ADIOLOGY 11111 NCOLOGY 1998 Vol. 32 No. 3 Ljubljana ISSN 1318-2099 UDC 616-006 CODEN: RONCEM RADIOLOGY AND ONCOLOGY Radiology and Oncologtj is a joumal devoted to publication oj original contributions in diagnostic and interventional radiology, computerized tomography, ultrasound, magnetic resonance, nuclear medicine, radiotherapy, clinical and experimental oncology, radiobiology, radioplzysics and radiation protection. Editor-in-Chief Gregor Serša Ljubljana, Slovenia Executive Editor Viljem Kovac Ljubljana, Slovenia Editor-in-Chief Emeritus Tomaž Benulic Ljubljana, Slovenia Editorial board Marija Auersperg Be1a Fornet Maja Osmak Ljubljana, Slovenia Budapest, Hungary Zagreb, Croatia Nada Bešenski Tullio Giraldi Branko Palcic Zagreb, Croatia Trieste, Italy Vancouver, Canada Karl H. Bohuslavizki Andrija Hebrang JuricaPapa Hamburg, Germany Zagreb, Croatia Zagreb, Croatia Haris Boka Laszl6 Horvath Dušan Pavcnik Zagreb, Croatia Pecs, Hungary Portland, USA Nataša V. Budihna Berta Jereb Stojan Plesnicar Ljubljana, Slovenia Ljubljana, Slovenia Ljubljana, Slovenia Marjan Budihna Vladimir Jevtic Ervin B. Podgoršak Ljubljana, Slovenia Ljubljana, Slovenia Montreal, Canada Malte Clausen H. Dieter Kogelnik Jan C. Roos Hamburg, Germany Salzburg, Austria Amsterdam, Netherlands Christoph Clemm Jurij Lindtner Slavko Šimunic Miinchen, Germany Ljubljana, Slovenia Zagreb, Croatia Mario Corsi Ivan Lovasic Lojze Šmid Udine, Italy Rijeka, Croatia Ljubljana,Slovcnia Christian Dittrich Marijan Lovrencic Borut Štabuc Vienna, Austria Zagreb, Croatia Ljubljana, Slovenia Ivan Drinkovic LukaMilas Andrea Veronesi Zagreb, Croatia Houston, USA Gorizia, Italy Gillian Duchesne Metka Milcinski Živa Zupancic Melbourne, Australia Ljubljana, Slovenia Ljubljana, S/ove11ia Publis/zers Slovenian Medica[ Association -Slovenian Association of Radiology, Nuclear Medicine Society, Slovenian Society for Radiotherapy and OncologtJ, and Slovenian Cancer Society Croatian Medical Association -Croatian Society of Radiologij Ajjiliated with Societas Radiologorwn Hu11garorum Friuli-Venezia Giulia regional groups oj S.I.R.M. (Italian Society oj Medica/ Radiology) Correspondence address Radiology and Oncologtj Institute oj Oncology Vrazov trg 4 SI-1000 Ljubljana Slove11ia Tei: +386 6.1132 00 68 Tel/Fax: +386 61 133 74 10 Readcr jor English Olga Shrestha Design Monika Fink-Serša Key words Eva Klemencic Secretaries Milica Harisch Betka Savski Printed by Imprint d.o.o., Ljubljana, 5/ovenia Published quarterly in 750 copies Bank account number 50101 678 48454 Foreign currency account number 50100-620-133-27620-5130/ 6 NLB -Ljubljanska banka d.d. -Ljubljana Subscription jee jor institutions 100 $, individuals 50 $ Single issue jor institutions 30 $, individuals 20 $ The publication oj this joumal is subsidized by the Ministry oj Science and Technology oj the Republic oj Slovenia. According to the opinion oj the Government oj the Republic oj Slovenia, Public Relation and Media ' Ojjice, tlze journal Radiology and Oncology is a publication oj injormative value, and as such subject to taxation by 5% sales tax. Indexed and abstractcd by: BIOMEDICINA SLOVENICA CHEMICAL ABSTRACTS EMBASE / Exccrpta Medica This journal is printcd on acid-jrec paper Radiology and Oncology is now available on the internet at: http://www.onko-i.sijradiolog/rno.htm CONTENTS DIAGNOSTIC ANO INTERVENTIONAL RADIOLOGY Invasive oncoradiology in the diagnosis of breast tumor. Case report L,, Szalai G, Kaiser L, Kalmrin E l, 257 ULTRASOUND Diagnosis of childhood intussusception: Ultrasound features \JRoic G, Cop S, Posaric V, Odorcic-Krsnik M Role of color Doppler US in the diagnosis of focal nodular hyperplasia of the liver: a case report \_ Vidmar D, Višnar Perovic A, Cernelc B, Markovic S, Ferlan Marolt V, Gorenc M NUCLEAR MEDICINE 1./ 261 L--265 Recent developments in nuclear medicine instrumentation v Mester], Bohuslavizki KH, Klutmann S, Sera T, Buchert R, Privics L, Henze E, Clausen M L-271 / v I-131 total body burden in postsurgical patients with thyroid cancer / Medvedec M, Huic D, Žuvic M, Grošev D, Popovic S, Dodig D, v Pavlinovic Ž 281 Apparatus for positron emission tomography Staric M, Korpar S, Margan R, Šifrar M, Stanovnik A, Budihna N, Milcinski M, Šket B .9 EXPERIMENTAL ONCOLOGY VFlow cytometric pitfalls in immunophenotyping of lymphomas IhanA L, 297 ,Simple but extremely effective autologous tumor vaccines / Novakovic S, Jezeršek B 303 1 CLINICAL ONCOLOGY .------------­ Acceptability of simultaneous irradiation and mono/polichemotherapy with cis/carboplatin v Kragelj B 311 \., REPORT Report from the First Congress of Croatian Geneticists OsmakM 319 BOOKREVIEW _ __ Biological systems Serša G 321 SLOVENIAN ABSTRACTS 322 NOTICES 327 Radio/ Oncol 1998; 32(3): 257-60. Invasive oncoradiology in the diagnosis of breast tumor. Case report Gabor Szalai1 , Laszl6 Kaiser2, Endre Kalman2 1 Department oj Radiology, 2Department oj Pathology, University School oj Medicine, Pecs, Hungary In the haemorrhage dischargi.ng breast oj an elder woman no tumor mass eould be deteeted by mammogra­phy. An obstruetion in a duet without tumor mass was deteeted by duetography. Fine needle aspiration biopsy was pe1jormed in the area close to and behind the obstruetion. The eytopathological diagnosis was "Papilloma seu eareinoma papillare". Surprisingly, the same duet jilled eompletely during duetography ajter biopsy. Ajter ultrasound-guided wire localization, the sueeess oj surgi.eal treatment was eonjirmed by his­tology Key words: breast neoplasms-diagnosis-pathology; mammography, duetography; biopsy, needle, jine-nee­dle aspiration biopsy (FNAB), wire localization Introduction Haemorrhage discharge of the mamilla is fre­quently caused by papilloma or papillary car­cinoma.1,2 Ductography is generally accepted procedure to assess the localization and extension of tumor.3 Case Report A 62-year old woman was referred to the hos­pital because of the haemorrhage discharge of the left breast. There was no palpable abnormality. A papillary growth was detect­ed cytopathologically and the cells in the dis- Correspondence to: Gabor Szalai, MD, University School of Medicine, H-7624 Pecs, Ifjusag 13, Fax: +36 72 311214. charge indicated to the presence of a cystic lesion. No tumor could be identified by mam­mography (Figures la,b). The contrast media filled up a short, wide part of a duet during ductography (Figures 2a,b). The diameter of this retroareolar part of the duet, measured by sonography, was 2.8 mm and there was not any solid lesion visible (Figure 3). From the area immediately behind the obstruction, US-guided aspiration biopsy was performed (Figure 4). Papillary neoplasm was detected by cytology. One month later (in the mean­while, discharging stopped), ductography was repeated. The ducts of the upper-outer quadrant were filled-up with contrast media. A part of the tumor closing the central duet was removed by biopsy, and the total obstruction was thus eliminated. Multiple filling defects were seen intraductally (Fig­ 258 Sznlni G et ni. Figure 1 a,b. No tumor could be indentified by mam­mography. ures 5a,b). Immediately after this procedure, a US-guided wire localization was performed (Figures 5a,b and Figure 6) and an excision was made within an hour. The surgical sam­ple was examined by mammography (Figures 7a,b). In this preparatum, the tumor could not be seen macroscopically, but the area immedi­ately at the end of the wire was histologically examined: it proved to be a papilloma. Figure 2 a,b. The contrast media filled up a short, wide part of a ducat during ductography. Discussion Beside mammography,4 sonography is a basic procedure in diagnosing breast diseases.5, 6 Ductography has long been a procedure used for examination nipple with haemorrhage 3 discharge (suspicious of intraductal mass),1­and it has usually been followed by surgery. When a tumor obstructs completely the intra­ Dingnosis of brensl tu!llor Figure 3. The diameter of the ducet, measured by sonog­raphy, was 2.8 mm and there was not any solid lesion visible. Figure 4. From the area immediately behind the obstruc­tion, Us-guided aspiration biopsy was performed (arrow shows to the needle). Figure 6. The left arrow shows to the canula, the tight to the wire; multiple filling defects were seen intraductally. Figure 5 a,b. A wire locatization was performed after second filling of the duet dueta! passage, the contrast media eannot fill the duet behind the obstruction,7 so the exact extension is not known before o·peration. Imaging proeedures performed and recom­mended by many authors are the following: mammography, sonography and ductogra­phy.8 The radiologist should perform biopsy to obtain a sample for cytologieal examina­tion and to estimate the total bloek. Repeated 260 Szalai G et ni. References l. Tabar L, Dean PB, Pentek Z. Galactography: The diagnostics procedure of choice for nipple dis­charge. Radiologi; 1983; 149: 31-8. 2. Baker KS, Davey DO, Stelling CB. Dueta! abnor­malities detected with galactography. Amer J Roentgeno/ 1995; 162: 821-4. 3. Cardenosa G, Doudna C, Eklund GW. Ductogra­phy of the breast: Technique and findings. Ainer J Roe11tge110/ l995; 162: 1081-7. 4. Soo MS, Williford ME, Walsh R, Bentley RC, Kornguth PJ. Papillary carcinoma of the breast: lmaging findings. A111er J Roentgenol 1995; 164: 321-6. c 5. llilton S, Leopold GR, Olson LK, Willson SA. Real-tirne breast sonography. Amer J Roentgenol 1986; 147: 479-86. 6. Basset LW, Kimme-Smith C. Breast sonography. Amer J Roentgenol 1991; 156: 449-55. 7. Cardenosa G, Eklund GW. Benign papillary neo­plasms of the breast: Mammographic findings. Amer J Roentgenol 1991; 181: 751-5. 8. Fajardo LL, Jackson VP, Hunter TB. lnterventional procedures in diseases of the breast: Needle biop­sy, pneumocystography, and galactography. Amer] Roentgeno/ 1992; 158: 1231-8. 