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Purpose & Methods: Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using 68 Ga-DOTA-conjugated peptides, as well as 18 F-DOPA imaging for various neuroendocrine neoplasms., Results & Conclusion: The previous procedural guideline by EANM regarding the use PET/CT tumour imaging with 68 Ga-conjugated peptides has been revised and updated with the relevant and recent literature in the field with contribution of distinguished experts.

Introduction: Since April 201, we have introduced PET/CT using a ligand of prostate-specific membrane antigen labeled with gallium-68 (PSMA-11). We aimed to evaluate its positivity rate and impact in patients presenting biochemical recurrence of prostate cancer whose 18 F-fluorocholine (FCH) PET/CT was non-contributive., Patients and Method: Patients were prospectively included between April and December 2016. PET/CT was performed 60min after injection of 2MBq/kg of body mass of 68 Ga-PSMA-11. Three anatomical areas were considered: prostatic lodge, pelvic lymph nodes and distant locations. The impact of PSMA-11 PET/CT was assessed by comparing changes in therapeutic strategy decided during multidisciplinary meeting., Results: Thirty-three patients were included. The mean PSA serum level measured on the month of the PSMA-11 PET/CT was 2,8ng/mL. Twenty-five (76%) PSMA-11 PET/CT were positive, 7 (21%) negative and 1 (3%) equivocal. Of 11 patients whose FCH PET/CT showed equivocal foci, PSMA-11 PET/CT confirmed those foci in 5 cases. Follow-up was available for 18 patients (55%). PSMA-11 PET/CT results led to a change in management in 12 patients (67%)., Conclusion: 68 Ga-PSMA-11 PET/CT is useful in detecting recurrence of prostate cancer, by identifying residual disease which was not detected on other imaging modalities and by changing management of 2 patients out of 3., Level of Evidence: 5., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Purpose: Hybrid positron emission tomography/computed tomography (PET/CT) has now become available, as well as whole-body, low-dose multidetector row computed tomography (MDCT) or magnetic resonance imaging (MRI). The radioactive glucose analogue 18F-fluorodeoxyglucose (FDG) is the most widely used tracer but has a relatively low sensitivity in detecting multiple myeloma (MM). We compared FDG with a more recent metabolic tracer, 18F-fluorocholine (FCH), for the detection of MM lesions at time of disease relapse or progression., Methods: We analyzed the results of FDG and FCH imaging in 21 MM patients undergoing PET/CT for suspected relapsing or progressive MM. For each patient and each tracer, an on-site reader and a masked reader independently determined the number of intraosseous and extraosseous foci of tracer and the intensity of uptake as measured by their SUVmax and the corresponding target/non-target ratio (T/NT)., Results: In the skeleton of 21 patients, no foci were found for two cases, uncountable foci were observed in four patients, including some mismatched FCH/FDG foci. In the 15 patients with countable bone foci, the on-site reader detected 72 FDG foci vs. 127 FCH foci (+76 %), whereas the masked reader detected 69 FDG foci vs. 121 FCH foci (+75 %), both differences being significant. Interobserver agreement on the total number of bone foci was very high, with a kappa coefficient of 0.81 for FDG and 0.89 for FCH. Measurement of uptake in the matched foci that took up both tracers revealed a significantly higher median SUVmax and T/NT for FCH vs. FDG. Almost all unmatched foci were FCH-positive FDG-negative (57/59 = 97 % on-site and 56/60 = 93 % on masked reading); they were more frequently observed than matched foci in the head and neck region., Conclusions: These findings suggest that PET/CT performed for suspected relapsing or progressive MM would reveal more lesions when using FCH rather than FDG.

Purpose: To evaluate, in children with Hodgkin lymphoma (HL), the frequency and intensity of visually diffuse FDG uptake by selected organs at baseline (bPET) and on interim PET/CT (iPET), and to evaluate the relation between FDG uptake, metabolic response and evolution of the disease with treatment., Patients and Methods: Thirty children with HL had bPET and then iPET after two cycles of treatment, which were blind-read retrospectively. Excluding sites with focal uptake, diffuse FDG uptake by thymus, bone marrow at iliac crests, liver, spleen, and the spinal cord at the 12th thoracic vertebra (Th12) was evaluated visually using a three-point scoring method and semiquantitatively by measuring SUVmax. Visualisation of activated brown adipose tissue (BAT) was also quoted. Five children had refractory HL. Recurrence-free survival was determined for each patient. Nine patients relapsed; in 21 non-relapsing patients, the median follow-up period was 43 months (range: 28-61)., Results: On bPET, the rate of diffuse and intense (visual score = 3) FDG uptake was 48 % in the spleen, 43 % in the spinal cord at Th12, 37 % in bone marrow, 21 % in the thymus and 7 % in BAT. At least one of those sites showed diffuse and intense FDG uptake in 77 % of patients. On iPET, a significant decrease in SUVmax was observed in thymus, iliac crest bone marrow and spleen, but not in spinal cord. In contrast, the FDG uptake by the liver significantly increased. The absence of SUVmax increase in the liver between bPET and iPET was the best criterion to predict a refractory disease (PPV = 55 %, NPV = 100 %). Its area under ROC (AUC) was 0.9 vs. 0.73 for five-point Deauville criteria. For prediction of relapse, two criteria were derived from the evolution of diffuse uptake between bPET and iPET: no increase in liver uptake and an increase > 5 % in spinal cord uptake. As compared with 13 patients who matched none of those criteria, the hazard ratio (HR) for relapse was 2.1 in 13 patients who matched one criterion, and 10.3 in four patients who matched both (Kaplan-Meier analysis p = 0.005)., Conclusion: Diffuse and intense FDG uptake by organs is frequent in children with HL on bPET. On iPET, it is frequently reduced in all sites except the liver, which may pose problems for visual quotation of the FDG intensity of HL foci. The variation of SUVmax between bPET and iPET permitted us to achieve a prediction of refractory or relapsing HL that was at least as effective as using criteria based on FDG uptake by the HL lesions. The results of this retrospective pilot study need further validation.

