ADIOLOGY .,.11 NCOLOGY September -2002 Vol. 36 No. 3 Ljubljana ISSN 1318-2099 SIEMENS SiemensMedical.com/oncology SEEK-FIND-ACT-FOLLOW -the Continuum of Oncology Care™ Siemens oncology portfolio comprises comprehensive maximized utilization potential, and patient-friendly design workflow solutions integrating the full spectrum of care and features. from screening/early detection and diagnosis through therapy and follow-up. AII from one provider -with over Every day in the United States alone, 29,000 cancer 100 years history of innovation in medica\ technology. patients receive radiation therapy delivered by Siemens linear accelerators. As clinical protocols transition to Siemens praven clinical methods can help you to achieve include IMRT and IGRT, Siemens seamlessly integrates more successful outcomes. How? Through industry­the diagnostic and treatment modalities. That's what we leading technology, increased productivity measures for call Best Practice Oncology Care. Siemens medical Solutions that help ADIOLOGY AND NCOLOGY Editurinl office Radiology cmd OncologiJ l11,tit111,, of O11cology Z11lošk11 2 Sl-1000 Li11bljn1111 Slo,1 1'11it1 Pho11c: +386 1 4320 068 PJ,011c/F11x: +386 1 4337 410 E-111nil: gsersn(l•'onko-i.sin Aims and scope Septe111/1er 2002 Vol. 36 No. 3 Pnges 201-263 ISSN 1318-2099 UDC 616-006 CODEN: RONCEM Rndiology nnd Oncology is n journnl devoted to publicntion of originnl contributions in dingnoslic nnd interve11tio1111/ rndiology, computerized tomogrnphy, ultrasound, magnetic resonance, nuclenr medicine, rndiolhernpy, cli11icnl n11rf experimentnl oncologiJ, rndiobiology, rndiophysics nnd rndintion protection. Editor-in-Chief Gregor Serša Ljubljnnn, Slovenin Executive Edi tor Viljem Kovac Ljubljnna, Slovenin Editorial board Marija Auersperg Ljubljnnn, Slovenin Nada Bešenski Zngreb, Cronfin Karl H. Bolrnslavizki Hn111/1111s, Gem11111y Haris Boka Zngre/1, Crontin Nataša V. B11dihna Lj11bfin11n, S/ovenin Ma,jan B11dihna Li11bljn11n, Slove11in Malte Cla11se11 Hn111l111rg, Gen11n11y Christoph Clemm Mii11cl1e11, Ger111n11y Mario Corsi Udine, ltnly Ljubomir Diankov So/in, 811/gnrin Christian. Dittrich Viennn, A11slrin Ivan Drinkovic Zngreb, Crontin Gillian Duchesne Melbourne, Australia Editor-in-Chief Emeritus Toma.ž Benulic Ljubljann, Slovenin Editor Uroš Smrdel Ljubljann, Slovenia Valentin Fidler Ljubljnnn, Slovenia Bela Fornet Budapest, Hungary Tullio Giraldi Trieste, Jtnly Andrija Hebmng Zagreb, Crontia Laszl6 Horvath Pecs, H u nga ry Berta Jereb Ljubljana, Slovenia Vladimir Jevtic Ljubljana, Slovenia H.nDieter Kogelnikn Salzburg, Austrian Jurij Lindtner Ljubljnnn, Slovenian Ivan Lovasicn Rijeka, Crontinn Marijan Lovrencic Zagreb, Crontian Luka Milasn Houston, USAn Metka Milcinski Lj11blja11n, SlovenianMaja Osmak Zagreb, Crontin Branko Palcic Vnncouver, Cannda ]urica Papa Zagreb, Croatia Dušan Pavcnik Portland, USA Stojan Plesnicar Ljubljnnn, Slovenia Ervin. B. Podgoršak Montren/, Cnnada Jan C. Roos A111sterdn111, Nelherlands Slavko Šinrnnic Zngreb, Croalin Lojze Šmid Ljubljnnn,Slovenia Borut Štabuc Ljubljnna, Slovenia Andrea Veron.esi Avinno, Jtaly Živa Zupancic Ljubljana, Slovenia Publisher Association of Radiology and Oncology Affiliated with Slovenian Medica/ Association -Slovenian Association of Radiologij, Nuclear Medicine Society, Slovenian Society for Radiotherapy and Oncologi;, and Slovenian Cancer Society Croatian Medica/ Association -Croatian Society of Radiology Societas Radiologorum Hungarorunz Friuli-Venezia Giulia regional groups of S.1.R.M. (Italian Society of Medica/ Radiologi;) Copyright © Radiology and Oncology. All rights reserved. Reader far English Mojca Cakš Key words Eva Klemencic Secretaries Milica Harisch Mira Klemencic Desig:n Monika Fin/c-Serša Printed by Imprint d.o.o., Ljubljana, S/ovenia Published quarterly in 700 copies Bank account number 02010-0090006751 Foreign currency account number 010-7100-900067 /4 NLB d.d., Podružnica Ljubljana Center,.Ljubljana S. W.I.F. T. Code LJBASI2X Subscription fee far institutions $ 100 (16000 SIT), individua/s $ 50 (5000 SIT) The publication of this journal is subsidized by the Ministry of Education, Science and Spori of the Republic of Slovenia. Indexed and abstracted by: BIOMEDICINA SLOVENICA CHEMICAL ABSTRACTS EMBASE / Excerpta Medica Sci Base This journal is printed on acid-free paper Radiology and Oncology is available on the internet at: http://www.onko-i.sijradiolog/rno.html COLOGY Ljubljana, Slovenia ISSN 1318-2099 September 2002 UDC 616-006 Vol. 36 No. 3 CODEN: RONCEM CONTENTS DIAGNOSTIC ANO INTERVENTIONAL RADIOLOGY Endovascular treatment of intracranial arteriovenous malformations Šeruga T Pseudoaneurysm of the celiac trunk following acute pancreatitis. Case report Bmic Z, Hebrang A, Novacic K, Popic ], Januš D SONOGRAPHY 201 209 Anal ultrasound in patient with leukoplakia of the anal canal. Case report Sudot-Szopiiiska 1, Kotodziejczak M, Ja/cubowski W 215 Endosonographic and manometric assessment of the anal sphincters in patients operated on for Crohn' s disease of the colon Sudof-Szopiliska I, Ciesielski A, Bielecki K, Baczuk L, ]akubows/ci W, Tarnowski W 219 ONCOLOGY Extranodullary plasmocytoma of the larynx: report of three cases Strojan P 225 RADIA TION BIOLOGY Effects of 5-Gy irradiation on fertility and mating behaviour of Nezara viridula (Heteroptera: Pentatomidae) Žunic A, Coki A, Serša G RADIOPHYSICS Static dosimetry space image in which urology diagnostics are performed Banduka MS, Vasic DO 239 European Project BRAPHYQS Burger J 245 IN MEMORIAM 249 SLOVENIAN ABSTRACTS NOTICES 257 Radiology and Oncology is covered in Biomedicina Slovenica, Chemical Abstracfs, EM BASE/ Excerpta Medica, a11d Sci Base Endovascular treatment of intracranial arteriovenous malformations Tomaž Šeruga Department of Radiology, Teaching Hospital Maribor, Maribor, Slovenia Background. The aim of the study was the introduction of endovascular interventional treatment of cere­bral arteriovenous malformations (AVM) with superselective embolization with cyanoacrylic polymerisa­tion agent. Case reports. Endovascular embolization was performed in five patients with cerebral AVMs. Three of these patients were presented with intracerebral haemathomas whereas in other two patients, cerebral AVM was an incidental finding. Superselective catheterisation of AVMs was performed and acrylic glue was se­lectively injected into the nidus. Conclusions. Control cerebral angiography after embolization of AVM showed different results. In one pa­tient, AVM was totally occluded after three sessions and in second case AVM was occluded in a single ses­sion. The rate of occlusion in other two cases was estimated between 70% in 80%. Both of these two pa­tients underwent surgery. One patient is still in the process of treatment. Endovascular treatment of cere­bral AVMs with superselective embolization with liquid cyanoacrilyc adhesive agent is a safe and effective alternative treatment paths next to microsurgery. Endovascular treatment in combination with radiosurgery could become the method of choice in the therapy of cerebral AVMs in the future. Key words: intracranial arteriovenous malformation; embolization , therapeutic; cyanoacrylic glue; micro-catether Introduction For a successful endovascular treatment of in-tracranial arteriovenous malformations (AVM) their structure and localisation must be examined closely and in detail. Detailed Received 6 August 2002 Accepted 15 August 2002 Correspondence to: Assist. Tomaž Šeruga, M.D., M.Sc., Splošna bolnišnica Maribor, Ljubljanska 5, 2000 Maribor; Phone: +386 2 321 2248; Fax.: +386 2 321 2982; E-mail: tomaz.seruga@sb-mb.si position is determined only by an examina­tion using a magnetic resonance imaging (MRI). For structure or angioarchitecture ex­amination of AVM, the structure of its nidus must be defined accurately which may be achieved only by selective angiography. Finally, an impeccable microcatheter em-bolization must be carried out. Various topo­graphic and angiographic factors are very im­portant for choosing either surgical or en-dovascular treatment. Endovascular treat­ment can be applied as final treatment, i.e. when the AVM can be completely occluded, or when we can use it as initial part of treat­ment followed by microsurgical operation or radiosurgery with gamma knife.1 The final aim of embolization is a stable occlusion of the AVM nidus with a preserved normal arte­rial blood flow in the adjacent brain pare-nchyma and with preserved venous outflow. Intracranial AVMs are categorised as le­sions of cerebral vasculature and consist of pathological vessel elements, that lead to a di­rect arteriovenous contact or passage without the usual capillary net. The ethiology of in-tracranial AVMs formation is not as yet com­pletely established. AVMs have most likely an embryological basis in abnormal develop­ment of venous endothelium.2 Intracranial AVM was first described by Pfannenstil in 1887 in post-mortem examination record. The first complete surgical excision of first AVM was carried out in 1889 by dr. Pean, a French surgeon.3 The introduction of cerebral angiography by Moniz in 1929 allowed more detailed analysis of the structure and localisation of le­sions. On the other hand, new microsurgical technique also required more selective details with more distinctive angiographyc analysis of blood flow within the AVM, its relation to the size and position of cerebral AVM and its relation to the circulation in adjacent brain parenchyma. Detailed analysis of AVM’s haemodynamics increased the safety and rad-icality of the operation. It is estimated that intracranial AVMs can be discovered in 0.2-0.8% of the North American population.4 The annual bleeding rate of 4% occurs in non treated AVMs. The probability of rupture and subsequent bleed­ing is higher when AVM contains an aneurys­mal widened vessel and deep venous drainage. The size of malformation does not represent significantly higher risk of bleed­ing, but in microsurgical treatment there is a greater possibility of complications. Pred­isposition to epileptic attacks in patients with cerebral AVM is very common, especially when the AVM lies within the temporal lobe or in motoric strips.5,6 Neurological deficits are caused by repeated minute bleeding, haemodynamic blood steal, stenosis of arter­ies, venous hypertension or mass effect be­cause of venous anomalies. Headaches are very often a consequence of haemodynamic changes in the meningeal circulation connect­ed with AVM, widened meningeal veins or with smaller clinically undetected bleedings. The location of AVM and arteriovenous structure of the lesion is shown preoperative-ly by means of selective angiography and MRI evaluation. Angiographic evaluation of in-tracranial AVM requires a four-vessel angiog­raphy and additional projections of external carotid arteries. We must evaluate the feed­ing arteries, venous part of AVM as well as the rest of venous outflow, the flow velocity inside the lesion and the size of the nidus, its form and vein structure.7 MRI examination enables a better understanding of the topo­graphic position, size and geometry of the in-tracranial AVM as well as spatial evaluation of the main draining veins of the malforma­tion. MR angiography with intravenous con­trast application is also of great value in AVM evaluation. Classification of AVMs A modification of Yasargils classification of intracranial AVM divides malformations clin­ically in convex and deep AVMs.3 Convex AVMs are further subdivided into sulcal and gyral types. Deep AVMs are further divided by their relations to cerebral anatomic struc­tures into ventricular system and deep grey matter nuclei. The cortical brain supply con­sists of three types of arteries that split rec­tangular from pial arteries and pass through the brain cortex. Regarding their nutritional role they are divided into cortical, corti­comedullar and medullar arteries.8,9 Topographically, we distinguish three sub­groups of convexional AVMs due to their lo- Radiol Oncol 2002; 36(3): 201-8. cation to sulcal, gyral and mixed sulcal-gyral AVMs. In sulcal AVMs, the nidus lies within the subpial space of the sulcus. The AVM ad­justs to the form of the sulcus and compress­es the adjacent gyrus. So the shape of the malformation is triangular with apex pointed towards the ventricle or skull base. After branching of the pial arteries to the cortical and corticomedular arteries, they terminate in the nidus of the AVM. Gyral AVMs, unlike the sulcal malformations, are fully encircled by the brain parenchyma and cortex. The gyrus grows larger and compresses adjacent sulci. Because of its position inside the gyrus, the malformation outgrows branches over different pial arteries. Smaller lumen and larger number of pial arteries aggravate the access of microcatheter into the feeding ar­tery. Mixed sulcal-gyral type of AVM is larger than both previous ones because of its locali­sation in subpial space, gyrus and subcortical brain parenchyma. They receive their main blood supply through mixed terminal pial ar­teries, but are supplied also by meningeal and basal perforating arteries. Subcortical AVM are very rare and represent less than 1 % of all AVM. They lie deep under the cortex and are supplied mostly by corticomedullar and medullar arteries and are drained by deep and surface veins.10 Deep AVMs are divided by their relation to brain structures. Subarachnoid AVMs lie in­side basal cisterns and fissure and are sup­plied by the cisternal segments of perforating and chorioidal arteries. Parenchymal AVMs lie inside deep nuclei and are supplied main­ly by basal perforating and circumferential arteries. Ventricular (plexial) AVMs originate from chorioid plexus and are supplied by ter­minal parts of choroidal arteries and from subependymal branches of Willis’ circle.9 Structure of intracranial AVM Malformations consist of feeding arteries, nidus and draining veins. They can have one or more compartments. A compartment con­sists of one or more angiographically seen feeding arteries and one draining vein. The feeding arteries which supply the major part of the AVM are known as main feeders. Other arteries have less influence on the nidus and are feeding smaller compartments of AVM. The main feeders are of larger diam­eter; therefore the flow through them is faster than the flow through other supplying arter­ies. Due to larger diameter, the feeders are more accessible for catheter embolization and have a better therapeutic prognosis. Part of AVM are also the so-called pseudoterminal feeding arteries that do not terminate in the nidus and are visualised during angiography due to suckling effect. This effect is seen as a subtile flush of unopacified blood into AVM. It requires much attention because of possi­ble ischaemic complications that may arise due to haemodynamic changes in blood flow during embolization. The nidus of AVM is a part of malformation located between the far­thest feeding artery and the nearest draining vein.3,4 The flow patterns of nidus are divided into three types of arteriovenous patterns: plexiform type (36%), fistolous type (11%) and mixed pattern type (53%).3,10 A compartment consists of one or more angiographicaly seen feeding arteries and one draining vein. The draining veins of AVM terminate in the sur­face or deep venous circulation. Higher pres­sure on the venous side causes the appear­ance of venous anomaly and pseudoa­neurysms, venous infarcts, venous conges­tion and mass effect. Rupture of pseudoa­neurysm is the most frequent reason of bleed­ing from AVM (41%).11,12 The rupture mecha­nism probably result from a sudden change of pressure on the arterial side and subse­quent venous hypertension.13 Endovascular treatment technique The aim of AVM treatment is the prevention of intracerebral bleeding and elimination of Radiol Oncol 2002; 36(3): 201-8. the malformation from the circulation. When we decide on the way of treatment, we have to consider the risk of treatment, patient’s neurological symptoms, general state of health, as well as the patients expectations about the effects of the treatment.1,14,15 The purpose of the endovascular treatment is a complete occlusion of AVM and its exclusion from the circulation. When this is not possi­ble we opt for the partial occlusion of AVM, which increases the effectiveness of gamma knife ablation or microsurgical resection. For the embolization of the AVM nidus, liquid cyanoacrylic polymerisation agent is used. In contact with blood polymerisation occurs and cianoacrylat glue sticks on the vessel wall. The result is a permanent occlu­sion of the nidus. Particles of polyvinyl alco­hol, can be used for blocking the smaller veins after the embolization of the main part of the AVM. Platinum coils can also be used for AVM immobilisation. They are especially effective in the treatment of high flow arteri­ovenous fistulae. With their use we slow down the flow