9. Cilotti A. lntraductal solitary papilloma: Sono­ graphic findings. Eur Radio/, 1993; 3: 38-40. Radio/ Onco/ 1998; 32(3): 261-4. Diagnosis of childhood intussusception: Ultrasound features Goran Roic, Slavko Cop, Vesna Posaric, Mirjana Odorcic-Krsnik Department of Radiology, Children's Hospital Zagreb, Zagreb, Croatia We report ultrasonographic features of 24 children with surgically confirmed intussusception. Ultrasonog­raphy was the primary diagnostic procedure in ali children, and in 22 patients ultrasound examination was followed by barium enema study. In 2 patients barium enema was contraindicated due to long duration of symptoms and early signs of peritonitis. Those 2 patients were operated following the ultrasound findings only. Key words: intussusception; ultrasonography; child; infant lntroduction Intussusception refers to invagination of a segment of bowel into its contiguous neigh­bour. Most cases of intussusception are idio­pathic ileocolicl and occur in children between the ages of 3 months and 2 years, thus representing the most common abdomi­nal emergency of early childhood.2-4 The use of ultrasonography has brought considerable changes in the diagnosis and therapy of intussusception in the past few years.5,6 The preference of ultrasound (US) is based on its performance and ability to image entire abdomen, solid organs and hollow gastroin­testinal tract. US proved to be sufficient for high-accuracy investigation of clinically sus­pected intussusception, enabling selection of those patients in need of an enema diagnos­tic or therapeutic study. Correspondence to: Dr. Goran Roic, Department of Radiology, Children's Hospital Zagreb, Klaiceva 16, 10000 Zagreb, Croatia. Patients and methods In our study we reviewed 24 patients with intussusception diagnosed on US. The US findings were confirmed either by barium enema study or on surgery The equipment used in all examinations was ALOKA 1700 and ACUSON 128 XP, with curved and linear transducers of 5 and 7 MHz. Patients were not specially prepared for the examination. All patients lied in supine position and there were no anesthesia or sedation needed. After an orientational investigation of the entire abdomen by curved transducer, a linear array transducer was used to analyze the intussuscepted part of the bowel. In 2 patients with long lasting symptoms of intussusception barium enema study was not done and the patients were referred to surgery. Intussusception was con­firmed in both cases. >. -. > t-. 262 Roic G et ni. ..-'-t. /-.:tJ:'; fi-. ; ;;:,.;._ ­ - . . f'I-:>." --,·- 160 kcps Maximum Count Rate > 200 kcps Nuc/enr 111edicine instn1111e11tntion A new class of SPECT cameras is suitable for 511 keV coincidence imaging. These devices have two detectors and can also be used effectively for state-of-the-art single photon imaging. Finally, groups of dedicated equipment should be mentioned. Whole body scintigra­phy, thyroid imaging or bedside imaging in intensive care units can be performed most effectively using specially developped pla­nar gamma cameras. Dedicated SPECT sys­tems have been introduced for heart, brain or recently, for breast imaging. Attenuation correction Myocardial perfusion imaging is often ham­pered by attenuation artefacts. Image read­ing reveals perfusion defects which are located typically in the anterior region in women and in the inferior wall in men. Therefore, whether an intensity deficit is caused by real perfusion defects or merely by an attenuation artefact may be uncertain in an estimated 20 % of cases in men and even in as much as 40-45 % in women. Thus, there is a real need for compensation. From a theoretical point of view, there are four groups of methods for attenuation cor­rection. -Initially, a uniform attenuation coeffi­cient was assumed in the wholebody region reconstructed. However, in practical patient management this simplified assumption is only applicable in brain studies, but it is not feasible in the thoracic region since attenua­tion is rather non-uniform there. -Methods using CT images for correction are hampered by their complexity and by an additional necessity for registration of images from different equipment. To over­come these limitations, combined PET/CT devices for simultaneous data acquisition and registering for exact localisation of tumour/metastasis are under development. The principles of that equipment can be the­oretically extended to attenuation correc­tion. -Segmentation is a new method for the identification of major structures with dif­ferent attenuation features in the thoracic region.3 For this purpose a low dose mixture of Tc-99m-MAA and Tc-99m-colloid is given for simultaneous localisation of the liver and the lungs. Additionally, a body wrap with Tc-99m highlights the patient's outline. The identified areas are then considered with their assigned attenuation coefficients. This attempt for attenuation correction seems to be very promising especially in myocardial scintigraphy, however, it is not widely used. -Recently, transmission based attenua­tion correction was introduced in SPECT. The idea of measuring real attenuation in order to correct emission data is originating from positron emission tomography (PET). In PET, the measured distribution of linear attenuation coefficients is already routinely used in order to quantitatively calculate trac­er distribution. To this, an external radioac­tive source is needed in order to generate a clearly defined radiation field. Presently, most cameras use Gd-153 for transmission imaging. Some additional experience exists with Am-241, Tc-99m, and Co-57. Technical­ly, the source(s) may be arranged either as single fixed line sources e.g. at the focus of a fan beam collimator, as scanning line sources or as an array of fixed line 2 4S sources.,, The patient's body is positioned between the radiation source and the gamma camera detector. Consequently, dis­tribution of attenuation coefficient within the body can be determined from the acquired transmission projection images. In the individual patient under investigation the measured attenuation can then be taken into account during reconstruction. Howev­er, an iterative reconstruction algorithm is mandatory. On the other band, this is no more a real problem, since computing time Mester J et ni. may be kept in the range of only a few min­utes when a powerful computer is available. Requirements of transmission based atten­uation correction There are some fundamental requirements, which should be fulfilled to ensure that transmission based attenuation correction can be usefully utilised in clinical patient management. In short, first, the method should work in a wide range of body mass independent of the patient's body size. Sec­ond, it should not increase the investigation tirne significantly. Third, measurement of transmission and emission should be strict­ly performed in the same geometric posi­tion of the patient. Fourth, attenuation cor­rection should not generate image artefacts by itself, and therefore, it should be espe­cially free of overcompensation. Fifth, transmission measurement should not sig­nificantly increase the radiation exposure both of the patient and of the staff. Finally, the additional costs should be acceptable. In the following, some critical points of attenuation correction are discussed in detail. Truncation free data acquisition An important issue to obtain correct trans­mission images is the careful positioning of the patient. It is well-known from SPECT technique that the target organ should be completely within the field-of-view of the gamma camera in all projections acquired. Otherwise, so called truncation artefacts may occur, and image interpretation will be hampered. Since in case of transmission imaging the total body of the patient reflects the "target organ", large field-of­view detectors with their long axis posi­tioned perpendicular to the long axis of the patient are needed in general. Early attempts using triple headed gamma cameras and focusing collimators exhibited truncation artefacts even in slightly over­weight patients. To compensate for this, asymmetric fan beam collimators were intro­duced (Figure 1) in which the radiation detector (parallel holernll detector (par­ allel hole colli- \77 !J . set fan bearn collirnator Figure l. Measurment of attenuation using asymrnetric fan beam collimator. source is placed in the collimator focus. The radiation field then covers one half of the patient's body in each projection. Therefore, a full 360 degree-rotation is necessary to acquire a complete set of data for this rather highly sophisticated approach. Up to now, most clinical experience has been gained using scanning line sources and large field-of-view, double headed gamma cameras (Figure 2). Using two sources and (nearly) simultaneous data acquisition, cmn­plete emission/transmission data can be obtained theoretically in the same duration which is required for a 90 degree SPECT acquisition, i.e. in about 15 minutes. This duration of acquisition meets best the clinical requirement of high patient throughput. Cross-talk For practical reasons, transmission images will be usually acquired following the injec­tion of radioactivity into the patient. There­fore, transmission data may be contaminated by emitted radiation being acquired in the Nuclenr 111edici11e i11s/n1111e11tntio11 / detectors ' / Transmission line sources Figure 2. Scanning line sources for attenuation measur­ment. The sources scan along the lenght of the patient at each angle. transmission energy window. On the other hand, radia tion of the transmission source may scatter as well into the emission energy window, especially when transmission and emission data are acquired simultaneously. However, attenuation correction algorithms presume both contamination free emission and transmission data. Therefore, cross-talk described above, should be minimised suffi­ciently. Gd-153, the most widely used transmis­sion source has a gamma energy of 100 ke V. Performing simultaneous emission/transmis­sion acquisition, and using Tc-99111 as an emission source, there is no cross-talk of Gd­153 into the higher energy emission photo­peak window of Tc-99111. However, Tc-99111 may scatter down into the Gd-153 window and contaminate the transmission data. Using Gd-153 in connection with Tl-201 myocardial scintigraphy, the relations are practically vice versa. The most effective way to keep both trans­mission and emission data fairly free of cross contamination is the use of a transmission source as a scanning line source. Mechanical collimation of a moving Gd-153 line source ensures an appropriate focus of transmission radiation only to a small area of the gamma camera detector, lying opposite to the current position of the line source. On the detector surface a narrow electronic mask is estab­lished. This mask is scanning over the face of the detector in synchrony with the collimated line source. This enables only the corre­sponding detector area