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The preferred hypothesis for the dissemination patterns of Hodgkin lymphoma (HL) is the contiguity hypothesis. However, this hypothesis is based on studies performed before the advent of [We retrospectively analyzed [A total of 196 patients were included. Our results showed strong relationships between nearby involved lymph node regions (for example between the left pelvic and the abdominal lymph node regions (relationship strength = 0.980)) and between more distant regions (for example between right and left axillary lymph node regions (strength = 0.714)). Furthermore, involvement of the infra-diaphragmatic lymph node regions was significantly correlated with Ann Arbor stage IV (phi = 0.56, p 0.001).This study confirms the hypothesis of lymphatic dissemination of HL in a contiguous mode, with additional links between more distant regions. These predictable dissemination patterns could be useful for the initial staging assessment of patients with HL using [

Objective(s)To systematically assess the extent to which bone scintigraphy (BS) could improve the detection rate of skeletal injury in children suspected of physical abuse with an initial negative radiological skeletal survey (RSS).Study designWe searched MEDLINE and Web of Science for series of ≥20 children suspected of physical abuse who underwent RSS and add-on BS. We assessed the risk of bias and the heterogeneity and performed random-effects meta-analyses.ResultsAfter screening 1140 unique search results, we reviewed 51 full-text articles, and included 7 studies (783 children, mostly ≤3 years old). All studies were of either high or unclear risk of bias. Substantial heterogeneity was observed in meta-analyses. The summary detection rate of skeletal injury with RSS alone was 52% (95% CI 37 to 68). The summary absolute increase in detection rate with add-on BS was 10 percentage points (95% CI 6 to 15); the summary relative detection rate was 1.19 (95% CI 1.13 to 1.25); the summary number of children with a negative RSS who needed to undergo a BS to detect one additional child with skeletal injury (number needed to test) was 3 (95% CI 2 to 7).ConclusionsFrom the available evidence, add-on BS in young children suspected of physical abuse with a negative RSS might allow for a clinically significant improvement of the detection rate of children with skeletal injury, for a limited number of BS procedures required. The quality of the reviewed evidence was low, pointing to the need for high-quality studies in this field.

International audience; Background: Quantification of dynamic and static parameters extracted from 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (F-18-DOPA, FDOPA) positron emission tomography (PET)/computed tomography (CT) plays a critical role for glioma assessment. The objective of the present study was to investigate the impact of point-spread function (PSF) reconstruction on these quantitative parameters. Methods: Fourteen patients with untreated gliomas and investigated with FDOPA PET/CT were analyzed. The distribution of the 14 cases was as follows: 6 astrocytomas-isocitrate dehydrogenase-mutant; 2 oligodendrogliomas/1p19q-codeleted-isocitrate dehydrogenase-mutant; and 6 isocitrate dehydrogenase-wild-type glioblastomas. A 0-20-min dynamic images (8x15 sec, 2x30 sec, 2x60 sec, and 3x300 sec post-injection) and a 0-20-min static image were reconstructed with and without PSF. Tumoral volumes-of-interest were generated on all of the PET series and the background volumes-of-interest were generated on the 0-20-min static image with and without PSF. Static parameters (SUVmax and SUVmean) of the tumoral and the background volumes-of-interest and kinetic parameters (K1 and k2) of the tumoral volumes-of-interest extracted from using full kinetic analysis were provided. PSF and non-PSF quantitative parameters values were compared. Results: Thirty-three tumor volumes-of-interest and 14 background volumes-of-interest were analyzed. PSF images provided higher tumor SUVmax than non-PSF images for 23/33 VOIs [median SUVmax =3.0 (range, 1.4-10.2) with PSF vs. 2.7 (range, 1.4-9.1) without PSF; P