and thereby enable a safe use of cianoacrylic glue.16 Complications of endovascular AVM treatment They are divided into complications that oc­cur during the procedure and post-opera­tional complications. We distinguish is-chaemic and haemorrhagic complications. Ischaemic complications can occur during catheter manipulation where haemorrhagic complications are due damaged wall vessel or disturbances in the venous outflow. When bleeding occurs during the procedure, we can see it as an extravasation of contrast medium and we can react with an instant emboliza­tion. Late complications occur within 72 hours after the operation. Sudden deteriora­tion of the neurological status scan be identi­fied by computer tomography examination. Oedema or minor haemathomas can be treat­ed conservatively with manitol or, if circum­stances require, the haemathoma is surgically removed. Case reports Case No. 1 A 43-year old patient was submitted to a com-puterised tomography (CT) examination after his first epileptic attack. CT revealed a hyper-dense space occupying lesion, probably a haemathoma in the left parietal lobe. Digital subtractional angiography (DSA) revealed a large cortical AVM with plexiform type of nidus. Main feeding arteries were branches of the right anterior and posterior cerebral arter­ies. Venous blood was drained into the deep venous system to internal cerebral veins. Radiol Oncol 2002; 36(3): 201-8. Endovascular embolization was performed with the aim to reduce the volume of the AVM, to enable subsequent radiosurgery with gamma knife. After successful radiosur­gical ablation the latest control DSA, 3 years after the last radiosurgery session, revealed a complete AVM occlusion (Figures 1, 2). Case No. 2 A 24-year old patient was admitted to our hospital because of sudden onset of headache and nausea. CT examination revealed a small round hyperdense lesion, an intracerebral haemathoma in the temporooccipital part of left hemisphere. The DSA showed a deep AVM with fistulous nidus pattern. A single feeding artery was a branch of the left medial cerebral artery. Venous drainage was superfi­cial to the sigmoid sinus. Endovascular em-bolization was performed and AVM was com­pletely occluded at the end of the procedure (Figures 3, 4). Case No. 3 CT examination in a 40 years old male patient with clinical symptoms of intracranial bleed­ing revealed a minor AVM in the right tem-poroparietal region. Cerebral DSA showed two feeding arteries, branches of the middle cerebral artery. Venous outflow was of super­ficial type. After endovascular treatment AVM was partially closed. The patient was later on treated by microsurgical resection. Case No. 4 CT examination in a 30-year old male patient with sudden onset of headache revealed a larger cortical AVM in the right temporopari­etal region with an extensive intracerebral haemathoma, partially resorbed at the time of Radiol Oncol 2002; 36(3): 201-8. endovascular treatment. Feeding arteries were branches of the right middle cerebral ar­tery. Venous outflow was superficial and drained to the superior sagital sinus. Superselective angiography revealed that one of the feeding arteries supplied also the adja­cent brain parenchyma. It was not suitable for embolization. The other feeding artery was successfully embossed. The rest of AVM was later resected by microsurgical operation (Figures 5, 6). Figure 5. DSA angiography of the right internal carotid artery in a right oblique projection revealed a cortical AVM. Feeding arteries were branches of the right medial cerebral artery, the nidus was of mixed type and venous drainage was superficial to superior sagital sinus. One of the feeding arteries supplied also the adjacent brain parenchyma and was not suitable for embolization. Case No. 5. CT examination in a 66-year old female pa­tient revealed an extensive intracranial bleed­ing in the left cerebral hemisphere. A large deep AVM in the region of corpus callosum above the lateral ventricles with the blood penetrating into the ventricular system was disclosed. Cerebral DSA showed feeding ar­teries arising from all three main arteries of the left hemisphere. The nidus was of mixed type with plexiform and fistulous pattern. We decided to treat the AVM by endovascular procedure in three sessions. Control DSA af­ter the first treatment showed occlusion of approximately one third of AVM. The plan is to continue with endovascular treatment. Discussion Our experiences after treating five patients only are modest. We did not have any imme­diate or late (up to 72 hours after the proce­dure) complications. In 1999, a study from a leading European centre for endovascular AVM treatment in Zurich analysed the results of embolizations carried out between 1987 and 1996.10 They treated 387 patients with intracranial AVM and carried out 710 operations. Complete obliteration was achieved in 158 cases (40,8%). In 19 cases, more then 90 % oblitera­tion was reached, in 177 cases, the oblitera­tion was partial (up to 50%) and in 30 cases less than 50 % obliteration rate was achieved. So, the 158 patients were treated only by em-bolization. In 73 cases, microsurgical resec­tion was carried out after the embolization, and in 25 cases, radiosurgery was performed also after embolization. In 69 cases with com­plex AVM, a partial palliative embolization was carried out for treatment of severe chron­ic headaches. The remaining 62 patients were called back for further embolizations. Early haemorrhagic complications oc­curred in 8 (2.0%) out of 387 patients. In 3 Radiol Oncol 2002; 36(3): 201-8. cases the vessel wall was perforated, in other 5 cases, bleeding followed the occlusion of the venous outflow or the rupture of pseudoa­neurysm occurred. Late haemorrhagic com­plications occurred in 11 (2.8%) out of 387 pa­tients. In 6 cases, immediate craniotomy was carried out, because of a rapid deterioration of the neurological status, and 5 patients were treated conservatively. The outcome of early and late complications that occurred in 19 cases was good in 11 (58% ) patients, mod­est in 4 (21%) patients and poor in 1 (5%) case. Three patients died (16%). The analysis of 16 haemorrhagic complications, not linked with the perforation of vessel wall, showed that none of these malformations was completely closed. The most likely reason for bleeding were altered haemodynamic conditions in the venous outflow. Ischaemic complications were evaluated by MRI in 36 (9.3%) patients out of 387. Five of these patients were asymptomatic, 18 pa­tients had pre-existing neurological deficit. Thirteen patients had permanent neurologic deficit (3.3%). Six of them had minimal deficit, 4 had medium neurological deficit, 2 patients had poor neurological outcome and one patient died. Conclusions Endovascular treatment of intracranial AVM requires detailed knowledge of the anatomy of the cerebral arteries and cerebral circula­tion, of the structure of intracranial AVM and of its topographic position. We can simulta­neously follow the changes of blood flow dur­ing the embolization and, if circumstances re­quire, change the strategy of embolization procedure. The success of the treatment depends on the accessibility to the nidus, which depends on anatomic circumstances, as for example, the diameter of the feeding arteries or their tourtuosity. Special preoperative treatment is impor­tant in the patients who have the predisposi­tion for thrombembolic or haemorrhagic complications. Damages of the vessel wall, which could be caused by the catheter or guide wire, should be avoided. Today, in Slovenia, the majority of AVMs are adequate­ly treated by microsurgical operation. In or­der to achieve up to date standards, we have to establish the radiosurgery that, together with microsurgery and endovascular em-bolization, represent a method of choice of treatment of intracranial AVMs. References 1. Vinuela F, Halbach V, Dion E.J. Interventional Neuroradiology. Endovascular therapy of the central nervous system. New York: Raven Press; 1992. p 167-79. 2. Lasjaunias P. A revised concept of the congenital nature of cerebral arteriovenous malformations. Interventional Neuroradiol 1997; 3: 275-81. 3. Yasargil MG. Microneurosurgery. Stuttgart: Georg Thieme Verlag; 1987. p. 3-21. 4. Berenstein A, Lasjaunias P. Surgical neuroangiogra­phy. Vol 4. Heidelberg: Springer; 1991. 5. 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. 6. Crawford PM, West CR, Shaw MD, Chadwick DW. Cerebral arteriovenous malformations and epilepsy: Factors in the development of epilepsy. Epylepsia 1986; 27: 270-5. 7. Valavanis A. The role of angiography in the evalu­ation of cerebral vascular malformations. Neuroimag Clinics N Am 1996; 6: 679-704. 8. Hutchings M, Weller RO. Anatomical relation­ships of the pia mater to cerebral blood vessels in man. J Neurosurg 1986; 65: 316-25. 9. De Reuck T. The cortico-subcortical arterial an-gioarchitecture in the human brain. Acta Neurol Belg 1972; 72: 323-8. 10. Valavanis A, Christoforidis G. Endovascular man­agement of cerebral arteriovenous malformations. Nevrointerventionist 1999; 1: 34-40 Radiol Oncol 2002; 36(3): 201-8. 11. Muller-Forell W, Valavanis A. How angioarchitec­ture of cerebral arteriovenous malformations should influence the therapeutic considerations. Minim Invasive Neurosurg 1995; 38: 32-40. 12. Turjman F, Massoud TF, Vinuela F, Sayre JW, Guglielmi G, Duckwiler G. Aneurysms related to cerebral arteriovenousmalformations: Super-selective angiographic assessment in 58 patients. Am J Neuroradiol 1994; 15: 1601-5. 13. Willinsky R, Lasjaunias P, Terbrugge K, Pruvost P. Brain arteriovenous malformations: analysis of the angio-architecture in relationship to hemorrhage (based on 152 patients explored and/or treated at the hospital de Bicetre between 1981 and 1986). J Neuroradiol 1988; 15: 225-37. 14. Garcia-Monaco R, Rodesch G, Alvarez H, Iizuka Y, Hui F, Lasjaunias P. Pseudoaneurysms within ruptured intracranial arteriovenous malforma­tions: Diagnosis and early endovascular manage­ment. Am J Neuroradiol 1993; 14: 315-21. 15. Marks MP, Lane B, Steinberg GK, Snipes GJ. Intranidal aneurysms in cerebral arteriovenous malformations: Evaluation and endovascular treatment. Radiology 1992; 183: 355-60. 16. Vinuela F, Nombela L, Roach MR, Fox AJ, Pelz DM. Stenotic and occlusive disease of the venous drainage system of deep brain AVMs. J Neuosurg 1985; 63: 180-4. 17. Vinuela F, Drake CG, Fox AJ, Pelz DM. Giant in-tracranial varices secondary to high-flow arteri­ovenous fistulae. J Neurosurg 1987; 66: 198-203. Radiol Oncol 2002; 36(3): 201-8. Pseudoaneurysm of the celiac trunk following acute pancreatitis. Case report Zoran Brnic, Andrija Hebrang, Karlo Novacic, Jelena Popic, Dragutin Januš University Hospital »Merkur«, Department of Diagnostic and Interventional Radiology, Zagreb, Croatia Background. Visceral artery aneurysms (VAA) are well-known complication of pancreatitis. Splenic artery is the most common localisation, but other peripancreatic vessels may also be affected. Although VAA may develop palpable epigastric mass, bleeding and pain, they are often fully asymptomatic, being incidentally picked up on abdominal US, CT or angiography for other reasons. Case report. The authors report a case of a 38-year-old male with pseudoaneurysm of celiac trunk follow­ing an acute pancreatitis. The complex cystic-solid epigastric mass was initially detected by grey-scale US, and its vascular nature was suspected on colour-Doppler US scan. Precise localisation was determined by angiography. Conclusions. Colour-Doppler US is a reliable diagnostic method for detection of VAA, but hardly identifies the vessel of origin in many patients. Angiography is fundamental for the final diagnosis, followed by im­mobilisation in selected cases. Celiac axis always has to be kept in mind as a rare possible localisation of VAA. Key words: pancreatitis - complications; celiac trunk; aneurysm, false diagnosis Introduction The most common visceral artery aneurysm (VAA) is the splenic artery aneurysm (SAA), but other splanchnic vessels also may be af­fected by dilation.1,2 The dilation which does not affect all layers of the vessel wall is called pseudoaneurysm (PSAN). Blunt trauma of Received 27 March 2002 Accepted 7 May 2002 Correspondence to: Zoran Brnic, MD, PhD, Kopernikova 10, 10000 Zagreb, Croatia; Phone: +385 1 668 20 67; Fax: +385 1 243 14 14; E-mail: zoran.brnic @zg.hinet.hr the upper abdomen and enzymatic injury to the vessel wall in pancreatitis are the most common causes of PSAN. Vessel rupture causes the formation of haematoma, consecu­tively surrounded by fibrous capsule.3 Bleeding into the pseudocysts can also result in PSAN formation. The incidence of PSAN in patients with severe acute pancreatitis is up to 10%, and the affection of the celiac trunk is relatively rare.3-5 Although it may be asymptomatic, the pa­tients with VAA often suffer from the pain in the upper abdomen, or have gastrointestinal or peritoneal bleeding.4 Rupture is a serious complication seen in up to 37% of SAA, re­sulting in high mortality. Celiac trunk aneurysms (CTA) have the lowest rupture in­cidence among all localisations of VAA.2 The presence of VAA is mostly suspected on grey-scale ultrasound (US) scan, while colour- Doppler ultrasound (CDUS) success­fully indicates the vascular nature of the mass. Angiography is fundamental for con­firming the diagnosis and exact localisation of VAA. CT and MRI allow good analysis of localisation and morphology of the aneurysm. Pseudocyst and other peripancre­atic fluid collections, renal artery aneurysm and abdominal aortic aneurysm must be con­sidered in differential diagnosis of VAA. Transcatheter embolisation of VAA has to be performed immediately after diagnostic selective angiography. It may obviate the need for surgery in high-operative-risk-pa­tients or be lifesaving in the case of aneurysm rupture.6 Case report A 38-year-old male, without the history of al­cohol abuse, was admitted on 1st October 2001, because of constant, localised epigas­tric pain that increased on palpation. He suf­fered from nausea and vomited black con­tent. Ten days earlier he experienced similar symptoms and had melaena. On admittance he was afebrile, with laboratory tests indicat­ing acute pancreatitis, slight anaemia and marked hypertriglyceridaemia. Chest X-ray and plain abdominal film were normal. Abdominal US demonstrated inhomogeneous, hypoechoic, well-defined oval fluid-filled mass, 20 mm in diameter, near the neck of the pancreas. A jet of blood entering the mass was clearly visible on CDUS; hence, the pre­sumptive diagnosis of SAA was established. The pancreas was moderately enlarged, inho­mogeneous and hypoechoic. The enlarged hy­perechoic liver (diffuse lesion) with the slight­ly dilated hepatic veins, widened portal vein (15 mm), slightly enlarged spleen (130 mm) and normal appearance of other abdominal organs were shown. Five days later, abdominal US showed 53×51 mm cystic-solid oval mass near the pancreatic head, left to the midline. The cen­tral part of the lesion was anechoic (30×22 mm) with posterior sound enhancement (Figure 1), while the periphery was hypoe­choic. Turbulent flow within the central part of the mass was seen at CDUS (Figure 2a). Pulsed-Doppler demonstrated bi-directional (»to-an-for«) flow in the central part (Figure 2b). The communication with the splenic ar­tery was thought to exist; hence, the diagno­sis of SAA with mural thrombus was pre­sumed. US examinations were performed us­ing Hewlett-Packard Image Point scanner (Andover, Massachusetts, USA) with a con­vex, 3.5 MHz probe. The conservative treat­ment of acute pancreatitis was recommend­ed, and the immobilisation of suspected SAA was to be performed. Liver biopsy done in pre­interventional work-up revealed advanced cirrhosis. The patient had not alcohol abuse in his history, but was anti-HAV positive. Celiac trunk angiography was undertaken on 7th November 2000, with the intention of Figure 1. Grey-scale US of the upper abdomen (left parasagittal oblique scan) reveals a well-defined, 53×51 mm inhomogeneous (complex) mass, near the pancreatic head, posterior to the stomach, with ane­choic central part, and crescent-like hypoechoic part, peripherally. Posterior sound enhancement was re­markable. (Presumptive diagnosis at this moment seen in comment). Radiol Oncol 2002; 36(3): 209-14. aneurysm immobilisation. Film series re­vealed the dilatation of celiac trunk, with its greatest diameter three times larger than at its aortic orifice. Extraluminal contrast de­posit at the left side of celiac axis, with 20 mm in diameter, was observed. Faint crescent-like contrast filling was also seen caudally (Figure 3), corresponding to anechoic clefts at the pe­riphery of the mass seen at grey-scale US (Figure 1). Slight compression and dislocation of the proximal splenic artery from below in­dicated the presence of a mass greater