Table of Contents: A1 68Ga-PSMA PET/CT in staging and restaging of Prostate Cancer Patients: comparative study with 18F-Choline PET/CTW Langsteger, A Rezaee, W Loidl, HS Geinitz, F Fitz, M Steinmair, G Broinger, L Pallwien-Prettner, M BeheshtiA2 F18 Choline PET - CT: an accurate diagnostic tool for the detection of parathyroid adenoma?L Imamovic, M Beheshti, G Rendl, D Hackl, O Tsybrovsky, M Steinmair, K Emmanuel, F Moinfar, C Pirich, W LangstegerA3 [18F]Fluoro-DOPA-PET/CT in the primary diagnosis of medullary thyroid carcinomaA Bytyqi, G Karanikas, M Mayerhöfer, O Koperek, B Niederle, M HartenbachA4 Variations of clinical PET/MR operations: An international survey on the clinical utilization of PET/MRIT Beyer, K Herrmann, J CzerninA5 Standard Dixon-based attenuation correction in combined PET/MRI: Reproducibility and the possibility of Lean body mass estimationI Rausch, P Rust, MD DiFranco, M Lassen, A Stadlbauer, ME Mayerhöfer, M Hartenbach, M Hacker, T BeyerA6 High resolution digital FDG PET/MRI imaging for assessment of ACL graft viabilityK Binzel, R Magnussen, W Wei, MU Knopp, DC Flanigan, C Kaeding, MV KnoppA7 Using pre-existing hematotoxicity as predictor for severe side effects and number of treatment cycles of Xofigo therapyA Leisser, M Nejabat, M Hartenbach, G Kramer, M Krainer, M Hacker, A HaugA8 QDOSE - comprehensive software solution for internal dose assessmentWencke Lehnert, Karl Schmidt, Sharok Kimiaei, Marcus Bronzel, Andreas KlugeA9 Clinical impact of Time-of-Flight on next-generation digital PET imaging of Yttrium-90 radioactivity following liver radioembolizationCL Wright, K Binzel, J Zhang, Evan Wuthrick, Piotr Maniawski, MV KnoppA10 Snakes in patients! Lessons learned from programming active contours for automated organ segmentationM Blaickner, E Rados, A Huber, M Dulovits, H Kulkarni, S Wiessalla, C Schuchardt, RP Baum, B Knäusl, D GeorgA11 Influence of a genetic polymorphism on brain uptake of the dual ABCB1/ABCG2 substrate [11C]tariquidarM Bauer, B Wulkersdorfer, W Wadsak, C Philippe, H Haslacher, M Zeitlinger, O LangerA12 Outcome prediction of temporal lobe epilepsy surgery from P-glycoprotein activity. Pooled analysis of (R)-[11C]-verapamil PET data from two European centresM Bauer, M Feldmann, R Karch, W Wadsak, M Zeitlinger, MJ Koepp, M-C Asselin, E Pataraia, O LangerA13 In-vitro and in-vivo characterization of [18F]FE@SNAP and derivatives for the visualization of the melanin concentrating hormone receptor 1M Zeilinger, C Philippe, M Dumanic, F Pichler, J Pilz, M Hacker, W Wadsak, M MitterhauserA14 Reducing time in quality control leads to higher specific radioactivity of short-lived radiotracersL Nics, B Steiner, M Hacker, M Mitterhauser, W WadsakA15 In vitro 11C-erlotinib binding experiments in cancer cell lines with epidermal growth factor receptor mutationsA Traxl, Thomas Wanek, Kushtrim Kryeziu, Severin Mairinger, Johann Stanek, Walter Berger, Claudia Kuntner, Oliver LangerA16 7-[11C]methyl-6-bromopurine, a PET tracer to measure brain Mrp1 function: radiosynthesis and first PET evaluation in miceS Mairinger, T Wanek, A Traxl, M Krohn, J Stanek, T Filip, M Sauberer, C Kuntner, J Pahnke, O LangerA17 18F labeled azidoglucose derivatives as "click" agents for pretargeted PET imagingD Svatunek, C Denk, M Wilkovitsch, T Wanek, T Filip, C Kuntner-Hannes, J Fröhlich, H MikulaA18 Bioorthogonal tools for PET imaging: development of radiolabeled 1,2,4,5-TetrazinesC Denk, D Svatunek, T Wanek, S Mairinger, J Stanek, T Filip, J Fröhlich, H Mikula, C Kuntner-HannesA19 Preclinical evaluation of [18F]FE@SUPPY- a new PET-tracer for oncologyT Balber, J Singer, J Fazekas, C Rami-Mark, N Berroterán-Infante, E Jensen-Jarolim, W Wadsak, M Hacker, H Viernstein, M MitterhauserA20 Investigation of Small [18F]-Fluoroalkylazides for Rapid Radiolabeling and In Vivo Click ChemistryC Denk, D Svatunek, B Sohr, H Mikula, J Fröhlich, T Wanek, C Kuntner-Hannes, T FilipA21 Microfluidic 68Ga-radiolabeling of PSMA-HBED-CC using a flow-through reactorS Pfaff, C Philippe, M Mitterhauser, M Hartenbach, M Hacker, W WadsakA22 Influence of 24-nor-ursodeoxycholic acid on hepatic disposition of [18F]ciprofloxacin measured with positron emission tomographyT Wanek, E Halilbasic, M Visentin, S Mairinger, B Stieger, C Kuntner, M Trauner, O LangerA23 Automated 18F-flumazenil production using chemically resistant disposable cassettesP Lam, M Aistleitner, R Eichinger, C ArtnerA24 Similarities and differences in the synthesis and quality control of 177Lu-DOTA-TATE, 177Lu -HA-DOTA-TATE and 177Lu-DOTA-PSMA (PSMA-617)H Eidherr, C Vraka, A Haug, M Mitterhauser, L Nics, M Hartenbach, M Hacker, W WadsakA25 68Ga- and 177Lu-labelling of PSMA-617H Kvaternik, R Müller, D Hausberger, C Zink, RM AignerA26 Radiolabelling of liposomes with 67Ga and biodistribution studies after administration by an aerosol inhalation systemU Cossío, M Asensio, A Montes, S Akhtar, Y te Welscher, R van Nostrum, V Gómez-Vallejo, J LlopA27 Fully automated quantification of DaTscan SPECT: Integration of age and gender differencesF VandeVyver, T Barclay, N Lippens, M TrochA28 Lesion-to-background ratio in co-registered 18F-FET PET/MR imaging - is it a valuable tool to differentiate between low grade and high grade brain tumor?L Hehenwarter, B Egger, J Holzmannhofer, M Rodrigues-Radischat, C PirichA29 [11C]-methionine PET in gliomas - a retrospective data analysis of 166 patientsN Pötsch, I Rausch, D Wilhelm, M Weber, J Furtner, G Karanikas, A Wöhrer, M Mitterhauser, M Hacker, T Traub-WeidingerA30 18F-Fluorocholine versus 18F-Fluorodeoxyglucose for PET/CT imaging in patients with relapsed or progressive multiple myeloma: a pilot studyT Cassou-Mounat, S Balogova, V Nataf, M Calzada, V Huchet, K Kerrou, J-Y Devaux, M Mohty, L Garderet, J-N TalbotA31 Prognostic benefit of additional SPECT/CT in sentinel lymph node mapping of breast cancer patientsS Stanzel, G Pregartner, T Schwarz, V Bjelic-Radisic, B Liegl-Atzwanger, R AignerA32 Evaluation of diagnostic value of TOF-18F-FDG PET/CT in patients with suspected pancreatic cancerS Stanzel, F Quehenberger, RM AignerA33 New quantification method for diagnosis of primary hyperpatahyroidism lesions and differential diagnosis vs thyropid nodular disease in dynamic scintigraphyA Koljević Marković, Milica Janković, V Miler Jerković, M Paskaš, G Pupić, R Džodić, D PopovićA34 A rare case of diffuse pancreatic involvement in patient with merkel cell carcinoma detected by 18F-FDGMC Fornito, D FamiliariA35 TSH-stimulated 18F-FDG PET/CT in the diagnosis of recurrent/metastatic radioiodine-negative differentiated thyroid carcinomas in patients with various thyroglobuline levelsP Koranda, H Polzerová, I Metelková, L Henzlová, R Formánek, E Buriánková, M KamínekA36 Breast Dose from lactation following I131 treatmentWH Thomson, C LewisA37 A new concept for performing SeHCAT studies with the gamma cameraWH Thomson, J O'Brien, G James, A NotghiA38 Whole body F-18-FDG-PET and tuberculosis: sensitivity compared to x-ray-CTH Huber, I Stelzmüller, R Wunn, M Mandl, F Fellner, B Lamprecht, M GabrielA39 Emerging role 18F-FDG PET-CT in the diagnosis and follow-up of the infection in heartware ventricular assist system (HVAD)MC Fornito, G LeonardiA40 Validation of Poisson resampling softwareWH Thomson, J O'Brien, G JamesA41 Protection of PET nuclear medicine personnel: problems in satisfying dose limit requirementsJ Hudzietzová, J Sabol, M Fülöp.

