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  1. 1. Nuklearmedizin 3/2003 SWISS SOCIETY OF NUCLEAR MEDICINE (SGNM/SSMN) 4th ANNUAL CONGRESS LUCERNE JUNE, 26-28 2003 Main Topic: SPECT and PET Local Organizing Committee: Congress Secretary: J. Th. Locher (President) Dr. L. D. Frey L. D. Frey Dept. of Nuclear Medicine M. Brühlmeier Kantonsspital Aarau I. Engel CH-5001 Aarau B. Hofer Phone +41/(0)62/8 38 54 90 M. Kunz Fax +41/(0)62/8 38 54 91 E-mail: Scientific Committee: Further Information: A. Bischoff Delaloye, Lausanne Information on the detailed B. Bubeck, St. Gallen program, registration, hotel J. Th. Locher, Aarau accommodation and social program H. Steinert, Zürich is available online at: H. Maecke, Basel (Radiochemistry) Please direct your questions to:
  2. 2. Abstracts, Lucerne 2003 A144 Nuklearmedizin 3/2003 SWISS SOCIETY OF NUCLEAR MEDICINE (SGNM/SSMN) 4th ANNUAL CONGRESS, LUCERNE, June 26-28 2003 Thursday, June 26 2003 Common Events Radiology and Nuclear Medicine Nuclear Medicine 12:00 Opening Technical Exhibition; Lunch 12:00–13:45 General Assembly Swiss Society of Radiopharmacy/Radiopharmaceutical Chemistry (SGRRC) 14:00–15:10 Scientific Session 1: Invited Lectures PET-CT: New Developments and Technical Challenges Ratib O., Los Angeles Software Algorithms in Nuclear Medicine Missimer J., PSI Villigen 15:30–16:50 Scientific Session 2: Cardiology (O1-O6) 17:00–17:30 Congress Opening and Recception Friday, June 27 2003 Common Events Radiology and Nuclear Medicine Nuclear Medicine 08:00–9:45 Scientific Session 3: Antibodies and Peptides (O7-O12) Invited Lecture Animal PET Bruehlmeier M., Aarau 10:00–11:50 The Digital Image in the Clinical Environment 12:00–13:30 Lunch 13:30–15:15 H. R. Schinz-Lecture 16:00–18:00 General Assembly Swiss Society of Nuclear Medicine (SGNM/SSNM) 20:00 Gala Dinner at the Casino Lucerne Saturday, June 28 2003 Common Events Radiology and Nuclear Medicine Nuclear Medicine 09:00–10:00 Scientific Session 4: Invited Lectures Attenuation Correction Burger C., Zurich Image Fusion Juengling F., Bern 10:00–10:30 Scientific Session 5: Posters (P1-P7) 11:00–12:45 General Assembly 11:00–12:15 Scientific Session 6: Oncology (O13-O18) Swiss Society of Radiology (SGR/SSR) 13:00 Congress Closure
  3. 3. Abstracts, Lucerne 2003 A145 Nuklearmedizin 3/2003 Combined CT-angiogram and PET perfusion imaging for assess- ment of CAD in a novel PET/CT: pilot feasibility study M Namdar, T Hany, G K von Schulthess, P A Kaufmann Nuklearkardiologie, Universitätspital Zürich Aim: An accurate, noninvasive technique for the diagnosis of coronary disease would be an important advance. We present the first evaluation of image quality of a new integrated PET/CT scanner for combined acquisi- tion of coronary anatomy and perfusion. Methods: 10 patients with angiographically documented coronary artery disease were scanned in a newly developed GE Discovery LS PET-CT (GEMS, Milwaukee, WI), an integration of an Advance PET and a multy- row Lightspeed plus CT scanner. Contrast-enhanced CT angiography (CTA) was performed with retrospective ECG-gating after injecting 120 mL contrast media intravenously (iv) and myocardial perfusion was asses- sed with 13 N-ammonia (800 MBq) at rest and during adenosine stress. Results: In the CTA the entire coronary tree could be visualized in all pati- ents up to the mid segment. CTA and PET correctly identified a stenosis re- lated reversible defect in 3 patients and an irreversible perfusion defects without lesion (after angioplasty/stenting) in 2 patients. In one patient a coronary occlusion was correctly documented. In the remaining five pati- ents clinically non-relevant calcifications were detected by CTA and PET. Conclusions: Considering our first experiences with the new integrated PET/CT technique combined assessment of coronary lesion anatomy and its pathophysiological severity seems to be feasible. Gated 99m Tc-tetrofosmin SPECT to characterize fixed defects as infarct versus artifact S Fleischmann, M Namdar, P Köpfli, P A Kaufmann Nuklearkardiologie, Universitätspital Zürich Aim: Fixed perfusion-scan defects may result from attenuation artifacts. Gated 99mTc-tetrofosmin SPECT may help differentiate myocardial infarc- tion (MI) from artifact. Fixed defects with decreased function (wall motion and thickening) probably represent MI, whereas attenuation artifacts have normal function or not markedly reduced function Methods: Ungated resting and gated stress 99mTc-tetrofosmin SPECT was performed in 153 consecutive patients referred for evaluation of coronary disease. From resting and summed gated stress images, 107 patients (70%) were identified with isolated fixed defects. Function of the defects was as- sessed subjectively from gated stress images and results were correlated with clinical (history and/or ECG Q-waves) evidence of MI. Results: Of 62 patients with fixed defects and clinical MI, 60 (97%) had abnormal defect function. Of 45 patients with fixed defects but no clinical MI, 16 (36%) had decreased function of the defect, possibly indicating silent MI. In 29 of the 45 patients (64%) with no clinical MI, defect func- tion was normal. Because most (90%) of fixed defects with normal systo- lic function occurred in men with inferior fixed defects (86%) or women with anterior fixed defects (3%), these were most likely attenuation arti- facts. By reclassifying patients with fixed defects and normal function as normal, patients with unexplained fixed defects (no clinical MI) decreased from 29% to 10%. Conclusions: Gating provides a considerable added value to 99m Tc-tetro- fosmin SPECT in characterizing fixed defects and potentially improving test specificity. Prevalence of stress-induced myocardial ischemia and previous infarction in diabetic patients M Koehli1,2, D Monbaron2, J Ruiz2, JO Prior1, N Besseghir1, RC Gaillard2, A Bischof Delaloye1 Service de Médecine Nucléaire1, Division d’Endocrinologie, Diabétologie et du Métabolisme2, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland Objective: To analyse the prevalence of stress-induced myocardial ische- mia and myocardial infarct in diabetic patients as determined by gated- SPECT (g-SPECT) and to evaluate the association with clinical para- meters, ECG and ejection fraction. Methods: G-SPECT myocardial perfusion studies of 211 diabetic patients performed from 1997 to 2002 were retrospectively analysed for the presence of stress-induced ischemia and myocardial infarct. A 2-headed gamma-camera (E.Cam, Siemens) and a conventional 1-day protocol (dual isotope Tl-201/Tc-99m MIBI 40%, single-isotope Tl-201 27% or Tc-99m MIBI 33%) were used. Stress testing was performed by bicycle-ergometer (40%) or with a pharmacological agent completed by low-intensity physi- cal exercise (44%). Results: Among these 211 patients, 120 (57%) men, aged 64 ± 10 years; 120 (57%) had an