than that delineated with contrast filling. In the celiac trunk-splenic artery corner, partially thrombosed CTA was suspected. The emboli­sation was not performed because of the risk for rupture of the dilated celiac trunk. Figure 3b. Later film showed clearly that aneurysm was thrombosed in its greater part; the central part filled with blood exhibited colour signal at CDUS (s. Figure 2), peripheral crescent-like blood filling in the caudal part corresponded to anechoic clefts at the pe­riphery (s. Figure 1), and caused no Doppler signal be­cause of slow flow. The findings were additionally confirmed by magnetic resonance imaging (MRI), which showed partial thrombosis of CTA, and tortu­ous and dilated splenic artery compressed with CTA. Operative findings Five months after the onset of pancreatitis the patient was operated on. A firm mass in the upper abdomen, on the left of the mid- Radiol Oncol 2002; 36(3): 209-14. line, was found at surgery. Partially throm­bosed PSAN, measuring 70×63 mm, originat­ing from celiac trunk, was impressing into the lesser sac, being intimately adherent to the pancreatic head. The splenic artery was elon­gated, tortuous and coiled, which was consid­ered as congenital variant. The resection of the aneurysm with ligation of the celiac axis ostium and splenic artery were performed. Splenectomy was also done; the spleen was slightly enlarged and congested. After ten postoperative days of recovery, the patient was dismissed from hospital. Unfortunately, the patient died of injuries of car accident 3 months later. Discussion Splenic artery aneurysms (SAA) account for up to 60% of all VAA, but hepatic artery (20%), pancreaticoduodenal arcade (17%), su­perior mesenteric artery (5%), inferior mesen­teric artery (3%), gastroepiploic and gastric ar­tery (4%) and celiac trunk (4%) may also be af­fected.1,2 The most common cause of PSAN formation is pancreatitis. Activated and re­leased pancreatic enzymes cause the rupture of membrana elastica interna of the splanch­nic vessels, followed by segmental thrombo­sis of the vessel. Thrombosis of the vasa va­sorum causes ischemia and nutrient deficit to the arterial wall with its necrosis. Massive bleeding occurs if weakened vessel wall sud­denly ruptures, most probably with cata­strophic outcome. PSAN develops when the rupture contains the haematoma that is sur­rounded by reactive fibrous capsule.7 The patients with VAA are often (72%) asymptomatic, or may suffer from the pain in the upper abdomen, or have signs of gas­trointestinal bleeding and anaemia4 as was al­so the case in our patient who had sparse symptoms, relatively unspecific for PSAN. Haemathemesis and melaena in his history might be caused also by associated peptic ul­ceration or portal hypertension. In spite of a large mass growing near the head of the pan­creas, our patient did not have jaundice or di­latation of biliary tree or pancreatic duct. Diagnosis - imaging modalities: Typical grey-scale US features of PSAN include anechoic or hypoechoic, heterogeneous mass with dis­tal sound enhancement, possibly with hyper-echoic margins.8,9 This presentation lacks specificity and mismatch with pancreatic pseudocyst has to be avoided. Pulsations of the mass may indicate the correct diagnosis, even when CDUS is not available. In our case, US morphology was less typical because the lesion was predominantly solid, with throm­bosed lumen, and relatively small cavity filled with blood. Rapid enlargement of the mass was, however, suggestive of a vascular lesion. Blood flow in VAA is usually easily de­tectable,10,11 but even scrutinise Doppler analysis may be unreliable in obese individu­als with deeply located lesions, in patients having pains on probe contact or in thin pa­tients with marked aortic pulsations. A faint blood jet is sometimes detectable only with power Doppler, but one has to beware of false positive results due to motion-artefacts. In patients with pseudocyst, normal flow in one of peripancreatic arteries may occasional­ly be mistaken for extravasation into the pseudocyst or peritoneal space. A swirling jet of blood entering the aneurysm (Figure 2) was clearly visible with CDUS in our case. As the lesion was very close to the splenic artery, it was initially falsely diagnosed as SAA. In spite of careful topographic analysis, we were unable to determine exactly the origin of aneurysm without coeliacography. This, how­ever, was not a great shortage because the pa­tient management in that moment would not be significantly influenced with this finding. CT was not done in our case as we consid­ered that no additional valuable information would be acquired from this modality that carries the risk of contrast medium adminis­tration and radiation. As the patient was ex- Radiol Oncol 2002; 36(3): 209-14. amined by US under good conditions (no bowel gas, thin patient), it was considered re­liable. Typical CT finding of VAA includes well-defined mass with hyperdense centre that shows contrast enhancement, and less dense periphery corresponding to mural clot and fibrous wall. If CT reveals high density within peripancreatic collection of near to water density, the finding should raise the suspicion of haemorrhage into the pseudo-cyst that may be of similar CT appearance as PSAN. Due to the possibilities of multiplanar im­aging, signal void phenomenon and contrast medium use, MRI is of great value in diag­nostic work-up of unclear abdominal vascular masses. Flow in the lesion can be detected even without contrast medium.12 In our case, the diagnosis of CTA was established prior to MRI examination, which was done on pa­tient’s insistence in a private clinic. Partial thrombosis of CTA and compression of the splenic artery were additionally confirmed, but no additional data were yielded that were not known prior to MRI. Angiography remains the most fundamen­tal modality in the diagnosis of VAA. It can exactly determine the origin of aneurysm, but may lack to predict its real size when partial thrombosis is present. We did not consider the possibility of CTA prior to angiography as we were impressed by the compressive effect of the lesion onto the splenic artery; at this moment, we concluded to deal with SAA. The analysis of several projections in different an­gles leaded to better visualisation of celiac ax­is, and establishing the correct diagnosis. It can never be overemphasised how the precise preoperative detection of bleeding source is desirable in the case of VAA, as its identifica­tion on laparotomy may be exceedingly diffi­cult. In selected cases the risk of urgent sur­gery to control haemorrhage may be obviated by immobilisation. Unfortunately, in many cases aneurysms remain undiagnosed and the patients’ initial presentation will be acute haemorrhage. Endoscopy is of value to eliminate other caus­es of gastrointestinal bleeding, especially in patients with alcohol abuse. In rare cases of rupture of an aneurysm in pancreatic duct, presented with recurrent haematemesis or melaena, endoscopy may reveal »haemosuc­cus pancreaticus« or wirsungorrhagia.13 We conclude that PSAN of peripancreatic vessels have to be taken into account as pos­sible complication in each patient with pan-creatitis or pseudocyst, and although splenic artery is the most common site of PSAN, oth­er peripancreatic vessels including celiac trunk have to be considered. VAA of the upper ab­domen may be easily visualised by grey-scale US, and the vascular ethiology confirmed with CDUS as non-invasive and cheap modal­ity. Angiography has to be done to determine precisely the vessel involved. CT and MRI are not obligatory adjunct to US and angiography in patients with VAA, but may help in topo­graphic analysis or detection of concomitant pathology or complications. References 1. Busuttil RW, Gelabert HA. Visceral artery aneurysms. In: Ascer E, Holler L, Strandness DE, Towne JB, editors. Haimovici’s Vascular Surgery. Principles and techniques. Cambridge: Blackwell Science; 1996. p. 842-51. 2. Stanley JC, Zelenock GB. Splanchnic artery aneurysms. In: Rutherford RB, editor. Vascular Surgery. Philadelphia: W.B. Saunders Company; 1995. p. 1124-8. 3. White AF, Baum S, Buranasiri S. Aneurysms sec­ondary to pancreatitis. Am J Roentgenol 1976; 127: 393-6. 4. von Flue M, Kocher T, Herzog U, Looser C, Schuppisser JP. Blutung aus Pseudozysten infolge Pseudoaneurysma bei chronischer Pankreatitis. Diagnostik und Management. Helv Chir Acta 1992; 59: 785-9. 5. Wolstenholme JT. Major gastrointestinal haemor­rhage associated with pancreatic pseudocysts. Am J Surg 1974; 127: 377-81. Radiol Oncol 2002; 36(3): 209-14. 6. McDermott VG, Schlansky-Goldberg R, Cope C. Endovascular management of splenic artery aneurysms and pseudoaneurysms. Cardiovasc Intervent Radiol 1994; 17: 179-84. 7. Stroud WH, Cullom JW, Anderson MC. Hemorrhagic complication of severe pancreatitis. Surgery 1981; 90: 658-65. 8. Grech P, Rowlands P, Crofton M. Aneurysms of the inferior pancreaticoduodenal artery diagnosed by a realtime ultrasound and pulsed Doppler. Br J Radiol 1989; 62: 753-5. 9. Chiou AD, Joseph LG, Menzojan JO. Inferior pan-creaticoduodenal artery aneurysms: report of a case and review of a literature. J Vasc Surg 1993; 17: 784-9. 10. Golzarian J, Braude P, Bank WO, Zalcman M, Van Gansbeke D. Case report: colour-Doppler demon­stration of pseudoaneurysms complicating pseudocysts. Br J Radiol 1994; 67: 91-3. 11. Kahn LA, Kamen C, McNamara MP Jr. Variable color-Doppler appearance of pseudoaneurysms in pancreatitis. Am J Roentgenol 1994; 162: 187-8. 12. Martin KW, Morian JP Jr, Lee JK, Scharp DW. Demonstration of a splenic artery pseudoa­neurysm by MR imaging. J Comput Assist Tomogr 1985; 9: 190-2. 13. Bivens BA, Sachatello CR, Chaung VG, Brady P. Hemosuccus pancreaticus (hemoductal pancreati-tis). Arch Surg 1978; 113: 751-3. Radiol Oncol 2002; 36(3): 209-14. Anal ultrasound in patient with leukoplakia of the anal canal. Case report Iwona Sudol-Szopinska1, Malgorzata Konodziejczak2, Wieslaw Jakubowski1 1Department of Diagnostic Imaging, Second Faculty of Medicine, Warsaw, 2Department of Proctology, Warsaw County Hospital, Poland Background. Leukoplakia is considered to increase the risk of development of anal carcinoma. We present a case of leucoplakia which underwent a malignant transformation and usefulness of the anal endosonog­raphy (AES) in the assessment of the degree of infiltration of the anal canal. Case report. AES was performed with the use of Bruel & Kjaer scanner type 3535 with an axial 10.0 MHz endoprobe. Examination was performed in decubitus position. Anal ultrasound allowed the exact assessment of the depth of infiltration of the anal wall by the tumour. Assessment of the perianal lymph nodes was al­so possible. Conclusions. AES became a routine examination in staging anal tumours. In patients with leukoplakia AES proved valuable in assessing the depth of invasion and deciding on the choice of treatment and prognosis. Key words: anal neoplasms -ultrasonography; levkoplakia Received 3 June 2002 Accepted 17 June 2002 Correspondence to: Iwona Sudol-Szopinska, MD, PhD, Zaklad Diagnostyki Ultrasonograficznej, Wojewódzki Szpital Bródnowski, ul. Kondratowicza 8, 03 285 Warszawa, Poland; Phone/Fax: +48 22 811 95 91; Mobile +0 501 716 407, E-mail: mdyvonne @poczta.wp.pl Introduction Leukoplakia is found as white, circumferen­tial and flat-prominent lesions, located main­ly within the epithelium covering prolapsed haemorrhoids, or associated with non-specif­ic skin inflammation in this area. In general, it is not considered as premalignant lesion and does not require treatment. However, occasionally, within the area of leukoplakia in the distal part of the anal canal, microscopic examination reveals signs of dysplasia which, in time may undergo ma­lignant transformation. In such situations lo­cal surgical resection of the foci following histopathologic confirmation of the dyspla­sia, is recommended.1 We present a case of a woman, whose long time lesion in the anal canal representing leukoplakia underwent a malignant transfor­mation into the carcinoma planoepitheliale of the anus. Anal endosonography (AES) was performed to assess the stage of the disease. Case report A 56 year-old woman (surgeon) was admitted to proctologic outpatient clinic for further di­agnostics of a lesion typical for leukoplakia localised within the skin surrounding the anus and in distal part of the anal canal. The lesion was diagnosed six years earlier. During these six years, the patient was under derma­tological control. Her main complaints were sporadic pruritus and burning sensation in the anal area. No other symptoms, neither anal bleeding, were reported. She was treated with local anti-inflammatory drugs. After six years, due to the exacerbation of the disease (burning, pruritus) and slight en­largement of the area of leukoplakia, the pa­tient was sent to proctologist for consulta­tion. In the proctologic examination, a slight decoloration of the anoderm and mucous in the anal canal was visible. Around the anus, flat, callous, and non-mobile infiltrate was palpated, extending up to 1 cm of the anal canal height. In anoscopy, the overgrown, white mucosa with irregular surface was visi­ble. Specimens from the anal canal were tak­en in local anaesthesia. Histopathologic ex­amination revealed carcinoma planoepit­heliale akeratodes ani partim exulcerans. Before deciding on the treatment method, AES was performed to determine the depth of infiltration the tumour into the anal canal. For anal ultrasonography, Bruel & Kjaer scan­ner, type 3535, with axial endoprobe of a fre­quency 10.0 MHz covered by a plastic cone with external diameter of 17 mm was used. The cone was filled with a few millilitres of degassed water. The cone covered with a con­dom was introduced into the anal canal up to the depth of 5 cm. The patient was in decubi­tus position. High and mid anal levels were normal. In the low anal level a tumour locat­ed on the posterior and left walls of the anal canal and infiltrating into the subcutaneous part of the external anal sphincter was visu­alised. Half of the sphincter thickness was in­filtrated. Invasion into the distal end of the internal anal sphincter was also seen (Figures 1a, 1b). The tumour’s echotexture was ho-mogenous, hypoechoic. No enlargement of the lymph nodes were visible in the perianal tissues and the surrounding structures were not invaded. According to the sonographic classification (uTN), the stage of the disease was defined as uT2N0. The patient was sent for oncologic consultation where it was de­cided that she was eligible for radio-chemotherapy. Discussion Among risk factors of anal carcinoma there are many inflammations transmitted by sexu­al route, Bowen and Paget disease, Crohn’s Radiol Oncol 2002; 36(3): 215-8. disease, ulcerative colitis, postradiation in­flammation, chronic inflammations or leuko­plakia.1 Term »leucoplakia« was coined in XIX century.2 Taussig3 claimed that in half of patients with leucoplakia of the vulva, there is a risk of malignancy. In 70% of cases of planocellular carcinomas of the vulva, he found leukoplakia in the area surrounding cancer. Other authors, e.g. Janovski,4 also considered the lesions representing leuko­plakia as precancerous state. However, other opinions regarding leukoplakia as a precan­cerous state were different.5 Most of re­searchers consider leucoplakia as non-pre­cancerous state and with the increasing risk of anal carcinoma. If microscopic examination finds dyspla­sia, which with time may undergo malignant transformation, local excision of the foci of dysplasia is advocated.1 In the cases which have already undergone transformation, local excision of the lesion is performed. In the pre­sented case, the woman had been under ob­servation for six years. Within that period of time, microscopic examinations were not per­formed. Notably, however, a few years ago, the changes representing dysplasia might have been diagnosed and would have been suitable for local excision. The treatment and prognosis of leukoplakia which has under­gone malignant transformation differs from that for a typical, benign leukoplakia. It de­pends on the stage of disease. In cases of car­cinoma planoepitheliale in stage 0 (ca in situ) or in stage I, it may be limited to local exci­sion, whereas in stage II, a combination of chemoradiotherapy is used.1 In the presented case, AES enabled an exact assessment of the depth of infiltration and proper decision that the patient is eligible for an oncological treat­ment. Staging of anal canal carcinomas is impor­tant in planning treatment strategies.6-8 The TNM classification system currently used is based on the result of a digital rectal exami­nation where only margins of the tumour around anal circumference and its proximal and distal ends are assessed without the eval­uation of its mobility and the depth of pene­tration of the tumour into canal wall. Perianal lymph nodes can not be assessed either. Anal tumour diagnostics allows a precise evalua­tion of their local advancement with the use of AES because a layered structure of the anal canal is visible on AES.9-13Anal carcinomas are staged according to the TNM classifica­tion uTN, where »u« means that ultrasonog­raphy was used to determine the staging. In: 1) uT1 tumour is limited to submucosa and mucosa 2) uT2 is limited to sphincters 3) u T3 infiltrates perirectal tissues 4) u T4 invades surrounding structures. N0 and N1 mean lack or metastatic regional lymph nodes. Anal carcinoma in AES appears as hypoe­choic mass, with irregular outlines. the depth of invasion by tumours and their relation to surrounding structures is easily seen in AES. In the discussed case, AES showed partial in- Radiol Oncol 2002; 36(3): 215-8. filtration of the anal sphincters, which stayed within the external outlines of the sphincters, and reached only the mid anal level. Enlarged lymph nodes were not detected. These two findings,: limited penetration and lack of en­larged lymph nodes in perianal area led to the prognosis of the survival time. However, one of the most important markers of the progno­sis is the state of inguinal lymph nodes. Thereby, it is essential to complete AES with the assessment of these lymph nodes using linear probe. Such approach enables a better prognosis of patient’s life. When it concerns the diagnostics of malignant diseases of the anal canal, AES is very often used as a routine examination. Postoperatively, follow- up ex­aminations may allow for an early diagnosis of local recurrence in perianal tissues before they are evident on a clinical examination. An US guided fine needle aspiration biopsy of an abnormal lesion may also be possible.14 Leukoplakia is a benign anal disease and extremely rarely undergoes a malignant transformation. The presented case however indicates that, in cases of any abnormal le­sion in anus/anal canal periodic, regular check-ups should be carried out. Apart from digital rectal examination and histopatholog­ic evaluation of specimen, AES is the most suitable method for monitoring, not only be­cause it enables assessment of the stage of disease which has direct influence on treat­ment strategy, but also because of its simplic­ity, low-cost, availability and non-invasive­ness. References 1. Bielecki K, Dziki A. Proktologia. Warszawa: PZWL;, 2000. 