to the planning CT image using iPlan software (version 4.1, BrainLAB, Germany). Gross tumour volume (GTV) included gross visible tu­mour in spine, paraspinal, or epidural area on MR or enhanced planning CT images. Planning target volumes (PTV) were derived from GTVs by en­compassing involved vertebral body and including anterior and/or posterior elements of the spine de­pending on the location of metastatic lesions as de­scribed in RTOG 0631.21 Median PTV volume was 65.6 cc (range, 17.9.340.8 cc). The spinal cord was contoured starting from 6 mm above the superior of the PTV to 6 mm below the inferior of the PTV. However, the spinal cord was always excluded from the PTV, with a 1.2 mm free margin if the GTV did not abut onto the cord. Other organs, such as heart, lungs, oesophagus, large vessels, trachea, liver, and kidneys were delineated depending on tumour vertebral level. The most frequently prescribed dose was 36 Gy in 4 fractions, followed by 40 Gy in 5 fractions (Table 2). The requirement for clinical implementa­tion was > 80% of the prescription dose to > 90% of the PTV, or a mean PTV dose > 95% of prescription. The spinal cord dose was converted to equivalent total dose in 2-Gy fraction (EQD2) using the follow­ing formula provided below. This model was de­rived from the LQ model assuming an ./ß ratio of 2 for the late effect of spinal cord. Dose per fraction + ./ß EQD2 (Gy2/2) = Total dose x 2+ ./ß We tried to limit the maximum dose to the spi­nal cord or cauda equina less than 50% of prescrip­tion or 45 Gy2/2. Maximum dose per fraction to the spinal cord of each plan was investigated. All patients were treated using the Novalis TxTM (Varian, USA) equipped with a 2.5 mm multileaf collimator. Thirty-five patients received SBRT to TABLE 2. Prescription dose to planning target volume and maximum dose to spinal cord 26.0 Gy / 4 fractions 1 24.8 28.0 Gy / 4 fractions 1 25.4 30.0 Gy / 4 fractions 1 52.7 32.0 Gy / 4 fractions 2 25.5–56.4 36.0 Gy / 4 fractions 23 12.1–67.9 40.0 Gy / 4 fractions 1 24.3 44.0 Gy / 4 fractions 2 38.9–44.4 32.5 Gy / 5 fractions 6 16.6–43.0 35.0 Gy / 5 fractions 4 25.7–49.0 40.0 Gy / 5 fractions 19 24.2–41.1 42.5 Gy / 5 fractions 1 38.7 42.0 Gy / 6 fractions 2 39.8–62.4 BED = biologically effective dose; EQD2 = equivalent dose in 2-Gy fractions with an ./ß ratio of 2 a single treatment site spanning one to five ver­tebral segments. Eight patients received SBRT to 2 separate sites and 4 patients to 3 sites. Re-SBRT was performed in one patient with hepatocellular carcinoma at 5 months after initial SBRT because of the recurrence of severe pain due to tumour pro­gression. Patients were followed up clinically and radio­graphically at 1- to 3-month intervals. A visual ana­logue scale (VAS) was used to measure pain before and after treatment. Symptomatic responses were scored as defined by RTOG 0631.21 All available fol­low up MRIs were reviewed to assess radiographic responses. Radiologic local failure was defined as local tumour growth by MRI. Late complications were scored as described by Common Toxicity Criteria for Adverse Events, version 4.0. Overall survival was estimated by the Kaplan–Meier method. The relationship between radiologic local failure and variable candidate risk factors such as spinal cord to tumour distance, spinal cord to PTV distance, minimum dose administered to tumour, and tumour volume was analyzed by the Mann-Whitney U-test. The retrospective study was ap­proved by the institutional review board commit­tee and was according to the Helsinki Declaration. Results Inhomogeneous dose distributions inside the spi­nal cord and very steep dose gradients around it were observed (Figure 1A). Approximately 10% decrease of dose per millimetre was observed from 188 FIGURE 1. An example of dose distribution in a patient with disease of the T7 vertebral body only (ESCC grade20 0). (A, B) Dose profile from the center of the tumour (a) to the posterior edge of the thecal sac (d). Note that the dose gradient around the spinal cord in this case is steepest between (b) and (c), where 90% and 30% isodose lines, and is approximately 10% per millimeter. (C) Dose volume histogram of the patient shows much difference of the doses to target and spinal cord. The maximum dose per fraction to the spinal cord (arrow) was 37% (3.0 Gy) of the prescription dose (9.0 Gy). PTV margin to the surface of spinal cord (Figure 1B). Maximum dose to spinal cord was much lower than prescription dose (Figure 1C). According to PTV shape and spinal cord proximity, maximum spinal cord doses varied from 10.5 Gy to 33.2 Gy (median 20.2 Gy). When they were divided by cor­responding fraction numbers, the maximum spinal cord dose per fraction ranged from 2.6 to 6.0 Gy (median 4.3 Gy). Maximum EQD2 to spinal cords ranged from 12.1 to 67.9 Gy2/2 (median 32.0 Gy2/2). Six cords were administered more than 45 Gy2/2and doses of them were 48.0, 49.0, 52.7, 56.4, 62.4, and 67.9 Gy2/2, respectively. The ratio of maximum spinal cord dose to prescription dose increased up to 82.2% of prescription dose as the ESCC grade increased (Table 3). Median follow-up period was 7.1 months (0.5.53.9 months) and median overall survival was 10.2 months. During follow-up, 26 patients suc­cumbed to systemic disease progression. VAS re­sults were available for 46 of the 63 lesions. Mean VAS declined from 7.8 before to 2.7 after SBRT. Complete response was achieved for 10 lesions and partial response for 28 lesions. Follow-up MRIs were available for 27 lesions. Radiologic local failure occurred in 4 lesions (14.8%, Table 4). All patients in the radiologic local failure group (4 patients) had spinal cord compres­sion (ESCC grade 2) before SBRT. In the non-failure group (23 patients), distances between spinal cords and tumours or PTVs ranged from 0 to 14 mm (me­dian 2.3) or from 0 to 3.5 mm (median 1.0), respec­tively. Spinal cord to tumour distance (p < 0.001), spinal cord to PTV distance (p = 0.003), and mini­mum dose administered to tumours (p = 0.040) in the local failure group were significantly smaller than those in the non-failure group. No intergroup difference of tumour volumes was observed. There has been no grade 2 or more radiation-induced spi­nal cord toxicity during follow up period up to 53.9 months. There were three compression fractures (3 of 27, 11.1%); two resulted from progressions of ex­isting fractures and the other was a new fracture. Fractures occurred at 2, 3, and 4 months after treat­ment, respectively. Discussion BED based on the LQ model has been widely ac­cepted for the comparisons of doses adminis­tered in different treatment schedules in treating with conventional multifractionated irradiation. However, dose comparisons for fractionated spine SBRT based on simple BED calculations should be approached with caution. First, BED was devel­oped and validated based on homogenous radia­tion dose distributions in irradiated areas.22,23 The radiation dose administered to the spinal cord in SBRT is intrinsically inhomogeneous because it is performed with an intensity modulated radiation beam. The data regarding the tolerance of the rat cervical spinal cord suggested that small volume of rat spinal cord tolerates a greater dose compared to homogeneous radiation.24,25 Although those ob­servations were not found in swine model, the tolerance dose of spinal cord for partial-volume ir­radiation closely resembled that for rats, mice and guinea pigs receiving uniform spinal cord irradia­tion.26 Therefore, estimated spinal cord tolerance using BED calculation for partial-volume irradia­tion seems to be more conservative than, or at least comparable to that for uniform irradiation. Second, BED has been based on the data of con­ventional fraction size. However, in fractionated SBRT, prescription dose per fraction is relatively high, usually 6.20 Gy. Fundamental arguments have arisen as to whether the LQ model is a valid method for assessing BED when doses per frac­tion are high. Brenner et al. reported that the LQ model is reasonably well validated experimentally and theoretically up to about 10 Gy per fraction, and suggested that its use is reasonable up to about 18 Gy per fraction.27 However, several authors have argued to the contrary. Iwata et al. studied the applicability of the LQ model for dose conversion in high dose per fraction radiotherapy using cell survival data for V79 Chinese hamster lung fibro­blasts and EMT6 mouse mammary sarcoma cells.14 It was found that the LQ model fitted relatively well at doses of 5 Gy or less as compared with the repairable-conditionally repairable model and the multi-target model. Timmerman et al. proposed a universal survival curve that hybridizes the LQ model survival curve for the low-dose range and the multi-target model asymptote for the high-dose range.15 They reported a transition dose at which the LQ model smoothly transits to the terminal as­ymptote of the multi-target model. The transition dose calculated using 12 non-small-cell lung cancer (NSCLC) cell lines was 6.2 Gy, which means that LQ model may not be applicable for dose ranges of more than 6.2 Gy. Recently, Song et al. argued that the usefulness of the LQ model is likely to be limited when tumours are treated with high dose per fraction, usually more than 10 Gy, because LQ model and other modified-LQ models are based on the assumption that radiation-induced cell death in 189 TABLE 3. Spinal cord dose classified using the epidural spinal cord compression (ESCC) grading system20 0 14 12.0–25.5 (18.3) 15.0–38.9 (29.6) 33.4–60.7 (50.5) 1a 15 10.5–25.3 (20.8) 12.1–52.7 (32.0) 29.1–84.3 (52.0) 1b 9 13.9–23.4 (19.3) 16.6–44.4 (33.4) 40.3–56.2 (53.4) 1c 5 16.3–22.3 (17.5) 24.8–36.1 (28.0) 45.9–63.8 (57.1) 2 18 16.5–33.2 (21.8) 24.2–67.9 (36.1) 43.9–81.1 (58.4) 3 2 21.4–26.3 (23.9) 39.3–56.4 (47.9) 59.4–82.2 (70.8) Dmax = maximum dose to spinal cord; EQD2 max = maximum equivalent dose in 2-Gy fractions with an ./ß ratio of 2; ESCC = epidural spinal cord compression TABLE 4. Distances from spinal cord to tumour or planning target volume (PTV), minimum tumour doses, and tumour volumes according to radiologic local failure status Distance between SC and tumour (mm, median) 0* 0–14.0 (2.3) < 0.001 Distance between SC and PTV (mm, median) 0* 0–3.5 (1.0) 0.003 Minimum tumour dose (Gy, median) 15.4–23.8 (20.0) 15.3–44.7 (25.2) 0.040 Tumour volume (cc, median) 13.7–47.3 (20.8) 1.0–176.7 (20.9) 0.468 SC = spinal cord; * All tumours compressed the spinal cord; ** Statistical significance was determined using the Mann-Whitney U-test tumours is due solely to DNA strand breaks. They suggested indirect/necrotic cell death as a conse­quence of vascular damage plays an important role in SBRT.17,18 As of now, the applicability of BED based on the LQ model to the high dose per frac­tion radiation remains a controversial issue. According to the current radiobiological knowl­edge as mentioned above, BED based on the LQ model seems to be clinically applicable if the dose is limited to 6 Gy or less, especially for normal tissue, not tumour. With current technical developments, dose to the spinal cord can be maintained at much lower levels than the prescription dose due to the steep dose gradient just outside the target. In the present study, the maximum irradiation dose per fraction to the spinal cord varied from 2.6 to 6.0 Gy (median 4.3 Gy) depending on the PTV shape and its proximity to the spinal cord. Because the dose per fraction to the spinal cord was less than 6.0 Gy, it would be reasonable to estimate spinal cord tol­erance dose in fractionated SBRT using BED based on LQ model. Recently, Sahgal et al. recommended limiting maximum point dose to 23.0 Gy in 4 fractions 190 FIGURE 2. (A, B) Target volume (GTV: red, PTV: magenta) delineation in a patient with cord compression (ESCC grade20 2) and paraspinal mass. Five spine segments were involved in the PTV. (C) Dose distribution around the spinal cord. The 70% (arrow) and 50% (arrowhead) isodose lines are shown. The maximum spinal cord dose was 33.2 Gy, which was equivalent to 78.9% of the prescription dose of 42 Gy in 6 fractions. and 25.3 Gy in 5 fractions for a risk of radiation myelopathy of less than 5%.28 Dividing the con­straint dose by fraction number, maximum point doses per fraction to the thecal sac are 5.75 Gy and 5.06 Gy, respectively. The calculated EQD2 of the­cal sac based on the LQ model for these schedules were 44.6 Gy2/2 and 44.7 Gy2/2, respectively. These seem to be reasonable because the tolerance dose of spinal cord in conventionally fractionated ra­diation therapy is 45-50 Gy with fraction size of 1.8 or 2.0 Gy when full thickness of the cord is ir­radiated. In Sahgal’s data, there was no radiation myelitis after irradiation in 4 or 5 fractions, though the patient number is relatively small, 9 cases. In the present study, except 4 patients, all patients were administered a maximum spinal cord dose less than 50 Gy2/2 and no radiation myelopathy was observed among 63 cases. Gerszten et al. reported that post-SBRT tumour progressions often occurred at the edge of con­toured treatment volumes and the overall mean tu­mour volume of local failure cases was 40% greater than the average for their series.29 Chang et al. also reported that failure at the epidural space adjacent to the spinal cord is a major reason for tumour pro­gression after spine SBRT.10 In the present study, minimum tumour dose (p = 0.040), which is mainly affected by distance between spinal cord and tu­mour (p < 0.001) or PTV (p = 0.003) appeared to have more influence on local failure. Furthermore, when the tumour did not abut the spinal cord, lo­cal failure was not observed even in tumours larg­er than those in local failure group. These results mean that tumoricidal dose was not delivered to tumour because of the proximity of spinal cord in local failure group. BED calculation has clinical impact on choosing appropriate fraction size and number to deliver optimal tumour dose, especially for the lesions close to spinal cord, while limiting spinal cord dose of less than 45.50 Gy2/2. When a tumour abuts the spinal cord, increas­ing the number of fractions to deliver potentially tumoricidal dose, with lowering spinal cord BED, might be considered. In the patient shown in Figure 2, there was a large paraspinal tumour mass compressing the spinal cord. By increasing the number of fractions to 6 and decreasing the pre­scription dose per fraction to the PTV to 7 Gy, we tried to spare the spinal cord delivering 42 Gy to the GTV to improve local control. Although maxi­mum EQD2 of the spinal cord was 62.4 Gy2/2, we treated this patient in the palliative setting because local tumour control was important for the quality of life of the patient. 191 This study has several limitations; it is a retro­spective and single center study, cohort was small, and there was no myelopathy case. Rare but severe events like myelopathy require high patient num­bers to evaluate safe tolerance doses and it should not give a false sense of security. Although no my­elopathy was observed in 6 patients who were ad­ministered a maximum spinal cord dose greater than 45 Gy2/2, their survival period was only 1.5.6.4 months. They had multiple metastases in liver or lung and had short life expectancy. Therefore, it is not possible to suggest more doses for spinal cord tolerance above this dose level. However, we believe that the data of our study is important for apply­ing BED calculation for spinal cord tolerance dose in various clinical situations. We plan to conduct a multi-center prospective study with more patients. In conclusion, BED can be used to estimate spi­nal cord tolerance dose, provided that the dose per fraction to the spinal cord is moderate, e.g. < 6.0 Gy in fractionated spine SBRT. Within this dose range it appears that a maximum dose of up to 45.50 Gy2/2 to the spinal cord is tolerable. The minimum tumour dose, which is mainly affected by tumour to spinal cord distance, seems to sig­nificantly affect local failure. When a tumour abuts or is closely located to the spinal cord, we suggest adjustment of the fractionation schedule based on BED calculations, while maintaining the desirable dose to the target. Randomized controlled dose es­calation study is reserved to verify this suggestion. Acknowledgments This work was supported by Gachon University Gil Medical Center (Grant number : 2013-42). References 1. Ryu S, Jin R, Jin JY, Chen Q, Rock J, Anderson J, et al. Pain control by image-guided radiosurgery for solitary spinal metastasis. J Pain Symptom Manage 2008; 35: 292-8. 2. Wang XS, Rhines LD, Shiu AS, Yang JN, Selek U, Gning I, et al. Stereotactic body radiation therapy for management of spinal metastases in patients without spinal cord compression: a phase 1-2 trial. Lancet Oncol 2012; 13: 395-402. 3. Balagamwala EH, Angelov L, Koyfman SA, Suh JH, Reddy CA, Djemil T, et al. Single-fraction stereotactic body radiotherapy for spinal metastases from renal cell carcinoma. J Neurosurg Spine 2012; 17: 556-64. 4. Stinauer MA, Kavanagh BD, Schefter TE, Gonzalez R, Flaig T, Lewis K, et al. Stereotactic body radiation therapy for melanoma and renal cell carcinoma: impact of single fraction equivalent dose on local control. Radiat Oncol 2011; 6: 34. 5. Emami B, Lyman J, Brown A, Coia L, Goitein M, Munzenrider JE, et al. Tolerance of normal tissue to therapeutic irradiation. Int J Radiat Oncol Biol Phys 1991; 21: 109-22. 6. Schultheiss TE. The radiation dose-response of the human spinal cord. Int J Radiat Oncol Biol Phys 2008; 71: 1455-9. 7. Ryu S, Jin JY, Jin R, Rock J, Ajlouni M, Movsas B, et al. Partial volume toler­ance of the spinal cord and complications of single-dose radiosurgery. Cancer 2007; 109: 628-36. 