abnormal g-SPECT result (ischemia 41%, infarct 8%, ischemia+infarct 12%). The prevalence of stress-induced ischemia was similar between patients with (53%) or without (57%) angina during stress testing (p = 0.7). Stress-induced ST segment depression was observed in 82% of the patients with g-SPECT ischemia vs. 46% of those with normal g-SPECT (OR = 4.1, p = 0.001). The prevalence of positive g-SPECT was higher in men than in women (OR = 1.3, p = 0.05). The prevalence of infarction was greater in the eldest patients (p = 0.048). The systolic arterial pressure during stress was lower in patients having myocardial defects than in those with no defects (p = 0.02). The mean ejection fraction was 50% for patients with perfusion defects vs. 58% for those with no defects (p = 0.004). An increasing number of irreversible defects was associated with a decrease in ejection fraction (p <0.0001). Conclusions: The prevalence of positive g-SPECT was 57% in diabetic patients addressed for the evaluation of coronary artery disease (CAD). Angina during stress testing was not informative for the presence of CAD. ST depression was present in 82% of the subjects with a positive g-SPECT. A positive g-SPECT was associated with a lower ejection fraction. This confirms the importance of g-SPECT in assessing myocardial perfusion and long-term prognosis in diabetic patients. Abnormal myocardial blood flow (MBF) response to cold pressor testing (CPT) in post-menopausal women with and without coronary risk factors – relation to MBF at rest JO Prior1,2, TH Schindler1, MA Oxilia-Estigarribia1, L Nathan 1, AD Facta1, M Inubushi1, A Bischof Delaloye2, HR Schelbert1 UCLA School of Medicine1, Los Angeles, USA; Centre Hospitalier Universitaire Vaudois (CHUV)2, Lausanne Aim: To define the MBF response to CPT and adenosine as indices of the integrated and mostly endothelial-dependent (CPT) and endothelial-inde- pendent (adenosine) coronary vasomotion in post-menopausal women (PM) with and without coronary risk factor (RF). Methods: In 74 women (58 ± 8 years) with normal adenosine N-13-am- monia PET images, MBF during CPT and in response to adenosine was quantified by N-13 ammonia PET and a 2-compartment model. CPT was performed with a 2-min hand immersion in iced-water and adenosine stress testing with a standard 6-min infusion (0.14 mg·kg-1·min-1). RF included hypertension, hypercholesterolemia, diabetes, smoking and obesity. CPT response was defined “CPT+” when MBF increased from rest conditions (MBFCPT-MBFREST≥0) and “CPT-“ when it decreased (MBFCPT- O1 O2 O3 O4
  4. 4. Abstracts, Lucerne 2003 A146 Nuklearmedizin 3/2003 MBFREST <0). Comparisons used Kruskal-Wallis or Wilcoxon rank-sum tests and were considered significant if (p <0.05). Results: “CPT-“ response was observed in 27(36%) women and “CPT+” in 47(64%) women. For groups with the same “CPT” response, MBFCPT was similar in “RF-“ and “RF+” women. However, MBFREST was higher in PM women with risk factors and a negative response to CPT (“RF+/CPT-“) than in any other groups of women (p = 0.03). The “rate-pressure-pro- duct” as an index of cardiac work did not differ between groups during rest, CPT or adenosine. MBFADENOSINE was similar in the four groups (p = 0.8). Conclusion: A negative MBF response to CPT, possibly indicative of coro- nary endothelial dysfunction, was observed in 36% of PM women. This MBF response was associated with an elevated MBF at rest. The reason(s) for the increase in MBF relative to cardiac work remains uncertain, but raises the possibility of a “coronary inflammatory-like” hyperaemic state of coronary blood flow. Validation of ECG-gated SPECT in the assessment of left ventricular ejection fraction C Jaeggi, M Namdar, P Koepfli, PA Kaufmann Nuklearkaradiologie, UniversitätsSpital Zürich Background: The assessment of left ventricular ejection fraction (LVEF) provides strong diagnostic as well as prognostic information in patients with documented or suspected coronary artery disease (CAD). Gated SPECT is a modern technique for measurement of LVEF. Our purpose was to validate ECG-gated SPECT for the assessment of LVEF at our institute in comparison with echocardiography (ECHO) and left ventricular angio- graphy (ANGIO). Methods: 101 consecutive patients (26 men, 75 women, mean age 63 y ± 10 y) were included in the study. 58 of them had an ECHO, 44 an ANGIO in addition to gated SPECT. 53 patients were examined with technetium- 99m-tetrofosmin and 48 with technetium-99m-labeled sestamibi. An ROC-analysis was performed to assess the cut-off value of gated SPECT LVEF with best sensitivity and specificity for discriminating normal from pathologic LVEF. Bland-Altman correlation analysis was performed for all patients. Results: ROC-analysis of gated SPECT vs. ECHO revealed a cut-off value for normal LVEF of >57% (sensitivity 100%, specificity 78.3%). SPECT vs. ANGIO resulted in a cut-off of 45% (sensitivity 66.7%, specificity 76.3 %). The flat shape of ROC curve for ANGIO indicates that ANGIO values are less reliable. There was no significant bias for the comparison of gated-SPECT versus ECHO or ANGIO according to Bland and Altman. Conclusions: Assessment of LVEF by gated SPECT at our institution is accurate. The cut-off value for normal LVEF is >57%. Decreased coronary flow reserve after caffeine ingestion in healthy volunteers during acute exposure to simulated altitude M Namdar, R Grathwohl, R Delaloye, P Köpfli, P A Kaufmann Nuklearkardiologie, Universitätspital Zürich Aim: Caffeine antagonizes adenosine-induced hyperemic myocardial blood flow (MBF). Its impact on exercise-induced coronary flow reserve (CFR) remains unknown. Our aim was to determine the acute effect of caffeine on CFR during bicycle exercise at baseline and during exposure to simulated altitude. Methods: 15 O-labelled H2O and Positron Emission Tomography (PET) was used to measure CFR in 16 healthy volunteers (mean age 26 y ± 1 y) before and 50 minutes after oral ingestion of caffeine (200 mg). Supine bicycle exercise (mean workload 154 ± 27 Watts, 100 ± 5% of predic- ted) was used as stress. Measurements were performed at normoxia (n = 8) or during simulation of an altitude of 4500 m by inhalation of 12.5% oxygen in N2. Results: Caffeine levels were zero at baseline in all subjects and increased to 14.7 ± 2 µmo/l fifty minutes after caffeine intake. Rate pressure product (rest and exercise) was not affected by caffeine. Caffeine increased resting MBF significantly by 21 ± 18% (normoxia, p <0.01) and 35 ± 15% (hypoxia, p <0.0005), whereas hyperemic MBF decreased signifi- cantly by 17 ± 18% (normoxia, p <0.0005) and 25 ± 11% (hypoxia, p <0.0005), resulting in a decrease in CFR of 36% (normoxia, p <0.01) and 47% (hypoxia, p <0.005). Conclusions: Intake of a caffeine dose equivalent to two cups of coffee significantly reduces CFR during physical exercise. This