Introduction: Following orchiectomy patients with clinical stage I (CSI) testicular seminoma may be managed by active surveillance (AS) or adjuvant treatment (radiotherapy or chemotherapy). In view of the published data on long-term toxicity, mainly second malignant neoplasms (SMNs), adjuvant radiotherapy (ART) is currently no longer recommended as adjuvant therapy for these patients. The purpose of our recent study was to compare the impact of two selected treatment approaches - AS versus adjuvant chemotherapy (ACT) on survival in patients with CSI testicular seminoma., Material and Methods: The cross-sectional study analyzed a total of 106 patients collected at a single centre between 4/2008-8/2015, with CSI testicular seminoma, stratified into two groups according to risk-adapted therapeutic approaches., Results: In group A (low-risk), consisting of 84 patients, who underwent AS, relapse occurred in 10 (11.9%) patients after a mean follow-up of 13.8 months. In group B (high-risk), consisting of 22 patients, who were treated with ACT, relapse occurred in two (9.1%) patients after a mean follow-up of 13.8 months. Overall survival of patients in both groups was 100% with a mean follow-up of 25.3 months. The statistically significant difference in progression-free survival (PFS) between these two groups was not found., Conclusions: ACT seems to be adequate treatment for patients with high-risk of relapse, as well as AS for those with low-risk of relapse. Despite its excellent prognosis, optimal management of CSI testicular seminoma remains controversial, with variations in expert opinion and international guidelines.

We compared (18)F-fluorocholine hybrid positron emission tomography/X-ray computed tomography (FCH-PET/CT) with ultrasonography (US) and scintigraphy in patients with hyperparathyroidism and discordant, or equivocal results of US and (123)I/(99m)Tc-sesta-methoxyisobutylisonitrile (sestaMIBI) dual-phase parathyroid scintigraphy. FCH-PET/CT was performed in 17 patients with primary (n = 11) lithium induced (n = 1) or secondary hyperparathyroidism (1 dialyzed, 4 renal-transplanted).The reference standard was based on results of surgical exploration and histopathological examination. The results of imaging modalities were evaluated, on site and by masked reading, on per-patient and per-lesion bases.In a first approach, equivocal images/foci were considered as negative. On a per-patient level, the sensitivity was for US 38%, for scintigraphy 69% by open and 94% by masked reading, and for FCH-PET/CT 88% by open and 94% by masked reading. On a per-lesion level, sensitivity was for US 42%, for scintigraphy 58% by open and 83% by masked reading, and for FCH-PET/CT 88% by open and 96% by masked reading. One ectopic adenoma was missed by the 3 imaging modalities. Considering equivocal images/foci as positive increased the accuracy of the open reading of scintigraphy or of FCH-PET/CT, but not of US. FCH-PET/CT was significantly superior to US in all approaches, whereas it was more sensitive than scintigraphy only for open reading considering equivocal images/foci as negative (P = 0.04). FCH uptake was more intense in adenomas than in hyperplastic parathyroid glands. Thyroid lesions were suspected in 9 patients. They may induce false-positive results as in one case of oncocytic thyroid adenoma, or false-negative results as in one case of intrathyroidal parathyroid adenoma. Thyroid cancer (4 cases) can be visualized with FCH as with (99m)Tc-sestaMIBI, but the intensity of uptake was moderate, similar to that of parathyroid hyperplasia.This pilot study confirmed that FCH-PET/CT is an adequate imaging tool in patients with primary or secondary hyperparathyroidism, since both adenomas and hyperplastic parathyroid glands can be detected. The sensitivity of FCH-PET/CT was better than that of US and was not inferior to that of dual-phase dual-isotope (123)I/(99m)Tc-scintigraphy. Further studies should evaluate whether FCH could replace (99m)Tc-sestaMIBI as the functional agent for parathyroid imaging, but US would still be useful to identify thyroid lesions.

Currently, the most frequent approach in the oncologic applications of positron emission tomography (PET) is detecting the hypermetabolic activity of the cancer tissue. A more specific approach, which may be complementary, is detecting the overexpression of receptors. In this review article, we aim to evaluate the results that are currently available for PET imaging of the sex hormone receptors in clinical oncology. The indication of PET and now PET/CT has been more disputed in breast carcinoma than in many other primary cancers (e.g., lung, head and neck, colorectal, lymphoma). 18F-fluorodeoxyglucose (FDG), the glucose analogue for PET imaging, has a limited sensitivity to detect the primary breast tumors in case of lobular or in situ forms or small sized tumors localised on systematic mammography, and to identify minimal node invasion in the axilla. Using 16α-[¹⁸F]fluoro-17β-estradiol (FES), a fluorinated estradiol analogue, PET is able to detect the over-expression of the oestrogen receptor (ER) in lesions, at a whole-body level. FES and FDG appear complementary for a better diagnostic performance in staging locally advanced breast cancer or restaging recurrent or metastatic breast cancer. Another potential indication is predicting the response to starting or resuming hormone therapy in patients with metastatic breast cancer, in relation with the ER status of all lesions revealed by FES PET. In two retrospective studies, FDG PET was also able to predict the response to hormone therapy, on basis of a metabolic flare, observed either after 7-10 days of treatment or during an estradiol challenge. A prospective comparison of those approaches is warranted. One study reported predicting response to neoadjuvant chemotherapy thanks to a low value of FES SUV(max) or FES/FDG SUV(max) ratio. The presence of ER in uterine tumors, including the benign ones, in ovarian cancers or even in meningiomas, may have therapeutic consequences and FES PET could have a clinical utility in those settings; only initial results are available. The indication of PET and PET/CT has been even more disputed in prostate carcinoma, due to the lack of significant FDG uptake in most cases, at least before the castration-resistant stage. Using FDHT, a fluorinated testosterone analogue, PET is able to detect the over-expression of the androgen receptor (AR) in lesions, at a whole-body level. At least partly due to the rather large number of alternative tracers that are in development or even routinely available in some countries, few FDHT studies have been published until now. From absorbed dose values previously published for FES by the team of University of Washington School of Medicine at Seattle, and for FDHT by the teams of Memorial Sloan-Kettering Cancer Center at New York and of Washington University at St. Louis, we applied the coefficients of ICRP publication 103 and calculated an effective dose per unit of injected activity of 0.023 mSv/MBq for FES and 0.018 mSv/MBq for FDHT. The radiation exposure is of the same order of magnitude as with FDG.

