Background - Whole body F-18 deoxyglucose positron emission tomography (FDG PET) has the potential to improve the management of non small cell lung cancer (NSCLC) We prospectively evaluated the impact of combining FDG PET with conventional staging methods, including cornputed tomography (CT), on the staging and management of patients with potentially resectable NSCLCMethods - Ninety four consecutive patients with newly diagnosed/suspected NSCLC were enrolled Each patient was first staged by using conventional methods, and then by FOG PET FDG PET results were forwarded in a sealed envelope and divulged at the weekly staff meeting on staging and treatment, only after "Decision 1", based on conventional staging, had been reached by consensus, reevaluation taking FDG PET into account yielded "Decision 2" The validity of these latter decisions was analyzed retrospectivelyResults - Eighty nine patients were eligible Relative to standard imaging, FDG PET led to clinical staging changes in 26 (29 2%) patients The stage was lowered in eight cases (9%) and raised in 18 cases (20 2%) "Decision 2" differed from "Decision 1" in 19 patients, modifying the surgical procedure in four cases, indicating other investigations to confirm FDG PET evidence of metastases in 12 cases, or modifying the medical treatment in three cases These modifications were retrospectively justified in 9/19 cases, and consisted of 2/4 modifications of the surgical procedure (one hilar and one adrenal metastasis not confirmed histologically), 4/12 further investigations (axillary and liver biopsies, mediastinoscopy, occult colon cancer) and three indications for palliative treatment, in patients who all died within 3 months after FDG PETConclusions Based on FDG PET, management was modified in 19/89 (21 3%) patients, but these changes were justified in only 9/89 patients (10 1%) FOG PET can detect asymptomatic local and distant metastases and improves the preoperative assessment of NSCLC, thereby avoiding unnecessary surgery However, histological verification is required because of the risk of false positive results (C) 2010 Elsevier Masson SAS All rights reserved

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.

1543 Objectives: To evaluate the impact of FDOPA-PET and the pertinence of the induced decisions. Methods: Between April 2002 and December 2007, 27 examinations (exs) have been performed in 24 patients for suspicion of pheochromocytoma (9 cases), staging (2 cases), restaging (3 cases), suspicion of recurrence (10 cases), systematic evaluation after surgery (3 cases). 21 exs were performed with combined CT. The impact of FDOPA PET was evaluated, on a per-patient basis, thanks to a questionnaire prospectively filled in by the referring physician and the pertinence of the induced decisions was assessed thanks to the follow-up data. Results: - Suspicion of pheochromocytoma: All the 9 exs were true negative (TN). - Staging (2 cases): One examination was true positive (TP) and one (performed after surgery) was TN without impact on management. - Restaging (3 cases): Two exs were TP without impact on management. One ex was FN although FDG PET/CT was TP. - Suspicion of recurrence (10 cases): On the 8 evaluable exs, 4 were TP (3 in the same patient) and led to surgery in 2 patients. 0ne ex showing bone foci led to MRI which confirmed the bone lesions. Two exs were TN. One ex was TP but showed fewer lesions than mIBG scintigraphy and FDG PET. - Systematic evaluation after surgery (3 cases): Two exs were TN. One ex was TP, showing a single focus, leading to re-intervention. Conclusions: Sensitivity and specificity of FDOPA PET were respectively 10/11 =91% and 14/14 = 100%, confirming the excellent performance of the technique in the settings of pheochromocytoma. On patient basis, the overall rate of change in patient management was 12% (3/24)and 3/15 (20%)in proven pheochromocytoma, leading to pertinent decisions. In case of aggressive disease, FDOPA PET can however give false negative results and FDG PET is indicated.

Cet article illustre, à l’aide du cas de trois patients examinés à l’hôpital Tenon, l’aide potentielle de la TEP/TDM à la fluorométhycholine-(18F) (FCH) dans trois circonstances de récidive de cancer de la prostate : récidive précoce ou persistance de tissu néoplasique, restadification d’une récidive décelée en IRM alors que la concentration de PSA est inférieure à 1ng/mL ou enfin détection d’une récidive suspectée sur la biologie et jusque là occulte. L’expérience de notre équipe et l’analyse de la littérature ont permis de poser les jalons d’un PHRC national ICHOROPRO qui vient d’être accepté, pour évaluer les performances diagnostiques et l’impact de la TEP/TDM à la FCH en cas de récidive occulte de cancer de la prostate.

Décrire l’évaluation de la taille et de l’extension tumorale en mammographie et en échographie. Savoir utiliser les techniques de radiologie interventionnelle. Définir la place de 1’IRM. Définir la place de la tomographie par émission de positons (TEP).