2. Bobkiewicz P.Dystrofie sromu. Pat Pol 1990; 41: 173-7. 3. Taussig YJ. Leukoplakic vulvitis and cancer of vul­va. Am J ObstetGynecol 1978; 21: 955-61. 4. Janovski NA. Classification of dysplastic and pre- malignant lesions of the vulva with histologic and histochemical considerations. Int J Obstet Gynecol 1970; 8: 581-6. 5. Miecznikowski A. Choroby sromu. Warszawa: PZWL; 1993. 6. Góral R. Chirurgia odbytnicy i okreznicy. Warszawa: PZWL; 1993. 7. Herzog U, Boss M, Spichtin HP. Endoanal ultra-sonography in the follow-up of anal carcinoma. Surg Endosc 1994; 8(10): 1186-9. 8. Novell F, Trias M. Intraluminal anorectal ultra-sonography in the staging of anal canal cancer. Rev Esp Enferm Dig 1993; 84(3): 153-5. 9. Beynon J. An evaluation of the role of rectal en-dosonography in rectal cancer. Ann Royal Coll Surg Engl 1989; 71: 131-8. 10. Beynon J, Mortensen NJ, Foy DM, Channer JL, Rigby H, Virjee J. Preoperative assessment of mesorectal lymph node involvement in rectal can­cer. Br J Surg 1989, 76: 276-9. 11. Hildebrandt U, Feifel G, Ecker KW. Rectal en-dosonography. Baillieres Clin Gastroenterol 1989; 3: 531-41. 12. Mortensen N. Rectal and anal endosonography Gut 1992; 33: 148-9. 13. Zainea GG, Lee F, McLeary RD, Siders DB, Thieme ET. Transrectal ultrasonography in the evaluation of rectal and extrarectal disease. Surg Gynecolo Obstet 1989; 169: 153-6. 14. Magdeburg B, Fried M, Meyenberger C. Endoscopic ultrasonography in the diagnosis, staging, and follow-up of anal carcinomas. Endoscopy 1999; 31(5): 359-64. Radiol Oncol 2002; 36(3): 215-8. Endosonographic and manometric assessment of the anal sphincters in patients operated on for Crohn's disease of the colon Iwona Sudol-Szopiriska, 1 Adam Ciesielski, 2 Krzysztof Bielecki2, Lech Baczuk,2 Wieslaw Jakubowski1, Wieslaw Tarnowski2 1Imaging Diagnostic Department, Second Medical Faculty, Warsaw, 2Postgraduate Education Medical Centre, Department of General Surgery, Warsaw, Poland Background. The aim of this study was to compare endosonography and manometry of the anal sphincters in patients operated on for Crohn's Disease (CD) of the colon. Patients and methods. Ten patients aged between 21-67 years operated on for CD between 1988 and 1999 were examined with anal endosonography (AES) and anorectal manomem;. Results. AES visualized abnormal image of the internal anal sphincter (lAS) in 8 patients (80%). Defects of the external anal sphincter (EAS) and puborectalis muscle (PR) were shown in 7 patients (70%). Correlation between endosonographic and manometric assessment of the !AS was found in 9 patients (90%). Correlation for the EAS and PR was found in 7 cases (70%). Conclusions. AES and manometry allow assessing the morphology as well as functioning of the anal sphincters and in most of the patients operated on for CD of the colon show high correlation in the above assessment. Both methods may be very helpful in choosing an optimal surgical procedure in patients with CD. Key words: Crohn disease -surgery; anus; endosonography; manometry Introduction Crohn's Disease (CD) is a progressive disease which diminishes the quality of life. The best results in the treatment of this entity are achieved when there is a good cooperation Received 15 July 2002 between gastrologist and surgeon.1 Unfor­Accepted 12 August 2002 tunately, pharmacological treatment is not ef­ fective enough; therefore, surgical treatment Correspondence to: I. Sudoi-Szopiriska, M.D., Ph.D. has become the basic method of treatment of Wojew6dzki Szpital Br6dnowski, ul. Kondratowicza CD.2 Surgery of CD is a complex procedure. 8, 03 285 Warszawa; Fax: +48 22 811 95 91; Mobile +48 501 716 407; E-mail: mdyvonne®poczta.wp.pl It frequently requires extensive resection of the bowels and, in some patients, it is per­formed as a multistage operation. In this group of patients, the assessment of the anal sphincters before the decision on reconstruc­tive surgery is of great importance, in partic­ular because CD often affects anorectal func­tion even in the patients without any macro­scopic rectal or anal lesions.3 One of the basic methods enabling visualization and assess­ment of the function of these muscles are anal endosonography (AES) and anorectal manometry. In the present study, we were seeking correlation betweef! the endosono­graphic and manometric assessment of anal sphincters in the patients operated on for CD in the colon. Patients and methods Ten patients (8 women and 2 men) aged be­tween 21-67 years (median age 34.1 years) op­erated on for CD of large bowel in years from 1988 to 1999 were examined with the use of anal endosonography and anorectal manome­try. Tn 6 patients of this group, hemicolecto­my was performed, in 2, colectomy and ileostomy, and the remaining 2, partial resec­tion of the colon with colostomy. Exami­nations were performed 3-11 years after sur­gery (menn 5.5 yeilrs). Only one woman had an operntion on the anal canal prior to surgi­cal trentment of CD for ano-vaginal fistula. Anal endo!'onography was performed with the use of Bruel and Kjaer scanner, type 1846, with ,1 7.0 MHz rotating endoprobe that pro­vides .1 360° image. The probe was covered with a pl.1stic cnnc with an external diameter of 17 mm, \\'hich \\'as filled with degassed wa­ter for acoustic coupling. The cone was cov­ered with a condom. Patients were examined in the prone pnsition <1nd no preparation was required prior to AES. As the probe was be­ing withdra\\·n from the ann! canal, images of the puborectalis muscle (PR), external anal sphincter (EAS) and internal anal sphincter (IAS) were documented. The endosonograph­ ic image of the anal sphincters: thickness, echogenicity, outlines and continuity of the IAS, and echogenicity and continuity of the EAS were assessed on each level of the anal canal. The thickness of the IAS was measured at 3 and 9 o'clock positions of the coronal plane of imaging using electronic calipers on the monitor. The normal IAS was defined as a homogenous, hypoechoic ring with the thickness greater than 1 mm.3 The increased and non-homogenous echogenicity and ill-de­fined margins or presence of tear of the IAS were diagnosed as abnormal. The EAS was identified as non-homogenous muscle with striated echogenicity and was defined as ab­normal if hypoechoic areas were visible with­in it.4 Dynamic activity of the EAS and PR was assessed as good or as lacking contrac­tion on the basis of a subjective scale which depended on comparing their images at rest and durirlg maximal voluntary contraction. Anorectal manometry was performed with the patients in the left lateral position with their hips flexed at 90°. No enema was given. Lower gastrointestinal manometry system (PC Polygraf HR; Synectics Medical Stockholm, Sweden) with four -lumen polyvinyl chloride catheter with rectal dis­tendirlg balloon (AMC4-B; Zinectics Medical, Stockholm, Sweden) was used. Perfusion ports were located at 1 cm intervals and arranged circumferentially. A pressure trans­ducer was incorporated to each perfusion line and connected to a polygraph device. During the study the manometric recordings were displayed on the screen of an on-line comput­er and were stored for later analysis with the . use of a dedicated software program. After positioning at a depth of 6 cm from the anal verge, the catheter was kept at rest for sever­al minutes to accommodate. Maximum rest­ing anal pressure (MRP), maximum voluntary pressure (MVP), sphincter endurance (SE), and maximum tolerated rectal volume (MTRV) were recorded. Radio/ 0 11col 2002; 36(3): 219-2.1. Sudoi-Szopinska I et al./ Anal endosonography, anorectal manometry and Crohn's disease f21 Results The results of anal endosonography and anorectal manometry are presented in the Tables 1, 2 and 3. In anal endosonography, thinning of the !AS was visible in 4 patients (40%). Increased echogenicity of the IAS in 3 (30%) and ill-de­fined borders in 3 patients (30%). Tear of the IAS was visible in 4 cases (40%), including 1 woman with a history of operation for ana­vaginal fistula and 2 following obstetric trau­ma (non-symptomatic), and 1 man, where the reason of the IAS tear was unclear (congeni­tal?). Defect of echogenicity of the EAS was visible in 5 cases (50%}, tear in 1 patient (10%) (following obstetric trauma). Dynamic exami­nation revealed good EAS and PR contraction in 7 patients (70%}, and lack in 3 patients (30%) . Manometry revealed decreased maximum resting anal pressure suggesting dysfunction of the IAS in 7 cases (70%). Dysfunction of the EAS and PR was found in 7 patients (70%): decreased maximum voluntary pres­sure with shortage of sphincter endurance was seen in 6 patients (60%), in one case only decreased maximum voluntary pressure, and in another only shortage of the sphincter en­durance indicated a defect of the EAS and PR, as well. Table 1. Anal endosonography in patients operated for CD No IAS The correlation between AES and man?m­etry for the TAS was found in 9 cases (9Q'X.). The correlation for the EAS endosonographic image and its manometric assessment was observed in 7 cases (70%), and the correlation for the endosonographic evaluation of its con­traction and manometry in 6 cases (60%). Full correlation (for all analyzed musc_lcs: the IAS, EAS and PR) between endosonogra­phy and manometry was found in 4 patients (40%), in 2 patients (20%) for the IAS only, in 1 (10%) for the EAS only. In the remaining 3 cases, partial correlation was found (Table 1, cases 1, 6, 7). Table 2. Anorectal manometry in patients operated for CD (sequence of patients as in table 1) No MRP MVP SE MTRV 1. 40 53 10 90 2. 25 80 40 350 3. 80 138 15 140 4. 35 67 45 80 5. 50 195 40 80 6. 65 208 65 35 7. 40 92 30 70 8. 25 50 10 40 9. 40 216 42 60 10. 70 210 50 110 Normal 60-80 100-250 >40 100-300 values MRP = Maximum resting pressure [mmHg]; MVP = Maximum voluntary pressure [mmHg]; SE = Sphincter endurance [sec]; MTRV =Maximum tolerat­ed rectal volume [ml] Lack of EAS dynamic activi Thin Increased lli-defined Tear Thin Scars Tear [<1mm) echogenicity borders 1. + + 2. + + + + + + 3. + 4. + + + 5. + + + 6. + + + + 7. + + 8. + + + 9. + 10. Radio/ Oncol 2002; 36(3): 219-23. Table 3. Correlation between endosonographic and manometric assessment of anal sphincters No Correlation Correlation for IAS forEAS Endosonographic Dynamic image activi~ 1 + + 2 + + + 3 + + 4 + 5 + 6 + 7 + + 8 + + + 9 + + + 10 + + + Normal image of the IAS was visible in 2 patients in AES, and manometry confirmed preserved resting pressure. In the remaining 8 cases with abnormal endosonographic im­age of the IAS, the correlation with manome­try was found in 7 cases. In patients with nor­mal image of the EAS (3 patients) manometry confirmed normal pressures in 2 out of 3 cas­es. Abnormal endosonographic image corre­lated with manometry in 5 out of 7 cases (71.4%). Lack of dynamic activity of the EAS and PR function found in 3 patient correlated with abnormal result of manometry, on the other hand, normal function of these muscles found in AES correlated with manometry in only 4 cases (4 out of 7; 57.1 %). Discussion Anal endosonography, apart from magnetic resonance imaging using endorectal coil, is the most appropriate method to assess the morphology of the anal sphincters. In CD of the rectum, AES enables visuali­zation of the abscesses, fistulas, and carcino­ma. Thickening of the rectal wall, and non­homogenicity of anal sphincters are well visi­ble in AES, too, and all the above changes are detected earlier by means of AES than by tra­ditional tests (endoscopy, barium studies).5 Radio/ Oncol 2002; 36(3): 219-23. This study, though, presents a group of pa­tients operated on for CD of the colon. Evaluation of anal sphincters in these pa­tients is important before decision on recon­structive surgery. CD may affect anorectal function by impairing anal pressures and functional capacity of the rectum as a reser­voir even in patients without any macroscop­ic rectal or anallesions.3 Endosonographic as­sessment of the morphology of the anal sphincters and manometric measurements of their function allow such evaluation. 6-9 Defects of anal sphincters were found in most of the patients (up to 80% in AES, and 70% in manometry). Only 2 patients had nor­mal image of the lAS. Manometry confirmed this diagnosis. Even in the patients with ab­normal image of the IAS (8 patients), manom­etry found decreased resting pressure in most of them (7 patients). Thinning of the lAS was the most frequent abnormality we observed in our study (4 patients). There are several causes of the thinning of the IAS, such as denervation, ischemia or a direct trauma to the TAS as a result of obstetric trauma (as it was in 3 of our patients). The possibility of the IAS degeneration, relevant with age and manifested typically as thinning that in­creased echogenicity and ill-defined borders of the IAS, was excluded because of young age of our patients (mean age 34.1 years). On the other hand, there were predominantly women in our group of patients (8 versus 2) and it has been shown in the literature10 that a relevant number of women who have had even uncomplicated deliveries endosono­graphically show sphincter defects. The lack of dynamic activity of the EAS and PR was observed in 3 patients in AES. It was confirmed by manometry in all cases; howev­er, normal function of these muscles in re­maining 7 patients was confirmed manomet­rically in only 57% of the cases. Therefore, dy­namic AES appeared to be a valuable adjunct to the examination at rest, especially sensitive in diagnosing non-functioning muscle. Assessment of the anal sphincters in both anorectal manometry and anal endosonogra­phy in patients operated on for CD enables morphological and functional evaluation of the sphincters. It might be relevant for better patient selection for restoration of large bow­el continuity after resection for CD. Incompetence of the sphincter is a con­traindication for large bowel restorative sur­gery. Although our small study does not lead to ultimate conclusions, AES and manometry identified satisfactory correlation in most pa­tients. Conclusions Anorectal monometry and anal endosonogra­phy are complementary methods in the as­sessment of the anal sphincters. In most pa­tients operated on for CD of the large bowel, both methods revealed defects of morphology and function of anal sphincters and correlat­ed in 90% of the IAS assessments, and in 70% of the evaluations of morphology and dynam­ic activity of the EAS. It seems that AES to­gether with manometry may be a good com­bination for the assessment of the function of the anal sphincters in Crohn's Disease. References 1. Bielecki K, Dziki A. Proktologia. Warszawa: PZWL; 2000. 