International audience; The aims of this multicenter study were to identify clinical and preop-erative PET/CT parameters predicting overall survival (OS) and distant metastasis???free survival (DMFS) in a cohort of head and neck squa-mous cell carcinoma patients treated with surgery, to generate a prog-nostic model of OS and DMFS, and to validate this prognostic model with an independent cohort. Methods: A total of 382 consecutive patients with head and neck squamous cell carcinoma, divided into training (n = 318) and validation (n = 64) cohorts, were retrospectively included. The following PET/CT parameters were analyzed: clinical parameters, SUVmax, SUVmean, metabolic tumor volume (MTV), total lesion glycolysis, and distance parameters for the primary tumor and lymph nodes defined by 2 segmentation methods (relative SUVmax threshold and absolute SUV threshold). Cox analyses were performed for OS and DMFS in the training cohort. The concordance index (c-index) was used to identify highly prognostic parameters. These prognostic parameters were externally tested in the validation cohort. Results: In multivariable analysis, the significant parameters for OS were T stage and nodal MTV, with a c-index of 0.64 (P < 0.001). For DMFS, the significant parameters were T stage, nodal MTV, and maxi-mal tumor???node distance, with a c-index of 0.76 (P < 0.001). These combinations of parameters were externally validated, with c-indices of 0.63 (P < 0.001) and 0.71 (P < 0.001) for OS and DMFS, respec-tively. Conclusion: The nodal MTV associated with the maximal tumor???node distance was significantly correlated with the risk of DMFS. Moreover, this parameter, in addition to clinical parameters, was associated with a higher risk of death. These prognostic factors may be used to tailor individualized treatment. Superscript/Subscript Available

We aimed to compare spatial extent of high-grade subregions detected with combined [Participants with suspected diffuse glioma were prospectively included between June 2018 and September 2019. Volumes of high-grade subregions were delineated respectively onThirty-eight biopsy samples from sixteen participants were analyzed. Six participants (38%) had grade IV IDH wild-type glioblastoma, six (38%) had grade III IDH-mutated astrocytoma and four (24%) had grade II IDH-mutated gliomas. Three patients had intratumoral heterogeneity with coexisting high- and low-grade tumor subregions. High-grade volumes determined with combinedThe addition of

BackgroundDiagnostic and patients’ management modifications induced by whole-body 18F-FDG-PET/CT had not been evaluated so far in prosthetic valve (PV) or native valve (NV) infective endocarditis (IE)-suspected patients.MethodsIn sum, 140 consecutive patients in 8 tertiary care hospitals underwent 18F-FDG-PET/CT. ESC-2015-modified Duke criteria and patients’ management plan were established jointly by 2 experts before 18F-FDG-PET/CT. The same experts reestablished Duke classification and patients’ management plan immediately after qualitative interpretation of 18F-FDG-PET/CT. A 6-month final Duke classification was established.ResultsAmong the 70 PV and 70 NV patients, 34 and 46 were classified as definite IE before 18F-FDG-PET/CT. Abnormal perivalvular 18F-FDG uptake was recorded in 67.2% PV and 24.3% NV patients respectively (P < .001) and extracardiac uptake in 44.3% PV and 51.4% NV patients. IE classification was modified in 24.3% and 5.7% patients (P = .005) (net reclassification index 20% and 4.3%). Patients’ managements were modified in 21.4% PV and 31.4% NV patients (P = .25). It was mainly due to perivalvular uptake in PV patients and to extra-cardiac uptake in NV patients and consisted in surgery plan modifications in 7 patients, antibiotic plan modifications in 22 patients and both in 5 patients. Altogether, 18F-FDG-PET/CT modified classification and/or care in 40% of the patients (95% confidence interval: 32–48), which was most likely to occur in those with a noncontributing echocardiography (P < .001) or IE classified as possible at baseline (P = .04), while there was no difference between NV and PV.ConclusionsSystematic 18F-FDG-PET/CT did significantly and appropriately impact diagnostic classification and/or IE management in PV and NV-IE suspected patients.Clinical Trials RegistrationNCT02287792.