effect is even more pronounced at exposure to simulated high altitude, suggesting that caffeine may antagonize intrinsic adenosine mediated hyperemic response to exercise and hypoxia. Ein Vergleich zwischen 111 In-DOTATOC und 111 In-DOTATATE: Biodistribution und Dosimetrie in Patienten mit neuroendokrinen Tumoren F Forrer, H Uusijärvi*, M Cremonesi**, C Waldherr, H Mäcke***, J Müller-Brand Institut für Nuklearmedizin Kantonsspital, Basel, Department of Radiation Physics*, Göteborg, Divisione di Medicina Nucleare Istituto Europeo di Oncologia**, Milano, Institut für Radiochemie Kantonsspital***, Basel Ziel: Es existieren noch keine Vergleiche über die Bioverteilung von DOTA-Tyr3-octreotid (DOTATOC) und DOTA-Tyr3-Thr8-octreotid (DOTATATE) im Menschen. Deshalb soll mit dieser Studie geprüft werden, ob es relevante Unterschiede gibt und ob für die Therapie neu- roendokriner Tumore eines der Peptide Vorteile hat. Insbesondere interes- siert das Tumor-zu-Nieren-Verhältnis, da die Niere meist das dosislimitie- rende Organ ist. Methoden: Drei Patienten mit metastasierenden neuroendokrinen Tumoren wurde im Abstand von zwei Wochen 222 MBq 111 In-DOTATOC bzw. 111 In-DOTATATE injiziert. Ganzkörperszintigraphien und Blutentnahmen in Serie wurden bis 48 h p.i. angefertigt. Urin wurde bis 48 h p.i. gesam- melt. Mittels ROI-Technik und MIRDOSE 3.0 wurden die zu erwartenden absorbierten Dosen für Nieren, Leber und Milz sowie für insgesamt 7 Me- tastasen bestimmt (5 Leber- und 2 Knochenmetastasen). Wir benutzten 111 In als Surrogat für 90 Y. Resultate: Bei allen Patienten zeigte sich in den Nieren, in der Leber und in der Milz sowie in insgesamt 4 der 7 Metatsatsen eine stärkere Akkumulati- on [%iA] von DOTATATE. In allen drei Patienten war die „residence time“ in den gesunden Organen bei DOTATATE länger. Folglich berechnet sich eine höhere Dosis in mGy/MBq für die gesunden Organe bei DOTATATE. Das Verhältnis zwischen den absorbierten Dosen von Tumor zu Normal- gewebe variierte stark zwischen den einzelnen Patienten und den verschie- denen Metastasen. O5 O6 O7
  5. 5. Abstracts, Lucerne 2003 A147 Nuklearmedizin 3/2003 Verhältnis der durchschnittlich absorbierten Dosen von Metastasen zu Nor- malgewebe: Schlussfolgerungen: Aufgrund der vorliegenden Studie scheinen die beiden Peptide gleichwertig für die Therapie neuroendokriner Tumore. Insbesondere das Verhältnis der Tumordosis zur Nierendosis, zeigt keinen signifikanten Unterschied. Durch die gleichzeitige Infusion einer Ami- nosäurenlösung lässt sich die Nierendosis signifikant reduzieren. Ob in dieser Beziehung ein entscheidender Unterschied zwischen den beiden Peptiden besteht, muss noch geklärt werden. Premiers résultats d’un analogue de la neurotensine, 99m Tc-NT-XI, évalué chez des patients avec un adénocarcinome pancréatique F Buchegger1 , F Bonvin1 , M Kosinski1 , AO Schaffland1 , J Prior1 , JC Reubi3 , P Bläuenstein4 , E García Garayoa4 , M Gillet2 , PA Schubiger4 , A Bischof Delaloye1 Services de Médecine Nucléaire1 et de Chirurgie2 , Centre Hospitalier Universitaire Vaudois, Lausanne, Division de Biologie Cellulaire3 , Institut de Pathologie, Université de Berne et Centre des Sciences Radiopharmaceutiques4 , Institut Paul Scherrer, Villigen Objectif: La sûreté, la biodistribution et l’uptake tumoral de NT-XI, analo- gue de la neurotensine, a été étudié chez 4 patients prévus pour être opérés d’un adénocarcinome pancréatique primaire. Méthodes: L’hexapeptide NT-XI contenant la séquence carboxyterminale modifiée de la neurotensine a été radiomarqué au 99mTc via un histidine- Nα-acétate. Les patients ont été suivis par scintigraphie durant 4 heures et par des prélèvements sanguins durant ~20 heures jusqu’à l’opération. La radioactivité tissulaire et l’expression tumorale du récepteur de la neurotensine ont été déterminées dans les prélèvements chirurgicaux. Résultats: L’injection du 99mTc-NT-XI n’a pas provoqué d’effet secondaire. Les demi-vies α et β sanguines étaient de 35 (17 à 62) et 230 (107 à 383) minutes, respectivement. L’élimination, essentiellement rénale, était rapide (92 à 97% / 20 h). La scintigraphie montrait une captation rénale, hépatique, splénique et de la moelle osseuse chez tous les patients ainsi qu’une hyperactivité importante digestive chez 2 patients. La tumeur n’a pas été visualisée chez 3 patients, alors qu’elle était localisée par SPECT au niveau de la tête du pancréas chez le 4ème. L’uptake tumoral du 99mTc- NT-XI mesuré ex-vivo était le plus élevé chez le 4ème patient, en relation avec l’observation d’une forte expression du récepteur. Deux autres tumeurs ne montraient pas d’expression du récepteur et une autre était positive mais que sur de rares cellules tumorales dispersées. Conclusion: L’injection du 99mTc-NT-XI a bien été tolérée et a permis de visualiser la seule tumeur présentant une haute densité de récepteurs de la neurotensine tandis que 2 tumeurs n’exprimant pas le récepteur et une ne l’exprimant que sur quelques cellules éparses ne pouvaient pas être mises en évidence. Ces résultats sont similaires aux observations pré-cliniques et parlent en faveur d’une poursuite de l’évaluation clinique des analogues radiomarqués de la neurotensine. Radioimmunotherapy with lutetium-177-DOTA-rituximab: a phase I/II-study in patients with follicular and mantelcell lymphoma: an interim analysis F Forrer, A Lohri*, J Chen, R Herrmann**, H Mäcke, J Müller-Brand Nuclear Medicine, University Hospital, Basel, Medical Oncology Kantonsspital*, Liestal, Medical Oncology University Hospital**, Basel Ziel: Radioimmunotherapy with 131 I and 90 Y labelled anti-CD20 antibodies showed convincing results mainly in treatment of indolent lymphomas. We analyzed the pharmacokinetics and dosimetry of 177 Lu labelled, chimeric (human-mouse) anti-CD20-antibody rituximab. The antibody was modi- fied with up to 4 DOTA-chelators with retained immunoreactivity. 