Context: Preoperative ultrasonography and scintigraphy using (99m)Tc-sestamibi are commonly used to localize abnormal parathyroid glands. In cases of discrepant results between scintigraphy and ultrasonography, it is important to rely on another diagnostic imaging modality. (18)F-fluorodeoxyglucose (FDG) and (11)C-methionine positron emission tomography (PET) have been studied, but are imperfect to detect abnormal parathyroid glands. Recently, first cases of abnormal parathyroid glands taking-up radiolabelled choline were discovered incidentally in men referred to (11)C-choline or (18)F-fluorocholine (FCH)-PET/CT for prostate cancer. We checked if FCH uptake was a general feature of adenomatous or hyperplastic parathyroid glands., Methods: FCH-PET/CT was performed in 12 patients with primary (n = 8) or secondary hyperparathyroidism (1 dialyzed, 3 grafted) and with discordant or equivocal results on preoperative ultrasonography (US) and/or (123)I/(99m)Tc-sestamibi dual-phase scintigraphy. The results of the FCH-PET/CT were evaluated, with surgical exploration and histopathologic examination as the standard of truth., Results: On a per-patient level, the detection rate of FCH-PET/CT (at least one FCH focus corresponding to an abnormal parathyroid gland in a given patient) was 11/12 = 92%. FCH-PET/CT detected 18 foci interpreted as parathyroid glands and correctly localized 17 abnormal parathyroid glands (7 adenomas and 10 hyperplasias). On a per-lesion level, FCH-PET/CT results were 17 TP, 2 false negative ie, a lesion-based sensitivity of 89%, and 1 false positive., Conclusion: As the main result of this pilot study, we show that in patients with hyperparathyroidism and with discordant or equivocal results on scintigraphy or on ultrasonography, adenomatous or hyperplastic parathyroid glands can be localized by FCH-PET/CT with good accuracy. Furthermore, FCH-PET/CT can solve discrepant results between preoperative ultrasonography and scintigraphy and has thus a potential as a functional imaging modality in the detection of abnormal parathyroid glands. Our preliminary results are encouraging and prompt us to further evaluate FCH-PET/CT as a functional imaging agent in patients with biochemical hyperparathyroidism.

Introduction: Several treatments are proposed for castration-resistant prostate cancer (CRPC) at the metastatic stage. Monitoring of response using serum prostate-specific antigen (PSA) levels (sPSA) can be insufficient at this stage. Imaging has been proposed, in particular, nuclear medicine functional imaging and MRI, since response of predominant bone metastases is hardly evaluable on CT. Our aim was to evaluate in patients with CRPC with bone metastases, before and after various treatment lines, the evolution of sPSA, whole-body 18F-fluorocholine (FCH) PET/CT and spine MRI (sMRI) that has been proposed for detection of imminent malignant spinal cord compression., Patients and Methods: We retrospectively gathered a pilot series of 10 patients with CRPC metastatic to bone who had 47 PSA assays, FCH PET/CT, and spine-MRI (sMRI) performed concomitantly as routine examinations, before the beginning and at the end of 37 therapeutic intervals (TIs). Blinded reading of FCH PET/CT and sMRI was performed to evaluate visually whether or not the disease has been progressing (new lesions, greater size, or greater uptake intensity of known lesions) between the initial and the final examination of each TI., Results: Visual interpretations limited to spine FCH (sFCH) PET/CT and sMRI were in accordance for 34 TIs (92%): 14 progressions and 20 nonprogressions. In 2 cases, sFCH did not detect lesions visible on sMRI: one epiduritis and one 6-mm lesion. In 1 case, MRI missed a lesion in the sacrum that was detected on sFCH. When whole-body FCH (wbFCH) PET/CT was taken into account, the agreement with sMRI was limited to 29 TIs (78%). The 8 discrepant cases were all wbFCH positive and sMRI negative, that is, a significantly higher frequency of positivity for wbFCH (P < 0.008). Serum PSA levels increased by more than 25% during 21 TIs, whereas no progression was visible in 8 TIs on sMRI and in 2 TIs on wbFCH. In 5 TIs, sPSA decreased by more than 50%, and progression was never detected on imaging., Conclusion: In detecting progression in patients with CRPC metastatic to bone, results of spine imaging with sMRI and sFCH PET/CT were highly correlated, whereas wbFCH PET/CT showed significantly more progression statues comparing to sMRI alone related to the exploration of other parts of the skeleton and of soft tissue.

18 fluorine-fluorodihydroxyphenylalanine (FDOPA) PET/CT is currently the first-line imaging technique to distinguish between focal and diffuse forms of congenital hyperinsulinism (CHI) and to accurately localize focal forms. However, this technique has a number of limitations, mainly the very small size of focal forms or inversely a very large focal form mimicking a diffuse form, and misinterpretation of physiologic uptake masking hot spots or inversely mimicking focal forms. The other limitation is the limited availability of the radiopharmaceutical. FDOPA PET/CT has no recognized competitor to date among the available morphologic and functional imaging techniques. Other potential approaches using specific tracers for positron emission tomography (PET) are discussed, using radiopharmaceuticals specific for β cell mass or targeting somatostatin receptors. These radiopharmaceuticals can be labeled with gallium-68, a PET emitter readily available in PET centers equipped with 68Ge/68Ga generators.

Background: Positron emission tomography-computed tomography (PET/CT) with (18)F-fluorocholine (FCH) is routinely performed in patients with prostate cancer. In this clinical context, foci of FCH uptake in the head or in the neck were considered as incidentalomas, except for those suggestive of multiple bone metastases., Results: In 8 patients the incidental focus corresponded to a benign tumour. The standard of truth was histology in two cases, correlative imaging with MRI in four cases, (99m)Tc-SestaMIBI scintigraphy, ultrasonography and biochemistry in one case and biochemistry including PTH assay in one case. The final diagnosis of benign tumours consisted in 3 pituitary adenomas, 2 meningiomas, 2 hyperfunctioning parathyroid glands and 1 thyroid adenoma. Malignancy was proven histologically in 2 other patients: 1 papillary carcinoma of the thyroid and 1 cerebellar metastasis., Conclusions: To the best of our knowledge, FCH uptake by pituitary adenomas or hyperfunctioning parathyroid glands has never been described previously. We thus discuss whether there might be a future indication for FCH PET/CT when one such tumour is already known or suspected: to detect a residual or recurrent pituitary adenoma after surgery, to guide surgery or radiotherapy of a meningioma or to localise a hyperfunctioning parathyroid gland. In these potential indications, comparative studies with reference PET tracers or with (99m)Tc-sestaMIBI in case of hyperparathyroidism could be undertaken.