International audience; Purpose We aimed to compare spatial extent of high-grade subregions detected with combined [F-18]-dihydroxyphenylalanine (F-18-DOPA) PET and MRI to the one provided by advanced multimodal MRI alone including Contrast-enhanced (CE) and Perfusion weighted imaging (PWI). Then, we compared the accuracy between imaging modalities, in a per biopsy analysis. Methods Participants with suspected diffuse glioma were prospectively included between June 2018 and September 2019. Volumes of high-grade subregions were delineated respectively on F-18-DOPA PET and MRI (CE and PWI). Up to three per-surgical neuronavigation-guided biopsies were performed per patient. Results Thirty-eight biopsy samples from sixteen participants were analyzed. Six participants (38%) had grade IV IDH wild-type glioblastoma, six (38%) had grade III IDH-mutated astrocytoma and four (24%) had grade II IDH-mutated gliomas. Three patients had intratumoral heterogeneity with coexisting high- and low-grade tumor subregions. High-grade volumes determined with combined F-18-DOPA PET/MRI (median of 1.7 [interquartile range (IQR) 0.0, 19.1] mL) were larger than with multimodal MRI alone (median 1.3 [IQR 0.0, 12.8] mL) with low overlap (median Dice's coefficient 0.24 [IQR 0.08, 0.59]). Delineation volumes were substantially increased in five (31%) patients. In a per biopsy analysis, combined F-18-DOPA PET/MRI detected high-grade subregions with an accuracy of 58% compared to 42% (p = 0.03) with CE MRI alone and 50% (p = 0.25) using multimodal MRI (CE + PWI). Conclusions The addition of F-18-DOPA PET to multimodal MRI (CE and PWI) enlarged the delineation volumes and enhanced overall accuracy for detection of high-grade subregions. Thus, combining F-18-DOPA with advanced MRI may improve treatment planning in newly diagnosed gliomas.

International audience

Background: A skeletal survey (SS) of high technical quality is the standard method of investigation for identifying bone injuries in suspected physical child abuse worldwide. We aimed to assess the contribution of Whole-Body Magnetic Resonance Imaging (WBMRI) and BS in addition to SS in detecting traumatic bone lesions and soft-tissue injuries. Methods: PEDIMA is a prospective, multicenter, diagnostic accuracy study. Eligible children were less than three years of age and suspected of non-accidental injury. Each child underwent SS, BS and WBMRI. A blinded first review was jointly conducted by five paediatric radiologists and three nuclear medicine physicians. A second review investigated the discrepancies, in full knowledge of the results of all the imaging modalities in order to reach a consensus as the reference standard. We calculated the sensitivity, specificity, and corresponding 95% confidence interval for each imaging modality (SS, WBMRI and BS) and for the combinations [SS+WBMRI] and [SS+BS]. Findings: 170 children under three years old were included. Sixty-four children had at least one lesion for a total of 146 lesions. The sensitivity and specificity of each examination was, respectively, as follows: 88.4% [95% CI: 82.0-93.1] and 99.7% [95% CI: 99.5-99.8] for the SS, 69.9% [95% CI: 61.7-77.2] and 99.5% [95% CI: 99.2-99.7] for WBMRI, and 54.8% [95% CI: 46.4-63.0] and 99.7% [95% CI: 99.5-99.9] for BS. Sensitivity and specificity were, respectively, 95.9% [95% CI: 91.3-98.5] and 99.2% [95% CI: 98.9-99.4] for the combination SS+WBMRI and 95.2% [95% CI: 90.4-98.1] and 99.4% [95% CI: 99.2-99.6] for the combination SS+BS, with no significant difference between them. Interpretation: SS is still the most sensitive imaging modality, but the combined examinations offer greater accuracy and WBMRI is emerging as a new imaging strategy that could influence a change of practice. Funding: French Ministry for Health as part of its interregional PHRC. Declaration of Interests: We declare no competing interests. Ethics Approval Statement: The local ethics committees approved the protocol and all children’s parents gave written informed consent before enrolment in the study.