8. Sahgal A, Ma L, Gibbs I, Gerszten PC, Ryu S, Soltys S, et al. Spinal cord toler­ance for stereotactic body radiotherapy. Int J Radiat Oncol Biol Phys 2010; 77: 548-53. 9. Fowler JF. The linear-quadratic formula and progress in fractionated radio­therapy. Br J Radiol 1989; 62: 679-94. 10. Chang EL, Shiu AS, Mendel E, Mathews LA, Mahajan A, Allen PK, et al. Phase I/II study of stereotactic body radiotherapy for spinal metastasis and its pat­tern of failure. J Neurosurg Spine 2007; 7: 151-60. 11. Sahgal A, Ames C, Chou D, Ma L, Huang K, Xu W, et al. Stereotactic body radiotherapy is effective salvage therapy for patients with prior radiation of spinal metastases. Int J Radiat Oncol Biol Phys 2009; 74: 723-31. 12. Ahmed KA, Stauder MC, Miller RC, Bauer HJ, Rose PS, Olivier KR, et al. Stereotactic body radiation therapy in spinal metastases. Int J Radiat Oncol Biol Phys 2012; 82: e803-9. 13. Nelson JW, Yoo DS, Sampson JH, Isaacs RE, Larrier NA, Marks LB, et al. Stereotactic body radiotherapy for lesions of the spine and paraspinal re­gions. Int J Radiat Oncol Biol Phys 2009; 73: 1369-75. 14. Iwata H, Matsufuji N, Toshito T, Akagi T, Otsuka S, Shibamoto Y. Compatibility of the repairable-conditionally repairable, multi-target and linear-quadratic models in converting hypofractionated radiation doses to single doses. J Radiat Res 2013; 54: 367-73. 15. Park C, Papiez L, Zhang S, Story M, Timmerman RD. Universal survival curve and single fraction equivalent dose: useful tools in understanding potency of ablative radiotherapy. Int J Radiat Oncol Biol Phys 2008; 70: 847-52. 16. Kirkpatrick JP, Brenner DJ, Orton CG. Point/Counterpoint. The linear-quadratic model is inappropriate to model high dose per fraction effects in radiosurgery. Med Phys 2009; 36: 3381-4. 17. Song CW, Kim MS, Cho LC, Dusenbery K, Sperduto PW. Radiobiological basis of SBRT and SRS. Int J Clin Oncol 2014; 19: 570-8. 18. Song CW, Park I, Cho LC, Yuan J, Dusenbery KE, Griffin RJ, et al. Is indirect cell death involved in response of tumors to stereotactic radiosurgery and stere­otactic body radiation therapy? Int J Radiat Oncol Biol Phys 2014; 89: 924-5. 19. Joiner MC, Bentzen SM. Fractionation: the linear-quadratic approach. In: Joiner M, van der Kogel A, editors. Basic Clinical Radiobiology. London: Hodder Education; 2009. p. 102-19. 20. Bilsky MH, Laufer I, Fourney DR, Groff M, Schmidt MH, Varga PP, et al. Reliability analysis of the epidural spinal cord compression scale. J Neurosurg Spine 2010; 13: 324-8. 21. Ryu S, Pugh SL, Gerszten PC, Yin FF, Timmerman RD, Hitchcock YJ, et al. RTOG 0631 phase II/III study of image-guided stereotactic radiosurgery for localized (1-3) spine metastases: phase II results. Int J Radiat Oncol Biol Phys 2011; 81: S131-2. 22. Fowler JF. Alpha, beta, and surviving fraction. Int J Radiat Oncol Biol Phys 1992; 24: 188-9. 23. Fowler JF. Modelling altered fractionation schedules. BJR Suppl 1992; 24: 187-92. 24. Bijl HP, van Luijk P, Coppes RP, Schippers JM, Konings AW, van der Kogel AJ. Unexpected changes of rat cervical spinal cord tolerance caused by inhomo­geneous dose distributions. Int J Radiat Oncol Biol Phys 2003; 57: 274-81. 25. Bijl HP, van Luijk P, Coppes RP, Schippers JM, Konings AW, van Der Kogel AJ. Regional differences in radiosensitivity across the rat cervical spinal cord. Int J Radiat Oncol Biol Phys 2005; 61: 543-51. 26. Medin PM, Foster RD, van der Kogel AJ, Sayre JW, McBride WH, Solberg TD. Spinal cord tolerance to single-fraction partial-volume irradiation: a swine model. Int J Radiat Oncol Biol Phys 2011; 79: 226-32. 27. Brenner DJ. The linear-quadratic model is an appropriate methodology for determining isoeffective doses at large doses per fraction. Semin Radiat Oncol 2008; 18: 234-9. 28. Sahgal A, Weinberg V, Ma L, Chang E, Chao S, Muacevic A, et al. Probabilities of radiation myelopathy specific to stereotactic body radiation therapy to guide safe practice. Int J Radiat Oncol Biol Phys 2013; 85: 341-7. 29. Gerszten PC, Burton SA, Ozhasoglu C, Vogel WJ, Welch WC, Baar J, et al. Stereotactic radiosurgery for spinal metastases from renal cell carcinoma. J Neurosurg Spine 2005; 3: 288-95. 192 research article Dynamic CT angiography for cyberknife radiosurgery planning of intracranial arteriovenous malformations: a technical/ feasibility report Anoop Haridass, Jillian Maclean, Santanu Chakraborty, John Sinclair, Janos Szanto, Daniela Iancu, Shawn Malone The Ottawa Hospital, Ottawa, Ontario, Canada Radiol Oncol 2015; 49(2): 192-199. Received 27 October 2014 Accepted 31 December 2014 Correspondence to: Dr. Jillian Maclean, The Ottawa Regional Cancer Centre, The Ottawa Hospital General Campus, Smyth Rd, Ottawa, Ontario, Canada. Phone: +613 737 7700, +613 737 0212; Fax: +613 247 351; E-mail: jillianmaclean@nhs.net Disclosure: No potential conflicts of interest were disclosed. Background. Successful radiosurgery for arteriovenous malformations (AVMs) requires accurate nidus delineation in the 3D treatment planning system (TPS). The catheter biplane digital subtraction angiogram (DSA) has traditionally been the gold standard for evaluation of the AVM nidus, but its 2D nature limits its value for contouring and it can­not be imported into the Cyberknife TPS. We describe a technique for acquisition and integration of 3D dynamic CT angiograms (dCTA) into the Cyberknife TPS for intracranial AVMs and review the feasibility of using this technique in the first patient cohort. Patients and methods. Dynamic continuous whole brain CT images were acquired in a Toshiba 320 volume CT scanner with data reconstruction every 0.5 sec. This multi-time-point acquisition enabled us to choose the CT data-set with the clearest nidus without significant enhancement of surrounding blood vessels. This was imported to the Cyberknife TPS and co-registered with planning CT and T2 MRI (2D DSA adjacent for reference). The feasibility of using dCTA was evaluated in the first thirteen patients with outcome evaluation from patient records. Results. dCTA data was accurately co-registered in the Cyberknife TPS and appeared to assist in nidus contouring for all patients. Imaging modalities were complementary. 85% of patients had complete (6/13) or continuing partial nidus obliteration (5/13) at 37 months median follow-up. Conclusions. dCTA is a promising imaging technique that can be successfully imported into the Cyberknife TPS and appears to assist in radiosurgery nidus definition. Further study to validate its role is warranted. Key words: arteriovenous malformation; radiosurgery; Cyberknife; dynamic CT angiogram Introduction Intracranial arteriovenous malformations (AVM) are congenital vascular abnormalities present in approximately 0.01–0.5% of the population.1 In AVM, arteries supply a serpiginous collection of vessels, called the nidus, which shunt blood from the feeding arteries directly to the draining veins without an intervening capillary bed. The nidus and draining veins become enlarged and tortuous to cope with the increased flow. Intracranial AVMs are clinically important as there is 1.5% annual risk of haemorrhage.2,3 Advances in the treatment of AVMs have re­sulted in a decrease in associated morbidity and mortality in the last two decades.4 Although mi­crovascular surgery remains the gold standard treatment, stereotactic radiosurgery (RS) is prov­ing increasingly useful in the treatment of small inoperable deep seated AVMs, those in eloquent areas where the risk of surgical morbidity is high, in medically inoperable patients and as part of 193 a multi-therapy approach for larger complex AVMs.5-7 The goal of RS for AVMs is to treat the nidus to a high dose while simultaneously minimising dose to the surrounding normal tissue. Improvements in image guidance, computing and radiation deliv­ery technology in the last two decades have made it feasible to deliver accurate highly conformal RS plans. However, a successful outcome following RS - optimal AVM obliteration with minimal tox­icity - is dependent on accurate definition of the nidus. This has always been challenging and inac­curacies in nidus definition are an important cause for treatment failure.8,9 The gold standard for imaging vascular struc­tures, such as the AVM nidus, is the catheter bi­plane high resolution digital subtraction angio­gram (DSA). The excellent temporal resolution of the DSA allows differentiation of the nidus from the feeding arteries and draining veins. However, the 2D nature of DSA images means they are of limited use to contour the nidus in 3D RS planning. Furthermore, DSA images cannot be co-registered in the Cyberknife (CK) RS treatment planning sys­tem as stereotactic localisation is frame-based in DSA, whereas CKRS uses skull tracking. Therefore, 3D imaging modalities, such as CT angiograms (CTA) and MR angiograms (MRA) are used for RS planning. Whilst CTA and MRA provide a view of the vascular tree with excellent 3D localization, the drawback of the standard ‘static’ CTA/MRA is that the images represent a snapshot of the blood flow through the AVM and draining veins at a pre-de­termined acquisition time. This snapshot is unlikely to be the optimal time-point for viewing the nidus, which can make differentiation of the nidus from the surrounding angio-architecture challenging. Dynamic CT angiography (dCTA) is a non-in­vasive vascular imaging technique that has been shown to provide both high temporal and spatial resolution in a 3D volume dataset. The entire cere­bral volume can be imaged in a single rotation of the gantry, generating a full CT dataset of the cerebral vasculature every second. The scanner splits each dataset to generate whole brain CTA volume with temporal resolution of 0.5 sec. The utility of dCTA has been described in the evaluation of AVMs10,11, but there are no published reports of using it to aid RS planning. Potentially dCTA would allow deline­ation of the nidus on the CT dataset captured at the point when the nidus is clearest. We incorporated dCTA into our CKRS planning protocol in 2010 and present a feasibility report regarding our initial findings in the first cohort of patients. Patients and methods All patients with AVMs who were treated with CKRS at our hospital between October 2010 and April 2012 underwent a dynamic CT angiogram as part of the planning process. Written informed consent of patients was obtained for the treatments and for the scientific use of the clinical data accord­ ing to Declaration of Helsinki. Procedure for dCTA Patients were scanned in an Aquilion ONE multi-detector volume CT scanner (Toshiba, Medical Systems, Japan) in a supine head first position with IV access as per departmental protocol. This system is equipped with 320 ultra-high resolution detector rows (0.5mm in width), 512 x 512 matrix and images 16cm in z-axis in a single gantry ro­tation which covers the entire brain. Whole brain CT data is acquired at multiple time points as per dCTA protocol. From this dataset Dynamic (time resolved) CT angiography (dCTA) images were re­constructed enabling the analysis of the blood flow in the entire cranial circulation in a non-invasive way with high spatial and temporal resolution. The radiation dose for the dCTA acquisition is approxi­mately (DLP= Dose length product) 2170 mGycm = effective dose 5 mSv, for comparison radiation dose for non-contrast CT head will be (DLP) 1335 mGycm) = 3 mSv. Timing bolus Following acquisition of a scout film, a 15ml timing bolus of the contrast agent (Isovue 370 followed by a 20 ml saline chaser) was power injected and low dose scans of the base of skull area were taken eve­ry two seconds to determine time taken for the con­trast to arrive at the internal carotid arteries at the skull base. The scan was discontinued when con­trast appeared in these vessels and contrast arrival time was determined. The usual timeframe varied between 10.15 seconds and depended on patients cardiac output and placement of IV access. dCTA The dCTA scan protocol (Figure 1) was initiated with simultaneous scanning and power injection of IV contrast (40 ml Isovue 370 @5ml/sec followed by a 20 ml saline chaser). A ‘mask’ scan was acquired at 7 seconds using 300mA and 80KV (Figure 1A). This dataset was used to digitally subtract bone 194 FIGURE 1. The upper panel (A) shows planning timeline for dCTA acquisition. Following simultaneous start of IV pump and the scanner, at 7 sec, a volume with 300 mA and 80 kV is taken as a mask for bone subtraction. This is a non-contrast image as the contrast bolus is yet to reach the cranial arteries. The next dynamic acquisition block (100 mA, 80 kV, 1 volume/sec for 16 volumes) will have different a start time, depending on the variable contrast arrival time at the internal carotid arteries at the base of skull as determined by the timing bolus. This will acquire 16 volumes starting 1 sec before the contrast arrival time. The lower panel (B) shows series of volumes following dCTA acquisition. Together they will show the timeline of contrast flow (dynamic CTA) thus permitting selection of the best volume showing the AVM nidus for CK planning. FIGURE 2. Sagittal reformatted dynamic subtracted images (A, B, C) show temporal flow of contrast through intracranial vessels and nidus of left occipital AVM. (A) very early arterial phase showing the AVM nidus before filling of contrast into the normal brain arteries due to rapid shunting through the AVM. Axial reformatted images in the arterial (D) and venous (E) phases demonstrate the difficulty in assessing the AVM nidus in the presence of enhancing surrounding vasculature. (F) an axial slice of non-subtracted dCTA volume co-registered in the CK system and used for SRS contouring. from the angiogram datasets and was performed at higher mA to allow clearer definition of the in­tracranial vasculature. The scanner was setup for dynamic acquisition one second before the contrast arrived at the skull base (as determined from the timing bolus) at 100mA and 80 KV (Figure 1A). The whole brain volume from skull base to vertex was imaged once every second for 16 seconds and the complete data volume was reconstructed every 0.5 seconds (temporal resolution 2 images/sec). The duration of the scan allowed imaging to start with no contrast, continuing to the phase of peak arte­rial enhancement (Figure 2A) and ending with the venous return phase (Figure 2C). Non-subtracted and bone subtracted dCTA datasets were created and reviewed by the neuro­radiologist (SC) to determine the temporal phase of imaging where the AVM nidus was best visualised (Figure 1B and Figure 2F) without significant con­trast in the draining veins and adjacent non-AVM vasculature. The optimum time-point for nidus visualisation varied between subjects depending on AVM flow rate. Treatment planning The entire CT dataset (320 slices) at the time point where the nidus was clearest was reformatted to the CKRS treatment planning specifications (1x1x1mm cubic voxels) and imported as a DICOM file to the CK Multiplan TP system (Accuray, Sunnyvale CA). The dCTA was co-registered with the non-contrast planning CT and T2 weighted MRI to contour the target and the surrounding organs at risk. Coregistration between planning CT, dCTA and MRI was visually assessed in the standard split-screen manner using bone and ven­ tricle landmarks. The 2D DSA was available for reference on an adjacent workstation. All imaging modalities were used to accurately delineate the nidus. Contouring was jointly performed by the neurosurgeon, radiation oncologist and neurora­diologist. Single fraction RS treatments were pre­scribed and the plan and the prescription isodose was finalized by the radiation oncologist to achieve coverage of the nidus and respect published nor­mal tissue constraints.12 Review of clinical use Tolerability and apparent utility of the dCTA was assessed prospectively. Follow up imaging was performed 6 monthly using MRA, followed by a confirmatory catheter angiogram if the MRA in­ 195 TABLE 1. Patient characteristics and outcomes 1 L basal ganglia 10 15 84 Yes No N Embolization after 33 months 45 2 L thalamus 40 15 82 Yes Yes N RS 15 years previous (lost to follow-up) 45 3 R occipital 50 18 85 No No C 45 4 L cerebellum 49 15 84 Yes No P Large AVM – only deep nidus treated, for embolization of remainder 44 5 L vein of galen 22 15 80 Yes No P 44 6 R parietal 70 18 82 No No C 38 7 Corpus callosum 22 16.5 75 No No C 37 8 Sup cerebellum 61 20 80 Yes No C 34 9 L occipital AVM 36 18 80 No No C 32 10 Pineal 29 16 85 No No C 30 11 Sup cerebellum 58 21 82 Yes No P 30 12 R CP angle 40 15 77 No No P 29 13 R thalamus 11 15 78 Yes Yes P RS 5 years previously 28 C = complete obliteration; L/R = left and right; N = no obliteration; P = partial obliteration; Pt = patient dicated obliteration. Nidus obliteration rates and toxicity were evaluated from imaging and patient charts. Results Between October 2010 and April 2012, 13 consecu­tive patients with inoperable AVMs were treated with CKRS at our hospital. Median age was 40 years (range 10.70). All patients tolerated the full dCTA protocol without adverse event and accu­rate co-registration of dCTA images with the CT and MRI within the CK planning system was per­formed in all cases. Treatments were all delivered as a single frac­tion. Median marginal RS dose delivered was 16Gy (range 15.21Gy at the 75.85% isodose). Median target volume was 1.31cc (range 0.4.2.93cc). Ten patients were treated with RS because the AVM was in an eloquent or inoperable area, two patients as part of staged multimodality treatment follow­ing surgery and one patient because of medical co­morbidities. Seven patients had prior intracranial haemorrhage. Two patients with thalamic AVMs had been previously treated at other centers with RS for AVM. Re-treatment in these cases occurred after a latency of five and fifteen years. Table 1 summarises the patient