177 Lu was chosen because of its low β-energy (0.497 MeV) and its imageable γ-energies. These are favorable physical characteristics for the treatment of small tumors or tumors that diffusely infiltrate visceral structures. Methoden: 7 patients (2 women, 5 men) with relapsed lymphoma were included so far. After pretherapeutic staging (18 F-FDG-PET, CT, bone marrow biopsy) patients received 250 mg/m2 rituximab on day 1. On day 8 patients received another course of Rituximab followed by the injection of 20 mCi/m2 177 Lu-DOTA-rituximab (32-40 mCi). Scintigraphic images were obtained up to 15 d p.i. to determine biodistribution and total dose. Blood samples were collected up to 15 d p.i. Urine was collected by male patients up to 72 h p.i. Calculations were done with dose-factors published on „RADAR“ (Stabin M et al.; Resultate: Early ␥-camera images showed mainly blood pool activity. Over time, in 6 of the 7 patients a clear specific uptake at tumor sites was seen. The effective half-life of the whole-body activity ranged from 95 to 136 h (mean 117 h ± 15 h), leading to diffuse whole-body-doses of 1007 mGy to 1459 mGy (mean 1150 ± 123 mGy). The dose to the red marrow ranged from 393 to 539 mGy (mean 447 mGy ± 55 mGy). Excretion of activity was found to be low in urine with a maximum of 10% of the injec- ted activity excreted within 72 h by the kidneys. The application of 177 Lu- 177-DOTA-rituximab was well tolerated. Clinical results and toxicity will be presented at the meeting. Schlussfolgerungen: 177 Lu-177-DOTA-rituximab seems to be an inter- esting, well tolerated compound with clinical activity already in a low dose range. Dose escalation is in progress. Synthesis and biological activity of a new and highly potent ligand for somatostatin receptors 2, 3, and 5 M Ginj1 , D Wild1 , JS Schmitt1 , JC Reubi2 , B Waser2 , M de Jong3 , HF Bernard3 , EP Krenning3 , HR Mäcke1 1 University Hospital Basel, Department of Nuclear Medicine, Radiological Chemistry, 2 University of Bern, Institute of Pathology, 3 University Hospital Dijkzigt, Department of Nuclear Medicine, Netherlands Aim: The prototypes for tumor targeting with radiolabelled peptides are derivatives of somatostatin (SRIF) like DTPA-octreotide or DOTA-TOC with high affinity mainly for sstr2 and moderate affinity to sstr5. We aimed at developing new SRIF-analogs for internal radiotherapy, which recog- nize different receptor subtypes, to expand the present range of accessible tumors. Methods: Using parallel solid phase synthesis, we synthesized new octa- peptides based on octreotide, by replacing Phe3 mainly with unnatural amino acids. The affinity profile was determined using transfected cell lines with sstr1-5. Internalization was determined using AR4-2J cell lines and bio-distribution was studied in a rat tumor model. Results: Parallel solid phase synthesis allowed quickly to synthesize a range of new SRIF-based radiopeptides. One of them, DOTA-NOC, showed high affinity to sstr 2,3 and 5, if complexed with Y(III) or In(III). The rate of internalization in this series was the highest for 111 In-DOTA- NOC. Bio-distribution in tumour bearing rats again showed very promising O8 O9 O10
  6. 6. Abstracts, Lucerne 2003 A148 Nuklearmedizin 3/2003 results. The uptake in sstr expressing tissues including the CA 20948 tumour was significantly higher for 111In-DOTA-NOC compared with 111In-DOTA-TOC and the tumour-to-kidney ratio was improved by a factor of 2. Conclusion: Parallel solid phase synthesis along with the suitable bioas- says is a powerful tool to select new radiopeptides with improved targeting properties. 111In and 90Y-DOTA-NOC are very promising radiopeptides for the diagnosis and peptide receptor mediated radiotherapy of a larger range of sstr expressing tumours like thyroid, colon or lung adenocarcinomas which were shown to overexpress SRIF receptor subtypes other than sstr2. New stabilised bombesin analogues as potential tumour imaging agents D Rüegg1, C Leonardi1, A Blanc1, M Lutz1, E García Garayoa1, P Bläuenstein1, A Beck-Sickinger2, D Tourwé3, PA Schubiger1 1 Paul Scherrer Institut, Villigen, Switzerland, 2University of Leipzig, Germany and 3Free University, Brussels, Belgium. Aim: Neuropeptides such as bombesin (BBS) bind cell-surface receptors overexpressed in several human tumours and show interesting properties for cancer diagnosis and therapy. However, their potential clinical utility is limited by their rapid degradation. New BBS(7-14) analogues have been synthesised and characterised. The different analogues were designed based on the results obtained in the stability experiments with an unmodi- fied BBS(7-14) analogue and enzyme inhibitors. Methods: The metabolic stability was tested in vitro in human plasma by means of HPLC. Enzyme inhibitors were used to identify the enzymes cleaving BBS. Binding assays were performed in PC-3 cells for analysing the affinity for GRP receptors. Results: The positions 9 (Ala), 13 (Leu) and 14 (Met) are important for the stability. The replacement of Ala9 by a DAla, Leu13 by a CHx-Ala or Met14 by a Nle increased the stability. The analogue with CHx-Ala showed the longer half-life (16 h). Differences were found in the affinity for GRP re- ceptors. The substitutions with CHx-Ala and Nle did not affect much the affinity whereas the introduction of DAla led to an important decrease in affinity. Conclusion: Modifications of the molecule BBS(7-14) can increase the plasma stability. However, BBS(7-14) seems to be more sensitive to struc- tural changes since they might decrease the affinity for GRP receptors. With longer plasma half-lives we ensure that enough intact peptide reaches the tumour area. Besides, a high affinity is also necessary to bind to the overexpressed GRP receptors and be uptaken by the tumour cells. Synthesis and evaluation of bombesin analogs modified with different linkers H Zhang, K Hinni, J Chen, JC Reubi*, HR Maecke Institute of Nuclear Medicine, University Hospital Basel, Basel, *Institute of Pathology, University of Berne, Berne Aim: Bombesin receptors are over-expressed on a variety of human tumors, and [D-Tyr6, ␤-Ala11, Phe13, Nle14]Bombesin(6-14) has been shown to bind to all bombesin receptor subtypes with high affinity. In pa- tients studies, a 99mTc labeled bombesin analog showed high uptake in breast(4/6) and prostate(1/4) carcinomas. We report here on DOTA/DTPA conjugated bombesin analogs based on the sequence [D-Tyr6 , ␤-Ala11 , Thi13 , Nle14 ]Bombesin(6-14) (HZ), and focus on the influence of different linkers on their characters. Method: Parallel solid peptide synthesis was used to synthesize the above mentioned bombesin derivatives. They were analyzed with mass spectros- copy and analytical HPLC. DOTA/DTPA-linker-HZ was complexed with YIII or InIII and their affinity were studied using cryostat sections of human prostate cancer tissue. 