International audience; Purpose To determine performances of 2-deoxy-2-(18F)fluoro-d-glucose (18F-FDG) positron emission tomography (PET) to detect the development of permanent thyroid dysfunction (PTD), and to evaluate the prognostic value of early increased thyroid uptake in stage IV melanoma patients treated with anti-programmed death 1 (anti-PD-1) antibodies. Methods Twenty-nine patients were retrospectively enrolled. PTD was defined as symptomatic thyroid disorder requiring long-term specific treatment. On the first PET performed during follow-up, maximal standardized uptake value of the thyroid (SUVmax-Th) and SUVmax-Th/SUVmax-blood-pool ratio (Th/B) were measured. Areas under ROC curves (AUC) of these parameters for the diagnostic of PTD were compared. Cutoff values were defined to maximize the Youden's index. Survival analyses were performed according to the Kaplan-Meier method and compared using the log-rank method between patients with and without enhanced thyroid uptake according to cutoff values defined with the Hothorn and Lausen method. Results Four patients presented PTD. Median SUVmax-Th and Th/B were, respectively, 2.11 and 1.00. The median followup period was 21.7 months. AUC were 1.0 (CI 95% 0.88-1.0) for both parameters. Optimal cutoff values were, respectively, SUVmax-Th > 4.1 and Th/B > 2.0, both conferring sensitivities of 100% (CI 95% 40-100%) and specificities of 100% (CI 95% 86-100%). The median progression-free survival and overall survival were 11.3 months and 33.5 months, respectively. Using optimized cutoffs, there was no statistically significant difference of survival. Conclusion SUVmax-Th > 4.1 and Th/B > 2.0 provided perfect diagnostic performances to detect patients that developed PTD. No significant survival difference was found between patients with and without increased thyroid uptake.

Background Suboptimal temporal sampling of time-activity curves (TAC) from dynamic 18F-fluoromethylcholine (FCH) PET images may introduce bias in quantification of FCH uptake in prostate cancer assessment. We sought to define an optimal temporal sampling protocol for dynamic FCH PET imaging. Seven different time samplings were tested: 5 × 60″, 10 × 30″, 15 × 15″–1 × 75″, 6 × 10″–8 × 30″, 12 × 5″–8 × 30″; 10 × 5″–4 × 10″–3 × 20″–5 × 30″, and 8 × 3″–8 × 12″–6 × 30″. First, the irreversible and reversible one-tissue compartment model with blood volume parameter (VB) (respectively, 1T1K+VB and 1T2k+VB, with K1 = transfer coefficient from the arterial blood to the tissue compartment and k2 = transfer coefficient from the tissue compartment to the arterial blood) were compared for 37 lesions from 32 patients who underwent FCH PET imaging for initial or recurrence assessment of prostate cancer, and the model was selected using the Akaike information criterion. To determine the optimal time sampling, K1 values extracted from 1000 noisy-simulated TAC using Monte Carlo method from the seven different time samplings were compared to a target K1 value which is the average of the K1 values extracted from the 37 lesions using an imaging-derived input function for each patient. K1 values extracted with the optimal time sampling for each tumoral lesion were compared to K1 values extracted from each of the other time samplings for the 37 lesions. Results The 1T2k + VB model was selected. The target K1 value as the objective was 0.506 mL/ccm/min (range 0.216–1.246). Results showed a significant difference between K1 values from the simulated TAC with the seven different time samplings analyzed. The closest K1 value from the simulated TAC to the target K1 value was obtained by the 12 × 5″–8 × 30″ time sampling. Concerning the clinical validation, K1 values extracted from the optimal time sampling (12 × 5″–8 × 30″) were significantly different with K1 values extracted from the other time samplings, except for the comparison with K1 values extracted from the 10 × 5″–4 × 10″–3 × 20″–5 × 30″ time sampling. Conclusions A two-phase framing of dynamic PET reconstruction with frame durations of 5 s (blood phase) and 30 s (tissue phase) could be used to sample the TAC for uptake quantification in prostate cancer assessment.