Background: Fluorocholine(18F) (FCH) was introduced at the beginning of April 2010 in France, Slovenia and three other EU member states for the localisation of bone metastases of prostate cancer with PET. The aim of the study was to compare the evolution of diagnostic imaging in patients with prostate cancer using a new radiopharmaceutical FCH, observed in France and in Slovenia, and to quantify the consequence of the results of new imaging modality on the detection rate of abnormal metastases and recurrences of prostate cancer., Patients and Methods: In two centres (France/Slovenia), a survey of the number of nuclear medicine examinations in patients with prostate cancer was performed, covering 5 quarters of the year since the introduction of FCH. For each examination, the clinical and biological circumstances were recorded, as well as the detection of bone or soft tissue foci., Results: Six hundred and eighty-eight nuclear medicine examinations were performed impatients with prostate cancer. Nuclear medicine examinations were performed for therapy monitoring and follow-up in 23% of cases. The number of FCH PET/CT grew rapidly between the 1(st) and 5(th) period of the observation (+220%), while the number of bone scintigraphies (BS) and fluoride(18F) PET/CTs decreased (-42% and -23% respectively). Fluorodeoxyglucose(18F) (FDG) PET/CT remained limited to few cases of castrate-resistant or metastatic prostate cancer in Paris. The proportion of negative results was significantly lower with FCH PET/CT (14%) than with BS (49%) or fluoride(18F) PET/CT (54%). For bone metastases, the detection rate was similar, but FCH PET/CT was performed on average at lower prostate-specific antigen (PSA) levels and was less frequently doubtful (4% vs. 28% for BS). FCH PET/CT also showed foci in prostatic bed (53% of cases) or in soft tissue (35% of cases)., Conclusions: A rapid development of FCH PET/CT was observed in both centres and led to a higher detection rate of prostate cancer lesions.

Among thyroid malignancies, medullary thyroid carcinoma (MTC) has some very specific features. Production and secretion of large amounts of peptides occur in malignant transformed C cells with few exceptions, leading to high serum levels of calcitonin (Ctn) and carcinoembryonic antigen (CEA), that act after thyroidectomy as tumour markers warning for the presence of persistent or metastatic MTC. The availability of those serum biomarkers with an excellent sensitivity challenges medical imaging to localise the recurrent cancer tissue, since surgery is a major therapeutic option. The aims of this article are (i) to review literature evidence about the efficacy and tolerance of radiopharmaceuticals for 3 targets of PET/CT imaging (glucose metabolism, bioamines metabolism and somatostatin receptors) and also bone scintigraphy which is recommended in the Guidelines of European Society for Medical Oncology (ESMO; (ii) to compare the availability and the costs in relation with those radiopharmaceuticals, (iii) and to discuss a possible sequence of those examinations, in order to optimise spending and to minimise the overall radiation dose. In this context of recurrent MTC suspected on rising tumour markers levels after thyroidectomy, this survey of literature confirms that FDOPA is the best radiopharmaceutical for PET/CT with significant diagnostic performance if Ctn>150 pg/mL; an early image acquisition starting during the first 15 min is advised. In negative cases, FDG should be the next PET radiopharmaceutical, in particular if Ctn and CEA levels are rapidly rising, and PET with a somatostatin analogue labelled with gallium-68 when neither FDOPA nor FDG PET are conclusive. Bone scintigraphy could complement FDG-PET/CT if FDOPA is not available.

6-Fluoro-((18)F)-L-3,4-dihydroxyphenylalanine (FDOPA) is an amino acid analogue for positron emission tomography (PET) imaging which has been registered since 2006 in several European Union (EU) countries and by several pharmaceutical firms. Neuroendocrine tumour (NET) imaging is part of its registered indications. NET functional imaging is a very competitive niche, competitors of FDOPA being two well-established radiopharmaceuticals for scintigraphy, (123)I-metaiodobenzylguanidine (MIBG) and (111)In-pentetreotide, and even more radiopharmaceuticals for PET, including fluorodeoxyglucose (FDG) and somatostatin analogues. Nevertheless, there is no universal single photon emission computed tomography (SPECT) or PET tracer for NET imaging, at least for the moment. FDOPA, as the other PET tracers, is superior in diagnostic performance in a limited number of precise NET types which are currently medullary thyroid cancer, catecholamine-producing tumours with a low aggressiveness and well-differentiated carcinoid tumours of the midgut, and in cases of congenital hyperinsulinism. This article reports on diagnostic performance and impact on management of FDOPA according to the NET type, emphasising the results of comparative studies with other radiopharmaceuticals. By pooling the results of the published studies with a defined standard of truth, patient-based sensitivity to detect recurrent medullary thyroid cancer was 70 % [95 % confidence interval (CI) 62.1-77.6] for FDOPA vs 44 % (95 % CI 35-53.4) for FDG; patient-based sensitivity to detect phaeochromocytoma/paraganglioma was 94 % (95 % CI 91.4-97.1) for FDOPA vs 69 % (95 % CI 60.2-77.1) for (123)I-MIBG; and patient-based sensitivity to detect midgut NET was 89 % (95 % CI 80.3-95.3) for FDOPA vs 80 % (95 % CI 69.2-88.4) for somatostatin receptor scintigraphy with a larger gap in lesion-based sensitivity (97 vs 49 %). Previously unpublished FDOPA results from our team are reported in some rare NET, such as small cell prostate cancer, or in emerging indications, such as metastatic NET of unknown primary (CUP-NET) or adrenocorticotropic hormone (ACTH) ectopic production. An evidence-based strategy in NET functional imaging is as yet affected by a low number of comparative studies. Then the suggested diagnostic trees, being a consequence of the analysis of present data, could be modified, for some indications, by a wider experience mainly involving face-to-face studies comparing FDOPA and (68)Ga-labelled peptides.

Purpose: 18F-Sodium fluoride is a bone tracer with a high signal-to-noise ratio, but its dosimetry is higher than that of 99mTc-labeled phosphonates at the recommended activities. The study's purpose was to determine whether the reduction by half of F-sodium fluoride-injected activity, mimicked by a short-timed reconstruction image, simulating a total dose less than or equal to that of 99mTc-hydroxymethane diphosphonate scintigraphy, had an impact on the accuracy of PET semiquantitative measurements and image quality., Methods: Whole-body time-of-flight 18F-sodium fluoride PET/computed tomography (CT) images were acquired prospectively from 40 adult patients for detection of bone metastases. 18F-Sodium fluoride was administered according to the European Association of Nuclear Medicine (EANM) and Society of Nuclear Medicine (SNM) practice guidelines. From the acquired 1 min/bed position list-mode data, 30-s reconstructions were extracted. Measurements of maximum standard uptake value were recorded with a region of interest applied to the same location on the 1-min and 30-s images, which were displayed side by side, and were analyzed using Bland-Altman plots. A masked reading was performed by two senior nuclear medicine physicians who counted the foci of visually increased uptake., Results: Bland-Altman plots showed an excellent agreement between the maximum standard uptake value measurements of the 60- and 30-s images. The paired Wilcoxon test results between the corresponding 60- and 30-s images read by masked readers A and B were not significant (P=0.15 and 0.19, respectively)., Conclusion: Reducing acquisition duration by half or injecting half of the activity recommended by the EANM and SNM practice guidelines can lead to 18F-sodium fluoride time-of-flight PET images of diagnostic quality, achieving a radiation dose less than or equal to that of 99mTc-labeled phosphonates.

The effect of erythropoietin stimulation on bone marrow uptake of FDG has been well documented. Similar metabolic activation of bone marrow with (18)F-fluorocholine (FCH) has not been previously reported. FCH PET/CT was performed in a patient with biochemical recurrent prostate cancer who was receiving erythropoietin for hemochromatosis. Diffuse skeletal uptake of FCH was seen. (18)F-Fluoride PET/CT performed the following day demonstrates multiple abnormal focal bone metastases. Generalized skeletal uptake of FCH results in poor contrast between the metastases compared to noninvolved bone. The metabolic activation of bone marrow by erythropoietin could result in false-negative FCH results for detecting bone metastases.