111 In/177 Lu/90 Y labeled analogs were used to study the stability in the human blood serum, the rate of internalization into AR4- 2J cells, and biodistribution in male Lewis rats bearing the rat pancreatic tumor AR4-2J. Results: The bombesin derivatives were synthesized with an overall yield of 23-32%. Compared to bombesin (IC50, 2.4 ± 0.6 nmol/l), all IC50 values of our analogs are similar with low nM range. It is interesting to find different linkers have a distinct effect on the stability and lead to a different rate of internalization. The uptake of the radiolabeled analogs in the GRP positive organs and the AR4-2J tumors was specific as shown by blocking experiments. The tumor uptake of 111In-DTPA-GABA-HZ in the rat was 1.71 ± 0.51% ID/g at 4 h p.i., and in the pancreas was 3.92 ± 0.86% ID/g; the tumor/blood, tumor/muscle, tumor/liver, tumor/kidney ratios were 107, 171, 33, and 1.5 respectively. Conclusion: The results indicate that DOTA/DTPA-linker-HZ have high binding affinities to the GRP receptor, and have a fast rate of internaliza- tion into AR4-2J cells. The biodistributions showed high specific uptake in AR4-2J tumor and GRP positive organs, indicating that it is promising in diagnosis or therapy of GRP receptor positive tumors. Management of small cell lung cancer: The role of whole-body 18 F-fluorodeoxyglucose positron emission tomography EM Kamel, D Zwahlen*, MT Wyss , KD Stumpe, GK von Schulthess, HC Steinert Department of Nuclear Medicine, and Department of Radiation Oncology*, University Hospital of Zurich, Switzerland Aim: To evaluate the role of whole-body 18F-fluorodeoxyglucose positron emission tomography (FDG PET) in the management of patients with small cell lung cancer (SCLC). Materials and methods: Forty two consecutive patients with small cell lung cancer were evaluated by FDG PET for initial staging (n = 24), and post- therapy restaging (n = 18). PET findings were correlated with clinical and radiological work-up which included CT of the chest and upper abdomen, bone scan, and CT or MRI of the brain. Results: Compared with the conventional initial staging tools PET equally identified 20 patients with limited disease (n = 14), and extensive disease (n = 6). Additionally, PET up-staged 3 patients, and down-staged 1 pa- tient. For post therapy restaging, discordant findings were observed in 6 (33%) patients, PET successfully differentiated post therapy changes from residual disease (n = 3), unmasked soft tissue metastases (n = 1), and excluded bone metastases (n = 1) when the other tools showed false re- sults. In one patient PET missed the presence of minimal disease residue. PET had a remarkable impact on the management of 9 (37%) patients of the initial staging and 3 (17%) patients of the restaging groups respective- ly. PET revealed low yield for the detection of cerebral metastases. Conclusion: FDG PET is a valuable tool in the management of patients with SCLC. Hilar staging of non small cell lung cancer using 3D-PET/CT image fusion EM Kamel, C Burger, D Lardinois*, W Weder*, GK von Schulthess, HC Steinert Department of Nuclear Medicine, and Department of Thoracic Surgery*, University Hospital of Zurich, Switzerland Aim: In non-small-cell lung cancer (NSCLC) accurate preoperative tumor staging is essential for choosing the appropriate treatment. PET/CT image fusion combines the metabolic and anatomic information of both methods. However, the exact localization of lymph node metastases in the hilus is a challenge. Lymph nodes distal to the mediastinal pleural reflection and within the visceral pleura are classified as N1 nodes. Lymph nodes within the mediastinal pleural envelope are classified as N2 nodes. Because the pleura is not visible neither in CT nor in PET, the exact classification of a hilar node as N1 node or N2 node remains difficult. Therefore, we under- O11 O12 O13 O14
  7. 7. Abstracts, Lucerne 2003 A149 Nuklearmedizin 3/2003 took a prospective blinded study to evaluate the additional incremental va- lue of 3D reconstruction of fused PET/CT images in the hilar nodal staging of patients with NSCLC Materials and Methods: 21 patients (age 47-76 years, 14 men, 7 women) with proven NSCLC were enrolled in the study. Integrated PET/CT imaging was performed (Discovery LS; GEMS). In all patients lymph node metastases in the hilar region were detected. 3D reconstruction of the hilar region was performed using an in house software ( Through using a negative CT threshold (-150HU), air passages and lung were identified. By means of VOI, lymph nodes with increased FDG uptake in PET were selected. The 3D-objects were displayed in a virtual room. The 3D-images were analyzed by two nuclear physicians and the N stage was defined. The findings were correlated with intraoperative and histopathologic staging results. Results: Discrimination between N1 (node distal to mediastinal pleural reflection) and N2 (node proximal to mediastinal pleural reflection) was performed accurately using the 3D mode in 19 out of 21 patients. More accurate mediastinoscopy results were obtained in light of the 3D data. Identification of microscopic invasion of the pleura was not amenable by the 3D mode. Conclusion: 3D PET/CT image fusion is a promising method for accurate localization of hilar metastatic lymph nodes. The proposed algorithm may offer additional information about the nodal stations which are beyond the reach of mediastinoscopy. Impact of whole body positron emission tomography on initial staging and therapy in patients with squamous cell carcinoma of the oral cavity DT Schmid, GK Eyrich*, KW Grätz*, GK von Schulthess, GW Goerres Division of Nuclear Medicine and Department of Cranio-Maxillo-Facial Surgery*, University Hospital Zurich, Zurich, Switzerland Aim: The purpose of this study is to evaluate the additional clinical infor- mation provided by whole body positron emission tomography (PET) with fluorodeoxyglucose (FDG) for initial staging of patients with squamous cell carcinoma (SCC) of the oral cavity. Methods: PET scans from the head to the pelvic floor of 34 consecutive patients (22 men, 12 women; mean age 71 years) with histologically con- firmed SCC of the oral cavity were retrospectively evaluated. Clinical information including CT of the head and neck and chest X-ray or chest CT was compared with information on nodal involvement and distant metastases or secondary tumors obtained with PET. Results: The primary tumor was identified with PET in 33 of 34 patients (97%). In 27 patients (81%) the clinical N-stage was confirmed with PET. In 2 Patients (6%) additional pathologic loco-regional lymph nodes were found. In 5 patients more lymph nodes were identified with CT. Distant lesions were seen with PET imaging in bone, lung, mediastinum, liver and colon. In 3 patients (6%) distant metastases were correctly identified. In another 4 patients (12%) a secondary cancer was detected. One false positive finding was described with PET. In 5 of 34 patients (15%) the additional findings as revealed with PET lead to a change of treatment. Conclusion: Whole body PET provides relevant additional information to a standard clinical staging procedure in patients with oral cavity SCC. The detection of distant metastases and secondary primary tumors can have a great impact on patient management. Comparison of 18 F-FDG-PET and bone scintigraphy for monitoring disease activity in patients with rheumatoid arthritis receiving treatment with a monoclonal chimeric anti-TNF antibody: a pilot study GW Goerres, A Forster*, V Treyer, D Uebelhart*, B Michel*, B Seifert**, GK von Schulthess, AH Kaim*** Division of Nuclear Medicine, Department of Rheumatology and *Institute of Physical Medicine, University Hospital Zurich; **Department of Biostatistics, University of Zurich, ***Department of Radiology, University of Basel, Switzerland