cohort and outcomes at a median follow-up of 37 months (range 28.45 months). The RS team found that all imaging modalities were complementary. The dCTA data could be accurately co-registered within the CK Multiplan TPS and it was possible to visualize the nidus on both MRI and dCTA in all 3 planes. The sagittal and coronal images were compared to the reference 2D Angiography images in the adjacent work station. dCTA was felt by all three clinicians to be beneficial to help define the boundaries of the nidus in every case. On MRI alone it was often difficult to distin­guish nidus from adjacent angiomatous change and draining veins often obscured the nidus on both MRI and on 2D Angiography. Careful selec­tion of the optimal dCTA data set where there was minimal uptake in large draining veins and that excluded surrounding angiomatous change helped the RS team clarify boundaries of the nidus. In our experience the dCTA was also helpful to define portions of nidus extending into CSF space in peri­ventricular AVMs and in cases where AVM nidus extended into adjacent sulci. Representative cases are illustrated in Figures 2.4. Example cases Case 1 (patient 9) A 36 year old female with a previous history of cervix cancer was investigated for headaches and found to have a 20 mm AVM in the left occipital area (Figure 2). The option of surgical management with risk of visual morbidity was discussed and 196 FIGURE 3. (A) Sagittal reformatted non-contrast CT head image showing iso-dense lesion in tentorial notch (arrow). (B) Axial T2 weighted MR image (3B) showing nidus with adjacent draining vein. (C) Sagittal reformatted image from T1 weighted VIBE image showing enhancing nidus with adjacent draining veins and venous sinuses. (D-E) Sagittal reformatted subtracted dCTA images in arterial (D) and venous (E) phase showing the AVM nidus in the arterial phase and occluded straight sinus. (F) Axial image from early arterial volume showing the nidus without contamination from surrounding enhancing vessels (full CT dataset from this temporal imaging phase imported into CBK for contouring). FIGURE 4. (A) Axial T2 image showing abnormal vasculature in right CP angle (black arrow). (B) Axial source image from the time of flight MR angiogram showing the nidus. (C) Source image from contrast enhanced axial T1weighted VIBE sequence showing enhancing AVM nidus with enhancement of adjacent vasculature. (D) arterial phase image of conventional catheter angiogram with injection from the left vertebral artery showing the AVM nidus (black arrow). This is a projectional 2-D image that cannot be coregistered in CBK. (E) sample axial image from the corresponding dCTA used for CK planning. (F) radiation target volume and isodose lines in CK planning system. patient declined. The patient had CKRS to a dose of 18 Gy to the 80% isodose and the nidus was com­pletely obliterated at 22 months. Case 2 (patient 10) A 29 year old female investigated for headaches against a background of recent haemorrhagic stroke in a close relative, was found to have a 22 mm AVM in the pineal region (Figure 3). The AVM was located in a region deemed not amenable to surgery. The patient had CKRS to a dose of 16 Gy to the 85% isodose. The nidus was obliterated 28 months following treatment. Case 3 (patient 11) A 40 year old asymptomatic patient was found to have a 15 mm AVM in the right CP angle (Figure 4) when being screened for aneurysms. The patient received 15 Gy to the 77% isodose with CKRS with partial obliteration of the nidus after 22 months. Discussion Accurate delineation of the AVM nidus is para­mount to successful RS. The steep dose gradients delivered by RS mean that inaccurate targeting will result in a subtherapeutic dose to regions of the AVM and increase the likelihood of treatment failure. Conversely, treating a larger volume than required increases the risk of toxicity. However, it can be challenging to effectively distinguish the nidus from its feeding and draining vessels as re­ported by Buis et al.13, who evaluated intraobserver variability in contouring AVMs for RS. They re­ported a mean agreement ratio of 0.45 amongst six observers and showed that differences were most marked in those with treatment failure. Improved definition of the nidus through the use of multiple imaging modalities should increase the likelihood of successful AVM RS. DSA remains the gold standard for visualisa­tion of the nidus in view of the excellent spatial and temporal resolution, but the 2D nature of standard DSA limits its use in 3D RS contouring. Furthermore, it is not possible to coregister the DSA within CKRS planning software as CK is not frame-based and the DSA is therefore viewed on an adjacent imaging workstation. This introduc­es errors. Therefore centres generally co-register CTA or MRA to provide 3D cross-sectional data. However, even with timed contrast boluses and acquisition, the temporal resolution of standard CTA/MRA is limited to a snapshot view of the 197 AVM. While this produces good cross-sectional imaging, the enlarged draining veins and contrast in adjacent non-AVM vasculature usually obscure parts of the nidus. Several groups have reported the use of 3D re­constructions of DSA. Veeravagu et al., reported smaller AVM target volumes for CKRS when con­tours were performed using a combination of 3D rotational angiography, CT and MRI versus CT and MRI alone.14 They concluded that the addition of 3D angiography into the planning protocol re­sulted in more precise target contouring, although patient outcome data and analysis of possible im­age distortion levels would strengthen their data. Zhang et al., reported similar results several years earlier using in-house software to create a 3D reconstruction of DSA images.15 Columbo et al., recently described a novel method of automatic nidus contouring using coregistered 3D rotational angiography (performed with direct intraarterial contrast injection).16 After establishing the radio­logical density of a region of nidus, the treatment planning software automatically contoured GTV based on corresponding voxel values, although manual correction was possible. They did not de­scribe their validation process for this technique, but did report complete angiographic oblitera­tion rates after . three years in 65 of 80 patients (81.2%). Various other non-invasive methods have been described that appear to assist in nidus definition in RS treatment planning or post-treatment follow-up. 3D time of flight (TOF) MRA has been advo­cated for the assessment of AVM nidus obliteration dynamics following CKRS17, although Bednarz et al., concluded that DSA and TOF MRA were com­plementary for nidus RS delineation as imaging artefact on MRA could obscure the nidus.18 High sensitivity (81%) and specificity (100%) has been reported for dynamic MRA in the post-treatment evaluation of AVMs treated with RS.19 The use of dCTA for imaging AVMs was first described by Matsumo et al.10, who imaged four patients with AVM (within a study of various brain lesions) and reported that dCTA effectively distin­guished the nidus from the feeding and draining vessels within the scanned range. Willems et al., recently evaluated dCTA versus DSA to evaluate AVMs using a scoring system.11 They reported that dCTA could be used to effectively diagnose and classify the shunt but, in some circumstances there were discrepancies on classifying the angio­architecture with dCTA compared to DSA due to difficulty in determining the nature of certain ves­sels. However, they focused upon 3D maximum in­tensity projection (MIP) views of the dCTA in their comparison rather than the cross-sectional images we have used. Indeed, they went on to discuss the benefit of using the cross-sectional data to distin­guish the nidus from surrounding vessels. In this feasibility report we have shown that dCTA data can be easily imported into the CKRS planning system and co-registered to the planning CT and MRI. This allows contouring to be per­formed on 3D cross-sectional images of the nidus at the point when it is clearest. In all of our 13 cases it was possible to identify the optimum dCTA vol­ ume, directly import this 3D dataset into the CKRS software and accurately coregister with other mo­dalities which allowed the nidus to be visualized in all 3 planes for contouring. The sagittal and coronal images can still be compared to the refer­ ence 2D angiography images on the adjacent work station. The AVMs in this report were of small vol­ume which demands even greater accuracy than for larger lesions. Direct contouring on the dCTA on the CKRS planning software certainly was an advantage compared to our previous technique where contours were drawn on static CT/MRI images with reference to the DSA on an adjacent screen. It is important to carefully choose the right arterial phase of the dCTA and use the non-sub­tracted volume to allow confident definition of the nidus on the dCTA. However, at this point in our analysis it would be premature to conclude that dCTA replaces the need for DSA in RS planning and we found the combination of imaging modali­ties to be complementary. The primary purpose of this study was to re­port our initial findings on the feasibility of us­ing dCTA to assist in targeting AVMs for RS on the Cyberknife TPS. Accordingly, our data is de­scriptive. We do not claim to have validated dCTA in nidus contouring. Formal validation of a new imaging technique in contouring is challenging. Although comparison of volumes contoured with and without the dCTA may show differences, such differences alone do not themselves reflect whether the dCTA improves contouring accu­racy. Improvement in contouring agreement be­tween observers using a new imaging technique is often used as a surrogate for improved accu­racy. However, we did not pursue this approach as we contour as a multidisciplinary group with different areas of primary expertise (radiology, neurosurgery and radiation oncology) and our fi­nal targets reflect a consensus opinion. Long-term patient outcomes will be the ultimate validation, 198 but patient numbers are too low and follow-up too short to accurately assess treatment success rates at this point as the latency period to complete obliteration following RS can be 4.5 years. We did evaluate preliminary patient outcomes to estab­lish whether it is reasonable to continue to study dCTA in AVM RS treatment planning and the data available so far is comparable to other published outcomes at this follow-up period. Complete ni­dus obliteration rates three years post-RS of 58%, 39% and 40% have been reported by various au­thors7,20,21, with successful obliteration rates in­creasing as follow-up continues. Six of our first thirteen patients (46%) contoured using dCTA had complete nidus obliteration at a median follow-up of 37 months. Five other patients have had partial responses and the nidus size continues to progres­sively decrease suggesting they may completely obliterate with further follow-up. Due to the small nidus volume in our cohort, we would hope for complete obliterations in approximately 80% of patients after 4.5 years follow-up. Clearly we do not suggest that our current outcomes themselves validate dCTA in contouring at this point, but we continue to prospectively collect long-term patient outcome and toxicity data. Two patients, both with complete nidus obliterations, required delayed steroid therapy, one for simple edema and one for a thrombosed draining vein, an unusual but docu­mented potential complication of RS for AVM.22 Review of this patients RS contours showed that the addition of the dCTA had in fact reduced the volume of draining vein included in the target. Conclusions It is feasible to integrate dCTA into a CKRS plan­ning protocol for AVM delineation. This technique combines the better spatial resolution of 3D CT volumes with the ability to select the best temporal phase of contrast filling. In our preliminary evalua­tion, we found dCTA to be a complementary addi­tion to the other standard imaging modalities used to contour the AVM nidus and particularly useful for CK planning as DSAs cannot be imported into the CK TPS. We have now incorporated dCTA into our standard treatment planning protocol and will continue to prospectively collect longer-term fol­low-up data in more patients for validation. References 1. Fleetwood IG, Steinberg GK. Arteriovenous malformations. Lancet 2002; 359: 863-73. 2. Brown RD Jr., Wiebers DO, Forbes GS. Unruptured intracranial aneurysms and arteriovenous malformations: frequency of intracranial hemorrhage and relationship of lesions. J Neurosurg 1990; 73: 859-63. 3. Ondra SL, Troupp H, George ED, Schwab K. The natural history of sympto­matic arteriovenous malformations of the brain: a 24-year follow-up assess­ment. J Neurosurg 1990; 73: 387-91. 4. van Beijnum J, van der Worp HB, Buis DR, Al-Shahi Salman R, Kappelle LJ, Rinkel GJ, et al. Treatment of brain arteriovenous malformations: a system­atic review and meta-analysis. JAMA 2011; 306: 2011-9. 5. Kano H, Kondziolka D, Flickinger JC, Yang HC, Flannery TJ, Niranjan A, et al. Stereotactic radiosurgery for arteriovenous malformations, Part 4: man­agement of basal ganglia and thalamus arteriovenous malformations. J Neurosurg 2012; 116: 33-43. 6. Kano H, Kondziolka D, Flickinger JC, Yang HC, Flannery TJ, Niranjan A, et al. Stereotactic radiosurgery for arteriovenous malformations, Part 5: manage­ment of brainstem arteriovenous malformations. J Neurosurg 2012; 116: 44-53. 7. Kano H, Lunsford LD, Flickinger JC, Yang HC, Flannery TJ, Awan NR, et al. Stereotactic radiosurgery for arteriovenous malformations, Part 1: man­agement of Spetzler-Martin Grade I and II arteriovenous malformations. J Neurosurg 2012; 116: 11-20. 8. Ellis TL, Friedman WA, Bova FJ, Kubilis PS, Buatti JM. Analysis of treatment failure after radiosurgery for arteriovenous malformations. J Neurosurg 1998; 89: 104-10. 9. Pollock BE, Flickinger JC, Lunsford LD, Maitz A, Kondziolka D. Factors associated with successful arteriovenous malformation radiosurgery. Neurosurgery 1998; 42: 1239-44; Discussion 44-7. 10. Matsumoto M, Kodama N, Endo Y, Sakuma J, Suzuki K, Sasaki T, et al. Dynamic 3D-CT angiography. Am J Neuroradiol 2007; 28: 299-304. 11. Willems PW, Taeshineetanakul P, Schenk B, Brouwer PA, Terbrugge KG, Krings T. The use of 4D-CTA in the diagnostic work-up of brain arteriovenous malformations. Neuroradiology 2012; 54: 123-31. 12. Timmerman RD. An overview of hypofractionation and introduction to this issue of seminars in radiation oncology. Semin Radiat Oncol 2008; 18: 215-22. 13. Buis DR, Lagerwaard FJ, Barkhof F, Dirven CM, Lycklama GJ, Meijer OW, et al. Stereotactic radiosurgery for brain AVMs: role of interobserver variation in target definition on digital subtraction angiography. Int J Radiat Oncol Biol Phys 2005; 62: 246-52. 14. Veeravagu A, Hansasuta A, Jiang B, Karim AS, Gibbs IC, Chang SD. Volumetric analysis of intracranial arteriovenous malformations contoured for CyberKnife radiosurgery with 3-dimensional rotational angiography vs computed tomography/magnetic resonance imaging. Neurosurgery 2013; 73: 262-70. 15. Zhang XQ, Shirato H, Aoyama H, Ushikoshi S, Nishioka T, Zhang DZ, et al. Clinical significance of 3D reconstruction of arteriovenous malformation us­ing digital subtraction angiography and its modification with CT information in stereotactic radiosurgery. Int J Radiat Oncol Biol Phys 2003; 57: 1392-9. 16. Colombo F, Cavedon C, Casentini L, Francescon P, Causin F, Pinna V. Early results of CyberKnife radiosurgery for arteriovenous malformations. J Neurosurg 2009; 111: 807-19. 17. Wowra B, Muacevic A, Tonn JC, Schoenberg SO, Reiser M, Herrmann KA. Obliteration dynamics in cerebral arteriovenous malformations after cyberknife radiosurgery: quantification with sequential nidus volumetry and 3-tesla 3-dimensional time-of-flight magnetic resonance angiography. Neurosurgery 2009; 64: A102-9. 18. Bednarz G, Downes B, Werner-Wasik M, Rosenwasser RH. Combining stereotactic angiography and 3D time-of-flight magnetic resonance angiog­raphy in treatment planning for arteriovenous malformation radiosurgery. Int J Radiat Oncol Biol Phys 2000; 46: 1149-54. 199 19. Gauvrit JY, Oppenheim C, Nataf F, Naggara O, Trystram D, Munier T, et al. Three-dimensional dynamic magnetic resonance angiography for the evalu­ation of radiosurgically treated cerebral arteriovenous malformations. Eur Radiol 2006; 16: 583-91. 20. Zacest AC, Caon J, Roos DE, Potter AE, Sullivan T. LINAC radiosurgery for cerebral arteriovenous malformations: a single centre prospective analysis and review of the literature. J Clin Neurosci 2014; 21: 241-5. 21. Blamek S, Tarnawski R, Miszczyk L. Linac-based stereotactic radiosurgery for brain arteriovenous malformations. Clin Oncol (R Coll Radiol) 2011; 23: 525-31. 22. Yen CP, Khaled MA, Schwyzer L, Vorsic M, Dumont AS, Steiner L. Early drain­ing vein occlusion after gamma knife surgery for arteriovenous malforma­tions. Neurosurgery 2010; 67: 1293-302; discussion 302. 