Objectifs Comparer l’etendue spatiale des regions de haut grade detectees par la combinaison de l’IRM et de la TEP a la [18F]-dihydroxyphenylalanine (18F-DOPA) a celle fournie par l’IRM seule. Puis, comparer la precision entre les modalites d’imagerie, en analyse par site de biopsie. Methodes Les patients presentant un gliome diffus presume ont ete inclus de maniere prospective entre juin 2018 et septembre 2019. Les volumes des regions de haut grade ont ete delimites respectivement par TEP a la 18F-DOPA et par IRM apres injection de contraste avec imagerie ponderee par la perfusion (PWI). Jusqu’a trois biopsies guidees par la neuronavigation ont ete realisees par patient. La precision diagnostique a ete comparee entre les modalites d’imagerie, par site de biopsie, a l’aide du test de McNemar. Resultats Trente-huit echantillons de biopsie provenant de seize participants ont ete analyses. Six participants (38 %) presentaient un glioblastome IDH-wt de grade IV, six (38 %) un astrocytome de grade III IDH-m et quatre (24 %) des gliomes de grade II IDH-m. Trois patients presentaient une heterogeneite intratumorale avec la coexistence de regions tumorales de haut et de bas grade. Le volume de haut grade determine avec la TEP/IRM combinee (mediane de 1,7 [intervalle interquartile (IQR) 0,0 a 19,1] mL) etait plus important qu’avec l’IRM multimodale seule (mediane de 1,3 [IQR 0,0 a 12,8] mL) avec un faible chevauchement (mediane du coefficient de Dice 0,12 [IQR 0,00 a 0,52]). Les volumes de delimitation ont ete substantiellement augmentes chez cinq patients (31 %). Dans une analyse par biopsie, la TEP/IRM combinee a detecte des sous-regions de haut grade avec une precision de 58 %, contre 42 % (p = 0,03) avec l’IRM apres injection de produit de contraste seule, et 50 % (p = 0,25) avec l’IRM multimodale. Conclusions L’ajout de la TEP a la 18F-DOPA a l’IRM avec l’imagerie ponderee par la perfusion a permis d’elargir les volumes de delineation et d’ameliorer la precision pour la detection des regions de haut grade. Ainsi, la 18F-DOPA devrait etre ajoutee a l’IRM avancee pour ameliorer la planification du traitement dans les gliomes nouvellement diagnostiques.

Objectif Evaluer l’interet de l’ajout de la tomoscintigraphie couplee au scanner au temps tissulaire au protocole standard de scintigraphie osseuse, lors de l’exploration des douleurs subaigues et chroniques des extremites inferieures. Methode Les patients adresses pour douleurs des extremites inferieures evoluant depuis au moins 6 semaines, sans antecedent chirurgical local, ont ete inclus prospectivement. Pour chaque patient, il a ete realise un protocole standard de scintigraphie osseuse incluant la TEMP/TDM au temps osseux et une TEMP/TDM au temps tissulaire. Deux medecins nucleaires independants ont interprete les images fournies par le protocole standard, d’une part, et le protocole modifie incluant la TEMP/TDM au temps tissulaire, d’autre part. Les conclusions diagnostiques, la confiance diagnostique et la concordance inter-observateur ont ete comparees entre le protocole standard et le protocole modifie. Resultats 118 extremites inferieures de 113 patients ont ete analysees. L’ajout de la TEMP/TDM au protocole standard de la scintigraphie osseuse a change la conclusion diagnostique dans 24,6 % (29/118) des extremites inferieures explorees. Le protocole modifie a revele au moins un diagnostic expliquant les douleurs dans 89 % (105/118) des extremites, contre 83,1 % (98/118) avec le protocole standard (p = 0,02). Des tendinopathies ont ete diagnostiquees dans 12,7 % (15/118) des extremites inferieures, contre 4,2 % (5/118) avec le protocole standard (p = 0,002). Il n’y avait pas de difference significative concernant les autres categories de conclusion diagnostique. L’ajout de la TEMP/TDM tissulaire a significativement augmente la confiance diagnostique de chaque observateur (p Conclusion L’ajout de la TEMP/TDM tissulaire au protocole standard de scintigraphie osseuse a impacte la conclusion diagnostique chez un quart des patients presentant des douleurs des extremites inferieures, en revelant significativement plus de tendinopathies. De plus, cela a significativement augmente la confiance diagnostique des lecteurs.

International audience; Purpose In the context of locally advanced oropharyngeal cancer (LAOC) treated with definitive radiotherapy (RT) (combined with chemotherapy or cetuximab), the aims of this study were: (1) to identify PET-FDG parameters correlated with overall survival (OS) from a first cohort of patients; then (2) to compute a prognostic score; and (3) finally to validate this scoring system in a second independent cohort of patients. Materials and methods A total of 76 consecutive patients (training cohort from Rennes) treated with chemoradiotherapy or RT with cetuximab for LAOC were used to build a predictive model of locoregional control (LRC) and OS based on PET-FDG parameters. After internal calibration and validation of this model, a nomogram and a scoring system were developed and tested in a validation cohort of 46 consecutive patients treated with definitive RT for LAOC in Lausanne. Results In multivariate analysis, the metabolic tumour volume (MTV) of the primary tumour and the lymph nodes were independent predictive factors for LRC and OS. Internal calibration showed a very good adjustment between the predicted OS and the observed OS at 24 months. Using the predictive score, two risk groups were identified (median OS 42 versus 14 months, p