Background: Metabolic syndrome (MS) is a cluster of proatherogenic risk factors (RF) (abdominal obesity, atherogenic dyslipidemia, impaired fasting glucose or type 2 diabetes mellitus, higher blood pressure or antihypertensive therapy) that move patients into a higher risk for development of cardiovascular disease (CVD) and type 2 diabetes. The preclinical (subclinical) target organ diseases (SOD) are early signs of atherosclerosis. An increased aortic stiffness characterised by an increased pulse wave velocity in aorta (PWV Ao) is one of SOD.The aim of the present study was to assess the impact of metabolic syndrome (MS) on aortic wall stiffness and the risk profile in premenopausal women., Methods: The aortic stiffness was measured using Arteriograph-Tensiomed, based on oscillometric measurement and analysis of the shape of brachial pulse wave, giving the PWV Ao. The results of measurements characterise a global aortic stiffness., Results: We examined 81 premenopausal women (without history of CVD). The MS (according to the 2009 "harmonizing" definition) was present in 31 women (mean age 41.5 y), in the control group, there were 50 women (39 y). The most frequent components of MS were abdominal obesity (93 % vs 42%), arterial hypertension (68 % vs 10 %) and dyslipidemia (29 % vs 8 %). The PWV Ao was significantly higher in women with MS (9.26 m/s) compared to the control group (7.44 m/s)., Conclusion: The aortic stiffness in women with MS compared to controls was significantly higher despite a presumed general protective hormonal effect on cardiovascular system in women with child-bearing potential (Tab. 4, Ref. 25).

Objective: Presurgical identification of patients at high risk for early recurrence of hepatocellular carcinoma (HCC) after resection could warrant additional therapies. F-fluorodeoxyglucose (FDG) uptake by the tumour on preoperative PET can predict HCC recurrence after resection as effectively as poor differentiation or presence of microvascular invasion (MVI) on postsurgical histology. A better sensitivity for the detection of HCC nodules has been reported with F-fluorocholine (FCH), a PET tracer of lipid metabolism. This pilot study aimed to compare preoperative FDG and FCH PET/CT for predicting early recurrence of unifocal HCC, occurring within 6 months after surgical resection., Methods: FDG and FCH tumour uptakes were assessed on preoperative PET/CT by two masked readers. On FCH PET/CT, a photopenic lesion and a hot focus were considered as indicative of malignancy. During postoperative follow-up, recurrence was searched for by regularly performing CT and MRI., Results: In 11 consecutive HCC patients, the detection rate was greater with FCH (80%) than with FDG (27%). After resection, the overall recurrence rate was 55%. Early recurrence occurred in four patients, who were the only ones with an FDG-positive and FCH-photopenic tumour, with a significant reduction in disease-free survival. On postsurgical histology, those four patients also presented with MVI and satellite nodules. Histological differentiation and capsule disruption appeared less accurate than PET/CT or MVI in predicting early recurrence., Conclusion: In unifocal HCC, the FCH photopenic pattern was associated with MVI and predicted early HCC recurrence after surgical resection as accurately as did an FDG uptake. Larger studies with FCH are warranted.

Various imaging modalities are currently available to diagnose bone metastasis. The two main anatomical modalities are computed tomography (CT) and magnetic resonance imaging (MRI), with many variants proposed for the MRI procedure, including diffusion-weighted imaging. The two main functional modalities are scintigraphy and PET, also with many variants in the radiopharmaceutical, from the "all purpose" 99mTc labelled bisphosphonates to very selective radiopharmaceuticals for rare neoplasia. The diagnostic strategy will become more and more individually tailored according to the patient's clinical and biological data (primary cancer type, phase of the evolution, markers of aggressiveness, serum levels of biological tracers of bone metabolism, circulating or disseminating tumour cells …). If imaging is indicated, the diagnostic strategy will also depend on the availability and the diagnostic performance of the imaging modalities. Assessment of diagnostic performance requires comparative studies, performed with an adequate methodology. The main methodological weaknesses encountered in studies intending to compare imaging modalities for diagnosing bone metastasis are summarised. Comparative studies have been reviewed, which address the initial diagnosis of skeletal metastases in solid tumours except primary bone cancers. The results of more than 140 such comparative studies are then summarised and briefly commented, according to the type of the primary cancer, and according to the compared imaging modalities.

Aim: The aim of this paper was to compare the diagnostic performance of positron emission tomography/computed tomography (PET/CT) with fluorocholine (18F) (FCH) or fluoride(18F) (FNa) for the detection of bone metastasis in patients with prostate cancer complaining from osteoarticular pain, taking into account whether they were referred for initial staging or recurrence localization. The initial hypothesis was that FCH site-based specificity would be superior to that of F Na, with no loss in sensitivity., Methods: Forty-two patients were enrolled in this prospective study, underwent both PET/CTs and were then followed-up for at least 6 months. The standard of truth (SOT) about the presence/absence and location of bone metastasis could be determined in 40 patients, by 2 independent medical assessors, blinded to the results of both PET/CTs. The comparison was performed according to the guideline of the European Medicines Agency, i.e. based on the results of blind reading with SOT as reference., Results: Bone extension was present in 22 patients and absent in 18. Patient-based performance for FCH vs. FNa was 91% vs. 91% for sensitivity, 89% vs. 83% for specificity and 90% vs. 88% for accuracy (no significant difference). Of 360 skeletal sites, 68 were malignant and 292 non-invaded. There was no significant difference in site-based performance in the group of patients referred at initial staging, but in the group of patients referred for suspicion of recurrence, FCH was significantly more specific than FNa (96% vs. 91%, P=0.033 with Obuchowski's correction) while sensitivity was the same, 89%., Conclusion: Both radiopharmaceuticals, based on a very different metabolic approach, showed good diagnostic performance. If FCH is available, it should be preferred in patients after initial treatment.

The impact of preoperative scintigraphy on the management of patients with primary hyperparathyroidism has been largely documented for more than two decades. More recently, preoperative scintigraphy has also been used to select patients for intraoperative detection of hyperfunctioning parathyroid glands thanks to a gamma-probe. This procedure is now widely used, with MIBI as the main radiopharmaceutical for both preoperative scintigraphy and intraoperative detection. However MIBI was not available in Slovakia until very recently and tetrofosmin (TF), the alternative 99mTc labelled radiopharmaceutical for myocardial imaging has some advantages over MIBI and a close biological behaviour. Thus we have been using TF also for parathyroid preoperative scintigraphy and for intraoperative detection, a systematic indication which has never been reported by others. This article aims to demonstrate the feasibility and to present our protocol for TF parathyroid imaging and intraoperative detection, closely associating surgeons, nuclear medicine specialists, pathologists and also biologists as intraoperative assay of intact PTH is necessary. The results of literature are subsequently reported and discussed (Tab. 2, Fig. 4, Ref. 35). Full Text in free PDF www.bmj.sk.