200 special communication The cost of systemic therapy for metastatic colorectal carcinoma in Slovenia: discrepancy analysis between cost and reimbursement Tanja Mesti1, Biljana Mileva Boshkoska2, Mitja Kos3, Metka Tekavčič4, Janja Ocvirk1 1 Department of Medical Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia 2 Faculty of information studies, Novo mesto, Slovenia 3 Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia 4 Faculty of Economics, University of Ljubljana, Ljubljana, Slovenia Radiol Oncol 2015; 49(2): 200-208. Received: 14 August 2014 Accepted: 2 October 2014 Correspondence to: Tanja Mesti, M.D., M.Sc., Institute of Oncology Ljubljana, Zaloška 2, Ljubljana. Phone: +386 1 5879 220; Fax: +386 1 5879 305; E-mail: tmesti@onko-i.si Disclosure: No potential conflicts of interest were disclosed. Background. The aim of the study was to estimate the direct medical costs of metastatic colorectal cancer (mCRC) treated at the Institute of Oncology Ljubljana and to question the healthcare payment system in Slovenia. Methods. Using an internal patient database, the costs of mCRC patients were estimated in 2009 by examining (1) mCRC direct medical related costs, and (2) the cost difference between payment received by Slovenian health insurance and actual mCRC costs. Costs were analysed in the treatment phase of the disease by assessing the direct medical costs of hospital treatment with systemic therapy together with hospital treatment of side effects, without assessing radiotherapy or surgical treatment. Follow-up costs, indirect medical costs, and nonmedical costs were not included. Results. A total of 209 mCRC patients met all eligibility criteria. The direct medical costs of mCRC hospitalization with systemic therapy in Slovenia for 2009 were estimated as the cost of medications (cost of systemic therapy + cost of drugs for premedication) + labor cost (the cost of carrying out systemic treatment) + cost of lab tests + cost of imag­ing tests + KRAS testing cost + cost of hospital treatment due to side effects of mCRC treatment, and amounted to €3,914,697. The difference between the cost paid by health insurance and actual costs, estimated as direct medical costs of hospitalization of mCRC patients treated with systemic therapy at the Institute of Oncology Ljubljana in 2009, was €1,900,757.80. Conclusions. The costs paid to the Institute of Oncology Ljubljana by health insurance for treating mCRC with sys­temic therapy do not match the actual cost of treatment. In fact, the difference between the payment and the actual cost estimated as direct medical costs of hospitalization of mCRC patients treated with systemic therapy at the Institute of Oncology Ljubljana in 2009 was €1,900,757.80. The model Australian Refined Diagnosis Related Groups (AR-DRG) for cost assessment in oncology being currently used is probably one of the reasons for the discrepancy between pay-outs and actual costs. We propose new method for more precise cost assessment in oncology. Key words: cost of treatment; metastatic colorectal cancer; cost of targeted therapy; monitoring costs Introduction Colorectal cancer is one of the most common can­cers in the developed world. Morbidity and mortal­ity caused by this form of cancer are increasing in Slovenia. In 2009 1,568 people were diagnosed with colorectal cancer.1,2 The increasing incidence also corresponds to increasing mortality because 50 to 60% of cases of the disease are discovered in an ad­vanced stage, of which 20 to 30% have metastasized. 201 Patients in Slovenia with metastasized colorec­tal cancer (mCRC) that are physically or medi­cally capable are mostly treated at the Institute of Oncology Ljubljana, where treatment takes place following guidelines adopted in line with globally recognized oncological guidelines, although the combinations of medications vary. 3,4 The costs of treating mCRC have risen quickly over the past decade, especially with the introduc­tion of targeted medications for treating mCRC. With the introduction of the new targeted medica­tions cetuximab and bevacizumab to mCRC treat­ment, the costs of standard care per person have increased from $500 to $250,000.5 There are no studies of defining mCRC treat­ment costs in Slovenia, and so we decided to take the first step and calculate what mCRC treatment costs amount to. For our analysis, we collected the costs of active patient mCRC treatment with sys­temic therapy at the Institute of Oncology Ljubljana in 2009 and compared them with payments by the Health Insurance Institute of Slovenia (ZZZS) with the goal to show if there is any discrepancy. The Institute of Oncology Ljubljana was the only healthcare facility in Slovenia where treatment of mCRC was carried out. Patients and methods First we used retrospective analysis from an inven­tory of patient diseases and defined the database of treatment for patients treated at the Institute of Oncology Ljubljana in 2009 with systemic therapy for mCRC, and then we carried out a retrospective analysis of average direct medical costs of patient treatment for mCRC with systemic therapy from the perspective of the hospital. The study was ap­proved by the institutional review board commit­tee and was according the Declaration of Helsinki. The study included costs of acute hospital pro­cedures, whereas costs of non-acute hospital proce­dures were excluded. For individual patients we took into account the information from the database shown in Table 1. Group characteristics We analysed a homogenous group of 294 patients that underwent hospital treatment with systemic therapy. From the group of 409 mCRC patients that were treated at the Institute of Oncology Ljubljana, we excluded patients that took part in additional forms of treatment such as surgical pro- TABLE 1. Data in the database 1 Age 2 Sex 3 Number of hospital procedures for 2009 Localization of primary cancer: colon, rectum, 4 colon-rectum transition Localization of mCRC metastasis: liver, lungs, liver 5 and lungs, local recurrence of disease, other Line of treatment with systemic therapy in 2009: first, second, third, fourth, and number of lines 6 of systemic therapy received by an individual patient in 2009 (one course, two or more lines) Systemic therapy regimen: number of hospital 7 applications and dose of individual medications in regimen and price of medicine Number, dose, and price of medication for 8 premedication per individual application Number, dose, and price of medication for 9 hydration per individual application Laboratory tests carried out for an individual 10 patient during hospital treatment due to systemic therapy, type, number, and price of lab tests Imaging tests carried out for an individual patient 11 during hospital treatment due to systemic therapy, type, number, and price of imaging tests Hospital services per patient due to side effects of 12 systemic therapy KRAS testing before the start of treatment with 13 systemic therapy for mCRC patients before the first line of therapy (yes/no) Labor costs for carrying out systemic therapy per 14 hospitalization mCRC = metastatic colorectal cancer cedures and radiotherapy (internal data from the gastrointestinal cancer team, Institute of Oncology Ljubljana) and 115 patients treated with systemic therapy only as outpatients, because evaluating the costs of outpatient therapy does not take place in the same way as evaluating the costs of hospital treatment. Evaluation of outpatient services takes place according to a point system (the Uniform List of Health Services, or green book), and hospital services are evaluated according to the diagnosis-related group (DRG) system. The group included 123 men and 86 women. Approximately two-thirds (66%) were under 65-year old. Approximately 60% of patients (122) had primary localization of the tumour in the co­lon, and one-third in the rectum (69). The most fre­quent localization of metastasis was the liver (125 patients). One-fifth of patients had metastasis in the lungs or simultaneously in the lungs and liver, local recurrence of disease was present in nine pa­tients, and the remaining one-third of patients had 202 Medication cost = dose and number of applications Medicationa of medication calculated according to medication supply priceb Test costs = (number of pointsc of test + number of Lab tests points scored (venous blood draw)) × cost price of a pointd Imaging tests Test costs = number of pointsc × cost price of a pointd Sum of the labor cost of nurses, physician, pharmacist, pharmaceutical technician, and administrative and Applying medication technical staff with regard to the average time used for application, and average value of an hour of labor for an individual involved in applying medication. Sum of the labor cost of nurses, physician, average Work during time used per patient, and average value of an hour hospitalization of labor for an individual during hospitalizatione Testing primarycancer or metastasis Cost of molecular analysis + labor cost for KRAS mutation Sum of the cost of medications used (parenteral Hospital treatment antibiotics, peroral antibiotics, parenteral feeding, for side effects of hydration, other medication), tests (lab and imaging), systemic therapy and labor during hospitalization. a Excludes cost of Xeloda (capecitabine) because patients receive it with a prescription at an external pharmacy and then continue their therapy at home. b Supply of medications at the Institute of Oncology Ljubljana takes place through a public procurement process as defined by law (Public procurement Act, Official Gazette of the Republic of Slovenia, no. 16/08). c The green book or Uniform List of Health Services contains a point value for health services based on the need for staff and time used expressed in minutes for carrying out these services. It is a very old and outdated document that contains a description of all health exams, care, and tests with precise codes, description of health services and of staffing and time standards, whereby all services are evaluated with points. This document is still used in calculating health services performed and in checking billing accuracy even though many modern services are not included in it. d The cost price of a point is defined retroactively for 2009 by individual diagnostic unit (Analysis of costs and physical indicators for 2009, Institute of Oncology Ljubljana) based on values from the green book. The cost price of a point per individual diagnostic unit represents the quotient between the total costs of an individual diagnostic unit for an individual year and the number of points realized. eSystemic treatment that includes capecitabine (capecitabine, oxaliplatin [XELOX], capecitabine, irinotecan [XELIRI], XELOX/bevacizumab, XELIRI/bevacizumab, XELOX/cetuximab, XELIRI/ cetuximab) involves one-day hospitalization, and systemic treatment that includes 5-FU (infusional fluorouracil, leucovorin, oxaliplatin [FOLFOX], fluorouracil, leucovorin, oxaliplatin, irinotecan [FOLFIRI], FOLFOX/bevacizumab, FOLFIRI/bevacizumab, FOLFOX/cetuximab, FOLFIRI/cetuximab) involves three-day hospital treatment. metastasis in the lymph nodes, bones, or pancreas and peritoneal carcinoma. The patients were treated with standard combi­nations of systemic therapy. Most patients received XELOX (capecitabine, oxaliplatin) + bevacizumab, which is understandable considering that capecit­abine as a per oral form of fluoropyrimidine offers better quality of life for patients and visits to an oncologist are at three-week intervals, in contrast to 5-fluorouracil, which is an infusion form of fluo­ropyrimidine that is applied in 46 h infusions every two weeks. Paired chemotherapy with cetuximab was received by half as many patients as paired chemotherapy with bevacizumab, primarily be­cause of the presence of KRAS mutation in the pri­mary cancer tissue. The distribution of systemic therapy is presented in Figure 1. Definition of medications and procedures Chemotherapeutics included fluoropyrimidine (5-fluororacil, capecitabine), irinotecan, and ox­aliplatin, which we used in various regimens (fluorouracil, leucovorin, oxaliplatin, irinotecan [FOLFIRI], infusional fluorouracil, leucovorin, oxaliplatin [FOLFOX], capecitabine, irinotecan [XELIRI], capecitabine, oxaliplatin [XELOX]) and in combination with targeted medications: cetuxi­mab, bevacizumab.6 The premedication included the following medications: dexamethasone 20 mg, granisetron 1 mg, and clemastine 2 mg. In the hy­dration we used 0.9% NaCl 2,000 ml or 5% glucose 2,000 ml (for only chemotherapy), or 0.9% NaCl 2,700 ml or 5% glucose 2,700 ml (for chemothera­py + targeted medication). Laboratory tests were divided into standard tests - a complete blood count (CBC), blood differential test, liver function tests, kidney function tests (nitrogen retention), electrolytes, C-reactive protein (CRP), and tu­mour markers (Carcinoembryonic antigen [CEA], carbohydrate antigen [CA 19–9]) and additional Laboratory tests that we carried out as needed: uri­nalysis, iron, ferritin, and transferrin. The imaging tests we included were: X-ray (lungs, abdomen, spine, pelvis), CT (thoracic cavity, abdomen), MRI (liver, lesser pelvis, head), bone scintigraphy, ab­dominal ultrasound, and PET-CT. Definition of costs Because direct medical costs are fixed costs and variable costs that are directly connected to health condition or health treatment, in this analysis we 203 defined direct medical costs as the sum of the following costs per patient per hospitalization (Table 2):7 • Cost of medications (cost of systemic therapy + cost of medications for premedication and hy­dration); • Cost of labor to carry out systemic treatment (cost of labor per application + cost during time of hospitalization); • Cost of lab tests carried out; • Cost of imaging tests carried out; • Cost of molecular test: defining KRAS mutation; • Cost of hospital treatment due to side effects of mCRC treatment. Results Total direct medical costs of mCRC hospital treatment with systemic therapy in 2009 In 2009 the direct medical costs for mCRC hospi­tal treatment with systemic therapy amounted to €3,914,697.00. Direct medical costs for systemic therapy (chem­otherapy + targeted medication) and medication for premedication and hydration amounted to €2,927,679.70. Direct medical costs for laboratory tests amount­ed to €50,736.14, and direct medical costs for imag­ing tests €160,050.45. Costs for testing for the presence of KRAS muta­tions amounted to €32,026.19. Costs for the labor of applying medications amounted to €262,142.96, and costs for labor dur­ing the time of hospitalization were €733,110.64, which means that the cost of labor for carrying out systemic treatment amounted to €995,253.60. Costs for hospital treatment due to side effects of systemic therapy amounted to €25,668.50. Only nine patients were treated, with an average length of hospital treatment of 12.9 days. The most com­mon reason was diarrhoea (five patients), followed by sepsis without neutropenia (three patients). One patient had an allergic reaction to cetuximab. The reason there was such a low number of pa­tients included in hospital care for side effects of systemic therapy is the good premedication and support therapy that the patients receive alongside systemic therapy, and especially hospital treat­ment of side effects of systemic therapy at special­ized healthcare facilities. The distribution of all direct medical costs is presented in Figure 2. Approximately seven-tenths (69%) of all direct medical costs were systemic ther­apy costs, which was also expected. One-fourth of the costs were the cost of carrying out systemic treatment. The greatest costs in the group of labo­ratory test costs were due to standard laboratory tests (84%). Thirteen percent of laboratory test costs were due to determining levels of iron, ferritin, and transferrin, and only 3% due to urinalysis. With regard to percentages, the greatest costs were for combined systemic treatment; specifical­ly, for chemotherapy in combination with bevaci­ 204 zumab, which was the most frequently used sys­temic mCRC treatment in 2009. Individually, out of all costs of medications for systemic treatment (chemotherapy and targeted medications), 19% of all costs were incurred for paired chemotherapy using FOLFIRI in combination with bevacizumab, 18% using XELIRI in combination with bevacizum­ab, and 17% using XELOX in combination with bevacizumab (Figure 3). Targeted medications (cetuximab/bevacizum­ab) represent approximately 50% of the overall direct costs (€1,851,003.30), and the cost of chem­otherapy is about 30% of all direct medical costs (€1,047,680.60). All other costs (laboratory tests, imaging tests, labor costs, costs of KRAS testing, and hospital treatment for side effects of systemic treatment) amount to 27% of direct medical costs, mostly due to the labor cost for carrying out sys­temic treatment (Figure 4). Average direct medical costs of hospital mCRC therapy with systemic therapy in 2009 per hospitalization In the group of 209 patients treated with systemic therapy in 2009, altogether 1,605 hospital procedures were carried out, and on average a patient was hos­pitalized 7.67 times. Average direct medical costs of systemic treat­ment amounted to €2,439.10 per hospitalization. The average costs of systemic therapy amounted to €1,806.00 per hospitalization The average labor cost for carrying out systemic treatment amounted to €620.10 per hospitalisation. Altogether, there were 1,629 standard labora­tory tests and 1,547 additional lab tests (urine: 840, iron, ferritin, transferrin: 707) and 600 imaging tests (x-ray: 252, CT: 220, US: 59, MRI: 38, PET CT: 31, bone scintigraphy: 10). The average cost for laboratory tests amounted to €15.97 per test, and for imaging tests €266.75 per test. On average, 1.98 lab tests and 0.37 imaging tests were conducted per hospitalization. TABLE 3. Estimate and actual value of costs for 2009 The average cost of systemic treatment amount­ed to €18,730.60 per patient. The average cost of systemic treatment regardless of hospitalization but with regard to the number of rounds of systemic therapy received (two hospitali­zations are necessary for one round with a combina­tion of systemic therapy that includes 5-FU amount­ed to €3,323.17 per patient per round. Altogether, 1,178 rounds of systemic therapy were received. Comparison of hospital treatment costs recognized by the ZZZS with direct medical costs of hospital treatment of mCRC at the Institute of Oncology Ljubljana in 2009 The