to collect transmis­sion photons, minimising the contamination with scattered emission photons. On the other hand, the remainder area of the detec­tor is electronically kept open for the collec­tion of emission photons and, due to the mechanical collimation of the line source, closed for transmission data. This method reduces cross-talk to less than 1 % Gd-153 scatter into the Tl-201 window, and to less than 7 % Tc-99m scatter into the Gd-153 win­dow.6 In general, cross-talk should be preferably minimised during acquisition. Subtraction routines that are employed after completed acquisition may substantially increase the amount of noise in the images.7 On the other hand, transmission data contaminated by emission may result in overcompensation of attenuation and, therefore, may rather intro­duce than avoid artefacts.4 Additional points of view To have a complete impression about the per­formance of a method introduced for attenu­ation correction, some additional points should be considered. First, the handling of the transmission source should be as simple as possible in order to minimise necessary interventions of the technician. This involves source placement, checking of the field-of­view, as well as the exclusion of truncation. Second, transmission measurement is a highly sophisticated tool, thus, appropriate quality assurance should be elaborated in order to establish valid results. Third, transmission measurements should not increase acquisition time and decrease patient throughput significantly, as in the Mester J et al. case when acquisition of transmission and emission data is performed successively. To avoid this, there are several attempts current­ly under clinical investigation. Fourth, considering the relatively high activity and long physical half-life of radia­tion sources for transmission measurement problems of radiation protection including handling with old sources should be carefully analysed. Finally, one should take into account that none of the methods developped for attenua­tion correction bas yet been sufficiently vali­dated and the interpretation of attenuation corrected images differs significantly from that of non-corrected images. Way towards quantitative SPECT Until recently, quantitative SPECT seemed to be an unrealistic dream for nuclear medicine specialists. Nowadays, intensive research is ongoing on this topic. Several camera pro­ducers are working on tools, making quantifi­cation feasible. Attenuation correction helps to come closer to images with a correct rela­tive distribution of radioactivity. However, to make quantification possible, images should be corrected for Compton scattering and for collimator response function as well. 511 ke V imaging with gamma camera Positron emission tomography has been con­sidered for a long tirne both an interesting and a highly expensive research tool. In the last few years, the glucose analogue F-18-fluo­rodeoxyglucose (FDG) initiated a break­through in answering numerous diagnostic questions.8, 9,10 Based on the results of clinical trials, well-defined indications for FDG imag­ing have been established and accepted both by the nuclear medicine community and by referring clinicians. The increase of number of sites perform­ing FDG imaging is facilitated by the fact, that the supply with the radionuclide F-18 is not limited to the place of its production. lts physical half-life of 110 minutes permits transportation within a radius of about 200 kilometers. Professional suppliers are build­ing up distribution networks in different european countries and offer price and avail­ability independent of the geographic loca­tion of potential users. In conclusion, there is an increasing demand for positron imaging devices at low cost. Traditional gamma cameras are opti­mised for the detection of photons with an energy of 100-150 keV. To answer the ques­tion, how the performance of these devices may be extended to F-18 imaging, the spec­trum of routine FDG-PET investigations should be considered. Accepted indications for FDG-PET cover about 70 % oncological, 20 % neurological and about 10 % cardiologi­cal patients with an even increasing tendency of oncological patients. In addition, within oncology one should differentiate between severa! questions arising in clinical patient's management, i.e. tumour detection, differen­hat10n between malignant and benign tumour masses, staging, detection of metas­tases, docurrientation of effectivity of treat­ment, and last but not least diagnosis of relapse after therapy. Moreover, each of the above mentioned questions may arise in dif­ferent regions of the body or in combination with each other. Given a special clinical question technical requirements may vary. For example the detection of metastases needs technical equipment providing high geometric resolu­tion. Follow-up of tumours may need quan­tifica tion, which is not essential in staging. This demonstrates, that a particular instru­ment may be a good compromise for one selected clinical question, but may not meet the requirements for other clinical prob­lems.11 Nuclear medicine instrumenta/ion History of 511 ke V imaging using conven­tional gamma cameras First attempts to obtain 511 keV images using conventional gamma cameras were undertak­en using seven-pinhole collimators. Results were presented in patients with chronic ischemic heart disease, i.e. in the detection of myocardial viability. The next step was the introduction of high energy collima tors for planar F-18 imaging. With increasing mechanical stability of SPECT gantries these 511 keV collimators were attached to rotating cameras as well. These initial efforts resulted in quite accepta ble image quality for F-18­FDG cardiac viability studies at low addition­al costs. In fact, up to now these high-energy collimators can be effectively used in cardiac scintigraphy only. For other clinical questions neither the requested minimum of resolution (brain imaging) nor the necessary count rate capability (oncology) could be achieved. Due to the fixed geometry of collimators and due to the limitations regarding imaging parame­ters, possibilities of further developments of collimated 511 keV imaging seem to be exhausted. Coincidence imaging Recent developments of computer technolo­gy opened the way to introduce coincidence detection in traditional gamma cameras. This development has been facilitated by the introduction of fully digitalized gamma cam­era detectors, with an analogue-to-digital con­verter connected to each photomultiplier tube. Data sampling in coincidence cameras is practically a 3D acquisition at any time. That means, that the whole, collimator-free detec­tor-surface is available for coincidence events. However, this type of coincidence measurement has severa! technical problems. Some of them result from detector geometry others result from physical parameters of the detector itself. The geometric position of the two detec­tors makes evident, that the detection of two gamma photons originating from a given positron annihilation has a higher probabili­ty, when this annihilation occurs at a position close to the middle of the detectors as com­pared to the detector edges. In other words, the sensitivity of the detector field-of-view is non-uniform. It is maximal at the centre and decreases toward to the edges (Figure 3). Figure 3. Relation between the position of radiation source and the coincidence count rate. Photons emitted from the source A have a higher probability to meet the detector as campaned to photons emitied from source B. A positron emitting point source positioned under the middle of the detectors results in a higher coincidence count rate, than the same source at the periphery. This difference has to be corrected subsequently. An important consequence is an increasing statistical noise towards the edges of the images. A further problem of coincidence imaging is in principle, that not all coincidences regis­tered are true ones, since data are contami­nated both by random as well as by scatter coincidences. Random coincidence occurs when two different events can not be separat­ed by the time window of the processing Mester Jat al. electronics. Consequently, an increase in the total count rate increases the probability of random coincidences as well as organs with high activity being placed close to the detec­tors field-of-view. The latter shows up when searching tumors or metastases in the tho­racic or in the neck region. Radiation emitted from the brain, which accumulates F-18-FDG intensively, may considerably increase the number of random coincidences resulting in a decreased signal-to-noise-ratio over the area of interest. Similar problems may result in body areas close to the urinary bladder. To overcome this problem, axial collimation may be helpful. Scattered coincidence means, that either one or both photons detected are scattered ones, but the energy window of the equip­ment considers them still to be trne ones. These events may contain a false position information. With these limitations in mind, an impor­tant task of coincidence imaging is to max­imise both the total and the relative number of trne coincidences. To meet this require­ment a high total count rate is needed. Thus, the detector sensitivity has to be maximised, the processing electronics should be fast, and the pile-up in the crystal should be negligible up to high count rates. In this case, technical solutions for subsequent separation of ran­dom and scatter events still result in an acceptable high rate of remaining trne coinci­dences. Coincidence detection with Nal crystal Nal based scintillation crystals have been originally developped for detecting of low energy gamma radiation. However, the tradi­tional crystal thickness of 3/8 inch (9.5 mm), optimised for 140 keV imaging in modern gamma cameras results in a poor efficiency for 511 keV. Therefore, most producers of gamma cameras designed for 511 ke V imag­ing use an increased crystal thickness of 5/8 inch (15.9 mm). This offers an almost twofold increase in the efficacy of absorption for 511 keV photons without significant loss of geo­metric resolution for Tc-99m. A further disad­vantage of Nal is its relatively long duration of light pulses of about 230 ns which is a lim­itation in case of high count rates due to pile­up effects induced. Thus, today's maximum detector count rate is rather limited by the tirne