Aim: The aim of this study was to compare 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) with conventional bone scintigraphy for the assessment of disease activity in patients with rheumatoid arthritis and to assess feasibility of PET scanning for monitoring treatment. Methods: Seven patients with active rheumatoid arthritis underwent FDG PET and bone scintigraphy before and after treatment with infliximab. A visual scoring system was used to evaluate disease activity in large joints of the body, the wrists and finger joints. Spearman rank correlation was used to compare the decrease in inflammatory activity as measured with FDG PET and early and late bone scans with the decrease in clinical disease activity. Results: FDG PET showed high scoring values before treatment onset and a significant decrease in FDG uptake in patients who responded to inflixi- mab therapy. In all patients the disease activity assessed with FDG PET was clearly correlated to clinical outcome (p = 0.04). In contrast, early and late bone images were less reliable for the assessment of treatment response and the changes were smaller. Conclusion: In this pilot study, FDG PET was better than conventional bone scintigraphy for assessing disease activity. Our preliminary results suggest that FDG PET has the potential to replace bone scintigraphy for monitoring disease activity and treatment effects in future studies. Does fluorodeoxyglucose positron emission tomographie (FDG-PET) of Echinococcus multilocularis (EM) liver lesions reflect parasite vitality? KDM Stumpe, EC Renner-Schneiter*, F Grimm**, Z Kadry***, P Deplazes**, PA Clavien***, RW Ammann*, EL Renner*, GK von Schulthess Dept. Nuclear Medicine, *Div. Gastroenterology and Hepatology, **Dept. Parasitology, ***Dept. Visceral and Transplantation Surgery, University Hospital, Zurich, Switzerland Aim: To evaluate whether FDG-PET reflects vitality of Echinococcus mul- tilocularis (EM) lesions. Methods: In an ongoing study, all EM cases newly diagnosed at our institution are subjected to FDG-PET. Diagnosis of EM is based on typical imaging (CT, MRI) and serology. Whenever technically feasible, radical surgery is attempted, inoperable/not radically operated cases being treated with benzimidazoles. At surgery, EM material is collected and subjected to vitality testing using a mouse model. Results: 20 patients (15 women, 5 men; median age 61 yrs. [range 40-73]) have been studied so far. 16 of the 20 patients showed increased FDG uptake of liver lesions in PET, in 4 patients FDG-PET was negative. At diagnosis, all of the latter showed extensively calcified lesions and in 2 serology was only weakly positive, suggesting inactive disease; one was nevertheless started on albendazole, but developed drug-induced hepatitis 14 weeks into treatment which rapidly resolved after discontinuation; in this patient FDG-PET was performed 14 weeks after stop of treatment; the patient was then successfully operated; in vivo vitality tests of the resected parasite material in mice remained negative. Conclusions: FDG-PET of liver lesions was positive in 16/20 untreated, and negative in 4/4 extensively calcified, presumably inactive human EM cases, one of the latter being proven to be avital. These preliminary data support that FDG-PET may reflect parasite vitality. Wether negativation of FDG-PET during benzimidazole treatment may be used as indicator for safely stopping therapy remains to be seen. O15 O16 O17
  8. 8. Abstracts, Lucerne 2003 A150 Nuklearmedizin 3/2003 Apport de la tomographie scintigraphique (SPECT) dans la pratique quotidienne de la scintigraphie osseuse A Keller1, M Zwimpfer2, A Chouiter1, T de Perrot1, L Terraneo2 1Division de radiodiagnostic et de radiologie interventionnelle, 2Division de médecine nucléaire, Hôpital cantonal universitaire de Genève Objectif: Evaluer l’apport de la tomographie (SPECT) par rapport à l’imagerie planaire (PLANE) dans la pratique de la scintigraphie osseuse (SCos). Matériel et méthode: En 2000-2001, 115 patients (66 F,49 H) âgés de 46.6 ± 24.2 ans, ont bénéficié d’une SCos avec des acquisitions PLANE et SPECT pour les indications suivantes: 1) Tumeur (n = 51), 2) Trauma- tisme (n = 31), 3) Infection (n = 16), 4) Nécrose aseptique (n = 4), 5) Divers (n = 13). L’acquisition PLANE a été pratiquée 3 heures après injection de 10.8 MBq/kg de poids corporel de Tc99m HDP (Mal- linckrodt® ) avec les paramètres techniques suivants: collimateur LEHR parallèle, matrice 128*128, vitesse de balayage de 8 cm/minute et des incidences statiques complémentaires de 7 minutes sur la (les) localisa- tion(s) pathologique(s). L’acquisition SPECT complémentaire a été réalisée sur une caméra « 3 têtes » (Toshiba® GCA 9300A), avec 30 paliers de 60 secondes sur 120º et une matrice de 256*1024. Les recons- tructions ont été pratiquées dans les plans coronal, sagittal et axial avec réalisation de coupes jointives en utilisant une méthode « filtered back projection ». Les SCos ont été analysées qualitativement par 2 lecteurs et considérées comme pathologique lorsqu’elles présentaient un (ou des) foyer(s) hyper ou hypofixant(s). Les résultats de la SCos ont été systéma- tiquement confrontés à l’évolution clinique (100%) et à d’autres techni- ques d’imagerie (34%) lorsque nécessaire. Résultats: Le SPECT a été réalisé sur le rachis (n = 78) [cervical (n = 7), dorsal (n = 21), lombaire (n = 50)], le bassin (n = 18), le crâne (n = 12) et autres (n = 7). Le résultat PLANE - SPECT était identique dans 61 cas / 115 (53%). Dans les 54 cas restants (47%), le SPECT a démontré un plus grand nombre de foyers dans et/ou précisé leur topographie dans 25 et 38 cas respectivement : tumeur (n = 32), traumatisme (n = 11), infection (n = 7), nécrose aseptique (n = 1), divers (n = 3). L’évolution clinique et la confrontation aux autres techniques d’imagerie (IRM = 24; CT =8; RX = 6; PET-FDG = 1) ont confirmé l’apport du SPECT comme un élément utile dans la prise en charge de 46 cas / 115 (40%). Dans les 8 cas restants, le résultat positif du SPECT par rapport à la PLANE n’a été corrélé à aucune autre anomalie clinique et/ou radiologique (« faux positif ») dans 5 cas, et dans 3 cas, l’interprêtation du SPECT a évoqué une autre pathologie que le diagnostic final. Conclusions: La réalisation d’un SPECT additionnel à la PLANE est un complément très utile dans le bilan de multiples pathologies osseuses du squelette axial, puisqu’il bénéficie d’une meilleure sensibilité de détection et localise avec plus de précision les anomalies scintigraphiques, élément séméiologique important dans la caractérisation des différentes patho- logies. Einfluss der Reduktion der Emissionszeit auf die Bildqualität einer Ganzkörper FDG-PET/CT T Berthold, D Schmid, C Britt, A Buck, TF Hany Klinik und Poliklinik für Nuklearmedizin, Universitätsspital Zürich, Zürich Ziel: Einfluss