average value of DRG weights was 1.12 with a value of €2,739.63 for patients treated for mCRC with systemic therapy in 2009 at the Institute of Oncology Ljubljana (altogether there were 910 DRG cases). On average, each patient was hospi­talized 4.35 times. Among the group of DRG cases that were present less than 10% in the calculation, there were 68, with a total weight number of 113.10 and an average value weight of 1.66. The average value of one DRG weight for 2009 at the Institute of Oncology Ljubljana was €2,446.10. The value of one DRG weight at the Institute of Oncology Ljubljana is higher in comparison with other providers of secondary activity because ter­tiary activity is also carried out. The basic value of one DRG weight (for second­ary treatment without added value for tertiary) amounted to €1,976.00 in 2009, which means that in 2009 the ZZZS paid the Institute of Oncology Ljubljana around €2,013,939.20 (if the average val­ue of the DRG weight is 1.12) for patients that re­ceived hospital treatment for mCRC with systemic therapy. Direct medical costs of hospital treatment for mCRC with systemic therapy at the Institute of Oncology Ljubljana in 2009, estimated as the cost of medications (cost of systemic therapy + cost of Costs estimated by ZZZS 2,013,939.20 2,213.12 2,213.12 Direct medical costs 3,914,697.00 2,439.10 3,323.17 Difference 1,900,757.80 225.98 1,110.1 DRG = diagnosis-related group 205 medications for premedication) + labor cost (cost of carrying out systemic treatment) + cost of lab tests performed + cost of imaging tests performed + cost of KRAS testing + cost of hospital treatment due to side effects of mCRC treatment, amounted to €3,914,697. The difference between paid and actual costs, estimated as the direct medical costs of hospital treatment for mCRC with systemic therapy at the Institute of Oncology Ljubljana, was €1,900,757.80 in 2009. The estimate and actual value of costs for hospi­tal treatment of mCRC with systemic therapy at the Institute of Oncology Ljubljana in 2009 is presented in Table 3. The average value of a DRG case amounted to around €2,213.12. Direct medical costs per hospi­talization amounted to €2,439.10. Direct medical costs per patient amounted to €18,730.60. Discussion Costs of treating colorectal cancer The most data on costs of treating metastatic can­cers are provided by the United States, which have a profit-oriented healthcare system. This trend is also on the rise in Europe. Analysis of the costs of mCRC, which are de­fined as the entire costs of the disease together with costs of treatment (costs during diagnosis, treat­ment, and follow-up) for a group of 6,746 mCRC patients treated between 2004 and 2009 showed that 52.2% of costs were incurred because of hos­pital treatment of patients, 22.2% of these because of surgical treatment and 47.7% because of out­patient treatment, 10.6% of costs connected with mCRC were incurred because of chemotherapy, and 11.1% were due to targeted medications.8 Costs connected with mCRC were defined as the percentage share of total costs and also contained the cost of chemotherapy and targeted medications (cetuximab, panitumumab, and bevacizumab). The cost of chemotherapy rose from 6.9% of total costs in 2004 to 8.1% in 2008. The cost of targeted medica­tions rose from 4.8% in 2004 to 9.4% in 2008. Costs connected with mCRC were $9,978 per month. It is interesting that costs in the mCRC treatment phase were the lowest. The most costs were in the death phase ($26,649), followed by the diagnostic phase ($16,340). Ferro et al. determined that there was growth in the total costs of mCRC treatment from 1996 onwards, specifically due to increased choice among possible medications. Targeted medications have increased the cost of treating mCRC by a full 340-fold.9 The main cause of the overall costs of mCRC treatment are hospital treatment of patients ($37,369) and outpatient treatment ($34,582), which include chemotherapy. Monthly costs in the diag­nostic phase ($12,205) were similar to in the death phase ($13,328), and costs in the treatment phase were considerably lower ($4,722).10 Information from England, where Bending de­termined the direct costs of treating bowel cancer to the National Health Service, where they used the clinical path to determine screening costs, diagnos­tic costs, treatment costs, and follow-up costs, indi­cate that the entire annual costs of treating bowel cancer were approximately L1.1 billion. The great­est share of the costs were in the diagnostic phase (L291 million). Treatment costs defined as primary treatment costs (surgery and pharmacotherapy) were approximately L201 million, L129 million for primary treatment of colon cancer, and L72 million for treatment of colon cancer.11 In Slovenia, some oncology studies have been carried out that have determined cost effective­ness. Piškur et al. analysed the cost effectiveness of the hormone medications anastrozole and tamox­ifen for breast cancer.12 Obradović et al. analysed the cost effectiveness of determining the UGT1A1 genotype for irinotecan in monotherapy for colo­rectal cancer.13 In Slovenia to date there has been no analysis that defines mCRC treatment costs, and there­fore there are no data from comparable studies in Slovenia. Evaluating the costs of hospital treatment In Slovenia the main share of healthcare expendi­tures are provided from public funds. In 2008 these expenditures comprised of public sources amount­ed to 72.3% of all funds.14 In 2004 Slovenia moved from financing hospi­tals on the basis of services (the criterion was the green book), to length of stay-based financing on the model of paying DRG to those providing spe­cialized hospital activities. Acute hospital treat­ments in the DRG model are categorized by diag­noses and procedures performed according to the Australian modification of the tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10-AM), adapt­ed to Slovenian circumstances, and confirmed by the Health Council. 206 The DRG system is the most common payment method internationally. This is a payment system that was developed by a group of hospital admin­istration experts at Yale University in the United States by setting up twenty-three main diagnostic groups containing 467 diagnoses. Since 1982, the DRG system has been used as a system for financ­ing health services in the American Medicare pro­gram.15 Various countries have adopted the DRG system with adaptations to their national envi­ronments (Canada, Australia, the Scandinavian countries, France, Italy, Austria, and Germany). In Slovenia the DRG system was introduced in 2003 based on the model used in Australia (Australian Refined Diagnosis Related Groups, AR-DRG). The model is based on the principle of “the money follows the patient.” At the Institute of Oncology Ljubljana, as at all other hospitals carrying out acute hospital care, since 2004 assessment of health treatment has taken place following the DRG system. DRG are defined through diagnoses and procedures carried out following ICD-10-AM and other information such as length of treatment, age, sex, weight upon admission, and hours of mechan­ical ventilation. The DRG system is essentially a method of clas­sifying patients into groups based on different lev­els of demandingness for whom approximately the same funds are used. An individual acute hospital treatment for a patient is categorized into one DRG case. The price of an individual group of similar cases is expressed in relative terms, and is weight­ed with regard to price, or the price of an average case. The weight is expressed based on a coefficient of 1. More demanding or expensive DRGs have a weight greater than 1, and less demanding or cheaper ones have a weight less than 1. According to the current method, the ZZZS sends the price of one weight to all hospitals in Slovenia, on the basis of which the hospitals then calculate the services they carry out. Together with the weight of this DRG case and based on the price of one weight, they can calculate the price of a particular acute hospital treatment and, based on the weight of an individual case and the value of the weight, they can define the price of a case. This method of evaluating hospital treatments— the DRG system or groups of comparable cases— obviously has its disadvantages. Disadvantages of the DRG model may include excessive reduction of costs by limiting necessary tests and choosing less appropriate medications, admitting patients that do not need hospitalization, and false representa­tion of diagnoses and treatments with higher pric­es, or the provider adapting the data for greater profit with worse medical treatment.16 Obviously this is not the case for non-profit providers such as the Institute of Oncology Ljubljana, where direct medical costs are higher than those actually paid by the ZZZS. In his master’s thesis, Jurij Stariha draws atten­tion to the lack of uniformity in DRG weight for comparable groups of cases in various hospitals in Slovenia.17 In principle, for equivalent cases (i.e., cases in which the same amount of resources is used) hospitals should receive the same payment defined by the price of handling an individual case or the weight of the DRG case and the price of one weight. Stariha showed that in 2007 there was not a uniform weight for all providers, which means that providers received different payment for han­dling equivalent DRG cases. The confirmation that there is a lack of connection of price weight with indicators of operation shows that the current sys­tem of financing is not optimal, and so providers or hospitals adapt the value of the weight that they receive. From the analysis of the DRG system by the Public Health Institute (2003-2008) it is also clear that the current system of financing is not the best and that the level of weight is in great need of ad­justment.18 According to Marušič et al.15, in order to define standard costs of cases the improvement process ought to take into account clinical paths that pre­cisely describe the handling of a particular case fol­lowing evidence-based principles of modern medi­cine. For less frequent cases, actual average costs can be used. It is important to adapt statistical data by taking into account the relationship between the costs of work performed and the differences in length of hospital stay. The DRG model cannot rep­resent all of the complexities of hospital organiza­tion. Likewise, a very complicated individual case cannot be classified such that the costs are rejected. In defining weighting, it is not possible to take into account the likelihood of very rare complications, which result in very high additional costs. Monitoring costs by business process activities as better model for cost assessment in oncology Currently in Slovenia the AR-DRG 4.2 version of the classification system from 2000 is still be­ing used, even though the updated AR-DRG 6.0 from 2008 (Australian Government, Department of Health and Ageing) is available. 207 The old version of AR-DRG being used in Slovenia is one of the reasons for the discrepancy between pay-outs and actual costs. Of course, the comparison is not optimal because this study did not include complete costs, but it can be concluded that the discrepancy would be even greater if it took into account the entire cost. Regardless of the version of the evaluation system, it is necessary to adapt the weighting to the actual costs. Oncology is an area of medicine that is developing and chang­ing extremely quickly, which is shown in everyday news on treating cancer. One of the most dynamic areas in oncology in the last decade has been treat­ing mCRC. Classifications and cost evaluation sys­tems for treatments are quite rigid and changes in these areas take place slowly, which is reflected in non-objective evaluation of the costs of mCRC treatment. Classifying and financing procedures following the DRG model should orient providers towards cost-effective treatment, but not also toward qual­ity. Marušič, Ceglar, and Prevolnik-Rupel suggest including financing criteria such as user satisfac­tion and treatment outcome for the most common procedures. In this manner, the dimension of qual­ity will be built into payment.15 The solution to the problem could be that which was proposed by the Public Health Institute in its DRG analysis (2003–2008): it is necessary to carry out a cost analysis among providers and to define the nationally acceptable average for cancer treat­ment. However, it is especially emphasized that that it is necessary to define oncology treatment at the Institute of Oncology Ljubljana as the oncol­ogy center in Slovenia where most patients with mCRC are treated as a separate entity. Specifically, the price of DRG in Slovenia is based on evaluating the cases of three pilot hospitals, which was car­ried out based on data on hospital costs in 2001: the Ljubljana Medical Center, Maribor General Hospital, and Jesenice General Hospital. In 2003, based on cost analysis data from the study of pi­lot hospitals and the Australian weights in the National Hospital Cost Data Collection Round 6 (2001-2002), weights were calculated and then the demandingness of individual cases was deter­mined in Slovenia.15 Considering that in the costs we include every monetized use of business elements in achieving the effects of a business process, which in addi­tion to costs in the narrowest sense also includes all elements that are deducted from the profits for a given period, the ideal cost system should ensure completely precise data on all costs with regard to all business effects that a company achieves.19 The costs, which should ensure one hundred percent reliable information, would far exceed the benefits because they would be too high. Because of this, a company must seek the optimal level of informa­tion precision, which can be achieved by monitor­ing costs by business process activities. Monitoring costs by business process activi­ties makes it possible to classify general costs and is based on constant improvement of individual parts of the business process; this therefore handles costs at the level of an individual activity, because the activity is the thing that creates the cost. The process of determining and monitoring costs by business process activities takes place such that it is necessary to first define the areas that will be in­cluded in defining the costs; for example, the costs of the overall oncological process (pre-hospital testing, pre-hospital care or screening and limiting tests, operation costs, anaesthesia, postoperative costs, material used for this, radiotherapy costs, systemic therapy costs) or for only one area of care. This is followed by defining sources included in analysing the costs that were defined in the previ­ous stage. The third phase defines the specific ac­tivities carried out by each of the sources; for exam­ple, precisely defining the services that the internal oncology department carries out, a description of the services by staff in an individual department, and the time needed for a particular health service. In the final phase it is necessary to assign a cost to each part. For this we use direct costs, for example, for medicines, services such as lab tests, imaging tests, the material use costs using material, includ­ing consumables and technology used, staff, and total direct and indirect labor costs, including em­ployee benefits.20 In this manner we can discover and eliminate all unnecessary activities in a healthcare organization so that those that are essential from the viewpoint of treatment and operations will be carried out with maximum efficiency. This will make it pos­sible to achieve lower overall healthcare costs. This analysis is based on a treatment reality of mCRC that has since remained virtually un­changed. Hence, it can be assumed that the results are still valid today. Conclussions The costs paid to the Institute of Oncology Ljubljana by health insurance for treating mCRC with sys­temic therapy do not match the actual cost of treat­ 208 ment. In fact, the difference between the payment and the actual cost estimated as direct medical costs of hospitalization of mCRC patients treated with systemic therapy at the Institute of Oncology Ljubljana in 2009 was €1,900,757.80. Classifications and cost evaluation systems for treatments are quite rigid and changes in these ar­eas take place slowly, which is reflected in non-ob­jective evaluation of the costs of mCRC treatment. The model AR-DRG for cost assessment in on­cology being currently used is probably one of the reasons for the discrepancy between pay-outs and actual costs. We propose new method for more pre­cise cost assessment in oncology. Monitoring costs by business process activities makes it possible to classify general costs and is based on constant im­provement of individual parts of the business pro­cess; this therefore handles costs at the level of an individual activity, because the activity is the thing that creates the cost. We conclude that the only solution is establish­ing better communication between oncology, eco­nomics, and pharmacoeconomics, which also de­mands considerably greater transparency of data and accessibility, and only after this it is possible to develop a suitable model for defining costs in oncology. Acknowledgement The work of the second author is supported by Creative Core FISNM-3330-13-500033 ‘Simulations’ project funded by the European Union, The European Regional Development Fund. References 1. Zakelj MP, Zadnik V, Zagar T, Zakotnik B. Survival of cancer patients, diag­nosed in 1991-2005 in Slovenia. Ljubljana: Institute of Oncology Ljubljana, Epidemiology and Cancer Registry, Cancer Registry of Republic of Slovenia; 2009. p. 229. 