resolution of the crystal than by the pro­cessing electronic. Despite some feasible electronic corrections for pile-up, the maxi­mum count rate, the maximum patient dose, and the maximum rate of true coincidences still remain limited using Nal crystal based detectors. The upper performance limit of modern dual headed gamma cameras is in the range of a total count rate of about 2 million cps. However, about 1 % of the total count rate are detected as trne coincidences only, and there­fore contribute for imaging. Consequently, the sensitivity of the system is better charac­terised by the maximum coincidence rate, than by the maximum total count rate. Despite some sophisticated possibilities to increase sensitivity using appropriate elec­tronic solutions, image acquisition tirne with coincidence cameras will always be signifi­cantly longer, than that with ring detector PET systems in 3D mode. Today's experience clearly shows, that even the fastest coinci­dence cameras need about 40 minutes for imaging of one single body region. The same image quality could be achieved in 3D PET in less than 3 minutes. To increase the detec tor' s suitability for 511 keV imaging, promising experimental results have been presented recently using lutetium oxyorthosilicate (LSO). This materi­al has an about twofold density as compared to NaI, and consequently, an increased prob­ability of interaction with high energy pho­tons. Moreover, the duration of light pulses is in the range of about 40 ns, thus being Nuclear medicine instrwnentntion extremely short as compared to Nal. This enables a corresponding increase of the total count rate. However, the applicability of LSO for low energy radiation is limited due to its poor energy resolution. Thus, for imaging in low energy range as well as in high energy range a combination of LSO and YSO (yttri­um oxyorthosilicate) as a sandwich detector is considered. First cameras are expected to be presented in the near future. Up to now, the clinical usefulness of gamma camera coincidence imaging has to be proven. Attenuation Unfortunately, the well-known attenuation arte­facts of single photon imaging may also be pre­sent on coincidence images. This is especially problematic in cardiac imaging. The explana­tion for this is that the two annihilation photons after positron emission have to pass the whole body before being detected. In contrast, a garnma photon used for single photon imaging has only to pass the body layer between its ori­gin and the detector surface. Due to the longer way, the probability of absorption or scattering is higher for the two high energy photons, than for the one photon of single photon emitters. This is only partly compensated by the 54 % higher linear attenuation coefficient of 140 keV photons. Attenuation correction algorithms for garnma camera coincidence imaging are cur­rently under clinical evaluation. Reconstruction Reconsh·uction of coincidence data is tirne consuming. Since the images are relatively noisy best results are achicved with maximum likelihood iterative methods. Witl1 state-of-the­art computers, results can be obtained within 5 minutes after completion of data acquisition. However, reconstruction tirne can reach about 30-60 minutes when less powerful computers have to be utilised. Conclusions Based on the recent successful development of the industry it can be expected, that with­in the next 2-3 years validated attenuation correction will be part of clinical practice in nuclear medicine. As a next step, 1-2 years thereafter, leading edge cameras will allow to perform scatter and collimator response cor­rection and, thus, open the way to quantita­tive SPECI. Considering 511 keV imaging, clinical questions still have to be defined in which PET imaging can be replaced by low cost coin­cidence gamma cameras without significant loss of information. The results of ongoing investigations are, however, still uncertain. The most important task today is a careful validation of these new methods. In particu­lar, validation should be performed for each type of devices as well as for each type of software algorithm. Carefully designed multi­center studies should be started in order to facilitate the acceptance of these new tech­nologies. References l. Jarrit PH, Acton PD. PET imaging using gamma camera systems: A review. Nucl Med Comm.un 1996; 17: 758-66. 2. Kuikka JT, Britton KE, Chengazi VU, Savolainen S. Future developments in nuclear medicine instru­mentation: A review. Nucl Med Co111111u11 1998; 19: 3-12. 3. Madsen MT, Kirchner PT, Edlin JP, Nathen MA, Kahn D. An emission-based technique for obtain­ing attenuation correction data for myoacardial SPECI studies. Nucl Med Commun 1993; 14: 689­95. 4. Miron SD, Conant RG, Sodee DB, Amini SB. Ciin­ Mester J et al. ical valuation of simutaneous transmission-emis­ sion SPECT rnyocardial perfusion images (STEP}. J Nucl Med 1995; 36: 12. 5. Tan P, Bailey DL, Meikle SR, Eberl S, Fulton RR, Hutton BF. A scanning line source for simultane­ous emission and transmission measurements in SPECT.] Nucl Med 1993; 34: 1752-60. 6. Groch MW, Spies SM, Hines H, Liebig J, Hendel RC. Evaluation of a scanning line source method for attenuation correction using an anthromor­phic phantom. J Nucl Med 1996; 37: 211-2. 7. Frey EC, Tsui BMW, Perry JR. Simultaneous acqui­sition of emission and transmission data for improved Thallium-201 cardiac SPECT imaging using a Technetium-99m transrnission source. J Nucl Med 1992; 33: 2238-45. 8. Autorenkollektiv. Konsensus -Neuro-PET. Nuk­learmedizin 1997; 36: 259-60. 9. Autorenkollektiv. Konsensus -Onko-PET. Nuk­learmedizin 1997; 36: 298-9. 10. PET-Arbeitsgruppe / Arbeitsgruppe Nuklearkardi­ologie. Indikationen fi.ir die klinische Anwendung der Positronen-Emissions-Tomographie in der Kardiologie. Positionsbericht der Arbeitsgruppe PET-Kardiologie der Deutschen Gesellschaft fi.ir Nuklearmedizin und des Arbeitskreises Nuklear­kardiologie der Deutschen Gesellschaft fiir Kardi­ologie. Z Knrdiol 1996; 85: 453-68. 11. Schwaiger M, Ziegler S. PET mit Koinzidenzkam­era versus Ringtomograph, Fortschritt oder Riickschritt? Nuklearmedizin 1997; 36: 3-5. Radia/ Oncal 1998; 32(3): 281-7. 1-131 total body burden in postsurgical patients with thyroid cancer Mario Medvedec, Dražen Huic, Marija? Žuvic, Darko Grošev, Slavko Popovic, Damir Dodig, Zeljka Pavlinovic Department oj Nuclear Medicine and Radiation Protection, University Hospital "Rebro," Zagreb, Croatia A whole body counter was used to study whole body retention oj I-131 in order to estimate parameters oj the retention curve, the total body absorbed dose, the correlation with the urine assay and the ratio oj the ablation-therapeutic over the diagnostic body burden. The retention in 48 patients after surgery far thyroid cancer was measured 2, 24, 48 and 72 h after the diagnostic administration oj 82±24 MBq, and in 26/48 patients 72 h after the therapeutic administration of 4361±216 MBq I-131. In 16 patients the activity oj excreted urine was compared with in vivo measurements. In 44/ 48 patients the whole body retention curve was characterized by two exponential components, even in patients witlwut evidence oj radioiodine-con­centrating thyroid tissue. The mean effective half-time was 10.9±2.1 h and the total body absorbed dose 5.0±2.2E-02 mGy/MBq. The urine assay overestimated whole body retention by a Jactor 2-5. The ratio oj therapeutic versus diagnostic retention at 72 h was 0.82±0.41 and significantly negative correlated with the retention at 72 h and the residence tirne of diagnostic activity, and with the tirne period between surgery and diagnostic study. Radioiodine kinetics in postsurgical patients with thyroid cancer is dependent on dif­ferent variables. Accurate in vivo measurements oj whole body retention provided some novel data about non-standard kinetics oj radioiodine, and timing and dosage during I-131 ablation procedure Key words: thyroid neoplasms-surgery, body burden, whole-body counting, radioiodine kinetics, interna[ dosimetry; iodine radioisotopes, radioiodine therapy Introduction When a large amount of radioactivity is administered, the knowledge of the radiation burden on the critical organ and total body is Correspondence to: Mario Medvedec, EE , MSc, Department of Nuclear Medicine and Radiation Pro­tection, University Hospital "Rebro", Kišpaticeva 12, HR-10000 Zagreb, Croatia; Phone: +385 1 2333850; Fax: +385 1 2335785; E-mail: mmedvede@rebro.mef.hr certainly of importance not only for patients and hospital personnel, but also for the patient's family members and others. In the case of postsurgical patients with thyroid cancer, the ultimate goal to be achieved is a successful radioiodine ablation of residual thyroid tissue or functioning metastases using minimal amount of 1-131 activity. Therefore, one may at the same tirne be con­cerned about the absorbed dose of more than Medvedec Metal. 80-300 Gy delivered to the metastatic thyroid cancer or thyroid remnant 1-5 and less than 2­3 Gy delivered to the blood, 1,2,6-9 the retained whole body activity of maximum 1110 MBq on the day of the patient's discharge from hospital, 10,11 the predictability of diagnostic 3, 6,12,13 study for subsequent therapy, and the accuracy of methods for assessing patient body burden.11,14 The purpose of this work was to investi­gate the curves of initial whole body reten­tion after the administration of the diagnostic activity of I-131 in patients following surgery for differentiated thyroid cancer, to estimate the mean whole body absorbed dose, to com­pare urine assay with whole body counting, and whole body retention after the diagnostic and ablation-therapeutic dose. Patients and methods A total of 48 patients were investigated after surgical thyroidectomy for thyroid cancer. Patients' demographic and clinical 3 51.8±15.7 13 -- Tws(h) < 16.5 98.9±42.4 13 <0.02 > 16.5 64.3±31.8 13 Tsurgery-dg ( d) :c:; 38 >38 100.7±47.1 62.5±21.0 13 13 <0.04 TSH (rnIU/1) >50 64.1±41.0 8 <0.09 98.4±39.2 18 ?. 