Resume Introduction La semi-quantification est un outil precieux augmentant la precision diagnostique de l’interpretation visuelle de la tomoscintigraphie d’emission monophotonique (TEMP) cerebrale au 123I-FP-CIT (DaTSCAN®), surtout en cas de doute, notamment sur le putamen posterieur. Le logiciel DaTQUANT® (GE® Healthcare) permet de realiser une evaluation rapide et simple de la fixation sur plusieurs regions d’interet et d’obtenir une valeur de deviation par rapport a une base de sujets sains issue de l’etude ENC-DAT, mais aucune valeur seuil n’est actuellement validee en routine. Patients et methodes Nous avons realise une etude retrospective sur 55 patients (33 hommes, 22 femmes), adresses pour un doute diagnostique neurologique et ayant beneficie d’une TEMP au DaTSCAN® sur une camera D670 GE®. Le gold standard etait le diagnostic final porte par le clinicien a distance de l’examen, conforte par l’evolution clinique. L’analyse etait initialement visuelle par deux medecins nucleaires experts, en insu des resultats semi-quantitatifs, puis par DaTQUANT® avec analyse statistique par calcul d’indices de Youden et courbes ROC afin de definir les valeurs seuils pour six regions d’interet (noyau caude, putamen anterieur, putamen posterieur, bilateralement). Resultats La concordance inter-observateur pour l’analyse visuelle en insu etait excellente avec un coefficient de kappa = 0,91, IC a 95 % = [0,87–0,95]. L’analyse semi-quantitative par DaTQUANT® et statistique a permis d’obtenir une valeur seuil pathologique pour chaque region d’interet en pourcentage de deviation standard par rapport a une base de sujets sains, calculee a −16,3 % pour la region du putamen posterieur droit (sensibilite de 100 % et specificite de 88 %) et −18,3 % pour le putamen posterieur gauche (sensibilite de 100 % et specificite de 97 %). Conclusion Les valeurs seuils pathologiques definies par notre etude permettraient de mieux apprehender l’analyse des donnees obtenues du logiciel DaTQUANT®, dans l’aide a l’analyse visuelle du DaTSCAN®. Ces valeurs restent cependant statistiques et complementaires a l’analyse visuelle.

PURPOSE We evaluated the prognostic value of baseline total metabolic tumor volume (TMTV) measured using pretreatment FDG PET for patients with transformation of chronic lymphocytic leukemia (CLL) into diffuse large B-cell lymphoma (DLBCL). METHODS A total of 28 patients with transformation of CLL into DLBCL who had undergone FDG PET before treatment were retrospectively reviewed. Univariate and multivariate analysis of conventional clinicopathologic variables (sex, age, World Health Organization performance status score, International Prognostic Index score, Binet stage, lactate dehydrogenase serum level [LDH], platelet count, presence or not of prior therapies for CLL, the time from CLL to Richter syndrome, Ann Arbor stage, Bulky or not) and metabolic parameters (SUVmax, SUVmean, TMTV, and total lesion glycolysis) at the time of the transformation of CLL into DLBCL were tested for overall survival (OS). RESULTS Of the 28 patients, 14 patients (50%) died during the follow-up period. Low platelet count, World Health Organization performance status score >1, high LDH, and high TMTV were found to be significant prognostic factors for OS on univariate analysis. The 5-year estimates of OS were 63% in the low metabolic burden group (TMTV ≤1200 cm) and 0% in the high metabolic burden group (TMTV >1200 cm). Multivariate analysis revealed that only high LDH was a significant predictor after adjustment for other variables of OS. CONCLUSIONS TMTV extracted from FDG PET at the time of the transformation of CLL into DLBCL is a predictor of OS.