der Reduktion der Emissionszeit von 4 auf 2 Minuten von CT-schwächungskorrigierten PET Datensätzen auf die Bildqualität. Methoden: In 10 Patienten (Durchschnittsalter 57,3 Jahre; 28-77 Jahre; 5 Männer, 5 Frauen) mit einem durchschnittlichen Body-mass-Index (BMI) von 32,2 (25,4-38,0) wurde eine Ganzkörper FDG-PET/CT (Stan- darddosis 370 MBq) auf einem kombinierten PET/CT Gerät (Discovery LS, GEMS, USA) durchgeführt. Dabei wurden für jedes axiale Gesichts- feld Emissionsdaten während 4 und anschließend während 2 Minuten im 2D-Modus aufgenommen. Für die Schwächungskorrektur wurde eine Niedrig-Dosis-CT (80 mA, 140 kV, 0,5 s Rotationszeit, Schichtdicke 4,25 mm, totale Aufnahmezeit 22,4 s) verwendet. Für die quantitative Be- wertung der resultierenden Bilddaten wurde das Rauschen (Standardab- weichung der Impulsrate/ mittlere Impulsrate) eines Volumendatensatzes in der Leber bestimmt. Die qualitative Bewertung wurde blind bezüglich der Emissionszeiten durchgeführt, wobei auf die Beurteilbarkeit des patho- logischen Befunds eingegangen wurde. Zusätzlich wurde die Bildqualität subjektiv auf einer Skala (von sehr gut – gut – genügend – nicht diag- nostisch) eingeteilt. Resultate: Das Bildrauschen war durchschnittlich 12% (3-19%) stärker mit 2 Minuten Aufnahmezeit. Es zeigte sich keine direkte Korrelation zwischen Bildrauschen und BMI. Es konnte kein Unterschied in den pathologischen Befunden der beiden Gruppen gefunden werden. In 14 von 20 Datensätzen wurde die Bildqualität als sehr gut, in 6 als gut beurteilt, ohne Unterschied zwischen 2 und 4 Minuten Aufnahmezeit Schlussfolgerungen: In unserem Patientenkollektiv mit erhöhtem BMI führte die Reduktion der Emissionszeit von 4 auf 2 Minuten im 2D-Modus erwartungsgemäß zu erhöhtem Bildrauschen ohne aber die diagnostische Sicherheit einzuschränken. Characterizing adrenal lesions with 18 F-FDG-PET S Merk, M Hentschel, I Brink, T Kelly, M Reincke*, E Moser Department of Nuclear Medicine, *Department of Internal Medicine II, University Clinic Freiburg Ziel: Compared with adrenal metastases primary adrenal tumours are very seldom. Purpose of this study was to evaluate FDG whole-body PET during staging and restaging of primary adrenal carcinomas and to answer the question whether PET provides information on the dignity of adrenal masses. Methoden: Within the framework of primary staging and post-surgical restaging 35 patients were examined with FDG-PET, 9 with primary adrenal carcinomas, 6 adrenal incidentalomas and 20 with adrenal meta- stases of lung tumours (14 SCLC and 6 NSCLC). The examination was performed according to a standard protocol. The results were compared with morphological imaging and/or post-surgical histology. The images were evaluated visually and semi-quantitatively by SUV calculation. Therefore maximum values from circular ROIs were used. 3 independent investigators evaluated 3 representative tumour layers. Resultate: In comparison with morphological imaging (Sono, X-ray, CT, MRI) the PET detected all adrenal tumours as well as all distant metastases in patients with primary adrenal carcinomas. Moreover, the PET identified previously undetected metastases in 2 persons (1x trunk wall, 1x lung). The uptake of adrenal carcinomas (3.6 ± 0.8 (min/max 2.6/6.3)) is in the lower range of values showing adrenal metastases (SUV 6.2 ± 2.5; min/max 2.6/16.5). In case of the incidentalomas divergent uptake behaviour was observed. 3 metabolically active adrenal adenomas showed slightly increased glu- O18 P1 P2
  9. 9. Abstracts, Lucerne 2003 A151 Nuklearmedizin 3/2003 cose metabolism (SUV 2.5, 1.3, and 1.2). In the other 3 incidentalomas (1 Conn-syndrome, 2 metabolically inactive adenomas) the FDG-uptake could not be visually differentiated from the background. Schlussfolgerungen: 18F-FDG-PET is a highly sensitive method for detction and staging of adrenal carcinomas. It seems to allow differentia- tion between malignant and benign adrenal lesions. PET as an aid to diagnose and monitor giant cell arteritis: feasibility and first clinical results EU Nitzsche, MA Walter, U Schirp, F Forrer, S Wickli, A Tyndall, J Müller Divisions of Nuclear Medicine & PET Center, and Rheumatology, University of Basel Medical Center Aim: Polymyalgia rheumatica (PR) and arteritis temporalis (AT) may overlap clinically in about 50%. Since involvement of AT is usually segmental, the diagnosis may be missed on routine biopsy. PM does not have a histo-pathological correlate. Therefore, we tested the hypophesis, that FDG PET may aid diagnosis and monitoring of giant cell arteritis. Methods: 18 patients (pts.), age: 58 ± 20 years, underwent whole body FDG PET imaging after overnight fasting. According to results of kinetic imaging of inflammation by PET, acquisition was initiated after 45 min- utes uptake time. All images were interpreted by 3 investigators blinded to the clinical information of all patients. The PET results were correlated with the results obtained by biopsy, lab tests and clinical course. Results: 3 of 18 pts. showed intense uptake of the wall of the whole aorta and supraaortal branches. These pts. were not on any antiinflammative medication. Scans of the other 15 pts. were read unremarkable. Of these, all but 2 were on glucocorticoid therapy. The latter 2 achieved complete remission, which was maintained after withdrawal of medication. Conclusion: FDG PET appears to be suitable to determine the extent of inflammation of large vessels in suspected giant cell arteritis. Moreover, it may represent a sensitive tool to diagnose and monitor giant cell arteritis. SPECT is superior compared to planar imaging for diagnosis of pulmonary embolism U Schirp, MA Walter, J Müller, EU Nitzsche Division of Nuclear Medicine & PET Center, University of Basel Medical Center Aim: In the past, comparison of diagnostic imaging for diagnosis of pulmonary embolism (PE) was based on spiral computed X-ray tomog- raphy (CT) and planar scintigraphy based on PIOPED criteria. The latter resulted in a high percentage of inconclusive results. Because of this, we tested the hypophysis, that SPECT imaging may enable more accurate diagnosis of PE compared to planar imaging. Methods: 350 patients (pts.), age: 73 ± 46 years, underwent SPECT im- aging for suspected PE under clinical routine conditions. Transaxial, coro- nal and sagittal images, and 8 standard planar images were reconstructed from the SPECT data set for comparison of tomographic and planar im- aging. Images were read by two investigators blinded to the patient data. Read out was based on three categories: PE positive, PE negative, nondiag- nostic for PE. Results: Positive diagnosis of PE was established in 31% (110 pts.), exclud- ed in 64% (224 pts.) and nonconclusive in 5%. Diagnostic performance for SPECT was significantly higher compared to planar imaging (p <0.01). Regarding anatomic localization