2. G6ral R. Cfrirurgia odbytnicy i okr~inicy. Warszawa: PZWL; 1993. 3. Crysos E, Athanasakis E, Tsiaoussis ), Zoras 0, Nickolopoulos A, Vassilakis JS, et al. Rectoanal motility in Crohn's disease patients. Dis Colon Rectt1m 2001; 44: 1509-13. 4. Bartram Cl, Frudinger A. Handbook of anal en­dosonograpfry. Petersfield, Bristol: Wrightson Biomedical Publishing LID; 1997. 5. Lavery IC, Tuckson WB, Easley KA. Internal anal sphincter function after total abdominal colecto­my and stapled ileal pouch-anal anastomosis with­ out mucosal proctectomy. Dis Colon Rectum 1989; 32: 950-3. 6. Gantke B, Schafer A, Enck P, Lubke HJ. Sonographic, manometric and myographic evalua­tion of the anal sphincters morphology and func­tion. Dis Colon Rectum 1993; 36(11): 1037-41. 7. Hill MC, Rifkin MD, Tessler FN. Ultrasound eval­uation of the anal sphincter in fecal incontinence. Ultrasound Quarterly 1998; 14(4): 209-17. 8. Schafer R, Heyer T, Gantke B, Schafer A, Frieling T, Haussinger D, et al. Anal endosonography and manometry. Comparison in patients with defeca­tion problems. Dis Colon Rectum 1997; 40(3): 293­7. 9. Law PJ, Kamm MA, Bartram Cl. Anal endosonog­raphy in the investigation of faecal incontinence. Br J Surg 1991 : 78: 312-4. 10. Sultan AH, Kamm MA, Hudson CN, Thomas JM, Bartram Cl.. Anal-sphincter disruption during vaginal delivery. N Engl] Med 1993; 329(26): 1905­11. Radio/ Oncol 2002; 36{3): 219-23. Extramedullary plasmacytoma of the larynx: a report of three cases Primož Strojan Department of Radiation Oncology, Institute of Oncology, Ljubljana, Slovenia Purpose. To report three cases of extramedullary plasmacytoma of the larynx treated at the Institute of Oncology in Ljubljana between 1969-1999. Results. All three patients were treated with radiotherapy only, which resulted in permanent local and re­gional control of 7.8, 4.7 and 3.5 years. The function of the larynx was preserved in all of them. Two pa­tients died, both to the causes other than plasmacytoma. In none of the patients disease progressed to mul­tiple myeloma. Conclusions. Extramedullary plasmacytoma of the larynx is a rare disease, highly curable when radiother­apy is used. Moderate radiation doses and limited fields ensure excellent cosmetic and functional result. Key words: laryngeal neoplasms - radiotherapy; plasmacytoma Introduction Extramedullary plasmacytoma (EMP) is a rare tumor of the larynx. Whereas more than 80 % of all EMP arise in the upper aerodigestive tract, only about 10 % of them are laryngeal.1 Since the first report on EMP of the larynx in 1913 by Wachter1, less than 100 additional cases have been described in the world litera­ture, the subglottis and epiglottis area being the most commonly involved subsites within Received 10 September 2002 Accepted 20 September2002 Correspondence to: Assoc. Prof. Primož Strojan, M.D., Ph.D., Department of Radiation Oncology, Institute of Oncology, Zaloška 2, SI-1000 Ljubljana, Slovenia. Phone: +386 1 232 3063; Fax: +386 1 431 41 80; E-mail: pstrojan@onko-i.si the larynx.2 It occurs approximately three times more often in men than in women, and is usually seen at the age of 50-70 years.2 In the present report, we describe three cases of EMP of the larynx, which were seen at the Institute of Oncology in Ljubljana be­tween 1969-1999. The incidence and difficul­ties in diagnosing the disease, and treatment options currently available are discussed. Case reports Case 1. A 65-year-old male was diagnosed with EMP after a two-year history of hoarseness. From the very beginning, a reddish thickening that extended downwards toward the anterior commisure, with yellowish cystic top was seen on the anterior third of the left ventricu­lar fold on indirect laryngoscopy. No clinical­ly evident lymphadenopathy could be found on the neck. No further diagnostic proce­dures were carried out at that time. After 18 months, a directoscopy with biopsy was per­formed due to gradual deterioration of his voice. Histopathological examination of tis­sue sample revealed highly vascularized fi­brous stroma with intense lympho-plasma­cytic infiltration, partially covered with parakeratotic squamous epithelium with par­tially ulcerated surface. Because of inconclu­sive histological report, further enlargement of the lesion, and persistent hoarseness, a second biopsy was taken one month later. Nonspecific granulation tissue with multinu-cleated giant cells was found; after staining, extensive deposits of amyloid with numerous plasma cells were seen, and a differential di­agnosis of amyloidosis was made. On the re­view, the patient was diagnosed as having plasmacytoma with kappa light chain restric­tion. Of diagnostic tests aimed to exclude multiple myeloma, only skeletal survey was performed, which showed no abnormality. The patient was treated with radiotherapy, using cobalt-60 unit and the technique of two opposing lateral fields covering larynx and nodal regions Ib-IV. A tumor dose of 40 Gy was delivered in 2 Gy daily fractions five times per week. Afterwards, a boost of addi­tional 20 Gy, using the same fractionation regimen and technique, was applied to the Table 1. Incidence of extramedullary plasmacy­toma of the larynx in relation to other laryngeal neoplasms: review of the literature Author (Ref.) Incidence (%) Cady, 1968 (3) 0.04 Shaw, 1972 (4) 0.07 Gorestein, 1976 (5) 0.19 Kralj, 1988 (6) 0.16 Kost, 1990 (7) 0.45 Present report 0.10 larynx and level II-III neck nodes only. Partial response regarding the size of the lesion with mobile larynx was seen at the end of the ther­apy, and at all subsequent follow-up visits. The patient died 7.8 years after having diag­nosed EMP due to cerebrovascular insult. There were no tumor recurrence or systemic dissemination observed, while the patient’s voice improved considerably even if not com­pletely compared to pre-diagnostic state. Case 2. A 72-year-old male presented with a three-week history of acutely evolved hoarseness. Indirect laryngoscopy revealed a corn grain size polyp on the middle third of the right vo­cal cord. The vocal cord mobility was intact, as was the airflow. No enlarged lymph nodes were detected on the neck. Ablation of the tu­mor was performed under local anesthesia. Histological diagnosis was EMP, im­munoglobulin-negative, with lambda light chain restriction. To exclude dissemination of the disease, immunoelectrophoresis of the serum and urine, and skeletal survey were done. Bone marrow biopsy was, however, not performed. The patient was irradiated with Co-60 gamma rays and two opposed lateral fields of 7×7 cm2 covering the glottis and nearby structures only; there was no inten­tion to treat regional lymphatics. The tumor dose of 46 Gy was applied in 2 Gy-daily frac­tions five times per week. On regular follow­up examinations, there was no tumor recur­rence or disease dissemination detected. The patient retained the functional larynx with normal voice preserved for the next 4.7 years when he died due to a new primary tumor, colorectal adenocarcinoma. Case 3. A 50-year-old healthy female had a seven-month history of increasing hoarseness. On microlaryngoscopy under general anesthesia, Radiol Oncol 2002; 36(3): 225-9. a pinky lesion occupying the anterior part of the right sinus of Morgagni, the size of a pea, was described by the examiner, and declared clinically for adenoma. There was no restric­tion in vocal cord mobility or clinically evi­dent regional lymphadenopathy. The diagno­sis of extramedullary plasmacytoma with kappa light chain restriction and negative im­munohistochemistry for immunoglobulins was made on histopathological examination of bioptic specimen. The results of both serum and urine immunoelectrophoresis were within normal ranges as were those of beta-2-microglobulin and bone marrow biop­sy. No osteolytic lesions were detected on skeletal survey. She was treated by radiother­apy using cobalt-60 gamma rays. First, the whole larynx and neck lymphatics of regions Ib-V were irradiated. A three-field technique of two opposing lateral fields and low anteri­or field was used to a tumor dose of 40 Gy de­livered in 2 Gy-daily fractions five times per week. A booster dose of 10 Gy (2 Gy/fraction) was than added through two opposing fields to the tumor bed only. At the end of the ther­apy, no tumor was visible on indirect laryn­goscopy with vocal cord mobility preserved. At the moment - 3.5 years after the diagnosis - the patient complains of mild xerostomia and caries; there is no sign of local recurrence or systemic dissemination, with serum beta-2-microglobulin being within the normal range. Her voice is preserved and its quality satisfactory. Discussion Even in specialized oncology centers, the probability of coming across with patient with EMP of the larynx is extremely small. According to the literature, it represents only 0.04-0.45 % of malignant laryngeal tumors (Table 1).3-7 In other words: EMPs originating in the larynx account for 11 % of the upper aerodigestive tract plasmacytomas,2 whose incidence is estimated to be less than 1 % of all head and neck malignancies.8 In Slovenia, there were 2895 new malignant tumors of the larynx and 31 EMPs registered by the Cancer Registry during the years 1969-1999.9 Three cases reported here represent 0.10 % and 9.7 %, respectively, of tumors in these two groups. Diagnosis of EMP of the larynx is often de­layed. Presenting symptoms are usually limit­ed on non-specific, slowly progressive hoarseness over the period of months to years. Acute presentations are rare. Dysphagia, stridor, and pain are late symp­toms, associated with locally advanced dis­ease.10 Secondly, the gross appearance of the lesion is variable: from yellow gray to dark brown polypoid or sessile mass, or diffuse thickening of the involved organ. The surface is usually smooth and the consistency semi-firm and rubbery.5,8 In addition, there are also problems with tissue sampling and histological identifica­tion. The plasma cells are commonly found in abundance in a variety of benign conditions, including chronic inflammation, which is of­ten present in the immediate proximity of malignant tumors. For example, Pahor11 dis­cussed a case with initial diagnosis of a plas­ma cell polyp that was, two years later, cor­rectly identified as laryngeal plasmacytoma. Two of three cases presented by Maniglia and Xue 12 were initially misdiagnosed as chronic inflammation and »amyloid deposit«, respec­tively, while Kost 7 reported on difficulties in diagnosing EMP in two of four patients. In the present series, we share the same experi­ence in case 1. In all of our cases, however, immunohistochemical assessment of mono-clonality was performed to exclude benign polyclonal lesions, which was not the case in the majority of other reports.13 After defining the locoregional extent of the disease, all additional hematological, bio­chemical and radiological tests are focused to identify or exclude the presence of other plas- Radiol Oncol 2002; 36(3): 225-9. macytomas, or of systemic dissemination to multiple myeloma.2 So far, none of the tumor characteristics or laboratory parameters could have predicted reliably the dissemina­tion of the disease, which occurs most often in the first two years following the diagnosis of EMP.14 EMP, however, has a tendency of being localized disease. According to the re­sults of extensive literature review reported by Alexiou et al. 2, regional nodes are invaded in less than 10 % of EMP patients, and in ap­proximately 16 % of patients, the disease pro­gresses to multiple myeloma. The same holds true also for laryngeal tumors and our experi­ence supports the rule. A number of treatment options are avail­able for EMP of the larynx, including radio­therapy, laser surgery, several endoscopic or open conservation procedures, and chemotherapy. The advantage of radiothera­py is its effectiveness due to proven radiosen­sitivity of the disease, high probability of ex­cellent voice preservation 15, and less restric­tive treatment selection criteria as compared to surgery. The disadvantages include a course of radiotherapy extending over several weeks and troublesome acute radiation toxic­ity. Analyzing larger series of EMP patients from our institution, we came to the conclu­sion that EMP is a highly curable disease when radiotherapy is used with or without previous surgery. According to the bulk of disease, 40-50 Gy, conventionally fractionat­ed, is recommended for macroscopic disease, while after radical surgery, close observation only is justified. No elective radiotherapy should be considered in node-negative pa­tients, but neck dissection followed by radio­therapy (36-40 Gy) or only radiotherapy (40­50 Gy) is recommended for node-positive cas­es. Irradiated volume should include surgical bed or affected nodal region(s) on the neck only.14 Surgery is, however, usually employed as a salvage procedure after unsuccessful radio­therapy, even though some authors consider it for the first-line therapy to avoid long-term sequeale of radiotherapy.2,13 The role of chemotherapy in the treatment of primary tu­mors, recurrent disease, or in preventing or delaying progression to MM is controversial. As a rule, it is reserved for inoperable recur­rences or disseminated disease.14 After radi­cal therapy, tumor control rate is approaching 100 %, but overall survival rate, ranging wide­ly, is critically dependent on the degree of conversion to multiple myeloma.2,14 In conclusion, EMP of the larynx is a rare tumor, representing only 0.1 % of laryngeal malignancies in Slovenia. Diagnosis is often delayed due to non-specific presenting symp­toms and gross tumor appearance, and diffi­culties related to histological identification of the disease. Tests to search for systemic dis­semination are mandatory. Radiotherapy is highly effective in EMP, ensuring larynx preservation with excellent voice in the ma­jority of patients treated. Acknowledgement This work was supported by the Ministry of Edication, Science and Sport of the Republic of Slovenia, Grant J3-3010-0302-01. References 1. Wachter H. Ein fall von multiplem plasmazytom der oberen luftwege. Arch Otolaryngol Rhinol 1913; 28: 69-73. 2. Alexiou C, Kau RJ, Dietzfelbinger H, Kremer M, Spieß JC, Schratzenstaller B, et al. Extramedullary plasmacytoma: tumor occurrence and therapeutic concepts. Cancer 1999; 85: 2305-14. 3. Cady B, Rippey JH, Frazell EL. Non-epidermoid cancer of the larynx. Ann Surg 1968; 167: 116-20. 4. Shaw H. Tumours of the larynx. In: Scott-Brown 3rd (ed): Diseases of the air, nose, and throat. ed. London: Butterworth; 1972. 5. Gorenstein A, Nell HB, Devine KD, Weiland LH. Solitary extramedullary plasmacytoma of the lar­ynx. Arch Otolaryngol 1977; 103: 159-61. Radiol Oncol 2002; 36(3): 225-9. 6. Kralj Z, Šarcevic B, Deponte V. Solitarni ek­stramedularni plazmocitom larinksa. Lijec Vjesn 1989; 111: 147-9. 7. Kost KM. Plasmacytomas of the larynx. J Otolaryngol 1990; 19: 141-6. 8. Webb HE, Harrison EG, Masson JK, ReMine WH. Solitary extramedullary myeloma (plasmacytoma) of the upper part of the respiratory tract and oropharynx. Cancer 1962; 15: 1142-55. 9. Cancer Registry of Slovenia. Cancer incidence in Slovenia, 1999. Report no. 41. Ljubljana: Institute of Oncology; 2002. 10. Bjelkenkrantz K, Lundgren J, Olofsson J. Extramedullary plasmacytoma of the larynx. J Otolaryngol 1981; 10: 28-31. 11. Pahor AL. Plasmacytoma of the larynx. J Laryngol Otol 1978; 92: 223-32. 12. Maniglia AJ, Xue JW. Plasmacytoma of the larynx. Laryngoscope 1983; 93: 741-4. 13. Hotz MA, Bosq J, Schwaab G, Munck JN. Extramedullary solitary plasmacytoma of the head and neck: a clinicopathological study. Ann Otol Rhinol Laryngol 1999; 108: 495-500. 14. Strojan P, Šoba E, Lamovec J, Munda A. Extramedullary plasmacytoma: clinical and histopathologic study. Int J Radiat Oncol Biol Phys 2002; 53: 692-701. 