2. Treglia G, Taralli S, Salsano M, Muoio B, Sadeghi R, Giovanella L. Prevalence and malignancy risk of focal colorectal incidental uptake detected by 18F-FDG-PET or PET/CT: a meta-analysis. Radiol Oncol 2015; 49(2): 200­208.; 48: 99-104. 3. Ocvirk J. Advances in the treatment of metastatic colorectal carcinoma. Radiol Oncol 2009; 43: 1-8. 4. Ocvirk J, Heeger S, McCloud P, Hofheinz RD. A review of the treatment op­tions for skin rash induced by EGFR-targeted therapies: Evidence from ran­domized clinical trials and a meta-analysis. Radiol Oncol 2013; 47: 166-75. 5. Reeder CE, Gordon D. Managing oncology costs. Am J Manag Care., 2006; 12: 3-16. 6. Van Cutsem EJD, Oliveira J. On behalf of the ESMO Guidelines Working Group. Advanced colorectal cancer: ESMO Clinical Recommendations for diagnosis, treatment and follow-up. Ann Oncol 2008; 19(Suppl 2): ii33-4. 7. Mesti T. [The cost of systemic therapy for metastatic colorectal carci­noma at Institute of Oncology Ljubljana in the year 2009]. Master’s thesis. [Slovenian]. University of Ljubljana, Faculty of Economics; 2011. Available at: http://www.cek.ef.uni-lj.si/magister/mesti4363.pdf 8. Song X, Zhao Z, Barber B, Gregory C, Zhun C, Sue G. Cost of illness in patients with metastatic colorectal cancer. J Med Econ 2011; 14: 1-9. 9. Ferro SA, Myer BS, Wolff DA, Poniewierski MS, Culakova E, Cosler LE, et al. Variation in the cost of medications for the treatment of colorectal cancer. Am J Manag Care 2008; 14: 717-25. 10. Paramore LC, Thomas SK, Knopf KB. Estimating costs of care for patients with newly diagnosed metastatic colorectal cancer. Clin Colorectal Cancer, 2006; 6: 52-8. 11. Bending WM, Trueman P, Lowson KV, Pilgrim H, Tappenden P, Chilcott J, et al. Estimating the direct costs of bowel cancer services provided by the National Health Service. Int J Technol Assess Health Care 2010; 26: 362-9. 12. Piškur P, Sonc M, Čufer T, Borštnar S, Mrhar A. Pharmacoeconomic aspects of adjuvant anastrozole or tamoxifen in breast cancer: A Slovenian perspec­tive. Anticancer Drugs, 2006; 17: 719-24. 13. Obradovič M, Mrhar A, Kos M. Cost effectiveness of UGT1A1 genotypes in second line, high dose, once every three week irinotecan monotherapy treatment of colorectal cancer. Pharmacogenomics 2008; 9: 539-49. 14. Organisation for Economic Cooperation and Development. Health data. 2008, May. Available from: http://www.oecd-ilibrary.org/economics/coun­try-statistical-profile-slovenia_20752288-table-svn. Accessed 10 August 2011. 15. Marušič D, Ceglar J, Prevolnik-Rupel V. [Reimbursement of health care ser­vices with special attention paid to drg reimbursement system in Slovenia]. [Slovenian]. Zdrav Varst 2009; 48: 177-83. 16. Busse R. Moving from passive to active provider payment systems: DRG-based financing. International conference markets in European health systems: opportunities, challenges and limitations; 2009. Available from: http://www.cef-see.org/health/#. Accessed 20 May 2009. 17. Stariha J. [The adequacy of funding for acute hospital treatment after a system comparable groups of cases.] [Slovenian]. Master’s thesis. University of Primorska, Faculty of Management; 2009. Available at: http://www. ediplome.fm-kp.si/Stariha_Jurij_20091028.pdf. Accessed 10 August 2010. 18. Zupanc I. [DRG: questions and answers about the classification system and the financing of hospitals.][Slovenian].Ljubljana: Inštitut za varovanje zdravja RS; 2008. 19. Tekavčič M. [Cost management]. [Slovenian]. Ljubljana : Gospodarski vest­nik, ISBN/ISSN: 867061149X; 1997. 20. Grandlich C. Using activity-based costing in surgery. AORN J, 2004; 79: 18-192. Slovenian abstracts Radiol Oncol 2014; 49(2): 107-114. doi:10.2478/raon-2014-0029 Ocena prepustnosti krvno-možganske pregrade s pomočjo perfuzijske računalniške tomografije Avsenik J, Bisdas S, Šurlan Popović K Izhodišča. Krvno-možganska pregrada je selektivna ovira difuzije na nivoju endotela možganskega žilja. Med preostale funkcije krvno-možganske pregrade sodijo transport, signaliziranje in regulacija osmoze. Povezave endotelnih celic z okoljnimi astrociti, periciti in nevroni so ključne za njihov razvoj, strukturno celovitost in delovanje. Pri boleznih, kot so možganska kap, vnetne bolezni osrednjega živčevja in nevrodegenerativne bolezni, pride do okvare krvno-možganske pregrade in posledič­no do povečane prepustnosti. Zaključki. Prepustnost krvno-možganske pregrade lahko ocenimo s pomočjo perfuzijske računalniške tomografije. To je radiološka preiskava, ki vključuje zajemanje slike v t.i. kino tehniki med intravensko aplikacijo jodnega kontrastnega sredstva. Danes perfuzijsko slikanje najpogosteje uporabljamo pri bolnikih z možganskimi tumorji ter v diagnostiki možganske kapi. Radiol Oncol 2015; 49(2): 115-120. doi:10.1515/raon-2015-0012 Ocenitev radioloških in metabolnih sprememb kostnih zasevkov z 18FDG-PET/CT po sistemskem zdravljenju Gunalp B, Oner AO, Ince S, Alagoz E, Ayan A, Arslan N Izhodišča. Namen raziskave je bila retrospektivna analiza radioloških in metabolnih sprememb kostnih zasevkov po sistemski kemoterapiji s pomočjo 18FDG-PET/CT ter določitev vloge teh kazalcev pri oceni odgovora na zdravljenje. Bolniki in metode. Retrospektivno smo s pomočjo 18FDG-PET/CT analizirali radiološke in metabolne značilnosti kostnih za­sevkov pri 30 bolnikih, ki so jih napotili na oceno odgovora na zdravljenje po sistemski terapiji. Pri vseh bolnikih smo integrirano preiskavo 18FDG-PET/CT opravili pred začetkom in po koncu zdravljenja. Rezultati. Pri skupini bolnikov z odgovorom na zdravljenje so bili osnovni morfološki radiološki vzorci tarčnih sprememb: litični, sklerotični, mešani in CT negativni. Po zdravljenju se je morfološki vzorec vseh opazovanih lezij spremenil v sklerotičnega, izmer­jene atenuacijske vrednosti so se povišale, ocenjena metabolna aktivnost pa se je znižala (p = 0,012). Dokazali smo korelacijo med ocenjenim upadom metabolne aktivnosti ter povišanjem izmerjenih atenuacijskih vrednosti tarčnih sprememb (r = -0,55) (p = 0,026). Pri skupini bolnikov brez odgovora na zdravljenje pa so bili osnovni morfološki radiološki vzorci tarčnih sprememb: litični, blastični, mešani in CT negativni. Po zdravljenju so skoraj vse tarčne lezije obdržale osnovni morfološki vzorec, samo ena CT negativna lezija se je spremenila v litično. Izmerjene atenuacijske vrednosti v lezijah so se znižale (p = 0,012), ocenjena metabolna aktivnost pa se je povišala (p = 0,012). Dokazali smo povezavo med ocenjeno povišano metabolno aktivnostjo ter zmanjšanjem izmerjenih atenuacijskih vrednosti (r = -0,65) (p = 0,032). Izjema so bile lezije, pri katerih je bil osnovni morfološki vzorec blastični. -Te so kazale napredovanje bolezni v smislu povečanja velikosti, povišane izmerjene metabolne aktivnosti ter izmerjenih atenuacijskih vrednosti. Zaključki. Raziskava kaže, da je ocena metabolne aktivnosti tarčnih lezij (na primeru kostnih zasevkov) bolj zanesljiv kaza­lec odgovora na zdravljenje kot so morfološko radiološki vzorci teh sprememb. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 121-127. doi:10.2478/raon-2014-0039 Ščitnične patološke spremembe, slučajno najdene pri preiskavi z 18F-FDG PET-CT. Retrospektivna raziskava, v kateri sta sodelovala dva centra PET-CT Jamšek J, Žagar I, Gaberšček S, Grmek M Izhodišča. Kadar s preiskavo PET-CT slučajno najdemo kopičenje 18F-FDG v ščitnici, smo pred diagnostičnim izzivom. Maksimalna vrednost privzema izotopa (SUVmax) nam je lahko v pomoč pri razlikovanju med benigno in maligno naravo takih ščitničnih sprememb. Bolniki in metode. Retrospektivno smo ovrednotili rezultate 5.911 preiskav z 18F-FDG PET-CT, ki smo jih v dveh zdravstvenih ustanovah opravili v letih 2010 in 2011. Slučajno odkritim spremembam s patološko povišanim kopičenjem 18F-FDG v ščitnici smo določili vrednost SUVmax, bolnike s takimi spremembami pa napotili na pregled k tirologu. Tu so opravili vse potrebne preiskave, po potrebi tudi aspiracijsko biopsijo s tanko iglo. Bolnikom, pri katerih je rezultat preiskave z aspiracijsko biopsijo s tanko iglo dopuščal možnost maligne bolezni ščitnice, smo svetovali operativno zdravljenje. Rezultati. Kopičenje 18F-FDG v ščitnici smo slučajno odkrili v 3,89 % pri 230 izmed 5.911 bolnikov, pri katerih smo naredili PET­CT preiskavo. Maligno spremembo v ščitnici, ki se je kazala s fokalno povišanim kopičenjem v ščitnici, smo diagnosticirali pri 10 izmed 66 bolnikov (v 15,2 %). V prvem centru ugotovljena vrednost SUVmax 36 benignih ščitničnih lezij je bila 5,6 ± 2,8; pri 5 malignih pa 15,8 ± 9,2 (p < 0,001). SUVmax vrednost 20 benignih ščitničnih lezij, diagnosticiranih v drugem centru, je bila 3,7 ± 2,2; pri 5 malignih pa 5,1 ± 2,3 (p = 0,217). Pri vseh 29 bolnikih s slučajno najdenim difuzno povišanim kopičenjem 8F-FDG v ščitnici smo ugotovili benigne spremembe. Zaključki. Povišano kopičenje 18F-FDG v ščitnici smo slučajno odkrili pri 3,89 % bolnikov, pri katerih smo naredili PET-CT pre­iskavo. Maligno bolezen ščitnice smo diagnosticirali v 15,2 % ščitničnih lezij, ki so imele fokalno povišano kopičenje 18F-FDG. Vrednost SUVmax predstavlja le enega izmed parametrov, ki je v pomoč pri opredeljevanju narave ščitničnih sprememb. Radiol Oncol 2015; 49(2): 128-134. doi:10.1515/raon-2015-0007 Primarni limfom centralnega živčnega sistema. Ali je odsotnost znotrajtumorske krvavitve karakterisičen znak pri slikanju z magnetno resonanco? Sakata A, Okada T, Yamamoto A, Kanagaki M, Fushimi Y, Dodo T, Arakawa Y, Takahaski JC, Miyamoto S, Togashi K Izhodišča. Dosedanje raziskave so pokazale, da je krvavitev pogosta radiološka najdba pri možganskih tumorjih, histološko opredeljenih kot glioblastomi, nasprotno pa jo zelo redko vidimo pri primarnih limfomih centralnega živčnega sistema. Namen raziskave je bil z oceno krvavitve v tumorju na T2 poudarjenih sekvencah in z oceno tumorskega signala dovzetnosti na ma­gnetno dovzetno poudarjenih slikanjih (SWI) razlikovati med primarnimi limfomi centralnega živčnega sistema in glioblastomi. Bolniki in metode. V retrospektivno raziskavo smo vključili 58 bolnikov z možganskim tumorjem (19 s primarnim limfomom centralnega živčnega sistema, 39 z glioblastomom) v obdobju od avgusta 2008 do marca 2013, ki so izpolnjevali vključitvene kriterije. Odsotnost krvavitve v tumorju smo ocenjevali na T2 poudarjeni sekvenci in s tumorskim signalom dovzetnosti, ki smo ga razdelili na 3 stopnje na sekvenci SWI. Primerjali smo dobljene rezultate v primarnih limfomih centralnega živčnega sistema in glioblastomih. Vrednosti P < 0,05 smo obravnavali kot statistično značilne. Rezultati. Krvavitve v tumorju na T2 poudarjeni sekvenci ni bilo pri 15 bolnikih (79 %) s primarnim limfomom centralnega živčnega sistema in pri 23 bolnikih (59 %) z glioblastomom. Z odsotnostjo krvavitve v tumorju torej nismo razlikovali med obema vrstama možganskih tumorjev (P = 0,20). Nasprotno pa je tumorski signal dovzetnosti 1. ali 2. stopnje pokazal 78,9 % občutljivost in 66,7 % specifičnost (P < 0,001) ter je bil značilen za primarne limfome centralnega živčnega sistema ne glede na odsotnost krvavitve v tumorju. Zaključki. Z nizko stopnjo tumorskega signala dovzetnosti lahko razlikujemo med primarnimi limfomi centralnega živčnega sistema in glioblastomi. Kljub temu je specifičnost naše raziskave nizka in primarne limfome centralnega živčnega sistema ne moremo radiološko izključiti zgolj na podlagi vrednosti tumorskega signala dovzetnosti. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 135-140. doi:10.1515/raon-2015-0011 Diagnosticiranje mehkotkivnih sarkomov z dopplerskim ultrazvokom. Učinkovitost presejalnega točkovalnika z ultrazvokom Nagano S, Yahiro Y, Yokouchi M, Setoguchi T, Ishidou Y, Sasaki H, Shimada H, Kawamura I, Komiya S Izhodišča. Znana je uporaba ultrazvoka v postopku presejanja mehkotkivnih tumorjev. Takšne tumorje smo razvrstili glede na vzorec prekrvavljenosti z dopplerskim ultrazvokom ter ponovno ocenili učinkovitost te slikovne diagnostične preiskave kot presejalne metode. Dopplerski ultrazvok smo združili tudi z ostalimi dobljenimi podatki pri ultrazvočni preiskavi, da bi izboljšali učinkovitost diagnosticiranja in da bi uvedli novo diagnostično orodje. Preiskovanci in metode. V preiskavo smo vključili 189 histološko potrjenih mehkotkivnih tumorjev (122 benignih primerov vključno z benignimi mehkotkivnimi tumorji in podobnimi tumorskimi spremembami ter 67 malignih primerov mehkotkivnih tu­morjev). Preiskava z ultrazvokom je vključevala oceno prekrvavljenosti z barvnim dopplerskim ultrazvokom. Vzpostavili smo točk­ovalnik za bolj učinkovito razlikovanje malignih od benignih mehkotkivnih tumorjev (ultrazvočni presejalni točkovalnik sarkoma). Rezultati. Srednja vrednost skupine benignih primerov je bila 1,47 ± 0,93, skupine malignih primerov pa 3,42 ± 1,30. Preiskovanci z malignimi spremembami so imeli pomembno višje vrednosti ultrazvočnega presejalnega točkovalnika sar­koma kot preiskovanci z benignimi lezijami. Z analizo značilnosti delujočega sprejemnika je bila površina pod krivuljo 0,88. Z določitvijo vrednosti (3 točke), izračunano z analizo krivulje značilnosti delujočega sprejemnika, je bila senzitivnost 85,1 % in specifičnost 86,9 %. Zaključki. Ocena prekrvavljenosti samo z d opplerskim ultrazvokom ni zadostna za razlikovanje med benignimi in malignimi mehkotkivnimi tumorji. Predoperativna diagnoza večine mehkotkivnih tumorjev je možna z združevanjem našega ultrazvoč­nega presejalnega točkovalnika sarkoma s kliničnimi in magnetnoresonančnimi značilnostmi. Radiol Oncol 2015; 49(2): 141-146. doi:10.2478/raon-2014-0037 Akutna ishemična možganska kap v povirju Percheronove arterije. Pregled literature s kliničnim primerom Lamot U, Ribarič I, Šurlan Popović K Izhodišča. Klinični simptomi in znaki, ki podajo sum na ishemično možgansko kap v področju posteriorne cirkulacije, zahte­vajo celovito radiološko obravnavo. To najbolje dosežemo z združevanjem različnih radioloških slikovnopreiskovalnih metod, kot so računalniška tomografija, perfuzijska računalniška tomografija, računalniška tomografska angiografija, magnetnore­sonančno slikanje in difuzijsko poudarjeno slikanje. Diagnozo akutne možganske kapi v obdobju, ko je možgansko tkivo še povratno prizadeto, omogoča ustrezen izbor zdravljenja ter prispeva k boljšemu izidu bolezni. Zaradi navedenih razlogov je nujno, da prepoznamo anatomske različice prekrvavitve v posteriorni možganski cirkulaciji, kot je tudi Percheronova arterija. Prikaz primera. Pri 69-letni bolnici, ki so jo še videli pri polni zavesti pred 10 urami, se je akutna ishemična kap v podro­čju Percheronove arterije klinično pokazala z dvema značilnima znakoma: odsotnostjo okulocefalnega refleksa in komo. Opravljeni preiskavi ob sprejemu, nativna računalniška tomografija glave in računalniška tomografska angiografija vratnega in možganskega žilja, smo sprva ocenili kot normalni. Ponovna nativna računalniška tomografija glave, ki smo jo opravili 24 ur kasneje, je prikazala hipodenzno področje v medialnih predelih obeh talamusov. Ostalih radioloških slikovnopreiskovalnih metod nismo opravili, saj smo predvideli, da je časovno okno za zdravljenje s trombolizo že preteklo. Združevanje vseh dosto­pnih radioloških slikovnopreiskovalnih metod bi morda prispevalo k diagnozi ishemične kapi še v akutnem obdobju bolezni. Diagnozo ishemične možganske kapi v povirju Percheronove arterije smo tako postavili retrospektivno, s ponovnim pregle­dom računalniške tomografske angiografije vratnega in možganskega žilja. Zaključki. Združevanje različnih dostopnih radioloških slikovnopreiskovalnih metod je nujno pri vsakem bolniku s sumom na is­hemično kap v področju posteriorne možganske cirkulacije nemudoma po nastanku simptomov. To še posebej velja za primere, ko so izvidi prvotno opravljenih radioloških slikovnih preiskav brez posebnosti, torej v nasprotju z hudimi nevrološkimi klinični znaki. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 147-154. doi:10.1515/raon-2015-0013 Izvedljivost in varnost elektrokemoterapije pri raku trebušne slinavke. Predklinična raziskava Girelli R, Prejano S, Cataldo I, Corbo V, Martini L, Scarpa A, Claudio B Izhodišča. Žlezni rak trebušne slinavke je največkrat smrtna bolezen, kjer je standardno sistemsko zdravljenje neuspešno. Glavni razlog za neobčutljivost trebušne slinavke na zdravljenje je fibroza, ki ovira pristop zdravil. Iščejo nove načine zdravlje­nja. Elektrokemoterapija je način lokalnega zdravljenja, kjer lahko z aplikacijo električnih pulzov povečamo privzem citostati­ka, kar poveča njegovovo učinkovitost. Namen raziskave je bil proučiti in vivo učinke elektroporacije na normalni zajčji trebu­šni slinavki, ki je bila eksperimentalni model. Proučili smo tudi citotoksičnost bleomicina in cisplatina ob njihovi elektroporaciji na celične linije trebušne slinavke. Pri tem smo uporabili celični liniji trebušne slinavke PANC1 in MiaPaCa2. Materiali in metode. Za elektroporacijo trebušne slinavke smo uporabili standardni protokol elektroporacije, t.j. 1000 V/ cm, 8 pulzov, 100 µs, 5 KHz, na belih zajcih Nove Zelandije ter sledili takojšnje in dolgoročne stranske pojave. Stopnjo perme­abilizacije celic smo merili s pretočno citometrijo, viabilnost celic in njihovo kemosenzitivnost pa s testom 3-(4,5-dimetiltiazol-2­-yl)-5-(3-karboksimetoksifenil)-2-(4-sulfofenil)-2H-tetrazolim (MTS). Rezultati. Elektroporacija trebušne slinavke zdravih zajcev ni imela lokalnih ali sistemskih toksičnih učinkov na živali. Rezultati zatorej dokazujejo potencialno varnost elektrokemoterapije. In vitro raziskava pa dokazuje povečano kemosenzitivnost dveh celičnih linij trebušne slinavke na zdravljenje z eletrokemoterapijo, tako z bleomicinom kot tudi cisplatinom. Zaključki. Podatki nakazujejo varnost aplikacije električnih pulzov v zdravi trebušni slinavki. Z aplikacijo takih električnih pulzov lahko vplivamo na citotoksičnost bleomicina ali cisplatina pri njihovi uporabi v elektrokemoterapiji. Radiol Oncol 2015; 49(2): 155-162 doi:10.2478/raon-2014-0044 Učinkovitost intenzitetno modulirane radioterapije in sočasne kemoterapije s karboplatinom pri raku nosnega žrela Songthong A, Chakkabat C, Kannarunimit D, Lertbutsayanukul C Izhodišča. Namen prospektivne klinične raziskave faze II je bil oceniti učinkovitost in toksičnost sočasnega zdravljenja s kar­ boplatinom in intenzitentno modulirano radioterapijo (IMRT) pri bolnikih z rakom nosnega žrela. Bolniki in metode. Med oktobrom 2005 in novembrom 2011 je 73 bolnikov z rakom nosnega žrela stadija II-IVB prejelo 70 Gy IMRT sočasno s tremi krogi karboplatina (AUC 5) na 3 tedne. Nato so bolniki v štiritedenskih intervalih dodatno prejeli tri kroge karboplatina (AUC 5) in 5-FU-ja (1.000 mg/m2, dnevi 1.4). Pri vseh bolnikih smo ocenili odgovor tumorja na zdravljenje s kriteriji RECIST, preživetje s Kaplan-Meierjevo metodo in toksičnost po običajnih terminoloških kriterijih za neželene učinke zdravljenja (CTCAE) verzije 4.0. Rezultati. Tri mesece po kemoradioterapiji sta bila popoln in delen odgovor dosežena pri 82,2 % oz. 17,8 % bolnikov. Po srednjem času sledenja 48,1 mesecev (razpon 1,3.97,8 mesecev) je imelo 8,2 % bolnikov lokalno ponovitev bolezni in 17,8 % oddaljene zasevke. Srednje preživetje ni bilo doseženo. Celokupno preživetje po treh letih opazovanja je bilo 83,6 % in preži­vetje brez napredovanja bolezni 65,3 %. Obsevanje je zaključilo 97,2 % bolnikov, sočasno kemoterapijo s karboplatinom 69,9 % in dodatno kemoterapijo 68,5 %. Akutna toksičnost stopnje 3.4 se je kazala kot oralni mukozitis (16,4 %), disfagija (16,4 %), kserostomija (15,1 %) in hematotoksičnost (6,8 %). Zaključki. Bolniki z rakom nosnega žrela, ki so sočasno prejeli karboplatin in IMRT, so imeli odličen odgovor tumorja na zdra­vljenje, toksičnost je bila obvladljiva in zdravljenje dobro tolerirano. Takš no zdravljenje predstavlja alternativo standardnemu zdravljenju s cisplatinom. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 163-172. doi:10.2478/raon-2014-0027 Predoperativno zdravljenje z radiokemoterapijo pri bolnikih z neresektabilnim rakom želodca in lokoregionalno napredovalim rakom gastroezofagealnega prehoda Ratoša I, Oblak I, Anderluh F, Velenik V, But-Hadžić J, Šečerov Ermenc A, Jeromen A Izhodišča. Namen raziskave je bil analizirati izide zdravljenja s predoperativno radiokemoterapijo pri bolnikih z neresektabil­nim rakom želodca in lokoregionalno napredovalim rakom gastroezofagealnega (GE) prehoda, zdravljenih na Onkološkem inštitutu v Ljubljani. Bolniki in metode. V retrospektivno raziskavo smo vključili bolnike z neresektabilnim žleznim rakom želodca in lokoregio­nalno napredovalim žleznim rakom GE prehoda, ki smo jih med januarjem 2004 in junijem 2012 zdravili s predoperativno radi­okemoterapijo. V shemi zdravljenja so bili trije krogi kemoterapije s 5-fluorouracilom in cisplatinom in 28 dni obsevanja, ki smo ga pričeli sočasno z drugim krogom kemoterapije. Bolnike smo obsevali s tridimenzionalno konformno tehniko na linearnem pospeševalniku, s fotoni energij 6 in 15 MV. Protokol obsevanja je predvideval v 5 tednih 25 dnevnih frakcij obsevanja po 1,8 Gy. Bolniki so bili operirani 4–6 tednov po zaključenem predoperativnem zdravljenju. Multidisciplinarni konzilij zdravnikov se je po operaciji posameznega bolnika individualno odločil še za dopolnilno zdravljenje s kemoterapijo. Primarna cilja raziskave sta bila stopnja radikalne patohistološke resekcije (R0) in stopnja patološkega odgovora na predoperativno zdravljenje. Sekundarna cilja raziskave pa sta bila ugotoviti preživetje bolnikov in zaznati stranske učinke predoperativne radiokemote­rapije. Rezultati. Po protokolu je predoperativno zdravljenje zaključilo 84 od 90 bolnikov (93,3 %). Pri dvajsetih bolnikih (22,2 %) kirurška odstranitev tumorja ni bila možna zaradi napredovanja bolezni, pridruženih bolezni, slabega splošnega stanja zmo­gljivosti ali zaradi tumorja, ki kljub predoperativnemu zdravljenju ni bil resektabilen v času operacije. Pri 13 bolnikih (14,4 %) smo zato zaradi neresektabilnosti tumorja ali difuzne karcinomatoze peritoneja naredili kirurško eksploracijo. S ciljem popolne odstranitve tumorja pa je bilo operiranih 57 (63,4 %) bolnikov. Resekcijo R0 smo naredili pri 50 bolnikih (55,6%), neradikalno operacijo (R1 ali R2) pa pri 7 bolnikih (7,8 %), ki so sodelovali v raziskavi. Od vseh operiranih bolnikov (n = 57) je popolni patološki odgovor doseglo 5 bolnikov (5,6 % od vseh zdravljenih bolnikov ali 8,8 % od vseh operiranih bolnikov). Zmanjšanje tumorja in/ali bezgavk je bilo doseženo pri 49 bolnikih (86 %), nespremenjen stadij pri enem (1,8 %) in povišanje stadija, predvsem na račun povečanja števila patoloških bezgavk, pa pri 7 (12,3 %) operiranih bolnikih. Slabost, bruhanje ali supresija kostnega mozga so predstavljali največji delež stopnje 3 ali 4 stranskih učinkov zdravljenja. Smrti zaradi predoperativne radiokemoterapije nismo zabeležili. En bolnik je umrl zaradi septičnega šoka po operaciji, vzrok smrti dveh bolnikov ni znan. 26 bolnikov (45,6 %) je umrlo zaradi raka želodca ali raka GE prehoda. 28 (49,1 %) bolnikov je bilo v času analize podatkov brez bolezni, medtem ko smo ponovitev bolezni – večinoma zaradi oddaljenih zasevkov – ugotavljali pri 29 bolnikih (50,9 %). 2-letna lokoregionalna kontrola bolezni je bila 82,9 %, preživetje brez bolezni 43,9 %, bolezensko specifično preživetje 56,9 % in celokupno preživetje 53,9 %. Zaključki. Predoperativna radiokemoterapija je omogočila zmanjšanje velikosti tumorja in/ali bezgavk, večji odstotek radi­kalnih resekcij ter zato več možnosti ozdravitve bolnikov. Toksičnost zdravljenja je bila sprejemljiva. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 173-180. doi:10.2478/raon-2014-0050 Febrilna nevtropenija pri kemoterapevtskem zdravljenju bolnikov z drobnoceličnim pljučnim rakom Režonja Kukec R, Grabnar I, Vovk T, Mrhar A, Kovač V, Čufer T Izhodišča. Zdravljenje drobnoceličnega pljučnega raka s kombinacijo kemoterapevtikov etopozida in cisplatina naj bi bilo povezano s srednjim (10.20 %) tveganjem za febrilno nevtropenijo. Onkološke smernice rutinske uporabe rastnih dejavnikov ob tem zdravljenju ne priporočajo, vendar v klinični praksi pri standardnem zdravljenju z etopozidom in cisplatinom pogosto srečujemo primere febrilne nevtropenije. Namen raziskave je bil oceniti pogostnost nevtropenije in febrilne nevtropenije pri bolnikih z razsejanim drobnoceličnim pljučnim rakom po prvem krogu standardne kemoterapije ter pri istih bolnikih raziskati povezavo med nevtropenijo visoke stopnje in maksimalnimi plazemskimi koncentracijami etopozida. Metode. Analizirali smo skupino 17 bolnikov z razsejanim drobnoceličnim pljučnim rakom zdravljenih s kombinacijo citosta­tikov etopozida in cisplatina. Ti bolniki so bili že vključeni v farmakokinetično raziskavo zdravljenja z etopozidom. Zbrali smo podatke o nevtropeniji stopnje 3 in 4 ter febrilni nevtropeniji po prvem krogu zdravljenja. Vrednosti nevtrofilcev smo določili prvi dan drugega kroga zdravljenja, razen, če so se simptomi povezani z nevtropenijo pojavili prej. Neželene učinke smo kla­sificirali s pomočjo kriterijev Nacionalnega inštituta za zdravljenje raka (NCI-CTC), verzija 4,0. Dodatno smo raziskali povezavo med nevtropenijo visoke stopnje in maksimalnimi plazemskimi koncentracijami etopozida, ki so bile izmerjene kot sestavni del farmakokinetične raziskave. Rezultati. Dva od 17 bolnikov sta prejela primarno zaščito z rastnimi dejavniki. Pri 15 bolnikih brez primarne zaščite je bil delež bolnikov z nevtropenijo stopnje 3 in 4 ter delež s febrilno nevtropenijo visok (8/15 [53,3 %] in 2/15 [13,3 %]) glede na dejstvo, da se podatki nanašajo samo na prvi krog zdravljenja. En bolnik je zaradi pljučnice povezane s febrilno nevtropenijo umrl. Domnevno so nevtropenični dogodki ob standardnem odmerku etopozida in cisplatina povezani s povečanimi plazemskimi koncentracijami etopozida. Najvišji koncentraciji etopozida (27,07 in 27,49 mg/l) sta namreč bili določeni pri bolnikoma, ki sta razvila febrilno nevtropenijo. Povprečna maksimalna plazemska koncentracija etopozida v prvem krogu je bila sicer 17,6 mg/l. Zaključki. Rezultati naše študije nakazujejo potrebo po zmanjševanju tveganja za nevtropenične dogodke pri kemotera­pevtskem zdravljenju drobnoceličnega pljučnega raka, začenši v prvem krogu zdravljenja. Ena izmed možnosti je obvezna primarna zaščita z uporabo rastnih dejavnikov. Druga možnost pa so izboljšani modeli za določanje tveganja z namenom ugotoviti, kateri bolniki imajo povečano tveganje za nevtropenijo. Individualizacija primarne zaščite, ki temelji ne samo na kliničnih lastnostih, ampak tudi na vrednostih plazemskih koncentracij etopozida, predstavlja dodatno možnost, ki bi jo bilo smiselno upoštevati. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 181-184. doi:10.2478/raon-2014-0024 Ishemija mezenterija po zdravljenju s kapecitabinom pri raku danke in posledičnim sindromom kratkega črevesja ni absolutna kontraindikacija za radikalno onkološko zdravljenje Perpar A, Brecelj E, Rotovnik Kozjek N, Anderluh F, Oblak I, Skoblar Vidmar M, Velenik V Izhodišča. Arterijski ali venski trombotični zapleti so resna obolevnost in pomemben vzrok smrtnosti pri bolnikih z rakom. Nagnjenost do razvoja teh zapletov je delno posledica bolezni, delno pa naših poskusov zdravljenja raka. Eden najredkejših in najbolj nevarnih trombemboličnih zapletov je ishemija mezenterija. Visoka smrtnost je posledica redkosti zapleta in neznačilnih simptomov, ki otežijo zgodnjo diagnozo in zdravljenje; zaplet običajno odkrijemo in zdravimo pozno. Bolniki, ki preživijo ishemijo mezenterija, imajo lahko sindrom kratkega črevesja, ki je po uvedbi parenteralne prehrane na domu postal kronična bolezen. Prikaz primera. Predstavljamo 73-letnega bolnika z rakom danke, pri katerem smo ugotovili akutno trombozo mezen­terične arterije na začetku predoperativne radiokemoterapije. Potrebna je bila resekcija ascendentnega kolona in skoraj celotnega tankega črevesja razen proksimalnih 50 cm. Bolnik je imel multiorgansko odpoved, nato pa se je njegovo stanje izboljšalo. Uspešno je zaključil radikalno zdravljenje raka danke (predoperativno radioterapijo in operacijo). Še vedno preje­ma parenteralno prehrano na domu, ker je preostanek črevesja prekratek, da bi zadostil bolnikovim prehranskim potrebam. Zaključki. Ishemija mezenterija in sindrom kratkega črevesja, ki je njena posledica, nista absolutni kontraindikaciji za radi­kalno onkološko zdravljenje, še posebej, če s tem lahko dosežemo ozdravitev. Radiol Oncol 2015; 49(2): 185-191. doi:10.1515/raon-2015-0008 Klinična uporabnost izračuna biološke učinkovite doze za hrbtenjačo pri zdravljenju s stereotaktičnim obsevanjem telesa Lee SH, Lee KC, Choi J, Ahn SH, Lee SH, Sung KH, Kil SH Izhodišča. Namen raziskave je bil ugotoviti, ali lahko izračun biološko učinkovite doze (BED), ki temelji na linearno-kvadra­tnem modelu, uporabljamo za ocenjevanje tolerančne doze hrbtenjače pri stereotaktičnem obsevanju telesa (SBRT) ob uporabi štirih ali več frakcij. Bolniki in metode. Retrospektivno smo ocenili 63 metastatskih sprememb hrbtenjače pri 47 bolnikih. Najpogosteje pred­pisana doza je bila 36 Gy v 4 frakcijah. Pri načrtovanju smo poskušali omejiti najvišji predpisani odmerek na hrbtenjačo ali na caudo equino na manj kot 50% ali 45 Gy2/2. Pri izračunu BED smo uporabili najvišjo točko doze na hrbtenjačo. Rezultati. Največja doza na hrbtenjačo v eni frakciji je bila v razponu 2,6–6,0 Gy (mediana 4,3 Gy). Enakovredna skupna doza v frakcijah po 2 Gy ni bila večja od 50 Gy2/2 (12,1–67,9; mediana 32,0), razen pri 4 bolnikov s 52,7, 56,4, 62,4 in 67,9 Gy2/2. Razmerje med najvišjo in predpisano dozo na hrbtenjačo se je povečalo do 82,2 % predpisane doze, ko se je povečala stopnja kompresije epiduralnega dela hrbtenjače. Pri nobenem bolniku se v obdobju spremljanja od 0,5 do 53,9 mesecev ni razvila druga stopnja toksičnosti hrbtenjače povzročene z obsevanjem. Zaključki. Pri SBRT v več frakcijah BED lahko uporabljamo za oceno tolerančne doze na hrbtenjačo pod pogojem, da je doza ene frakcije na hrbtenjačo zmerna, <6,0 Gy. Kaže se, da je največja doza do 45–50 Gy2/2 na hrbtenjačo sprejemljiva pri obsevanju s 4 ali več frakcijami. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 192-199. doi:10.1515/raon-2015-0006 Dinamična računalniško tomografska angiografija pri načrtovanju radiokirurškega zdravljenja intrakranialnih arteriovenskih malformacij z robotskim nožem (cyberknife). Tehnično poročilo in izvedljivost Haridass A, Maclean J, Chakraborty S, Sinclair J, Szanto J, Iancu D, Malone S Izhodišča. Pri uspešni radiokirurgiji arteriovenskih malformacij je potrebno natančno očrtati nidus za obsevanje v 3D načr­tovalnem sistemu. Za oceno AVM nidusa je za zlati standard veljal kateterski biplanirni digitalni subtrakcijski angiogram (DSA). DSA je zaradi dvodimenzionalnosti omejeval svojo vlogo pri očrtovanju; prav tako ga ni bilo mogoče uvoziti v delovno postajo pri načrtovanju zdravljenja z robotskim nožem. Predstavljamo tehniko pridobivanja in integracije 3D dinamičnih računalniško tomografskih angiogramov (dCTA) v delovno postajo pri načrtovanju obsevanja z robotskim nožem za intrakranialne arterio­venske malformacije ter oceno izvedljivosti uporabe te tehnike v prvi kohorti bolnikov. Metode. Dinamične zaporedne računalniško tomografske slike celotnih možganov smo pridobili z volumsko slikovno CT napravo Toshiba 320. Podatke smo rekonstruirali vsakih 0,5 sekund. Na ta način smo veččasovno točkovno zajeli podatke in izbrali CT slike z najbolj jasnim nidusom. Krvnih žil v okolici ni bilo potrebno pomembno ojačiti. Podatke smo uvozili v postajo za načrtovanje zdravljenja z robotskim nožem in jih sočasno registrirali z načrtovalnim CT in T2 MRI ter 2D DSA dodali kot referenco. Ocenili smo zmožnost uporabe dCTA pri prvih 13 bolnikih in iz njihovih kartotek ocenili tudi rezultate zdravljenja. Rezultati. Podatke dCTA smo pravilno zajeli v postajo za načrtovanje zdravljenja z robotskim nožem in videti je, da so bili v pomoč pri očrtanju nidusa pri vseh bolnikih. Slikovni načini so se dopolnjevali. Po srednjem času 37 mesecev spremljanja je imelo 85 % bolnikov popolno (6/13) ali napredujočo delno (5/13) obliteracijo nidusa. Zaključki. dCTA je obetajoča slikovna tehnika, ki jo lahko uspešno uporabimo za uvoz v postajo za načrtovanje zdravljenja z robotskim nožem. Videti je, da pomaga pri opredelitvi nidusa za potrebe radiokirurgije. Potrebne so nadaljnje raziskave za potrditev njene vloge. Radiol Oncol 2015; 49(2): I-IX. Slovenian abstracts Radiol Oncol 2015; 49(2): 200-208. doi:10.2478/raon-2014-0046 Stroški zdravljenja razsejanega raka debelega črevesa in danke v Sloveniji. Analiza neskladij med stroški in priznanimi plačili Mesti T, Boshkoska BM, Kos M, Tekavčič M, Ocvirk J Izhodišča. Naredili smo oceno dejanskih stroškov zdravljenja razsejanega raka debelega črevesa in danke (rRDČD) v Sloveniji za leto 2009. Onkološki inštitutu Ljubljana je bil edina ustanova, kjer smo to bolezen v Sloveniji zdravili. Stroške smo primerjali s plačilom Zavoda za zdravstveno zavarovanje Slovenije. Metode. Z retrospektivno analizo bolnikovih podatkov iz notranje baze podatkov smo (1) določili neposredne medicinske stroške zdravljenja rRDČD leta 2009 ter (2) določili razliko med prejetim plačilom Zavoda za zdravstveno zavarovanje Slovenije in dejanskimi stroških sistemskega zdravljenja. V obdobju zdravljenja bolezni smo analizirali neposredne medicinske stroške akutnega bolnišničnega sistemskega zdravljenja, skupaj s stroški bolnišničnega zdravljenja zaradi morebitnih stranskih učinkov. Izvzeli smo stroške možnega obsevanja ali kirurškega zdravljenja. Prav tako smo izvzeli indirektne medicinske stroške, nemedi­cinske stroške in stroški spremljanja. Rezultati. Skupina 209 bolnikov je izpolnjevala vključitvene kriterije. Neposredne medicinske stroške bolnišničnega zdravlje­nja rRDČD s sistemsko terapijo na Onkološkem inštitutu Ljubljana za leto 2009 smo ocenili kot strošek zdravil (strošek sistemske terapije + strošek zdravil za premedikacijo) + strošek dela (strošek izvedbe sistemskega zdravljenja) + strošek laboratorijskih preiskav + strošek slikovnih preiskav + strošek testiranja KRAS + strošek bolnišnične obdelave zaradi stranskih učinkov zdravljenja rRDČD. Znašali so 3.914.697 €. Razlika med izplačanimi stroški Zavoda za zdravstveno zavarovanje Slovenije ter dejanskimi stroški, ocenjenimi kot neposredni medicinski stroški bolnišničnega zdravljenja rRDČD s sistemsko terapijo na Onkološkem inštitutu Ljubljana za leto 2009, je bila 1.900.757,80 €. Zaklučki. Stroški, ki jih je plačal Zavod za zdravstveno zavarovanje Slovenije Onkološkemu Inštitutu Ljubljana za zdravljenje rRDČD s sistemsko terapijo, se ne ujemajo z dejanskimi stroški zdravljenja. Razlika med izplačanimi in dejanskimi stroški za leto 2009 je bila 1.900.757,80 €. Verjetno je eden od razlogov za razhajanja med izplačili in dejanskimi stroški avstralski model (AR­DRG), ki ga v Sloveniji uporabljamo za oceno stroškov v onkologiji. Predlagamo novo metodo za natančnejšo oceno stroškov . Radiol Oncol 2015; 49(2): I-IX. Spoštovani! UP Fakulteta za vede o zdravju bo v času od 18. do 22. maja 2015 v okviru projekta UP IN SVET organizirala mednarodno delavnico za študente z naslovom »CANCER WORKSHOP – Od preprečevanja do novih pristopov zdravljenja«. Delavnica bo potekala na Univerzi na Primorskem, v prostorih Fakultete za vede o zdravju, Polje 42, 6310 Izola, v popoldanskem času. Cilj delavnice je dobiti celovit vpogled v značilnosti raka iz biološkega in medicinskega vidika s posebnim poudarkom na preprečevanju te bolezni, molekularnih poteh, ki sodelujejo pri nastanku in napredovanju te bolezni, diagnostiki ter pristopih novih oblik zdravljenja. V okviru večdnevne delavnice bo tako predstavljenih več vsebinskih sklopov, v okviru katerih bodo svoje poglede na problematiko podali številni ugledni strokovnjaki in raziskovalci s področja. Delavnica je namenjena pretežno študentom Univerze na Primorskem, lahko pa se je udeležijo tudi ostali zainteresirani, ki jih tematika zanima. Udeležba na delavnici je BREZPLAČNA! Program najdete na spletni strani UP FVZ http://www.fvz.upr.si/sl/napovednik-izobrazevanje Prijave zbiramo na elektronski naslov: cancerworkshop@fvz.upr.si najkasneje do petka, 8. maja 2015. Prijava je obvezna tudi v primeru, da se želite udeležiti samo določenega dela programa oz. posameznega dne. Veseli bomo, če informacijo o dogodku posredujete svojim kolegom, poslovnim partnerjem in drugim morebitnim zainteresiranim v svojih okoljih. Vljudno vabljeni! UP IN SVET – Mednarodna vpetost Univerze na Primorskem: operacijo delno .nancira Evropska unija iz Evropskega socialnega sklada ter Ministrstvo za izobraževanje, znanost in šport. Operacija se izvaja v okviru Operativnega programa razvoja človeških virov za obdobje 2007-2013, razvojne prioritete: 3.: Razvoj človeških virov in vseživljenjskega učenja; prednostne usmeritve 3.3.: Kakovost, konkurenčnost in odzivnost visokega šolstva. Fundacija Doc. dr. Josip Cholewa razpisuje denarno pomoč za sofinanciranje materialnih stroškov pri znanstveno-raziskovalnih delih s področja onkologije. Prijava naj vsebuje: 1. kratko obrazložitev znanstveno-raziskovalnega dela s finančno konstrukcijo 2. kratko biografijo in bibliografijo prosilca/prosilcev Prijave, prosimo, pošljite do 30. 