7 101.4±42.7 8 tirne of 10.9 h was, however, in very good agreement with the results of others,7,11,18 but further analysis of component parameters revealed some interesting points. We found in group A the mean percentage intercept of the second component f2 (>10%) significantly higher and the mean effective half-time T 2 eff (<48 h) shorter than the values reported by Edmonds et al. (<1 % and >120 h).18 The dif­ferences may be partly attributed to the mea­surements performed exclusively before, as in our case, or after the fourth day (Edmonds). A diagnostic workup study simi­lar to our gave visually similar retention curves, although not much numerical data were provided.9, 11 Since the retention during the postadministration three-day period could not be described by a monocompart­mental model even in group A, the hypothe­sis of organic binding of radioiodine some­where in the body appeared reasonable. The influence of activity retention in lesion or other normal tissue on the retention of whole body during distinct hypothyroid conditions seems to require more detailed investigation, as it has already been suggested. 5,19,20 Because of usually small amount of thyroid remnant and consequently low mean neck uptake of about 3%, the overlapping ranges of calculated parameters did not enable us to discriminate the patients of group A and B on that basis. The latter also applies to the values of whole body radiation absorbed doses. They were calculated by assuming homogenous activity distribution and using recent 'S' val­ues17 corrected for the individual patient weight. The average value of 0.05 mGy/MBq was, however, not significantly different from the doses found by others.7, 20 The comparison of urine assay and whole body counting provided no particularly sur­prising information: retention overestimation of few times and 60% slower effective clear­ance rate of whole body activity as predicted by indirect in vitro measurement. Even with Medvedec M et al. the complete urine collection there will still be some other pathways (defecation, saliva, perspiration) of iodine excretion not taken into account. For example, a 10% loss in col­lection, resulting in change of cumulative excreted urine activity from 95% to 85%, will overestimate the retained body activity by factor three. For the reasons of accuracy and convenience, we also believe that carefully performed whole body counting is a superior method for assessing patient body bur­den 11,14 A number of authors have found retained whole body activity or delivered 6 weeks resulted in serum TSH values of 77.5±29.6 (n=6), 104.2±48.7 (n=14), 105.6±91.5 (n=13) and 99.6±53.6 mIU/1 (n=12) respectively. In conclusion, the diagnostic study using 37-74 MBq I-131 3-4 weeks after attempted total surgical thyroidectomy and radioiodine ablation-therapy more than 1 week later appears to be a reasonable step towards the optimization of timing and dosage during the ablation procedure. However, further investi­gation of radioiodine kinetics dependent upon different variables in postsurgical patients with thyroid cancer is necessary, and the whole body counting technique certainly has a role to play. References 1. Coffey JL, Watson EE. Calculating dose from remaining body activity: a comparison of two methods. Med Phys 1979; 6: 307-8. 2. Dworkin HJ, Meier DA, Kaplan M. Advances in the management of patients with thyroid disease. Semin Nucl Med 1995; 25: 205-20. 3. Hadjieva T. Quantitative approach to radioiodine ablation of thyroid remnants following surgery for thyroid cancer. Radiobiol Radiother 1985; 26: 819­23. 4. O'Doherty MJ, Nunan TO, Croft DN. Radionu­clides and therapy of thyroid cancer. Nucl Med Commun 1993; 14: 736-55. 5. Reynolds JC, Robbins J. The changing role of radioiodine in the management of differentiated thyroid cancer. Semin Nucl Med 1997; 27: 152-64. 6. Benua RS, Cicale NR, Sonenberg M, Rawson RW. The relation of radioiodine dosimetry to results and complications in the treatment of metastatic thyroid cancer. Am J Roentgenol 1962; 87: 171-82. 7. Giinter HH, Junker D, Schober O, Hundeshagen H. Dosimetrie des hamatopoetischen system bei der radiojodtherapie des schilddriisenkarzinoms. Strahlenther Onkol 1987; 163: 185-91. l-131 lota/ body burden 8. M'Kacher R, Legal JD, Schlurnberger M, Voisin P, Aubert B, Galliard N, et al. Biological dosirnetry in patients treated with iodine-131 for differentiated thyroid cancer. J Nucl Med 1996; 33: 1860-4. 9. Thomas SR, Sarnaratunga RC, Sperling M, Maxon HR. Predictive estirnate of blood dose frorn exter­nal counting data preceding radioiodine therapy for thyroid cancer. Nucl Med Biol 1993; 20: 157-62. 10. Culver CM, Dworkin JH. Radiation safety consid­erations for post-iodine-131 thyroid cancer thera­py. J Nuc/ Med 1992; 33: 1402-5. 11. Thomas SR, Maxon HR, Fritz KM, Kereiakes JG, Connell WD. A cornparison of rnethods for assessing patient body burden following I-131 therapy for thyroid cancer. Radiology 1980; 137: 839-42. 12. Huic D, Medvedec M, Dodig D, Popovic S, Ivance­vi<' D, Pavlinovi<' ž, et al. Radioiodine uptake in thyroid cancer patients after diagnostic applica­tion of low 131 1 dose. Nucl Med Commw1 1996; 19: 839-42. 13. Jeevanrarn RK, Shah DH, Sharrna SM, Ganatra RD. Influence of large dose on subsequent uptake of therapeutic radioiodine in thyroid cancer patients. Nucl Med Bio/ 1986; 13: 277-9. 14. Toohey R, Palrner E, Anderson L, Berger C, Cohen N, Eisele G et al. Current status of whole-body counting as a rneans to detect and quantify previ­ous exposures to radioactive rnaterials. Health Phys 1991; 60: 7-42. 15. Medvedec M. Measure111e11I system of body radioac­tivity. MSc thesis. Zagreb: University of Zagreb; 1995. 16. Medvedec M, Popovic S, Kasal B, Huic D, Ivance­vi<' D. Design and use of a s/it collimator far whole body counter. [abstract]. Eur J Nucl Med 1994; 21: 869. 17. Stabin MG. MIRDOSE: personal computer soft­ware for interna! 20 mm, d=38 mm), each one viewed by two of the 81 photomultipliers (RCA 6199) as shown in Figure 2. The existing readout system was quite complicated and slow due to the limited ­ . ;>.·.-.;:,.•:-. o..:i; , , 11111111 '' n: .. ;i i:;::;::; .. m,'· """/ 3 104 10 o 1 O 102 10 CD45 FITC -sto B C") o w o.C\J a, o . . 8 . o ., .. :\.(­., ... !.,,_.:) : /-.!'.._'.\ 0o "') 1 .100 1, ,i1111 11111111'"'T"-n't"t1111 102 CD3 FITC 1 1 rnn/ 104 o"""------.--------------, C :··,:. C") o .:•. rochrome. 5 j " .-__ :'\:-..-.-: ·­ ... ,;,,:. . ... .. . ' .:•·1· N .. •. •;. . Washing at the end of the labelling proce­ dure is important, especially if the cells are to be fixed. The usual fixation method is 1 % -2% paraformaldehyde. If soluble fluorochrome is present at the tirne of fixation, it may be fixed to the cell or may diffuse into the cell after fix­ation and lead to increased background. Selection of antibodies The major advantage of monoclonal antibod­ies over polyclonal antibodies is cleaner labelling with less background. This is because polyclonal antibodies are used at 10 .-•.r.c-..-.:...•-..-:.• .o 102 104 C03FITC Figure 2. Insufficient CD19 Ab concentration. The fluo­rescence dott-plott (B) consists of CD3/CD19 negativecells followed by the cells that scatter into the positiveCD19 range of the scale, but cannot be clearly separatedfrorn the negative population. Insufficient MoAb concen­tration rnay be due to low antibody titer, too rnany cellsin the sarnple, pipetting problerns or insufficient tube decanting before MoAb application. An addition of moreCD19 Ab reveal a clearly CD19 positive celi population(A). Flow cytometric pit/ni/s times higher concentrations or more. There­fore non-specific interactions and Fc receptor binding occur more often. F(ab)2 fragments of polyclonal antibodies usually markedly decreases the tendency of antibodies to aggregate on storage and bind to cellular Fc receptors. The preparation of F(ab)2 frag­ments of monoclonal antibodies is usually not necessary because they are used at low concentrations. The labelling of antibodies must achieve a high specific labelling of immunoglobulin molecules and as low as possible concentra­tion of nonlabelled fluorochrome in the preparation. FITC labelled antibody prepara­tions are usually relatively free of the prob­lems of non-specific labelling. On the other hand, rhodamine preparations of monoclonal antibodies may have relatively high concen­trati011 of free fluorochrome that cause non­specific binding. 6 Another major problem in multiple colour analysis may be unbalanced intensity of monoclonal antibodies labelling. When FITC and rhodamine are used together, it is neces­sary to correct the red signal for the spill of fluorescein emission into the red region. This cannot be easy achieved if both fluorescence intensities are not balanced enough to suc­cessfully set the compensation. A problem can especially arise if we combine monoclon­al antibodies of different manufacturers, or self-labelled antibodies with commercial anti­bodies, or polyclonal antibodies with mono­clonal antibodies. Non-specific fluorescence In some preparations of conjugated antibod­ies, a lot of free (unbound) fluorescence dyes may persist. In that case, antigen discrimina­tion may not be possible because most of the cells, especially monocytes, granulocytes and non-viable cells, exhibit fluorescence that is not linked to antigen expression. Antibodies must be purified (dialysis, gel chromatogra­phy) in order to get rid of unbound fluores­cence dyes. It is advisable to inform the man­ufacturer about the unproper antibody prepa­ration or simply -change it. Some subsets of lymphocytes (macrophages, NK cells) have receptors bound to immunoglobulins by their Fc por­tion (Fc receptors). Therefore it is better to use the F(abh fragments of antibodies to decrease the non-specific binding, in particu­lar when rabbit polyclonal antibodies are applied. F(abh fragments are also much more stable for long storage.6 Data analysis and gating methods Lymphoma samples may not contain a homogenous population of malignant cells. Moreover, some types of lymphoma samples may include only a minor part of malignant cells, while the rest of cells represent the infiltration of non-malignant lymphocytes (mainly T cells). In such case, the detection of cell clonality is possible only after the malig­nant cells are first separated from normal cell infiltration and then analysed. Many analysis tools in flow cytometry use the ability of the program to set gates on defining parameters. Only cells which fall within the gates are further analysed. For determination of cell clonality (e.g. Ig light chain restriction) a homogenous population of tumor cells may be first selected by setting gates on distinct parameters (e.g. cell size and granularity, CD19+, CDS+, CD23+ cells ... ). Moreover, a gate can be set on a combina­tion of selected parameters. It