15. Lesnicar H, Šmid L, Zakotnik B. Early glottic can­cer: the influence of primary treatment on voice preservation. Int J Radiat Oncol Biol Phys 1996; 36: 1025-32. Radiol Oncol 2002; 36(3): 225-9. Effects of 5-Gy irradiation on fertility and mating behaviour of Nezara viridula (Heteroptera: Pentatomidae) Alenka Žunic1, Andrej Cokl1 and Gregor Serša2 1 Department of Invertebrate Physiology, National Institute of Biology, Ljubljana, 2 Laboratory of Radiation Biology, Institute of Oncology Ljubljana, Slovenia Background. The polyphagous and cosmopolitan species Nezara viridula is one of the most important in­sect pests. The sterile insect technique (SIT) is a pest control strategy that involves sterilising males by ex­posing them to ionising radiation. Sterile males, released into wild population, mate with females, but eggs are not fertilised and the population gradually declines. Exposing insects to radiation during their growth stage might require lower sterilising dose. The aim of our study was to test whether 5-Gy irradiation of 5th instar nymphs significantly affects: (1) moulting and further development of the irradiated nymphs, (2) the male’s and female’s reproductive system and (3) the mating competitiveness of treated males, with special focus on vibrational communication. Methods: The 5th instar nymphs were irradiated with 5 Gy using X-ray generator and monitored daily. Results: The observed effects of irradiation were: prolonged moulting, increased mortality during develop­ment and during the first day of adult life, decreased males to females ratio, decreased fecundity, egg pro­duction, proportion of fertile eggs and progeny survival. The reaction of a male to stimulation with the mod­el female calling song was tested. The irradiated and non-irradiated males responded to stimulation with emission of the courtship song (MCrS). Temporal parameters of MCrS emitted by non-irradiated males dif­fered when compared with those of irradiated ones. Conclusions: The 5-Gy irradiation of 5th instar nymphs did not affect mating behaviour. However since the irradiation during growth stage decreased the fertility and fecundity of emerged adults, this technique, in combination with certain other suppression techniques, could be a successful control strategy for man­agement of Nezara viridula. On the other hand observed effects on moulting and further development of the irradiated nymphs could decrease the efficiency and application of this strategy. Key words: gryllidae - radiation effects; insect control; molting; animal communication; vibration Received 22 August 2002 Accepted 16 September 2002 Correspondence to: Alenka Žunic, B.Sc., National Institute of Biology, Vecna pot 111, P.O.Box 141, SI­1000 Ljubljana, Slovenia; Phone: +386 1 423-33-88; E­mail: alenka.uni@siol.net Introduction The southern green stink bug Nezara viridula (L.) is one of the most important pentatomid insect pests in the world. As a cosmopolitan and highly polyphagous species it infests many important vegetable crops.1,2 Nezara viridula and other stink bugs are difficult to control over wide areas, because of the large variety of crops on which they feed and the type of damage they produce.3 Even a low population density can cause large economic damage to the crops. Nezara viridula is a pro­lific, long-lived bug nourishing on short-sea­son crops and an area wide control strategy may bring success. Autocidal methods and genetic manipulation can be effective against low-density population dispersed across wide ranges and against pest within high-density, but localised population.4 Knipling proposed that the release of semisterile insects would bring damaging genetic stress on the target population.5 Partial sterility of adult hemipterans may be achieved after they are exposed to ionising radiation of 30-100 Gy.6,7 Dyby and Sailer showed that low-level radia­tion exposure of Nezara viridula during their growth stage (4th instar nymphs) has a greater impact on reproductive fitness.8 Females laid nonviable eggs in high proportion and had significantly lower fecundity than controls. They reasoned that exposure of 4th instar nymphs to ionising radiation of less than 10 Gy has no serious effect on mating behaviour and survivorship. The aim of our study was to test whether 5­Gy irradiation of 5th instar nymphs signifi­cantly affects: (1) moulting and further devel­opment of the irradiated nymphs, (2) the male’s and female’s reproductive system and (3) the mating competitiveness of treated males, with special focus on vibrational com­munication. Materials and methods The experiment was conducted on southern green stink bugs Nezara viridula of the Guadeloupe population. Bugs were reared in the laboratory in plastic cages (38×23×23 cm), at 22 - 26°C, relative humidity 70 - 80 %, 16 L: 8 D daily cycle, and on a diet of green beans (Phaseolus vulgaris L.), mung bean (Vigna mun-go (L.) Hepper), raw peanuts (Arachis hypoaea L.) and sunflower seeds (Helianthus annus L.). Nymphs and adults were kept in separate cages. One hour before irradiation, 5th instar nymphs of the same generation (a few days before the final moult) were separated into two groups (20 individuals each) of which one was irradiated and the other (non-irradiated) was used as the control. Experimental animals were placed into 2 plastic petri dishes (2r = 10 cm). The height of the cover was adjusted so that bugs could not move up or down during irradiation. At the Institute of Oncology one group of bugs was irradiated by a dose of 5 Gy (2 Gy/min) using a Darpac 2000-XE (Gulmay Medical, England) X-ray generator filtered with 0,55 mm Cu and 1,8 mm Al filter. The test was repeated six times with different bugs and named irra01 (January 2000), irra02 (February 2000), irra05 (March 2000), irra06 (April 2000), irra07 (November 2000) and ir­ra09 (February 2001). After irradiation the control and irradiated nymphs were placed in­to plastic cages reared in the way as before treatment. For each group we monitored dai­ly: the number of live individuals, moulted nymphs, male to female ratio, copulating pairs, egg masses, eggs per egg mass, sterile eggs, and the number of hatched eggs. Egg masses were placed into separate petri dishes. Emerging nymphs were then placed into plas­tic cages. We monitored the time from hatch­ing to the adult stage, so that the overall prog­eny survival was obtained. To investigate the effect of irradiation of the 5th instar on vibrational communication during mating behaviour, we used the reac­tion of a male to female calling song.9 In this reaction the male responds to the female call­ing song (FCS) with emission of the male courtship song (MCrS). Responses of the con­trol and treated males were tested in an ane­choic and sound insulated chamber (FA Amplaid, Italy) at room temperature Radiol Oncol 2002; 36(3): 231-7. (23±2°C), 65 - 75 % relative humidity and room light. We placed a control or treated male on a membrane of a cone low-middle frequency speaker (WS 13 BF, Visaton GmbH, Haan, Germany, impedance 8 W, 2r = 144 mm, 40 - 6000 Hz). To prevent male’s moving from the membrane, the loudspeaker was covered with a 2-mm thick Perspex sheet. The latter was not in contact with the membrane, which acted as a receiver of the male’s vibrational signals and as the emitter of a female vibrational signals (FCS). The FCS was synthesised with computer programme (Sound Forge for Windows 95, version 4.0c, Sonic Foundry Inc., Madison, USA). The stimulation programme consisted of 7 stimu­lation sequences (1 minute each) each fol­lowed by 1-minute pause. The 1-minute se­quences were composed of 120 Hz pulses re­peated every 4 seconds. The duration of puls­es varied between different sequences: 200, 500, 800, 1000, 1200, 1600, 2000 ms. The stimulation was played-back from the com­puter, amplified by laboratory made amplifi­er and fed into the loudspeaker. The intensi­ty of stimulatory signals was adjusted to the level of male response. Male responses were amplified by a tape recorder (Revox A - 77, Regensdorf, Switzerland) and fed into a PC computer. Digitised signals were stored and analysed later with a computer programme Sound Forge. We tested 5 males from the control group irra05 (group A) and 6 males from the laboratory culture (group B), and 5 males from irradiated group irra06 (group C) of bugs. Each individual was tested several times but only once in a day. Males from group A (N = 5) were tested 20 times (n = 20), from group B (N = 6) 14 times (n = 14) and males from group C 11 times (n = 11). We recorded the overall number of tests during which males responded to the stimulation at least once. We recorded the number of male’s responses (MCrS) to the model FCS and we analysed the duration of MCrS pulse trains and the latency (time between the on-set of stimulus and the male’s response) (Figure 1). A mean value from the analysed parameters was calculated for each group. Student’s T - test (Microsoft Excel 7.0) was used to determine the significance of differ­ence between the control and irradiated bugs. Figure 1. The male response (MCrS) to the model FCS and the analysed parameters: the duration of MCrS pulse train and the latency of the response. Radiol Oncol 2002; 36(3): 231-7. Results To investigate the effects of radiation we monitored and compared different parame­ters in control and irradiated group of bugs. Results are shown in the Table 1. Irradiated groups differed significantly from control groups in the group moult dura­tion (the time between the first and the last observed moult in a group). The time be­tween the first and the last moult within a group was longer in irradiated groups irra01, irra02 and irra05 (20-21 days) than in non-ir­radiated nymphs (8-11 days). In irra06, irra07 and irra09 groups moult duration was similar for the non-irradiated and irradiated nymphs (7-19 days). All the nymphs survived irradia­tion but mortality of irradiated nymphs dur­ing moult was different in different groups and ranged from 1 (irra07) to 16 (irra02). Mortality was significantly higher when com­pared with control in three groups: irra01, ir­ra02 and irra05. Nymphal mortality reached highest values 5-7 days after the first ob­served moult in irradiated and control groups. We found no difference in the time to reach 50% cumulative mortality (P = 0.47). In the groups irra01, irra02 and irra05 signifi­cantly more non-irradiated (10-15) than irra­diated (4-9) nymphs reached adulthood. In groups irra06, irra07 and irra09 similar num­ber of adults emerged from non-irradiated and irradiated nymphs. The number of emerged males was significantly different for the irradiated groups irra01 and irra02 (P < 0.05). In the group irra01 only 1 male emerged from irradiated nymphs (in control group 7), in group irra02 no males emerged from irradiated nymphs (in control group 5). On the other hand no significant difference was found in the number of emerged females. In the groups irra05, irra07 and irra09 we ob­served significantly higher mortality of adults during the first day after the moulting of irra­diated nymphs (P < 0.05). Adults that suc­cessfully emerged from irradiated nymphs lived as long as controls. No significant difference could be shown Table 1. Significance difference (P < 0.05) between control and irradiated group of bugs, shown separately for each test (irra01, irra02, irra05, irr06, irra07, irra09) for each monitored parameter Parameters irra01 irra02 irra05 irra06 irra07 irra09 (N* = 20) (N = 20) (N = 20) (N = 20) (N = 20) (N = 20) Group duration of moult +# + + -÷ - - Mortality of nymphs + + + - - - 50% cumulative mortality + + + - - - Number of emerged adults + + + - - - Number of emerged females - - - - - - Number of emerged males + + - - - - Number of adults which died a day after the moulting - - + - + + Longer lifespan - - - - - - Precopulation period - - - - - - Copulation period - - - - - - Duration of copulation - - - - - - Number of egg masses - - - - - - Total number of eggs + + + - - - % of fertilised eggs /. / / / + / % of hatched nymphs + + + - - - Overall progeny + + + - - - * the number of bugs in the group # The significance of differences (P < 0.05). ÷ No significance of differences (P > 0.05). . no data avalible Radiol Oncol 2002; 36(3): 231-7. in precopulation period (time between the first emerged adult and the first observed copulation within one group) as well as in copulation period (time between the first and last observed copula). On the contrary we found significant difference between control and irradiated groups in the number of de­posited and fertilised eggs (P < 0.05), in the percentage of hatched eggs and in overall progeny. Females of control groups (N = 26) laid 927 eggs in 24 egg masses, females of ir­radiated groups (N = 18) laid in 11 egg mass­es 297 eggs. In irradiated group irra07 we ob­served only 23.4% (N = 248) fertilised eggs as compared to 80,4% (N = 386) in control group. Eggs laid by females of control groups (irra01, irra02, irra05) hatched in 87,3% (N = 541) and eggs laid by females of irradiated groups (ir­ra01, irra06) in only 35,7 % (N = 49). In con­trol groups we have obtained 61 adults from 927 eggs, in irradiated only 1 adult from 297 eggs (P < 0,05). In control and irradiated groups typical mating behaviour was observed.9,10,11 We analysed vibrational communication between males and females of two controls (A, B) and one irradiated group (C). In all three groups we recorded regularly male calling (MCS) and courtship (MCrS) song as a response to the stimulation with the model FCS (Figure 1). We found no difference in the number of re­sponses to the stimulation between the males of control and irradiated groups. The males of control group A (N = 6) responded to stimu­lation at least once in 30% of tests (n = 20), males of control group B (N = 6) in 35,7% of tests (n = 14). In the irradiated group C males (N = 5) responded to stimulation at least once in 27,3% of the tests (n = 11). The difference between each control group and irradiated one was not significant (PA/C = 0,46; PB/C = 0,11) (Table 2). In all three groups the number of MCrS pulse trains ranged from 22 to 32 during stimulation, and from 15 to 18 during pauses. We have found no significant differ­ence in the latency of male responses of each control and irradiated group (PA/C = 0,32; PB/C = 0,44). In all three groups most of the MCrS signals were recorded as a response to the stimulation pulse with duration of 1000 ms. The only difference between males of dif­ferent groups was found in duration of MCrS pulse trains. Males of control group A emit­ted significantly longer pulses than the males of group B and C (P < 0,05) (Table 2). Discussion Ionising radiation of 5 Gy had a significant impact on moulting, development of newly emerged adults and on the fecundity of adults 5th that emerged from irradiated instar nymphs. Moult duration of irradiated nymphs was two times longer than moult duration of non-irradiated nymphs in three groups. In groups showing prolonged moulting and higher mor­tality of nymphs we also observed lower number of emerged adults and their higher mortality during the first day after moulting. Since Dyby and Sailer 8 reported that low-lev­el radiation exposure of 4th instar nymphs has no serious effect on survivorship, we as­sumed that 5th instar nymphs are more sensi- Table 2. Vibrational communication. The significance difference (+), (P < 0.05) between control and irradiat­ed groups of bug, shown separately for two control groups (A, B) and for irradiated group (C) Parameters A. B** C•• (N* = 5) (N = 6) (N = 5) Type of response -÷ -­Number of responses --­Duration of pulse trains +# + ­Latency --­Number of response regarding of stimulation --­time . males of control group irra05 ** males of control group from laboratory culture •• males of irradiated group irra06 * The number of tested males # The significance of differences (P < 0.05). ÷ No significance of differences (P > 0.05). Radiol Oncol 2002; 36(3): 231-7. 