Unlabelled: This prospective study aimed to compare the diagnostic performance of (18)F-fluorocholine and (18)F-FDG for detecting and staging hepatocellular carcinoma (HCC) in patients with chronic liver disease and suspected liver nodules., Methods: Whole-body PET/CT was performed in a random order at 10 min after injection of 4 MBq of (18)F-fluorocholine per kilogram and at 1 h after injection of 5 MBq of (18)F-FDG per kilogram. PET/CT results were read in a masked manner by 2 specialists, and diagnostic performance was assessed from the results of consensus masked reading. Those focal lesions appearing with increased or decreased activity, compared with background, on (18)F-fluorocholine PET/CT were considered positive for malignancy. The standard of truth was determined on a per-site basis using data from a histologic examination and a follow-up period of more than 6 mo; on a per-patient basis, the Barcelona criteria were also accepted as a proof of HCC in 5 patients., Results: Eighty-one patients were recruited; standard of truth was determined in 59 cases. HCC was diagnosed in 34 patients. Therefore, sensitivity was 88% for (18)F-fluorocholine and 68% for (18)F-FDG (P = 0.07), and in 70 sites, sensitivity was 84% for (18)F-fluorocholine, significantly better than the 67% for (18)F-FDG (P = 0.01). Of the 11 patients with well-differentiated HCC, 6 had a positive result with (18)F-fluorocholine alone, whereas (18)F-FDG was never positive alone; corresponding site-based sensitivity was 94% for (18)F-fluorocholine and 59% for (18)F-FDG (P = 0.001). The detection rate of 18 sites corresponding to other malignancies was 78% for (18)F-fluorocholine and 89% for (18)F-FDG. In nonmalignant sites, (18)F-fluorocholine appeared less specific than (18)F-FDG (62% vs. 91% P < 0.01) because of uptake by focal nodular hyperplasia., Conclusion: (18)F-fluorocholine was significantly more sensitive than (18)F-FDG at detecting HCC, in particular in well-differentiated forms. In contrast, (18)F-FDG appeared somewhat more sensitive at detecting other malignancies and was negative in focal nodular hyperplasia. Thus (18)F-fluorocholine appears to be a useful PET/CT tracer for the detection and surveillance of HCC; however, performing PET/CT with both radiopharmaceuticals seems to be the best option.

Unlabelled: PET with fluoroethylthyrosine (FET), amino-acid analogue, has been performed in Germany since the beginning of the decade for molecular and metabolic imaging of brain tumours, since FDG, the glucose analogue which is the reference tracer for clinical PET, has this drawback to be taken-up intensely by cerebral cortex. We report on our preliminary results on the comparison of PET/CT with FET and FDG in 10 evaluable patients presenting with a brain lesion either at diagnosis or after treatment. In an attempt to optimise specificity, FET PET/CT has been acquired as a static image 1h after injection, while the most current practice is a dynamic 40 min acquisition starting at FET injection. With our acquisition protocol, diagnostic performance of FET was 88% sensitivity and 80% accuracy vs 13% and 30% respectively for FDG., Conclusion: FET is a radiopharmaceutical with clinical usefulness for the diagnosis, delineation and monitoring of brain tumours. Association with FDG allows identification of high-grade lesions or components, but it could be avoided providing that acquisition and quantification procedures of FET PET/CT would have been better optimised and standardised.

Aim: Bronchioloalveolar (BAC) cancer is a source of false-negative F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) results. A few studies reported better diagnostic performances with PET tracers of lipid metabolism, C-choline, or C-acetate, for the detection of well-differentiated adenocarcinoma or BAC. F-fluorocholine (FCH) is a lipid analogue for PET imaging, with advantages in terms of logistics and image resolution. We carried out this prospective pilot study to evaluate whether FCH PET/CT could detect lung cancer with a BAC component and could be more sensitive than FDG in this aim., Methods: Fifteen patients with a lung nodule or lesion suspected for BAC on CT and/or with a history of BAC had PET/CT 60-90 min after 5 MBq FDG/kg body mass and, on a separate day, 10-20 min after 4 MBq FCH/kg body mass. The standard of truth was histology and a 6-month follow-up., Results: Nine patients (12 lesions) presented BAC or adenocarcinoma with BAC features, two patients presented adenocarcinoma without BAC features (five lesions) and four patients presented benign lesions (15 non-malignant sites). For both FCH and FDG, patient-based sensitivity was 78% for detecting cancer with a BAC component and 82% for detecting malignancy. Site-based sensitivity for detecting malignancy was 76 and 75% for detecting cancer with BAC features, for both radiopharmaceuticals. Specificity was similar for FCH and FDG (site-based 93 vs. 81%, NS). In these early-stage cancers, only one adrenal metastasis was observed that took up FCH and FDG., Conclusion: In this population of patients with ground-glass opacities selected on CT suggestive of BAC or with a history of BAC and a recent lung anomaly on CT, FCH detected all malignant lesions with at least a 2.0 cm short axis. However, FDG had similar performance.

Aim: The clinical usefulness of 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) in head and neck squamous cell carcinoma (HNSCC) is now well-documented. However, its sensitivity is greater than its specificity due to false-positive results in inflammatory or infectious lesions, which are frequent in this area, in particular after treatment by surgery and/or radiotherapy. O-2-fluoro-(18F)-ethyl-L-thyrosine (FET) has been reported not to be taken up by such lesions, and a preliminary study indicated that this may be clinically useful in HNSCC. We performed a prospective study to compare the diagnostic performances of FDG and FET PET/CT in the different settings of HNSCC., Materials and Methods: Twenty-seven patients (20 men and seven women, aged 48-76, among 30 patients included) and 69 suspected cancer sites are now evaluable on basis of postsurgical histology and/or follow-up greater than 6 months; 15 patients were referred for initial staging and 12 during posttherapy follow-up, a recurrence being suspected in eight of them. FDG and FET PET/CT were performed on two different days, the patient fasting for 6 h, 1 h after injection of 5 MBq/kg of body mass of each radiopharmaceutical. Both PET/CT examinations were blind read more than 6 months after the end of inclusions in a random order for each tracer and with a time interval greater than 1 month between FDG and FET PET/CT blind readings., Results: Overall diagnostic performances, derived from blind reading: FDG PET/CT on a per patient basis: sensitivity 100%, specificity 71%, accuracy 93%; FDG PET/CT on a per site basis: sensitivity 95%, specificity 63%, accuracy 83%; FET PET/CT on a per patient basis: sensitivity 70%, specificity 100%, accuracy 78%; FET PET/CT on a per site basis: sensitivity 64%, specificity 100%, accuracy 78%. At site level, sensitivity was significantly greater with FDG (p<0.02) and specificity with FET (p<0.01). The statistical level of significance was not reached at patient level., Conclusion: Although its good specificity was confirmed, FET did not appear to be suited as a first-line PET tracer in HNSCC imaging and cannot replace FDG for staging due to insufficient sensitivity. However, it was useful in a few selected cases to favor a wait and see attitude when a FDG+ FET- focus was discovered in patients referred for systematic FDG PET during follow-up. In contrast, second primary cancers should not be ruled out if FDG was clearly positive in the lungs or the digestive tract.