is also possible to distinguish accurately lymphocytes from other leukocyte popula­tions (bone marrow, peripheral blood) using the combination of fluorescence associated with CD45/CD14 and forward and orthogo­nal light scatter. By identifying the cell popu­lation of interest based on immunofluores­ 302 Ihan A cence, a light scattering window can then be drawn to include all of the lymphocytes. The combination of light scattering and immuno­fluorescence can also be used to define the purity of the gate. Once the optimal data acquisition gate has been established and characterized, it is possible to correct the subsequent analyses with that particular sample since the reactivity of monoclonal antibodies on monocytes and granulocytes can be accounted for once the nonlympho­cytes have been identified as being within the acquisition gate.7 Reporting of data The flow cytometric data are usually present­ed as: 1. percentages of positive cells 2. mean fluorescence intensities ad.1. This operation requires that the positive cells be clearly resolved from the negative cells. In multicolour labelling, dot-blott dia­grams must clearly demonstrate that a single, homogenous population is analysed. Other­wise, a calculation of "positive" cells by sim­ply integrating a histogram data can be extremely misleading. For example, two dif­ferent cell populations on fluorescence dot­plot can represent as single, homogenous population on histogram. ad.2. There are some instances in which it is not possible to resolve correctly the positive population. Some antigens are expressed in accordance to the physiological state of the cell. For example, there are some molecules, expressed on the cell surface during their activation (e.g. HLA-DR on T cells). Some other molecules are expressed constantly, but during cell activation, the level of their expression is increased (e.g. CD18, CD25). In the case of gradually expressed antigens, there is no sharp delineation between "posi­tive" and "negative" cells. The use of isotype controls may be useful for cursor setting between "negative" and positive". Conclusion Flow cytometry is fast, easy, quantitative and reliable method for estimation of different lymphoid cells. The sample for flow-cytomet­ric analysis must be prepared as a single cell suspension, hence, the loss of tissue structur­al information is inevitable. A flow-cytometry may therefore be of value as a method of sub­classification of lymphoid cells observed in histological samples. Well selected panels of antibodies may provide a firm immunological basis for the classification, prognosis and treatment monitoring of lymphomas. References l. Tbakhi A, Edinger M, Myles J, Pohlman B, Tubbs RR. Flow cytometric immunophenotyping of non­Hodgkin's lymphomas and related disorders. Cytometry 1996; 25: 113-24. 2. Katz RL. Cytologic diagnosis of leukemia and lym­phoma. Values and limitations. Ciin Lab Med 1991; 11: 469-99. 3. Pirc-Marjanovic B, Ihan A. Algorithm for immunophenotyping of low-grade B lymphomas. Blood 1996; 58: 2361-2. 4. Othmer M, Zepp F. Flow cytometric immunophe­notyping: principles and pitfalls. Eur ] Pediatr 1992; 151: 398-406. 5. Geary WA, Frierson HF, Innes DJ, Normansell DE. Quantitative criteria for clonality in the diag­nosis of B-cell non-Hodgkin's lymphoma by flow cytornetry. Quantitatžve Pathol 1993; 6: 155-61. 6. Perfetto S, Ross W, Riley RS, Mahin EJ. Quality assurance and quality control in flow cytornetry. In: Reily RS, Mahih EJ, Ross W, eds. C/inžcal applž­catžon oj flow cytometry. New York: JGAKU­SHOIN; 1993: p.859-84. 7. Loken MR. Brosnan JM. Bach BA. Ault KA. Estab­lishing optirnal lyrnphocyte gates for imrnunophe­notyping by flow cytometry. Cytometry 1990; 11: 453-9. Radio/ Oncol 19 98; 32(3): 303-9. Simple but extremely effective autologous tumor vaccines Srdjan Novakovic? and Barbara Jezeršek2 1 Department oj Tumor Biology, 2Deparhnent oj Interna/ Medicine, Institute oj Oncology Ljubljana, Slovenia A simple autologous tumor vaccine was created by mixing oj autologous sublethally irradiated tumor cells with a non-specific immunomodulator MVE-2 (a polymer Jraction oj 1,2-co-polymer oj divinyl ether and maleic anhydride). Two different tumor models, i.p. B-16 melanoma in C57Bl/6 mice and i.p. Sa-1 sarcoma in A/J mice, were used to assess the effectiveness oj vaccine in the prevention oj tumor development after challenge with viable tumor cells. Animals' survival was observed and the average day oj death was calcu­lated. With the prevaccination (7 days prior to tumor challenge) we managed to protect 60% oj C57Bl/6 mice from tumor development -namely, they remained 100 days tumor free. The rest oj the animals which ultimately developed i.p. melanomas survived statistically significantly longer than moclc treated animals ar animals receiving MVE-2 ar 11011-replicating tumor cells alone. The results with sarcomas were less encouraging, since ali prevaccinated animals finally developed i.p. sarcomas and died oj it. Anyway, the survival oj prevaccinated animals was significantly longer than the survival oj mock treated animals, but a significant difference was obtained also when we compared animals treated with MVE-2 alone ar irradiated tumor cells alone to moclc treated animals. Interestingly, the animals that were treated with irradiated tumor cel/s alone had the longest survival. In conclusion, taking in account the results with genetically manipulat­ed vaccines our own outcomes confirm that equally effective priming and triggering oj the immune system could be obtained with a simple genetically unmanipulated and saje autologous tumor vaccine. The better results achieved with a less immunogenic B-16 melanoma remain unexplained so far. Key words: biological therapy; vaccine therapy; neoplasms Introduction Due to the fact that nowaday methods of can­cer treatment (chemotherapy, radiotherapy) are imperfect with regard to their toxicity and Correspondence to: Dr. Srdjan Novakovic, Depart­ment of Tumor Biology, Institute of Oncology Ljubl­jana, Zaloška 2, 1000 Ljubljana, Slovenia. Tei: + 386 61 323 06 3 ext. 51-18; Fax: +386 61131 41 80; E-mail: sno­vakovic@onko-i.si low specificity for tumor cells, tremendous efforts were put into the development of bio­logical methods that would be more effective, more specific for tumor cells and less toxic for the treated organism. The commonly used biological therapies against cancer include different non specific immunomodulators (e.g. Corynebacterium parvum, Bacillus Cal­mette-Guerin -BCG, Muramyl dipeptide ­MDP and its analogues), antitumor cytotoxic Novakovic S and Jezeršek B or immunomodulatory cytokines, growth fac­tors, immunomodulatory monoclonal anti­bodies, host defense cells (i.e. tumor infiltrat­ing lymphocytes, lymphokine activated killer cells), as well as tumor vaccines.1-5 Among these methods, designing and application of tumor vaccines seemed to be the most attrac­tive and promising ones, especially when the development of genetical engineering offered the possibility to create genetically modified vaccines.3, 6 However, the present-day knowl­edge still does not allow the preparation of absolutely controlled genetic constructs, which precludes their unlimited use in humans. The intention of this study was to design a potent autologous tumor vaccine, yet bypassing the dangers of low controllabil­ity of a genetically manipulated construct. Keeping this in mind, we designed a simple biphasic vaccine. We used unfractionated non-replicating (irradiated) autologous tumor cells as a source of tumor specific antigens that were intended to successfully and specif­ically prime the immune system. As the sec­ond component of the vaccine, used in order to enhance the cytotoxic macrophage activity, a non-specific immunomodulator MVE-2 was admixed to tumor cells. Materials and methods Tumor cel/s Murine B-16 melanoma (done F1) cells (American Type Culture Collection -ATCC, Rockville, Maryland) were grown in Eagle's minimal essential medium (EMEM) supple­mented with 10% fetal calf serum -FCS (Sigma, St Louis, MO), penicillin (100 units/ml, Pfizer, New York, NY), strepto­mycin (100 µg/ml, Pfizer) and gentamycin (11 µg/ml, Invenex, Chagrin Falls, OH). Fibrosar­coma Sa-1 tumour cells were grown in vivo as intraperitoneal tumours in A/J mice. Animal tumor model The experiments were performed on 8-10 week old syngeneic female C57Bl/6 or NJ mice (Instih1te Rudjer Boškovic, Zagreb, Croatia). Animals were provided with food and water ad libitum and held at a constant room tempera­ture (24 °C) in a standard animal colony with the natura! day/night cycle. Before the experi­ments, the animals were subjected to adapta­tion period of two to three weeks. At least 10 healthy animals, without signs of fungal or other infections, and with normal body weight, were included in each experimental group. Intraperitoneal (i.p.) B-16 melanoma as well as i.p. Sa-1 sarcoma were employed as tumor models. Intraperitoneal B-16 melanoma tumors were induced by i.p. inoculation of a variable number of viable tumor cells: 2x105 , 5x105 or lx106 in 0.2 ml EMEM supplemented with 2% FCS. Intraperitoneal Sa-1 tumors were induced by i.p. inoculation of 5x105 viable tumor cells in 0.2 ml saline. The viability of tumour cells was determined by trypan blue dye exclusion test. Mice with i.p. tumors were monitored for the day of death, and the proportion of sur­vivors (i.e. animals protected from tumor development) was notified. The average sur­vival (AM) ± standard deviation (SD) ± stan­dard error (SE) were calculated for animals that ultimately developed tumors and consequen­tially died of them. Ali given -----'-----' o 20 40 60 80 100 days after tumor cells implantation Figure 2. Survival -ilr=h=+l )'>-(.:x' ...... _,__..._ ___ ..._ ___ .... 