4th tive to low-level radiation then instar nymphs. In two irradiated groups we ob­served significantly lower proportion of males than females that emerged from nymphs which points to higher sensitivity of males to radiation. On the other hand we ob­served no significant difference between the control and irradiated groups in the life span, in the time of precopulation period and tem­poral parameters of copulation. We conclude that the irradiation had greater effect during moulting when the mitotic rate of epidermis cell is very high and the bugs are most vul­nerable to external factors. Comparison of the control and irradiated groups also showed that the radiation significantly reduced fecun­dity and egg production dropped. Semisterility increased after the radiation treatment, the number of fertile eggs and the proportion of hatched eggs decreased. Since the progeny life span of irradiated groups sig­nificantly decreased, we could not observe the impact of the radiation on progeny gener­ation. Dyby and Sailer 8 showed that recovery to normal fertility is an all or none event in the progeny generation. Some pairs are ster­ile and thus bred out of the population, whereas others show complete recovery. Lethal mutations are eliminated within one generation, however some pairs do not recov­er to normal reproductive fitness, probably because of the environmental stress. We also investigated whether the 5-Gy ir­radiation during growth stage changed mat­ing behaviour in Nezara viridula. Emission of vibrational signals is an important part of mating behaviour, providing the information needed for mate recognition and location.10,12 We therefore examined if males that emerged from irradiated nymphs respond differently to the model female calling song than con­trols. If irradiated males would be unable to recognise the FCS or if their vibrational re­sponses would be significantly altered, their competitiveness would be decreased. Comparison of mating behaviour of control and irradiated males revealed significant dif­ference only in the duration of vibrational sig­nals between the control group A and irradi­ated group C. Since duration of signals dif­fered also between the two control groups (A, B group), we cannot attribute the difference between groups A and C to irradiation. The biological effects of radiation on living organisms may be divided into somatic and genetic effects. In our study we observed the somatic effects like prolongation of moulting, the increase of nymphal mortality and in­creased adult mortality during the first day after the moult. Decreased fecundity and fer­tility and increased progeny mortality were the genetic effects of 5-Gy radiation on 5th in-star nymphs. In some bugs we observed no effect of ir­radiation. We assume that overall impact of 5-Gy irradiation is different for different indi­viduals. Some of the bugs could have been parazitised or diseased also, the effects of ra­diation could be exacerbated by inbreeding depression of laboratory reared bugs. The 5-Gy irradiation of 5th instar nymphs did not affect mating behaviour. However since the irradiation during growth stage de­creased the fertility and fecundity of emerged adults, this technique, in combination with certain other suppression techniques, could be a successful control strategy for manage­ment of Nezara viridula. On the other hand ob­served effects on moulting and further devel­opment of the irradiated nymphs could de­crease the efficiency and application of this strategy. Acknowledgements The authors are grateful to Mira Lavric and Viktor Triler for technical assistance during experimental work. The project was finan­cially supported by the International Atomic Energy Agency (Project No. 10967/RO). Radiol Oncol 2002; 36(3): 231-7. References 1. Todd JW. Ecology and behavior of Nezara viridu-la. Ann Rev Entomol 1989; 34: 273-92. 2. Panizzi AR. Wild hosts of pentatomids: Ecological significance and role in their pest status on crops. Ann Rev Entomol 1997; 42: 99-122. 3. Hoffman WE. The food plants of Nezara viridula (L.) (Hemiptera: Pentatomidae). Proc. VI Int Congr Entomol Madrid 1935; 6: 811-6. 4. Knipling EF. Present status and future trends of the SIT approach to the control of arthropod pests, 3-25. In Sterile insect technique and radiation in insect control. Proceeding, Symposia, Neuherberg, FRG, 1971. STI/PUBb/595. IAEA, Vienna. 5. Knipling EF. Concept and value of eradication or continuous suppression of insect populations, pp.19-32. In sterile-male technique for eradication or control of harmful insects. Proceeding, Pannel Viena, 1968. STI/PUB/224. IAEA, Vienna. 6. Mau R, Mitchell WC, Anwar M. Preliminary stud­ies on the effects of gamma irradiation of eggs and adults of the southern green stink bug, Nezara viri­dula (L.). Proc Hawaii Entomol Soc 1967; 19: 415-7. 7. Maudlin I. The inheritance of radiation-induced semi-sterility in Rhodinus prolixus. Chromosoma (Berl) 1976; 58: 285-306. 8. Dyby S, Sailer RI. Impact of low-level radiation on fertility and fecundity of Nezara viridula (Hemiptera: Pentatomidae). J Econ Entomol 1999; 92: 945-53. 9. Cokl A, Gogala M, Blaževic A. Principles of sound recognition in three pentatomidae bugs species (Heteroptera). Biološki vestnik 1978; 26: 81-94. 10. Ota D, Cokl A. Mate location in the southern green stink bug, Nezara viridula (Heteroptera: Pentatomidae), mediated through substrate-borne signals on ivy. J Insect Behav 1991; 4: 441-7. 11. Kon M, Oe A, Numata H, Hidaka T. Comparison of the mating behaviour between two simpatric species, Nezara antennata and N. viridula (Heteroptera, Pentatomidae), with special refer­ence to sound emission. J Ethol 1988; 6: 91-8. 12. Cokl A, Virant-Doberlet M, McDowell A. Vibrational directionality in the southern green stink bug, Nezara viridula (L.), is mediated by fe­male song. Anim Behav 1999; 58: 1277-83. Radiol Oncol 2002; 36(3): 231-7. Static dosimetry space image in which urology diagnostics are performed Milorad S. Banduka,1 Dušan D. Vasic2 1Institute of Biophysics, Faculty of Medicine Sarajevo, 2General Hospital, Doboj, Bosnia and Herzegovina Background. The effects of the dispersed radiation described theoretically imply complex picture of inter­action of the photon beam with the patient’s body, as well as its dispersion on other structures. Basic theo­retical laws of this phenomenon are highlighted, thus giving the opportunity to model the effect in total. Material and methods. The measurements of the absorbed dose in the air give isodose curves that show distribution of the radiation dose. For the urological procedures standard urological diagnostic methods were being used. Results. Through a large series of measuring, we got the distribution of the radiation dose in space, where urology diagnostics is being made using the X-ray. The parameters determining this picture are the most fre­quent ones in the total number of 20 random cases taken in General Hospital in Doboj, Bosnia and Herzegovina. Conclusions. Static dosimetric picture of the space (radiation zone) in the general sense is useful before all for organisation of the diagnostic procedures utilising ionised radiation. Obtained in any way, this picture enables an insight into the three-dimensional distribution of the dosage on the basis of which it is possible to correct the organisation of the diagnostics being performed under these conditions. The values of the ra­diation dosage show it is necessary to use the protecting means prescribed by law. For more frequent expo­sure, it would be useful to make a dynamic dosimetric picture for professional exposure and assessment of the radiation risk of these persons. Key words: urology; radiation dosage; photons Received 4 April 2002 Accepted 15 June 2002 Correspondence to: Prof. Milorad S. Banduka, Krfska 6, 78 000 Banja Luka, Bosnia and Herzegovina Introduction Within the frame of the general problem of electromagnetic interactions with the media, a problem of photon interaction is being con­sidered. It can occur on the electron cloud as well as in the atom core. The probability of occurrence of these processes, however, shows that three effects [photo-effect, elastic dispersion on free electrons - (Compton and Thompson effect), and pair effect] are highly dominating. All effects of interaction of pho­tons with atomic core in the domain of the energies of photons in diagnostic radiology are excluded since the condition to start that process is not fulfilled. Contemplating the mechanism of photo-effect on the cloud elec­tron directs to the significant component of absorbed energy spent to free the electron from the atom which, as a consequence, has an emission of characteristic radiation. This is particularly, the case, when dealing with the soft tissue or water (small ordinal number) whose K-electron connection energy, com­pared with the energy of incidental photon, is so small that practically all the energy that ra­diation brings in this way, is taken by the photo-electron.1,2 On the other hand, apply­ing the law on preservation of energy and im­pulse, it is easy to show that this effect cannot happen on free electron. This is visible on the across section graph of this effect and energy of the incidental photon. The dependence shows a significant rise of across section in the area where ener­gy of the incidental photon is close to the en­ergy of K, L, M electrons. The analytical ex­pression of this dependence is based on a quantum-electro-dynamical approach.3,4 In the effects of the elastic dispersion of photons there is a distinction between the ef­fects when the dispersed photons have the same wave length as the incidental photons (Thompson-coherent dispersion), and when the photons change their wave length with elastic dispersion (Compton’s effect). Both ef­fects happen on free electron. The coherent dispersion is discussed in a classic way and the value of the cut for this effect is given with2 e- where r0= mc2 is classic electron radius and it equals r0 = 2.8 x 10-10 m. In order to determine the radiation dose in space (outside primary beam), it is necessary to be familiar with the distribution of the dis­persed photons presented by Johns and Cunningham. Exploring the behaviour of the radiation dosage in the space (outside the primary beam), we can expect the influence of this ef­fect. That is why it is important to say that the distribution of dispersed photons in this process is given by the expression.2 I(.) . const (1 + cos2.) (2) where I(.) is an intensity of the photons dis­persed under the angle .. With the second, Compton’s effect, the dispersed photon changed its wave length depending on the dispersion angle .. = .'-. = .(1 - cos2.) (3) where . is a wave length of the dispersed photon under the angle ., while . is n .= =2.4 × 10-12 m mec This expression was also reached using the preservation laws starting from the fact that the dispersed photon and recoiled electron have mutually shared the energy of the inci­dental photon. The explanation of this mech­anism leads to the confirmation of the parti­cle characteristics of the photons (in classical approach the energy of the dispersed particle is a function of an angle of dispersion), which has its academic significance. Will this effect happen? And if it happens, what is the prob­ability that photon will be dispersed under a specific angle? Here is a complex expression for across section based on a quantum-me­chanic approach. This expression in the form of differential total section was given by Klein and Nishina as5,2 des - where presents probability that pho­ d. Radiol Oncol 2002; 36(3): 239-44. ton will be dispersed on an electron in a unit of the solid angle . under the angle .; - m - mass of the electron in peace; e - c - speed of light in vacuum. h.. 0 In the extreme case for low energies of the incidental photon when h.. 0 or a. 0 a. 0 and the complex equation (4) trans­forms into the classical one (Thompson’s case), that is aes e = 2c4 (1 + cos2.) (5) d. 2m0 which means that, with low energies, (soft Roentgen radiation-if the beam was not fil­tered), the contribution of coherent radiation will be significant, while with strongly fil­tered beam Compton’s effect is more proba­ble. In the soft tissue this process may occur on any electron of the atom since all electrons can be considered free - comparing their bound energy with the energy of incidental photon, which is the basic precondition for the development of this effect. h.. 0 Presenting the graphic equation of Klein-Nishina in the function of dispersion angle, it is evident that the distribution of dis­persed photons differs in the energies of inci­dental photon from Thompson h.. 0 distri­bution from the line at 10 MeV, when there is no photon dispersing back.5,2 By integrating the equation on all angles using the substitu­tion d.=2sin . d. we get the total section of the Compton’s ef­fect as a number whose value is expressed as a function of the incidental photon energy. Theoretical conclusion is that the total cross section of the Compton’s effect decreases with the increase of energy. The component of the section that at Compton’s process relates to the dispersion sR can be found by multiplying Klein-Nishina equation with the relation h.’/h. that is T /h., for the component that relates to the e absorption of s. a By integrating according to the dispersion angles, we get s = s+ sR a s = sR for low energies because, with Thompson’s process, a coherent radiation occurs and there is no absorption.5 The presented essence of these effects di­rects to the complexity of the mechanism of interaction of photon radiation with the mat­ter. The consequence of these effects are pho­tons dispersed in the space outside the pri­mary beam of the source. In this work, we will present the way of determining the level of the radiation dosage in the space around the X-ray source as a consequence of the dis­persion of the radiation in the patient during the examination and in other structures the beam encounters to. Material and methods Dosimetric methods A certain level of radiation is detected in every point of this space (structures encoun­tered by the radiation beam as well as walls of the room where the source is installed) with the effects of the dispersion. This value most­ly exceeds the value, which could, in a dy­namic picture, exceed the limited dosage (the limited dosage is the level prescribed by law). We determined the absorbed dosage in air for distant points by large series of measuring, which secured reliable results. Experimental methods for standard dosage measuring were used. The following equipment was used: Radiol Oncol 2002; 36(3): 239-44. - standard water phantom 200 x 200 x 150 mm with plastic walls; - dosage measuring system Ionex with appro­priate chambers by Nuclear Enterprises - the radiation source was X-ray Telestatic used for urology diagnostics with possible scopia and graphia. Methods applied in urology In order to have a completely objective review of urological conditions of individual parts of uro-system, invasive x-ray diagnostic meth­ods are applied in urology. Depending on the part of the uro-system to show, standard uro­logical practice in General Hospital Doboj re­quires the presence of urologist, next to the patient (in radiation zone), during some test­ing - x-ray scopia or x-ray graphia. These methods are applied in the following condi­tions: -retrograde urethrography -retrograde cystoscopy -retrograde uretheropyelography (Chevass method) -retrograde (ascendant) pyelography. The objective of the listed diagnostic pro­cedures is the evaluation of morphological situation of the uro-system by visualising pathological changes as well as their conse­quences on the channel system. Apart from morphological data, there are also data of pre­cious value for the estimation of functional condition, treatment and disease prognosis. Pathologic changes that we were detecting by these methods might occur in any part of the uro-system: in urethra, urinary bladder, ureter, pyelocalix of kidney system. If the clinical, laboratory and echotomographic testing - extratornally and urographically - do not allow us to set the correct diagnosis, we apply the invasive diagnostic urological-radi­ological methods. The basic principles should necessarily be followed for every single listed procedures that will be briefly explained: -In retrograde urethrography, contrasting substances are injected by a rubber attach­ment and special syringes. Imaging is per­formed in AP and oblique positions of the patient during the injection of diluted con­trasting substance. -In retrograde cystography, urinary bladder imagining in AP and oblique projection of the patient is performed after the injection of diluted iodine solution, air as a negative means or combination of both means in two-component cystography. -Contrasting substance intake may be direct - by the insertion of catheter under control or by the infusion system through the catheter installed in the urinary bladder. In such case, the liquid is 50 - 75 cm above uri­nary bladder level, and the gravity force helps fill it into the organ. The contrasting substance concentration ranges 10 - 30% (mostly 17%). The contrasting substance quantity is determined by the above stated conditions (it ranges from 20 - 120 ml in children, and 250 - 300 ml in adults). The contrasting substance quantity is usually determined individually per patient. -The retrograde cystography and uretrocis­tography are, in most cases, simultaneously performed. They are separated in practice only when we are sure that there is a patho­logical process in the urinary bladder, with­out any repercussion on the other organ. -In case of mictial cystourethrography, imag­ing is performed immediately after urinat­ing, and in case of polycystography, frac­tional intake of contrasting substance is si­multaneously followed by imagining in the same film, without changing of the patient’s position. -In retrograde ureteropyelography (Chevass method), retrograde pyelography and endo­scopic setting of ureteral stents, the urolo­gists control the performance personally and monitors the radioscopias. -Having performed endoscopy of ureteral opening, an ureteral sonda with conal peak Radiol Oncol 2002; 36(3): 239-44. of 4-6 Ch in diameter is inserted. Thus, the Chevass method applied in retrograde ureterocystography blocks the return of contrasting substance into the urinary blad­der. By injecting the contrasting substance, a proximal ureter and pyelocalix system of the kidney are shown. This is monitored by scopia and recorded by graphia. Results of measuring The aim of work is to determine the static pic­ture of the radiation