Comme pour l'adulte, la TEP au FDG est un outil d'imagerie performant pour la determination du stade, l'adaptatation du traitement et le suivi des lymphomes de Hodgkin de l'enfant. L'interpretation doit cependant tenir compte de certaines particularites specifiques a l'enfant qui sont la frequence de l'activation de la graisse brune et l'activation physiologique du thymus. Le role de la TEP au FDG en cas de lymphome non hodgkinien (LNH) de l'enfant est moins bien etabli. Bien que chez l'enfant, les LNH soient plus frequents que les lymphomes de Hodgkin, la TEP au FDG est peu prescrite au moment du diagnostic initial probablement en raison de l'urgence therapeutique de ces lymphomes toujours agressifs. Neanmoins, la TEP au FDG a montre son utilite lors du suivi des LNH en particulier pour la caracterisation des masses residuelles.

Évaluer les performances diagnostique et pronostique de la TEP au 18-FDG lors du bilan avant chimio-hyperthermie intra-péritonéale (CHIP).Trente-huit patientes atteintes de cancer ovarien de stade IIIC (11 primaires et 27 récidivants), ayant eu une CHIP, ont été incluses dans cette étude rétrospective monocentrique. Les examens TEP pré-CHIP ont été relus à l’aveugle, puis ont été comparés aux résultats chirurgicaux et histologiques et au suivi des patientes.Trente-deux patientes avaient une carcinose péritonéale selon les résultats chirurgicaux et histologiques et 19 selon la TEP. La TEP n’a montré aucun foyer sus-diaphragmatique suspect. Les sensibilité et spécificité étaient calculées à 56,2 et 100 %. Onze patientes parmi 14 faussement TEP négatives avaient uniquement des lésions péritonéales infracentimétriques. Il y avait significativement plus de patientes traitées par chimiothérapie dans le groupe TEP négative (p = 0,02), dont 13 appartenant aux faux négatifs. Malgré un taux d’évènements légèrement plus élevé dans le groupe TEP positive pour la survie sans évènements (68 % vs 64 % dans le groupe TEP négative) et globale (26,3 % vs 17,6 %), l’analyse des courbes de survie n’a pas montré de différence significative (respectivement, p = 0,62 et 0,59).La TEP/TDM a montré une excellente spécificité et une sensibilité moindre lors du bilan avant CHIP, essentiellement due à la présence de lésions de petite taille et au traitement par chimiothérapie précédent la CHIP. Il n’a pas été observé de valeur pronostique significative de la TEP, mais celle-ci reste utile dans la détection des métastases à distance avec un impact sur la prise en charge thérapeutique.Evaluate 18-FDG PET/CT diagnostic and prognostic value before HIPEC.This retrospective monocentric study included 38 patients with recurrent (n = 27) or primary (n = 11) ovarian cancer who were blinded reviewed for the presence of peritoneal lesions on PET/CT before HIPEC treatment. The results were compared to surgical and histopathological findings, and to survival curves.Thirty-two patients had peritoneal carcinomatosis based on surgical and histopathological findings, and 19 based on PET. There was no suspicious site of abnormal FGD uptake in the supradiaphragmatic regions. The sensitivity and specificity were respectively 56.2 and 100%. Among the 14 false negative patients, 11 had infracentimetric peritoneal implants, and most of them (n = 13) had chemotherapy before HIPEC. There was significantly more patients treated by chemotherapy in the negative PET group (P = 0.02). Even if the event rate observed was higher in the positive PET group for both event free and overall survival (respectively 68% vs. 64% and 26.3% vs. 17.6%), no significant difference was observed using the survival curves (respectively P = 0.62 and 0.59).FDG PET/CT before HIPEC showed excellent specificity and lower sensitivity, due to small peritoneal implants and probably to chemotherapy before HIPEC. No significant prognostic value of FDG PET was observed in our study. FDG PET could be considered as a useful tool for detecting distant metastasis with an impact on therapeutic management.