20 40 60 80 100 days after tumor celi implantation Figure 3. Survival of vaccinated and control i.p. B-16 tumor-bearing animals challenged with different concen­trations of viable B-16 tumor cells 7 days after the treat­ment. The results of controls preinjected with MVE-2 are not plotted since they do not differ from the results in other control groups. lenged with 5x105 viable tumor cells, 60% of mice survived and in the group challenged with 2x105 viable tumor cells, 55.5 % of pre­vaccinated mice survived. The animals in prevaccinated groups that ultimately devel­oped tumors, after the challenge with 2x105 viable tumor cells, 5x105 viable tumor cells, or lx106 viable tumor cells survived for 36.4±25.0 days, 32.4±12.9 days, and 27.0±14.4 days on average. No survivors were observed in the mock treated groups as well as in groups treated with irradiated tumor cells alone. Mock treated animals, challenged 7 days later with 2x105 viable tumor cells, 5x105 viable tumor cells, or lx106 viable tumor cells had an average survival of 20.4±5.8 days, 18.5±4.1 days, and 19.6±5.7 days, respectively. When the animals were preinjected with irradiated tumor cells (5x105) and seven days later challenged with 2x105 viable tumor cells, they survived on average 21.7±4.3 days. When challenged with 5x105 viable tumor cells, the animals sur­vived 23.2±9.1 days, and when challenged with lx106 viable tumor cells 23.5±6.5 days. Discussion The experiments reported here were motivat­ed by a large number of recent studies show­ing that a host response to tumor challenge could be influenced by inoculation of tumor cells genetically engineered to express partic­ular cytokines, MHC antigens, products of tumor suppressor genes, or B7 activation antigen.6, 7 At the same tirne, it seemed that the leading idea for the development of these vaccines was not always only their effective­ness for triggering host specific antitumor immunity, yet to design as complicated as possible constructs containing some foreign genes. Contrary to this concept, our efforts were put in the development of a simple tumor vaccine that would be easy to produce, and safe for application in cancer patients. Therefore, we elaborated the autologous tumor vaccine where non-replicating (irradi­ated) tumor cells were employed as a source of the specific antigens, and the non-specific immunomodulator MVE-2 as an agent for the stimulation of cytotoxic macrophage activity. Keeping in mind that the most important fac­tor for achieving specific antitumor immuni­ty is natura! immunogenity of tumor cells, we tested our vaccines on two different tumor models. It was encouraging to see that autolo­gous Sa-1 tumor vaccines were capable of inducing a protective effect in A/J mice (even though there were no survivors), but it was most unexpected when in accordance with Novakovic S and Jezeršek B the results of Dranoff et al. we could confirm that moderately immunogenic non-replicat­ing tumor cells were comparable in their effi­cacy of stimulating the immune system to genetically modified irradiated tumor cells.8 Namely, in our experiments the longest sur­vival after the challenge with viable Sa-1 tumor cells was achieved by pretreatment with irradiated Sa-1 tumor cells alone. The results in poorly immunogenic B-16 melanoma tumor model additionally verified the hypothesis that, for the development of an efficient tumor vaccine, it is not always obligatory to manipulate the tumor cells genetically. Specifically, the percentage of animals fully protected against tumor devel­opment in our experiments (60%) was com­parable to the results of the authors who employed genetically modified tumor cells as tumor vaccine.8-10 An even better evidence of the effectiveness of genetically non-manipu­lated vaccines provided Allione at al. who compared the efficacy of the vaccine contain­ing irradiated autologous tumor cells admixed with C.parvum to the vaccines con­taining replicating or non-replicating tumor cells engineered to produce cytokines. Only the replicating tumor cells which were trans­fected with GM-CSF gene (Granulocyte Macrophage Colony Stimulating Factor) were more efficient than the above described sim­ply created vaccine.11 Astonishing and interesting results were obtained when the antitumor protection was assessed after the challenge with different concentrations of viable B-16 tumor cells. The best protection was achieved in the prevacci­nated animals that were inoculated with the largest tested number of viable tumor cells though, according to our expectations these mice were to die first. So far, there is no material evidence to explain this, yet we can speculate that this fact speaks for a critical number of tumor cells that are essential for the triggering of immune system. Such a speculation is supported by the results of the authors who confirm that the most patent tumor vaccines are designed when replicat­ing tumor cells are transfected with a gene of in terest.11 In conclusion, we demonstrated a brand new approach in tumor vaccine preparation, which resulted in a tumor vaccine, simple but effective enough to merit further investiga­tion in animal tumor models as well as in humans. The main advantages of this kind of vaccine, besidesits efficacy, are facile prepa­ration, high controllability, and absence of toxic side effects or immunological deposits. Acknowledgment The expert technical assistance of Mrs. M. Lavric is gratefully acknowledged. Financial support was provided by the Slovenian Min­istry of Science and Technology, grant No. }3­7878. References l. Hock H, Dorsch M, Kunzendorf U, Qin Z, Dia­mantstein T, Blankenstein T. Mechanisms of rejec­tion induced by tumor cell-targeted gene transfer of interleukin 2, interleukin 4, interleukin 7, tumor necrosis factor, or interferon y. Proc Natl Acad Sci USA 1993; 90: 2774-8. 2. Guo YJ, Che XY, Shen F, Ma J, Wang XN, Wu SG, et al. Effective tumor vaccines generated by in vitro modification of tumor cells with cytokines and bis­pecific monoclonal antibodies. Nature Med 1997; 3: 451-5. 3. Hersh EM, Stopeck AT. Advances in the biological therapy and gene therapy of malignant disease. Ciin Cancer Res 1997; 3: 2623-9. 4. Novakovi<' S, Menart V, Gaberc-Porekar V, Štalc A, Serša G, Cemažar M, Jezeršek B. New TNF-cx ana­logues: A powerful but less toxic biological tool against tumors. Cytokine 1997; 8: 597-604. 5. Novakovi<' S, Boldogh I. In vitro TNF-cx production and in vivo alteration of TNF-cx RNA in mouse peritoneal macrophages after treatment with dif­ferent bacterial derived agents. Cancer Letters 1994; 81: 99-109. Si111ple autologous tumor vaccine 6. Pardoll DM. Cancer vaccines. TiPS 1993; 14: 202­ 7. Novakovi<:' S. Current approaches to gene therapy in oncology: Construction of tumor vaccines. Radi­o/ Oncol 1996; 30: 260-7. 8. Dranoff G, Jaffee E, Lazenby A, Golumbek P, Lev­itsky H, Brose K, et al. Vaccination with irradiated tumor cells engineered to secrete murine GM-CSF stimulates patent, specific and long lasting anti­tumor immunity. Proc Natl Acnd Sci USA 1993; 90: 3539-43. 9. Sampson JH, Archer GE, Ashley DM, Fuchs HE, Hale LP, Dranoff G, Bigner DD. Subcutaneous vaccination with irradiated, cytokine-producing tumor cells stimulates CD8+ cell-mediated immu­nity against tumors located in the "immunologi­ cally privileged" central nervous syste. Proc Natl Acad Sci USA 1996; 93: 10399-404. 10. Vieweg J, Rosenthal FM, Bannerji R, Heston WDW, Pfier WR, Gansbacher B, Gilboa E. Immunotherapy of prostate cancer in the Dun­ning rat model: use of cytokine gene modified tumor vaccines. Cm1cer Res 1994; 54: 1760-5. 11. Allione A, Consalvo M, Nanni P, Lollini PL, Caval­lo F, Giovarelli M, et al. Immunizing and curative potential of replicating and nonreplicating murine mammary adenocarcinoma cells engineered with interleukin (IL)-2, IL-4, IL-6, IL-7 , IL-10, tumor necrosis factor a, granulocyte-macrophage colony­stimulating factor, and y-interferon gene or admixed with conventional adjuvants. Cancer Res 1994; 54: 6022-6. Radio/ Onco/ 1998; 32(3): 311-8. Acceptability of simultaneous irradiation and mono/polichemotherapy with cis/ carboplatin Borut Kragelj Institute oj Oncology, Ljubljana, Slovenia By improving local and systemic control oj the disease, simultaneous polychemotherapy and radiotherapy could exert a javorable ejject on the curability oj patients with locally advanced tumors oj the urinary blad­der. The question remains, however, how to adjust both therapeutic schedules so as to keep the associated toxic side ejjects within acceptable limits. Our retrospective study was aimed to assess the toxicity oj con­current chemotherapy with cis-ar carboplatin and with/without vinblastine and methotrexate in combina­tion with irradiation in 14 patients with locally advanced carcinomas oj the urinary bladder ar symptoms oj obstructive uropathy. As compared to irradiation alone, the combined therapy was associated with greater -particularly gastrointestinal -toxicity (in 8/14 patients grade 2,3) and low tolerability, which required adjustment oj chemo-ar radiotherapy in more than halj oj the patients ( 8/14 ). Considering the indicated dependence oj toxic side ejjects from the type oj cytotoxic therapy, and the jact that the peak oj side ejjects occurs within 3-4 weeks oj therapy, perhaps an acceptable leve/ oj combined-treatment-related toxicity could be achieved by daily applications oj lower doses oj cytotoxic drugs and a split-course irradia­tion regimen, with discontinuation oj irradiation during the acute phase oj side ejjects. Key words: bladder neoplasms-drug therapy-radiotherapy; invasive bladder cancer, tolerability oj chemoradiotherapy Introduction Although cystectomy represents a standard therapy for invasive carcinoma of the urinary bladder, the so-called conservative approach ­ i.e. transurethral tumor removal with chemotherapy (ChT) and irradiation (RT)­offers equal chances of cure as cystectomy.1,2 As to the success of local control of disease in the bladder and pelvis, the conservative ther- Correspondence to: Borut Kragelj, M.D.,M.Sc., Insti­tute of Oncology, Zaloška 2, 1000 Ljubljana, Slovenia apy by enabling bladder preservation in 2/3 of patients yields results comparable to those obtained by radical cystectomy using modem surgical techniques, which ensures 70-85% probability of local disease-free survival.3A Local control with conservative therapy depends on T stage and patency of the ureters; the risk group consisting of the tumors which penetrate through the bladder wall and/or cause blockage of the ureters.2, 5 Apart from worse local control, patients with such tumors run a higher risk of metastatic dissemination. 