dosage outside the pri­mary beam, which is generated as a conse­quence of dispersion in the patient during ra­diological diagnostics. The static picture was obtained for the pa­rameters that were most commonly utilised in 20 cases of diagnostics. These parameters are: - Voltage 90 kV - Current 250 mA - FKD 1 m - Field 0.25 m x 0.25m We measured the absorbed dosage in the air for the points that lay in the plain 1.1m above the floor. The obtained results were distributed in columns and rows, which en­abled constructing the iso-dosage trajectories in that plain. The values of the strength of the absorbed dosage pointed in the picture are: A -2.5 10-3 Gy/h B -2 10-3 Gy/h C -1.5 10-3 Gy/h D -1 10-3 Gy/h E -0.5 10-3 Gy/h Monitoring the position of the operator during the diagnostics, we can see that his/her body is in the radiation field whose minimal value ranges from 2.5 10-3 Gy/h up to 10 10-3 Gy/h. In the immediate vicinity of the work-desk, the aforementioned chamber did not give reliable results so this area was con­trolled with a TL dosage-meter. It is expected that this picture will be useful for the assess­ment of the dosage that the patient receives during the examination (dynamic picture). Discussion The problem of dispersion as a complex phe­nomenon is discussed today from experimen­tal and theoretical view. Since experimental procedures are very long, avoiding certain phases can be done by modelling certain rela­tions as a part of the overall procedure. In today’s literature, different theoretical approaches, based on nuclear across section as statistical values helping to assess some physical values, such as the intensity of the energy flux, exposition dosage, and similar, are offered. For the purpose of calculating the section, Klein-Nishina’s equations of differ­ential section as function of the energy of in­cidental photon and angle of dispersion are used today. On the basis of these analytical approaches, several computer programs are used today with the ambition to cover this problem in the general picture. The differ­ences in the results gained through these pro­grams and via experimental measuring are Radiol Oncol 2002; 36(3): 239-44. sometimes unacceptable. Besides, in the premise of the analytical calculations a lot of assumptions are introduced, which some­times do not correspond with reality. However, we can be satisfied with the devel­opments and occurrence of improved pro­grams related to this problem.6 Conclusions Static dosimetric picture of the space (radia­tion zone) in the general sense is above all useful for the organisation of the diagnostic procedures utilising ionised radiation. Obtained in any way, this picture enables an insight into the three-dimensional distribu­tion of the dosage on the basis of which it is possible to correct organisation of the diag­nostics being performed under these condi­tions. The values of the radiation dosage show that it is necessary to use the protecting means prescribed by law (appropriate cloth­ing and glasses). For more frequent expo­sures, it would be useful to make a dynamic dosimetric picture for professional exposure and assessment of the radiation risk of these persons. References 1. Attix F. Introduction to radiological physics and radia­tion dosimetry. Medison: University of Wisconsin Medical School; 1986. 2. Johns HE, Cunningham JR. The physics of radiolo­gy. 4th edition. Springfield: Thomas; 1983. p 742. 3. Attix F, William C, Roesch C. Radiation dosimetry. Vol.1. New York: Academic press; 1968. 4. Attix FH, Tochilin E. Radiation dosimetry. Vol. 3. 2nd edition. New York: Academic press; 1969. p 22-33, 679-82. 5. Fitzgerald JJ, Brownell GL, Mahoney FJ. Mathematical theory in radiation dosimetry. New York: Gordon and Breach; 1967. 6. ICRU 42. Use of computers in external beam radio­therapy procedures with high-energy photons and elec­trons. USA: December 1987. 7. Cember H. Introduction to health physics. Oxford: Pergamon Press; 1969. Radiol Oncol 2002; 36(3): 239-44. European Project BRAPHYQS Janez Burger Department of Brachytherapy, Institute of Oncology Ljubljana, Slovenia Background. Quality assurance in radiotherapy and brachytherapy is extremely important because errors that may occur during treatment process can be fatal for the patient. European Society for Therapeutic Radiology and Oncology has therefore founded BRAPHYQS, a special group that is responsible for the re­vision of quality assurance procedures of treatment performed in brachytherapy centers and for outlining common standards of work in European countries. Conclusions. The project BRAPHYQS has the following aims: (1) to publish European recommendations for implementing QA/QC in European brachytherapy centers; (2) to set up a central dosimetry audit in European brachytherapy centers (this task will be delegated to ESTRO-EQUAL laboratory at the Institute Gustave Roussy in Paris); (3) to set up a central audit for the geometrical reconstruction of source positions with a special test phantom that will be available to each brachytherapy center. Hence, a series of »Baltas phantoms« will be elaborated and distributed to the brachytherapy centers in Europe; (4) to prepare a draft of booklet of QA/QC recommendations for testing the brachytherapy equipment and therapy planning sys­tems. Key words: quality assurance, health care; radiotherapy; brachytherapy; Europe Introduction Quality Assurance (QA) in radiotherapy en­sures accurate dose prescription and applica­tion of radiation doses for each individual lo­calization of tumor growth in cancer patients. The higher is the accuracy of radiotherapy, the greater are the chances of cure. QA in ra­diotherapy requires regular control of irradia- Received 22 April 2002 Accepted 6 May 2002-04-22 Correspondence to; Janez Burger, B.Sc., M.Sc., Department of Brachyradiotherapy, Institute of Oncology, Zaloška 7, 1000 Ljubljana; Phone: 00 386 1 522 4426; E-mail: jburger@onko-i.si tion equipment as well as continuous upgrad­ing of skills of the personnel in charge of QA. Dosimetric and electromechanic properties of the irradiadition devices and all related equipment should be regularly checked. QA in radiotherapy and brachytherapy is of ut­most importance because any failure in the treatment procedure may be fatal for the pa­tient. Brachytherapy physics quality assurance system (BRAPHYQS) In January 2001, the European Society for Therapeutic Radiology and Oncology (ES­ TRO) submitted an extensive and valuable project, entitled ESQUIRE (Education Science and Quality Assurance in Radiotherapy in Europe), to European Commission for financing (ESTRO 2001). The project was accepted. This is a great step for­ward in the endeavors for quality assurance in radiotherapy in Europe. Mr. Hans Svensson (Sweden) was appointed Chief of the Project. Professional and cost-wise, radio­therapy is considered to be the prevalent treatment modality of cancer patients, de­spite extremely high investments in the pur­chase of equipment. ESQUIRE project will take charge of quality control (QC) of the therapy as well as of upgrading the knowl­edge and skills of the personnel in the train­ing programs prepared by different commit­tees under the patronage of ESTRO. These are: -monitoring of radiation dose application -registration and data managing of radiation side-effects -transfer of technology experiences and skills to other radiotherapy centers in Europe -control over complete radiotherapy proce­ dure and research -quality assurance in Intensity Modulated Radiotherapy (IMRT) -quality improvement in brahytherapy (BRAPHYQS) The BRAPHYQS group will undertake the revision of QA procedures in brachytherapy centers in Europe and suggest common stan­dards to be respected in European countries. The revisions will involve the accuracy of dosimetry and geometric reconstruction of ra­dioactive sources implanted by different brachytherapy methods. The team is also in charge to publish a booklet containing a set of descriptions of QA/QC procedures in brachytherapy. In radiotherapy, the general tendency is to apply the doses to target tissue using the procedures that can avoid the expo­sure of the healthy surrounding tissue.1,2 Brachytherapy is a treatment modality that al­lows irradiation of smaller volumes with low­er doses to the surrounding tissue than those usually emitted in radiotherapy with external beam.3 At the same time, there is also a greater probability of committing errors in dosimetry, which urgently requires setting up uniform European QA standards in brachytherapy. Brachytherapy will continue to be the principal treatment modality of can­cer patients, particularly as an additional boost in combination with external beams during teletherapy. Brachytherapy has a sig­nificant role in clinical studies, e.g. in the fa­mous EORTC 22881/10882 study which com­pared two treatment modalities of breast can­cer, one with the boost and the other without it. The study confirmed that local control in younger patients was improved if these pa­tients received a boost with brachytherapy to the tumor.4 In the brachytherapy of the prostate, manual insertion of low-energy sources, such as J-125 and Pd-103, is still practiced,5 though at present radioactive sources are usually inserted by afterload de­vices, which certainly improved the protec­tion of the medical staff against ionizing radi­ation. Today, we generally use the isotopes Cs-137 and Ir-192. The progress in brachytherapy undoubtedly requires a con­stant checking of mechanized and computer­ized treatment procedures. These procedures have been extensively described in various ar­ticles and brochures published by different national and international organizations. Though numerous, they lack uniform and common QA standards of work that could be directly followed by other brachytherapy cen­ters. In addition to language barriers that arise from national protocols, there are also problems that are due to the differences in the definitions of QA/QC procedures regard­ing the frequencies and tolerances specified in these procedures. The principal task of BRAPHYQS is to analyze the currently valid protocols and to set up methodology together Radiol Oncol 2002; 36(3): 245-8. with the recommendations for work in European medical physics as well as else­where. New protocols would be a supplement to the existing QA/QC database. European brachytherapy centers should therefore get together and jointly work on the compilation and unification of the procedures in brachytherapy radiophysics and to collect them in a booklet that will be formally pub­lished by ESTRO. This kind of international cooperation is planned to go on for two years and is expected to be concluded by the end of 2002. Slovenia also takes part in this joint European project which is certainly most ad­vantageous for better flow of information in­to the country. In 1999, the Institute of Physics and Engineering in Medicine in United Kingdom published recommendations for QA in radio­therapy that also involve protection against irradiation and calibration of brachytherapy sources. In the Netherlands, such recommen­dations concerning low dose-rate (LDR) were published already in 1989, whereas the rec­ommendations for handling the high dose-rate facilities (HDR) were appeared as late as 1994. A particular emphasis was placed to the dosimetry of HDR sources. The last report of the year 2000 contains minimal requirements for QA/QC in brachytherapy as regards the frequencies and tolerances to be respected in testing brachytherapy equipment.6 In Germany, the dosimetry in brachytherapy was fixed in 1993 in accordance with the German standard DIN 6809-2, whereas in France, the appropriate standards are CFMRI dated from 1983 and NFC 74-210 from 1992. In Spain, TG 43 formulism,7 published in 1995 in American Association of Physicists in Medicine (AAPM), served as a base. From then onwards, formulism is applied to many planning systems and is more and more like­ly to develop into the standard for dose cal­culation. AAPM also published ‘Code of Practice for brachytherapy physics’ and ‘High dose rate brachytherapy treatment deliv­ery’. 8.9 This report covers all aspects of HDR, including dose prescription, safety, planning and dose calculation, and protection against ionizing irradiation. Intravascular brachy-therapy in America is covered by ‘Intra-vascular Brachytherapy Physics’.10 International Atomic Eneregy Agency (IAEA) has dealt with brachytherapy in sever­al publications. In 1996, IAEA founded the Department for Calibration of LDR Cs-137 Sources, and in 1999, the Agency published TECDOC-1079 »Calibration of brachytherapy sources«.11 Guidelines to Secondary Standard Dosimetry Laboratories and med­ical physicists on standardized methods for calibration of brachytherapy sources’. In 2000, the IAEA report No. 17 ‘Lessons Learned from Accidental Exposures in Radiotherapy’ appeared.12 The report com­prises descriptions of 92 unfortunate cases of patients having received miscalculated doses. Of these, 32 were treated with brachytherapy with sealed sources. The failures were mainly due to inaccurate assessment of source activ­ity, inaccurate dose calculation and entering of incorrect parameters into the planning sys­tem. The failures were also due to inade­quately inserted sources or unprofessionally removed sources by the patients themselves. The most serious failure that resulted in the death of a patient was caused by the mal­function of afterload device. The above cases are truly requiring an out­line of a well-conceived program for QA in brachytherapy. Conclusions The BRAPHYQS Projects has the following aims: 1.To publish European recommendations for implementing QA/QC in European brachytherapy centers; 2.To set up a central dosimetry audit in European brachytherapy centers (this task Radiol Oncol 2002; 36(3): 245-8. will be delegated to ESTRO-EQUAL labora­tory at the Institute Gustave Roussy in Paris); 3.To set up a central audit for the geometrical reconstruction of source positions with a special test phantom that will be available to each brachytherapy center. Hence, a se­ries of »Baltas phantoms« will be elaborated and distributed to the brachytherapy cen­ters in Europe; 4.To prepare a draft of booklet QA/QC rec­ommendations for testing the brachythera­py equipment and therapy planning sys­tems. References 1. ICRU, International Comission on Radiation Units and Measurements. Dose and volume specifica­tion for reporting reporting intracavitary therapy in gynecology. Report 38 of ICRU. Bethesda: ICRU Publications; 1985. 2. ICRU, International Comission on Radiation Units and Measurements. Dose and volume specifica­tion for reporting intrstitial therapy. Report 58 of ICRU. Washington DC: ICRU Publications; 1997. 3. Dutreix A., Marinello G., Wambersie A. Dosime­trie en curietherapie. Paris: Masson ed.; 1982. 4. Horiot JC, Collete L, Fourquet A, Jager JJ, Peterse JL, Pierart M, et al. Impact of a boost dose of 16 Gy on local control in patients with early breast can­cer: The EORTC \boost versus no boost\ trial. 2nd European Breast Cancer Conference. Brussels; 2000. 5. Beyer D, Nath R, Butler W, Merrick G, Blasko J, Nag S, et al. American brachytherapy society rec­ ommendations for clinical implementation of NIST-1999 standards for (103) palladium brachytherapy. Int J Radiat Oncol Biol Phys 2000; 47(2): 273-5. 6. Elfrink RJM, Van Kleffens HJ, Kolkman-Deurloo IKK, Aalbers AHL, Dries WJF, Rijnders A, et al. Quality control in brachytherapy current practice and minimum requirements. Report No.13 of the Netherlands Comission on Radiation Dosimetry. Delft; 2000. 7. Nath R, Anderson LL, Luxton G, Weaver KE, Williamson JF, Meigooni AS. Dosimetry of inter­stitial brachytherapy sources: Report of the AAPM Radiation Therapy Commitee Task Group No. 43. Med Phys 1995; 22: 209-34. 8. Nath R, Anderson LL, Meli JA, Olch AJ, Stitt JA, Williamson JF. Code of practice for brachytheapy physics: Report of the AAPM Radiation Therapy Commitee Task Group No. 56. Med Phys 1997; 24: 1557-98. 9. Kubo HD, Glasgow GP, Pethel TD, Thomadsen BR, Williamson JF. High dose rate brachytherapy treatment delivery: Report of the AAPM Radiation Therapy Commitee Task Grop No. 59. Med Phys 1998; 25: 375-403. 10. Nath R, Amols H, Coffey C, Duggan D, Jani S, Li Z, Schell M, et al. Intravascular brachytherapy physics: Report of the AAPM Radiation Therapy Commitee Task Group No. 60. Med Phys 1999; 26: 119-52. 11. IAEA International Atomic Energy Agency. Calibration of brachytherapy sources. Guidelines to secondary standard dosimetry laboratories (SSDLs) and medical physicists on standardized methods for calibration of brachytherapy sources«, TECDOC-1079. Vienna: IAEA; 1999. 12. IAEA International Atomic Energy Agency. Lessons learned from accidental exposures in ra­diotherapy. Safety Report Series No. 17. Vienna: IAEA; 1999. 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