and extent of perfusion defects, SPECT was again superior to planar imaging (p <0.01). Read out time for SPECT was not significantly different from that for planar imaging (p = n.s.). Observer agreement was 0.95. Overall procedure time amounted to 40 minutes for ventilation/perfusion imaging. Conclusion: SPECT imaging in pts. with suspected PE is the procedure of choice, because it offers better diagnostic performance in detecting the number, anatomic localization and extent of perfusion defects associated with PE compared to planar imaging. In addition, it permits routine tomography, which makes it competitive to other tomographic modalities performed for diagnosis of PE. Monitoring de pompes à diffusion intrathécale de médicaments: à propos de 3 cas A Boubaker1, D Chedel2, E Buchser2, A Bischof Delaloye1 1 Service de Médecine Nucléaire, CHUV, 1011-Lausanne, 2Service d’anesthésiologie, d’antalgie et de neuromodulation, Ensemble Hospitalier de la Côte, Hôpital de Morges, 1110 Morges Objectif: Dans les douleurs chroniques, ou certains cas de maladies neuro- logiques avec spasticité, la neuromodulation par implantation de pompes à diffusion intrathécale de médicaments, contrôlées par télémétrie est très utile. En cas d’échappement au traitement, les causes peuvent être multiples. Il est primordial de détecter un éventuel dysfonctionnement d’une pompe sans side port et/ou une fuite du système pompe-cathéter. Nous rapportons notre expérience chez 3 patients porteurs de pompes Medtronic, Synchromed®, sans side port. Méthodes: Après injection de 37 MBq d’In-111-DTPA dans le réservoir, une acquisition dynamique était réalisée suivie de vues supplémentaires jusqu’à 4 heures pi. Le débit appliqué au système était de 0.9 ml/h pour un volume total de 5 ml. Le premier patient souffrait de douleurs sur lésion séquellaire du nerf sciatique droit avec une brusque recrudescence des douleurs 14 mois après implantation du système. Le second souffrait d’une diplégie spastique douloureuse sur syndrome de Little, bien con- trôlée par Baclofène intra-thécal durant 10 ans, puis échappement malgré augmentation des doses. Le dernier patient présentait des douleurs sur adénocarcinome pancréatique métastatique, bien contrôlées durant 3 mois et en augmentation 3 semaines avant la scintigraphie. Résultats: Chez le premier patient, la scintigraphie a révélé un dysfonc- tionnement mécanique de la pompe, qui a été changée avec évolution cli- nique favorable. Chez le second, la scintigraphie a permis de localiser une fuite du cathéter sous-cutané à son entrée dans l’espace intra-thécal: après révision du système l’évolution a été favorable. Le dernier patient présen- tait une progression de la maladie métastatique: la scintigraphie était nor- male, le patient est décédé peu après. Conclusions : Chez nos 3 patients, la vérification des pompes à diffusion intra-thécale par scintigraphie à l’In-111-DTPA s’est révélée efficace, per- mettant de localiser l’origine du dysfonctionnement dans 2 cas et de dé- montrer la perméabilité du système chez le dernier. The influence of antithyroid drugs on iodine kinetics and on the outcome of radioiodine treatment MA Walter, B Eckard, M Christ-Crain*, B Müller*, E Nitzsche, J Müller-Brand Div. of Nuclear Medicine, *Div. of Endocrinology, University Hospital Basel Aim: The aim of this study was to analyze the influence of simultaneous antithyroid drug (ATD) treatment on pretherapeutic iodine uptake kinetics of the thyroid gland and its relation to the outcome after radioiodine (RAI) therapy. Methods: We included 229 patients suffering from toxic adenoma, multi- nodular goiter or Graves’ disease who were admitted for RAI therapy. A simultaneous ATD treatment was administered to high risk patients suf- fering from cardiovascular or cerebrovascular diseases. The maximum iodine uptake prior to therapy was compared to the outcome after radioiodine treatment Results: Overall, an euthyroid state was achieved in 137 patients (60%), a hypothyroid state was achieved in 46 patients (20%) and 46 patients (20%) remained hyperthyroid. Patients receiving simultaneous ATD medication showed a reduction of uptake and a decrease in the effective half life of ra- dioiodine in the thyroid. Simultaneous antithyroid medication negatively P3 P4 P5 P6
  10. 10. Abstracts, Lucerne 2003 A152 Nuklearmedizin 3/2003 influenced the outcome of radioiodine therapy in patients suffering from Graves’disease as well as in patients suffering from toxic nodular goiter. In addition, patients presenting with a low iodine uptake prior to therapy had a better success rate after radioiodine treatment. Success rate decreased with higher uptake levels. This effect was found in patients suffering from multi-nodular goiter as well as in patients suffering from Graves’ disease (Fig. 1). Méthode isotopique de contrôle de l’étanchéité du système de réduction du volume gastrique chez les patients obèses C Antonescu, E Chevalier, A Bischof Delaloye Service de Médecine Nucléaire, CHUV, Lausanne Objectif: Contrôler l’étanchéité d’un système de réduction de volume gastrique chez les patients obèses. Méthodes: Le système de réduction du volume gastrique est formé d’une bande de silicone avec un anneau intérieur gonflable relié par un tube à un port d’accès extra-abdominal. La mise en place du système est réalisée par laparoscopie et le diamètre intérieur réglé par l’injection de ser physiologi- que. La bande est placée à environ 1 cm de la jonction oeso-gastrique. Deux patients obèses, 1F et 1H, BMI = 34 et 32 kg/m2 , ont bénéficié d’un contrôle isotopique de leur système de limitation gastrique. Un vo- lume de 5ml de sulfures marqués au 99m Tc a été injecté dans le port d’accès du système. Les activités injectées étaient de 187 MBq et respectivement 221 MBq. Pendant et après l’administration plusieurs séries d’acquisitions dynamiques (5’’/image) centrées sur l’abdomen ont été réalisées. L’examen a été complété par des vues statiques tardives antérieures de l’abdomen (2’/vue). Résultats: Chez une patiente l’examen a montré une fuite à la jonction tube/port d’accès externe qui a été corrigé par une intervention chirurgi- cale simple. Chez l’autre patient il n’y avait pas de mise en évidence de fuite du système et aucune révision chirurgicale n’a été entreprise. Les deux patients ont bien supporté l’examen. Conclusions: La méthode isotopique de contrôle de l’étanchéité du système de réduction de volume gastrique chez les patients obèses est relativement simple, fiable et permet d’éviter une révision chirurgicale inutile. Son coût est très accessible. P7 Conclusion: In contrast to the present dogma, our results provide evidence that pretherapeutic height of iodine uptake level and posttherapeutic out- come are inversely correlated. Moreover, the negative effect of ATD on the outcome is not due to the reduced iodine uptake.