6 Treatment results could be 312 Kragelj B improved by immediate simultaneous applica­tion of chemotherapy and irradiation, which would result in a better local control attribut­able to the interaction between chemo-and radiotherapy, as well as to the systemic control exerted by chemotherapy. This was also the main objective of our study which was aimed to assess the acceptability of such treatment. Material and methods Our retrospective study was carried out on a series of patients with carcinoma of the uri­nary bladder invading the bladder wall or blocking the ureters, who were treated by irradiation and simultaneous cisplatin or car­boplatin based mono-or polychemotherapy in the period from 1994 to 1997. The decision about treatment with either one or both cytotoxic drugs depended on the preservation of renal function. The latter was assessed on the basis of the evaluation of serum levels of creatinine and blood urea nitrogen, as well as on the evaluation of endogenous creatinine and/or 125J hippuran clearance; with increased serum creatinine values or with more than half reduced creati­ 125J nine or hippuran elimination, the patients received carboplatin-based chemotherapy, while in other cases cisplatin was used instead. Sometimes the schedule would also include vinblastine or vinblastine and methotrexate. Two different methods of chemotherapy application were used: 1) low doses of cytotoxic drugs were given regularly every week throughout the duration of radio­therapy (continued chemotherapy -CChT), or 2) ChT schedule was applied in standard 3­week intervals (intermittent chemotherapy -IChT). Irradiation was carried out on linear accel­erators, using the 4-field technique and stan­dard regimen: the patients were irradiated once daily for 5 days weekly, in 2-2.2 Gy doses. In the case of disseminated disease, the irradiation field included the urinary bladder alone, while with the disease limited to the urinary bladder the field also included regional lymph nodes. The planned target doses were as follows: 46 Gy for the areas of microscopic disease, and 63.4 to 66 Gy for macroscopically visible tumors. In the case of disseminated disease, the target dose was limited to 50 Gy, also for the area of macro­scopic disease. The extent of disease was evaluated according to TNM classification (modified in 1997). Treatment related side effects, i.e. acute hemo-and nephrotoxicity, were assessed according to WHO recommendations; acute proctitis, enteritis and cystitis were evaluated by means of RTOG scale for the assessment of acute irradiation-related side effects: acute proctitis grade II was further classified as grade IIA in the cases when the acute diffi­culties persisted despite the supportive thera­py given. Symptoms of postirradiation cystitis and proctoenteritis was also assessed with respect to the radiation dose received, and the tirne interval from the beginning of irra­diation to the onset of difficulties. Problems associated with postirradiation cystitis were also evaluated against the signs of already present cystitis at the beginning of irradiation, attributable either to tumor growth, previous surgeries or to chemothera­py. Acceptability was assessed according to a possible need for discontinuation of chemo­and/or radiotherapy or premature cessation of treatment. Side effects as well as acceptability of treatment were assessed according to the type of therapy: mono / polychemotherapy, intermittent / continued and more (MChT) / less intensive (LChT) chemotherapy with cis­platin or carboplatin. The latter two groups were determined by the median cumulative dose of carbo-or cisplatin per m2 of body Simultaneous irradiation and chemolherapy surface / week, which was (in the case of more intensive ChT) or was not exceeded (less intensive ChT ). Results The study included 14 patients, 10 males and 4 females, aged 62-75 years (median age 65 years). The stage was assessed as T2 N0-x M0 in 5/14 patients, and as T3 N0-x M0 in 7/14 patients; in one the stage was defined as T4 N2 MO and T2 No-x Ml respectively. Histo­logical findings were as follows: transitiocel­lular ca. in 10/14 patients (grade 2 in 6/10, grade 2-3 in 2/10 and grade 3 in 2/10 patients), non-differentiated anaplastic carci­noma in 3/14 and microcellular carcinoma in 1 patient. Signs of obstructive uropathy were present in 7/14 patients, of these 3 presented with bilateral ureteral obstruction. Renal dys­function was observed in 8/14 patients; in all 7 with obstructive uropathy, and in one due to previous nephrectomy. The method of therapy is presented in Table 1. In 9/14 patients ChT was based on cisplatin, while in 5/14 it was based on carbo­platin. Either cisplatin or carboplatin was used as mono-ChT in 5/14, and as poly-ChT in 9/14 patients -vinblastine was added to the sched­ule in 4/9 and vinblastine plus methotrexate in 5/9 patients. As to the mode of application, CChT was used in 11/14, and IChT in 3/14 patients. The intensity of ChT applied simultane­ously with irradiation was as follows: platinol 22.2 -40 mg/m2/week (median 26.2 mg/m2/week), carboplatin 65-181 mg/m2/week (median 136 mg/m2/week), vin­blastine 0.8-1 mg/m2/week (median 1 mg/m2/week) and methotrexate 4.5-15 mg/m2/week (median 8mg/m2/week). All patients were irradiated on linear accelerators, using four-field technique. Tar­get doses (TD) applied to the urinary bladder ranged between 28 Gy -66 Gy (median 60 Gy), delivered in 2-2.5 Gy fractions (median 2 Gy). Treatment related side effects are present­ed in Table 2. These were most frequently associated with postirradiation proctitis, the difficulties being present in 13/14 patients. 5th The problems occurred within the 2nd ­week of therapy, in the majority of patients 4th (9/13) within the 3rd -week of therapy. In 8/13 patients the problems considerably influenced the patients' quality of life, and were actually intolerable, despite the sup­portive therapy (grade 2A-4), the patient's performance status being directly affected in 3/8 cases (grade 3, 4); in one of the latter three patients, side effects were an indirect cause of the patient's death. With respect to mono-or poly-ChT, the intensity of proctitis related difficulties was comparable: grade 2A, 3 problems were established in 3/5 patients with mono-ChT and in 5/8 patients with poly-ChT. The difference related to the mode and intensity of chemotherapy was more obvious: grade 2A-4 problems were observed in all ( 3/3) patients with IChT and in 4/11 with CChT, and in 6/7 and 2/7 with with MChT or LChT. Postirradiation cystitis related problems were less frequent. Cystitis symptoms prior to the onset of chemo-radiotherapy were pre­sent in 12/14 patients. Worsening of the symptoms during therapy occurred in 6/14 patients after 3-5 weeks from the beginning of treatment, in the majority of these (5/6) 5th within the 4th -week of therapy. All 6 patients presented with grade 3,4 side effects. There were no differences in the intensity of side effects noted with respect to mono vs. polychemotherapy, continuous vs. intermittent ChT„ and more intensive vs. less intensive ChT: thus grade 2A-4 difficulties were observed in 3/5 and 3/9 patients receiv­ing either mono-or polychemotherapy, in 1/3 and 5/11 with IChT or CChT, and in 3/7 and 3/7 with MChT or LChT. 314 Kragelj B Table 1.Treatment of 14 patients receiving concurrent ChT and RT by intensity of treatment with platino! and car­boplatin, type of adjuvant ChT, tumor -, -'\ -1 >ic:._,1 ;), .i......: . " 0 "'\ "'\ "'\ .1 >, C'-,'.:\ :--, . --., -'\ -, .i......: . 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'1}f. ·:·. ... . ----. ·:za mirno potovanje skozi kemoterapij o N .. avouan tropisteron • preprecevanje slabosti in bruhanja pri emetogeni kemoterapiji • ucinkovito zdravilo, ki ga odrasli in otroci dobro prenašajo • vedno 1-krat na dan • vedno 5 mg Skrajšano navodilo za uporabo: NavobanGI> kapsule, NavobanGI> raztopina za 1njiciranje 2 mg in 5 mg. Serotoninski antagonist. Oblika in sestava: 1 trda kapsula vsebuJe 5 mg tropisetronovega hidroklorida. 1 ampula po 2 ml vsebuje 2 mg tropisetronovega hidroklorida. 1 ampula po S ml vsebuje 5 mg tropisetronovega hidroklorida. Indikacije: Prepretevanje slabosti in bruhanja, ki sta posledici zdravljenia s citostatiki. Zdravljenje pooperativne slabosti in bruhanja. Preprecevanje pooperativne slabosti in bruhanja pri bolnicah, pri katerih je nacrtovana ginekološka operacija v trebušni votlini. Odmerjanje in uporaba: Preprecevanje slabosti in bruhanja, ki sta posledici zdravljeni• s citostatiki. Odmerjanje pri otrocih: Otroci starejši od 2 let 0,2 mg/kg telesne mase na dan. Najvecji dnevni odmerek ne sme preseti 5 mg. Prvi dan kot intravenska infuzija ali kot pocasna intravenska injekcija. Od 2. do 6. dne naJ otrok jemlje zdravilo oralno (raztopino v ampuli razredcimo s pomarancnim sokom ali koka kolo). Odmerjanje pri odraslih: 6-dnevna kura po 5 mg na dan. Prvi dan kot intravenska infuzija ali pocasna intravenska inJekcija. Od 2. do 6. dne 1 kapsula na dan. Zdravljenje in preprecevanje pooperativne slabosti in bruhanja: Odmerjanje pri odraslih: 2 mg Navobana z mtravensko infuzijo ali kot pocasno injekcijo. Glej celotno navodilo! Kontraindikacije: Preobcutljivost za tropisetron, druge antagoniste receptorjev 5-HT3 ali katerokoli sestavino zdravila. Navobana ne smemo dajati noseacnicam; izjema je prepretevanie pooperativne slabosti in bruhanja pri kirurških posegih, katerih del je tudi terapevtska prekinitev nosecnosti. Previdnostni ukrepi: Bolniki z nenadzorovano hipertenzijo; bolniki s prevodnimi ali drugimi motnjami srcnega ritma; ženske, ki dojijo; bolniki, ki upravljaJo s stroji ali vozili. Medsebojno delovanje zdravil: Rifampicin ali druga zdravila, ki inducirajo jetrne encime. Glej celotno navodilo! Stranski ucinki: Glavobol, zaprtje, redkeje omotica, utrujenost in prebavne motnje (boletine v trebuhu in driska), preobcutljivostne reakcije. Zelo redko kolaps, sinkopa ali zastoJ srca, vendar vzrocna zveza z Navobanom ni bila dokazana. Nacin izdajanja: Kapsule: uporaba samo v bolnišnicah, izjemoma se izdaja na zdravniški recept pri nadaljevanju zdravlJenJa na domu ob odpustu iz bolnišnice ,n nadaljnjem zdravljenju. Ampule: uporaba samo v bolnišnicah. Oprema in odlocba: Zloženka s 5 kapsulami po 5 mg; številka odlocbe 512/8-773197 z dne 1 O. 11. 1997. Zloženka z 1 ampulo po 2 ml (2 mg/2 ml); številka odlocbe 512/8-772197 z dne 10.11.1997. Zloženka z 10 ampulami po 5 ml (5 mg/S ml); številka odlocbe 512/8-771197 z dne 1 O. 11. 1997. Izdelovalec: NOVARTIS PHARMA AG. Basel, Švica. Imetnik dovoljenja za promet z zdravilom: NOVARTIS PHARMA SERVICES INC., Podružnica v Sloveniji, Dunajska 22, 1511 Ljubljana, kjer so na voljo informacije in literatura. Preden predpišete Navoban, prosimo preberite celotno navodilo.a ' NOVARTIS