In prostate cancer, use of FDG, the radiopharmaceutical currently most widely used in oncology, is limited to the most aggressive cancers and, in the absence of another tracer, to attempting to localise occult recurrences detected biochemically (elevated PSA serum levels). Four other PET tracers are currently suggested in various situations of prostate cancer development: for guiding biopsies, for diagnosis and staging of the primary cancer and of local or metastatic recurrences, especially in bone, and for localizing occult biochemical recurrence. This article is illustrated by cases summarising our experience with fluoromethylcholine-(18F) and PET/CT. They cover a wide spectrum of clinical settings: localisation of intraprostatic neoplastic lesions, initial staging, monitoring treatment by ultrasound, detection of occult recurrences and characterisation of images on conventional imaging modalities, which are questionable or difficult to interpret.

Objective: Prospectively evaluate the impact of fluorodeoxyglucose-fluorine-18 positron emission tomography (FDG-PET) in the management of recurrence of advanced head and neck squamous cell carcinoma during the first year after treatment., Study Design: Seventy patients were followed-up every 6 to 8 weeks during the first year after initial combined curative therapy. FDG-PET, together with conventional imaging and endoscopy were performed systematically at 1 year (group A) or prompted earlier in case of clinically suspicious recurrence (group B). The referring physician evaluated the impact of FDG-PET on the patient's management. Another clinician checked the pertinence of decisions., Results: FDG-PET had a therapeutic impact in 8 of 43 group A patients and in 16 of 27 group B patients; the overall rate was 34%. This change was pertinent in 5 of 8 and 14 of 16 cases, respectively. Overall pertinence rate of decisions was 90% versus 70% without FDG-PET., Conclusions: FDG-PET had a significant overall therapeutic impact; the induced decisions were either pertinent or just led to "futile" noninvasive examinations. Systematic FDG-PET had a significantly lesser impact in comparison with FDG-PET motivated by clinical suspicion.

FDG PET is useful when cancer in the head or neck (except for tumors of the salivary glands, which cannot be characterized accurately) is diagnosed or suspected but not confirmed by biopsy. It can, for example, find evidence of suspicious lymph nodes in clinically N0 necks, detect foci suggestive of distant metastases or second cancers, and provide useful prognostic information. Because it can be very difficult to identify anatomical structures and landmarks on PET images in the head and neck region, PET/CT fusion is very helpful in this area. In early assessment of chemotherapy, the absence of a significant reduction in FDG uptake after one or two cycles predicts lack of efficacy and thus indicates the need to modify the regimen. Conversely, the disappearance of FDG foci indicates effective treatment and good prognosis but cannot rule out the persistence of any malignant tissue at the end of treatment, especially neoadjuvant. Diagnostic impact is probably greatest in monitoring for recurrence and restaging known recurrence: FDG PET should be performed - perhaps routinely - early enough that curative options are still open, but long enough after the end of treatment to avoid false positive results from inflammation. The strategy and timing of FDG PET during follow-up should be determined in more detail in the future, as should the role (if any) of fluorotyrosine (FET) PET in squamous cell carcinoma.

In our hospital as in many others, primary lung cancer is the most frequent indication for FDG PET. Studies have assessed the clinical utility of this imaging modality in characterizing solitary pulmonary nodules or masses, initial staging, defining tumor volume in radiotherapy and searching for recurrence of or restaging non-small cell carcinoma; studies are currently underway to evaluate its use in early assessment of chemotherapy response. Small cell lung cancer has a high FDG uptake and PET/CT can be useful for rapid staging. False negative results may be due to pure bronchioloalveolar carcinomas and endocrine tumors. FDG-PET will certainly play a more important role in the diagnosis and follow-up of pleural cancers in the future. An unexpected positive FDG PET focus should be considered as a warning, but histological proof should precede any irrevocable decisions.

Unlabelled: While a great deal of work has been performed concerning the impact of [18F]-FDG imaging in isolated lung lesion(s), there are still very few data about its role in case of isolated pleural lesions. The aim of this preliminary study was to shed some light on the utility of [18F]-FDG imaging, using PET or CDET detection, in this context., Patients and Method: Sixteen patients referred for apparently isolated pleural lesions were included in this study, since their 22 [18F]-FDG examinations were evaluable on bases of histology (9 cases), rapid disease progression (4 cases) or a follow-up period of more than 6 months (9 cases). Twelve [18F]-FDG examinations were performed with a dedicated PET machine (C-PET, Adac) and ten with a coincidence detection gamma camera (Irix, Picker). The precise clinical settings were the following: characterization of pleural masses or search for the unknown primary tumor in case of adenocarcinoma (6 cases), staging of a mesothelioma (5 cases), suspicion of recurrence and/or residual lesions (11 cases)., Results: The malignant pleural lesions took up [18F]-FDG in all cases. There was one false positive result due to an inflammatory lesion. False negative results for the detection of lymph node invasion occurred in three patients and were in relation with their infracentimetric size and the difficulty to distinguish on [18F]-FDG images mediastinal lymph nodes from widespread pleural and pulmonary extension of cancer. A change in patient management resulted from the [18F]-FDG examination in 4 patients (25%) and the course confirmed that the change was correct. Unknown lesions or active lesions wrongly considered residual that could have modified the management were discovered in 3 other patients., Conclusions: This study highlights the fact that [18F]-FDG imaging has an impact on the management of patients with solitary pleural lesions and can detect recurrences, in some cases even more accurately than invasive procedures with histology. In our limited experience, the lack of anatomical details of the PET images is a major drawback in this setting and we are convinced that PET-CT will substantially enhance the impact of [18F]-FDG imaging.

Small cell lung carcinomas (SCLC) express neuroendocrine markers, and dihydroxyphenylalanine (DOPA) is known to accumulate in neuroendocrine tumours. This study was performed with the aim of evaluating the uptake of 3,4-dihydroxy-6-(18)F-fluoro-phenylalanine ([(18)F]FDOPA) by SCLC, based on comparison with the results of fluorine-18 fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) and standard imaging procedures. [(18)F]FDG PET and [(18)F]FDOPA PET were performed on four patients with newly diagnosed SCLC. There was agreement between the results of [(18)F]FDOPA PET and [(18)F]FDG PET in four tumoural sites out of 11, whereas [(18)F]FDG PET and standard imaging procedures were in full agreement. A semi-quantitative analysis based on standardised uptake values (SUVs) was performed in order to compare [(18)F]FDG and [(18)F]FDOPA tumour uptake. The median [(18)F]FDG SUV(max) was 5.9 (with a 95% confidence interval from 4.4 to 9.2), while the median [(18)F]FDOPA SUV(max) was 1.9 (with a 95% confidence interval from 1.6 to 3.8). The difference between [(18)F]FDG SUV(max) and [(18)F]FDOPA SUV(max) was significant ( P<0.01). [(18)F]FDOPA PET appeared less sensitive than [(18)F]FDG PET and standard imaging procedures in the staging of SCLC. No clear relation between [(18)F]FDOPA uptake and positivity of neuroendocrine markers on immunohistochemistry emerged from these preliminary results; however, since [(18)F]FDOPA uptake may reflect better differentiation of the tumour, and possibly a better prognosis, this point warrants clarification in a larger study.