La stadification initiale des cancers broncho-pulmonaires est essentielle pour adapter la stratégie thérapeutique. La TEP au fluorodésoxyglucose-(18F) (TEP-FDG) est maintenant considérée comme un « standard » dans cette indication. La scintigraphie osseuse au bisphonate-(99mTc) (SO) a longtemps été indiquée pour la recherche des métastases osseuses. A-t-elle encore une valeur ajoutée si on pratique la TEP-FDG ? Pour tenter de le préciser, les TEP et SO ont été relues à l’aveugle par deux observateurs et leurs résultats confrontés aux autres examens d’imagerie et au suivi. Entre février 2001 et mars 2004, 39 patients (F : 13, H : 26, âge = 62 ± 11 ans) ont eu une TEP-FDG et une SO (délai moyen de 17 ± 17 jours). Lorsque les deux examens ont été concordants pour le diagnostic d’extension osseuse, nous avons considéré que la SO n’avait pas de valeur ajoutée. Lorsque la recherche de l’atteinte osseuse était discordante entre TEP et SO, nous avons pris comme référence les autres examens d’imagerie, le suivi clinique et para-clinique du patient durant un minimum de 5 mois. La TEP-FDG et la SO ont été concordants chez 29 sujets (74 %) avec des résultats positifs dans 12 cas (31 %) et négatifs dans 17 cas (43 %). Ces examens ont été discordants dans 10 cas (26 %). Parmi les 5 cas discordants de SO positive sans anomalie osseuse en TEP-FDG, les anomalies étaient soit bénignes et expliquées par la clinique (3 cas), soit non confirmées par le suivi clinique et para-clinique (2 cas). Parmi les 5 cas discordants avec suspicion d’atteinte osseuse en TEP-FDG, aucune métastase n’a été confirmée durant le suivi clinique. La SO n’a pas permis d’identifier des métastases osseuses qui auraient été manquées en TEP et n’a donc pas à être systématique. L’association de la tomodensitométrie à la TEP pourrait encore réduire cette valeur ajoutée en localisant les foyers TEP de façon plus précise.

Initial staging of lung cancer is essential to determine the appropriate therapeutic strategy. 18F-FDG PET is currently considered to be the gold standard. 99mTc bisphonate bone scintigraphy has long been indicated to search for bone metastases but it is not know whether this exploration adds further information after an 18F-FDG PET scan. In order to answer this question, two observers unaware of the clinical situation reread PET scans and bone scintigraphies and results compared with other imaging findings. Between February 2001 and March 2004, 39 patients (13F, 26M, 62 +/- 11 yr) underwent 18FFDG PET and bone scintigraphy (mean interval 17 +/- 17 d). When the two explorations agreed for the diagnosis of bone extension, we considered that bone scintigraphy added nothing. When the two explorations were in disagreement, the other imaging examinations, the clinical features and laboratory results during the five-month minimal follow-up were used to establish the reference diagnosis. 18F-FDG PET and bone scintigraphy were in agreement in 29 patients (74%) with positive results in 12 (31%) and negative results in 17 (43%). The two explorations were in disagreement in 10 patients (26%). Among the five disagreement cases with positive bone scintigraphy and no bone anomaly on the 18F-FDG PET, the anomalies were benign and explained by clinical features (3 patients) or were not confirmed by the clinical course and laboratory results (2 patients). Among the 5 cases with a bone anomaly on the 18F FDG PET, no metastasis could be identified during clinical follow-up. Bone scintigraphy does not enable identification of any bone metastases which were not recognized on the PET scan and therefore should not be performed systematically. Using a computed tomography scan with the 18F-FDG PET could further limit the contribution of bone scintigraphy by providing more precision concerning foci identified on the PET scan.

La atención médica de los cánceres se encuentra en continua evolución debido a la aplicación de nuevos tratamientos, pero también a las innovaciones tecnológicas que contribuyen con métodos diagnósticos más precisos. La tomografía por emisión de positrones (PET) con fluorodesoxiglucosa (18F) (FDG) forma parte de esas modalidades de diagnóstico por imagen innovadoras. En un principio indicada en enfermedades como el linfoma o el cáncer broncopulmonar, esta técnica se usa cada vez más en los cánceres de la mujer. A partir de los datos más recientes de las publicaciones, se precisará la contribución de la PET-FDG en la detección, la valoración de la extensión, la búsqueda de recidiva y el control terapéutico de los cánceres de mama, de ovario y de cuerpo y cuello uterinos.

Objectif de l'étude. – Évaluer l'impact de la fusion d'images de tomographie par émission de positons (TEP) au 18fluorodéoxyglucose ([18F]-FDG) et détection en coïncidence par gamma caméra et d'images de simulation virtuelle par tomodensitométrie pour la radiothérapie conformationnelle des cancers de l'œsophage.

Objectif de l'étude. – Évaluer dans une série rétrospective l'impact du recalage d'images de tomographie par émission de positons (TEP) au 18fluorodéoxyglucose ([18F]-FDG) et détection en coïncidence (TEDC) par gamma-caméra et d'images de simulation virtuelle par tomodensitométrie pour la radiothérapie conformationnelle des cancers bronchiques non à petites cellules.