9. 2015 na naslov Združenje Fundacija Doc.dr. Josip Cholewa, Dunajska cesta 106, 1000 Ljubljana Fundacija "Docent dr. J. Cholewa" je neprofitno, neinstitucionalno in nestrankarsko združenje posameznikov, ustanov in organizacij, ki želijo materialno spodbujati in poglabljati raziskovalno dejavnost v onkologiji. Uporabljena moška slovnična oblika se enakovredno nanaša na oba spola. Activity of "Dr. J. Cholewa" Foundation for Cancer Research and Education – a report for the second quarter of 2015 The “Docent Dr. J. Cholewa Foundation for Cancer Research and Education” is a non-profit, non-political and non-government organisation that helps professionals, institutions and individuals obtaining finan­cial help for cancer research and education in the Republic of Slovenia. It carries the name of Dr. Josip Cholewa, one of the first researchers in cancer in Slovenia and the founder of the “Banovinski Inštitut za raziskovanje in zdravljenje novotvorb”, that later became the Institute of Oncology in Ljubljana, Slovenia. Already in the twenties of the previous century, his research was based on multidisciplinary approach to prevention, detection and treatment of cancer, as a harbinger of all the progress observed in a large part of the world until now. High quality cancer research demands a lot of financial support and many excellent ideas cannot be put into practical use for the simple lack of it. The most important activity of the Foundation is to provide at least some of the financial support needed by qualified individuals and organisations interested in cancer research. The Foundation aims to help with the transmission of the latest diagnostic and therapy proce­dures to the everyday research and clinical environment in Slovenia. This part of Foundation’s activity represents the most direct benefit for the ever increasing number of patients with various types of cancer in Slovenia, since the incidence rates of many cancer, like colon, prostate and breast cancer, have kept rising in recent decades. The Foundation continues to provide financial support to "Radiology and Oncology”, an international sci­entific journal that is edited and published in Ljubljana, Slovenia. It publishes scientific research articles, reviews, case reports, short reports and letters to the editor about research and studies in experimental and clinical oncology, supportive therapy, radiology, radiophyics, prevention and early diagnostics of different types of cancer. It is an open access journal freely available in pdf format and with a respectable Science Citation Index Impact factor. All the abstracts in “Radiology and Oncology” are available in Slovenian and the journal can thus provide sufficient scientific information from various fields of high quality cancer re­search to interested lay public in Slovenia. The “Docent Dr. J. Cholewa Foundation for Cancer Research and Education” has thus an important role in support of many scientists involved in cancer research, cancer education and in many of the related fields in the Republic of Slovenia. The next meeting of its Executive Board is to take place in late May this year, when its activity in 2014 and its future activity are to be discussed and reviewed. Borut Štabuc, MD, PhD Tomaž Benulič, MD Viljem Kovač, MD, PhD Andrej Plesničar, MD. MSc Kakovostna in količinska sestava 1 ml raztopine vsebuje 1,5 mg benzidaminijevega klorida, kar ustreza 1,34 mg benzidamina. V enem razpršku je 0,17 ml raztopine. En razpršek vsebuje 0,255 mg benzidaminijevega klorida, kar ustreza 0,2278 mg benzidamina. En razpršek vsebuje 13,6 mg 96 odstotnega etanola, kar ustreza 12,728 mg 100 odstotnega etanola, in 0,17 mg metilparahidroksibenzoata (E218). Terapevtske indikacije Samozdravljenje: lajšanje bolečine in oteklin pri vnetju v ustni votlini in žrelu, ki so lahko posledica okužb in stanj po operaciji. Po nasvetu in navodilu zdravnika: lajšanje bolečine in oteklin v ustni votlini in žrelu, ki so posledica radiomukozitisa. Odmerjanje in način uporabe Uporaba 2- do 6-krat na dan (vsake 1,5 do 3 ure). Odrasli: 4 do 8 razprškov 2- do 6-krat na dan. Otroci od 6 do 12 let: 4 razprški 2- do 6-krat na dan. Otroci, mlajši od 6 let: 1 razpršek na 4 kg telesne mase; do največ 4 razprške 2 do 6-krat na dan. Kontraindikacije Znana preobčutljivost za zdravilno učinkovino ali katerokoli pomožno snov. Posebna opozorila in previdnostni ukrepi Pri manjšini bolnikov lahko resne bolezni povzročijo ustne/žrelne ulceracije. Če se simptomi v treh dneh ne izboljšajo, se mora bolnik posvetovati z zdravnikom ali zobozdravnikom, kot je primerno. Zdravilo vsebuje aspartam (E951) (vir fenilalanina), ki je lahko škodljiv za bolnike s fenilketonurijo. Zdravilo vsebuje izomalt (E953) (sinonim: izomaltitol (E953)). Bolniki z redko dedno intoleranco za fruktozo ne smejo jemati tega zdravila. Uporaba benzidamina ni priporočljiva za bolnike s preobčutljivostjo za salicilno kislino ali druga nesteroidna protivnetna zdravila. Pri bolnikih, ki imajo ali so imeli bronhialno astmo, lahko pride do bronhospazma. Pri takih bolnikih je potrebna previdnost. Medsebojno delovanje z drugimi zdravili in druge oblike interakcij Pri ljudeh raziskav o interakcijah niso opravljali. Nosečnost in dojenje Tantum Verde z okusom mentola 3 mg pastile se med nosečnostjo in dojenjem ne smejo uporabljati. Vpliv na sposobnost vožnje in upravljanja s stroji Uporaba benzidamina lokalno v priporočenem odmerku ne vpliva na sposobnost vožnje in upravljanja s stroji. Neželeni učinki Bolezni prebavil Redki: pekoč občutek v ustih, suha usta. Bolezni imunskega sistema Redki: preobčutljivostna reakcija. Bolezni dihal, prsnega koša in mediastinalnega prostora Zelo redki: laringospazem. Bolezni kože in podkožja Občasni: fotosenzitivnost. Zelo redki: angioedem. Rok uporabnosti 4 leta. Zdravila ne smete uporabljati po datumu izteka roka uporabnosti, ki je naveden na ovojnini. Posebna navodila za shranjevanje Za shranjevanje pastil niso potrebna posebna navodila. Plastenko z raztopino shranjujte v zunanji ovojnini za zagotovitev zaščite pred svetlobo. Shranjujte pri temperaturi do 25°C. Shranjujte v originalni ovojnini in nedosegljivo otrokom. 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Therefore, the scope of the journal is to cover beside radiology the diagnostic and therapeutic aspects in oncology, which distinguishes it from other journals in the field. The Editorial Board requires that the paper has not been published or submitted for publication elsewhere; the authors are responsible for all statements in their papers. Accepted articles become the property of the journal and, therefore cannot be published elsewhere without the written permission of the editors. Submission of the manuscript The manuscript written in English should be submitted to the journal via online submission system Editorial Manager avail­able for this journal at: www.radioloncol.com. In case of problems, please contact Sašo Trupej at saso.trupej@computing.si or the Editor of this journal at gsersa@onko-i.si All articles are subjected to the editorial review and when the articles are appropriated they are reviewed by independent ref­erees. In the cover letter, which must accompany the article, the authors are requested to suggest 3-4 researchers, competent to review their manuscript. However, please note that this will be treated only as a suggestion; the final selection of reviewers is exclusively the Editor’s decision. The authors’ names are revealed to the referees, but not vice versa. Manuscripts which do not comply with the technical requirements stated herein will be returned to the authors for the cor­rection before peer-review. The editorial board reserves the right to ask authors to make appropriate changes of the contents as well as grammatical and stylistic corrections when necessary. Page charges will be charged for manuscripts exceeding the recommended length, as well as additional editorial work and requests for printed reprints. Articles are published printed and on-line as the open access (www.degruyter.com/view/j/raon). All articles are subject to 7 00 EUR + VAT publication fee. Exceptionally, waiver of payment may be negotiated with editorial office, upon lack of funds. Manuscripts submitted under multiple authorship are reviewed on the assumption that all listed authors concur in the submission and are responsible for its content; they must have agreed to its publication and have given the corresponding author the authority to act on their behalf in all matters pertaining to publication. The corresponding author is responsible for informing the coauthors of the manuscript status throughout the submission, review, and production process. Preparation of manuscripts Radiology and Oncology will consider manuscripts prepared according to the Uniform Requirements for Manuscripts Submitted to Biomedical Journals by International Committee of Medical Journal Editors (www.icmje.org). The manuscript should be written in grammatically and stylistically correct language. Abbreviations should be avoided. If their use is neces­sary, they should be explained at the first time mentioned. The technical data should conform to the SI system. The manu­script, excluding the references, tables, figures and figure legends, must not exceed 5000 words, and the number of figures and tables is limited to 8. Organize the text so that it includes: Introduction, Materials and methods, Results and Discussion. Exceptionally, the results and discussion can be combined in a single section. Start each section on a new page, and number each page consecutively with Arabic numerals. The Title page should include a concise and informative title, followed by the full name(s) of the author(s); the institutional affiliation of each author; the name and address of the corresponding author (including telephone, fax and E-mail), and an abbreviated title (not exceeding 60 characters). This should be followed by the abstract page, summarizing in less than 250 words the reasons for the study, experimental approach, the major findings (with specific data if possible), and the principal conclusions, and providing 3-6 key words for indexing purposes. Structured abstracts are required. Slovene authors are requested to provide title and the abstract in Slovene language in a separate file. The text of the research article should then proceed as follows: Introduction should summarize the rationale for the study or observation, citing only the essential references and stating the aim of the study. Materials and methods should provide enough information to enable experiments to be repeated. New methods should be described in details. Results should be presented clearly and concisely without repeating the data in the figures and tables. Emphasis should be on clear and precise presentation of results and their significance in relation to the aim of the investigation. Discussion should explain the results rather than simply repeating them and interpret their significance and draw conclu­sions. It should discuss the results of the study in the light of previously published work. instructions Charts, Illustrations, Images and Tables Charts, Illustrations, Images and Tables must be numbered and referred to in the text, with the appropriate location indi­cated. Charts, Illustrations and Images, provided electronically, should be of appropriate quality for good reproduction. Illustrations and charts must be vector image, created in CMYK color space, preferred font “Century Gothic”, and saved as .AI, .EPS or .PDF format. Color charts, illustrations and Images are encouraged, and are published without additional charge. Image size must be 2.000 pixels on the longer side and saved as .JPG (maximum quality) format. In Images, mask the identities of the patients. Tables should be typed double-spaced, with a descriptive title and, if appropriate, units of numeri­cal measurements included in the column heading. The files with the figures and tables can be uploaded as separate files. References References must be numbered in the order in which they appear in the text and their corresponding numbers quoted in the text. Authors are responsible for the accuracy of their references. References to the Abstracts and Letters to the Editor must be identified as such. Citation of papers in preparation or submitted for publication, unpublished observations, and personal communications should not be included in the reference list. If essential, such material may be incorporated in the appropri­ate place in the text. References follow the style of Index Medicus. All authors should be listed when their number does not exceed six; when there are seven or more authors, the first six listed are followed by “et al.”. The following are some examples of references from articles, books and book chapters: Dent RAG, Cole P. In vitro maturation of monocytes in squamous carcinoma of the lung. Br J Cancer 1981; 43: 486-95. Chapman S, Nakielny R. A guide to radiological procedures. London: Bailliere Tindall; 1986. Evans R, Alexander P. Mechanisms of extracellular killing of nucleated mammalian cells by macrophages. In: Nelson DS, editor. Immunobiology of macrophage. New York: Academic Press; 1976. p. 45-74. Authorization for the use of human subjects or experimental animals When reporting experiments on human subjects, authors should state whether the procedures followed the Helsinki Declaration. Patients have the right to privacy; therefore the identifying information (patient’s names, hospital unit num­bers) should not be published unless it is essential. In such cases the patient’s informed consent for publication is needed, and should appear as an appropriate statement in the article. Institutional approval and Clinical Trial registration number is required. The research using animal subjects should be conducted according to the EU Directive 2010/63/EU and following the Guidelines for the welfare and use of animals in cancer research (Br J Cancer 2010; 102: 1555 – 77). Authors must state the committee approving the experiments, and must confirm that all experiments were performed in accordance with relevant regulations. These statements should appear in the Materials and methods section (or for contributions without this section, within the main text or in the captions of relevant figures or tables). Transfer of copyright agreement For the publication of accepted articles, authors are required to send the License to Publish to the publisher on the address of the editorial office. A properly completed License to Publish, signed by the Corresponding Author on behalf of all the authors, must be provided for each submitted manuscript. The non-commercial use of each article will be governed by the Creative Commons Attribution-NonCommercial-NoDerivs license. Conflict of interest When the manuscript is submitted for publication, the authors are expected to disclose any relationship that might pose real, apparent or potential conflict of interest with respect to the results reported in that manuscript. Potential conflicts of interest include not only financial relationships but also other, non-financial relationships. In the Acknowledgement section the source of funding support should be mentioned. The Editors will make effort to ensure that conflicts of interest will not compromise the evaluation process of the submitted manuscripts; potential editors and reviewers will exempt themselves from review process when such conflict of interest exists. The statement of disclosure must be in the Cover letter accompany­ing the manuscript or submitted on the form available on www.icmje.org/coi_disclosure.pdf Page proofs Page proofs will be sent by E-mail to the corresponding author. It is their responsibility to check the proofs carefully and return a list of essential corrections to the editorial office within three days of receipt. Only grammatical corrections are ac­ceptable at that time. Open access Papers are published electronically as open access on www.degruyter.com/view/j/raon, also papers accepted for publication as E-ahead of print. Za zdravljenje odraslih bolnikov s predhodno zdravljenim, napredovalim nedrobnoceličnim pljučnim rakom, ki je ALK* pozitiven.