The aim of this retrospective multicentric study was to develop and evaluate a prognostic

International audience; Purpose - The aims of this multicentre retrospective study of locally advanced head and neck cancer (LAHNC) treated with definitive radiotherapy were to (1) identify positron emission tomography (PET)-F-fluorodeoxyglucose (F-FDG) parameters correlated with overall survival (OS) in a training cohort, (2) compute a prognostic model, and (3) externally validate this model in an independent cohort. Materials and methods - A total of 237 consecutive LAHNC patients divided into training (n = 127) and validation cohorts (n = 110) were retrospectively analysed. The following PET parameters were analysed: SUV, metabolic tumour volume (MTV), total lesion glycolysis (TLG), and SUV for the primary tumour and lymph nodes using a relative SUV threshold or an absolute SUV threshold. Cox analyses were performed on OS in the training cohort. The c-index was used to identify the highly prognostic parameters. A prognostic model was subsequently identified, and a nomogram was generated. The model was externally tested in the validation cohort. Results - In univariate analysis, the significant PET parameters for the primary tumour included MTV (relative thresholds from 6 to 83% and absolute thresholds from 1.5 to 6.5) and TLG (relative thresholds from 1 to 82% and absolute thresholds from 0.5 to 4.5). For the lymph nodes, the significant parameters included MTV and TLG regardless of the threshold value. In multivariate analysis, tumour site, p16 status, MTV35% of the primary tumour, and MTV44% of the lymph nodes were independent predictors of OS. Based on these four parameters, a prognostic model was identified with a c-index of 0.72. The corresponding nomogram was generated. This prognostic model was externally validated, achieving a c-index of 0.66. Conclusions - A prognostic model of OS based on primary tumour and lymph node MTV, tumour site, and p16 status was proposed and validated. The corresponding nomogram may be used to tailor individualized treatment.

18F-Choline (FCH) uptake parameters are strong indicators of aggressive disease in prostate cancer. Functional parameters derived by magnetic resonance imaging (MRI) are also correlated to aggressive disease. The aim of this work was to evaluate the relationship between metabolic parameters derived by FCH PET/CT and functional parameters derived by MRI. Fourteen patients with proven prostate cancer who underwent FCH PET/CT and multiparametric MRI were enrolled. FCH PET/CT consisted in a dual phase: early pelvic list-mode acquisition and late whole-body acquisition. FCH PET/CT and multiparametric MRI examinations were registered and tumoral volume-of-interest were drawn on the largest lesion visualized on the apparent diffusion coefficient (ADC) map and projected onto the different multiparametric MR images and FCH PET/CT images. Concerning the FCH uptake, kinetic parameters were extracted with the best model selected using the Akaike information criterion between the one- and two-tissue compartment models with an imaging-derived plasma input function. Other FCH uptake parameters (early SUVmean and late SUVmean) were extracted. Concerning functional parameters derived by MRI scan, cell density (ADC from diffusion weighting imaging) and vessel permeability (Ktrans and Ve using the Tofts pharmakinetic model from dynamic contrast-enhanced imaging) parameters were extracted. Spearman’s correlation coefficients were calculated to compare parameters. The one-tissue compartment model for kinetic analysis of PET images was selected. Concerning correlation analysis between PET parameters, K1 was highly correlated with early SUVmean (r = 0.83, p

Resume Les cholangiocarcinomes intrahepatiques sont des tumeurs biliaires rares frequemment diagnostiquees a un stade evolue non chirurgical avec une efficacite limitee des therapeutiques systemiques. Les therapies intra-arterielles sont devenues un traitement palliatif en plein essor pour les formes non resecables en l’absence de metastase, en association ou non a une chimiotherapie systemique. Un bilan d’extension precis est essentiel pour le ciblage tumoral pre-interventionnel et pour exclure une localisation extrahepatique. Cette etude evalue la TEP/TDM au 18F-FDG dans le bilan d’extension pre-radioembolisation intra-arterielle des cholangiocarcinomes intrahepatiques evolues non resecables en premiere ligne. Vingt et un patients porteurs d’un cholangiocarcinome intrahepatique confirme histologiquement ont ete inclus retrospectivement. Tous les patients ont eu une TEP/TDM et une TDM TAP dans un delai median de 3,6 jours. Une analyse a ete effectuee par lesion, par lobe, par segment et selon la localisation hepatique, ganglionnaire ou a distance. La sensibilite de detection du primitif etait de 0,9 en TEP, sans difference significative avec la TDM, mais l’association des deux modalites permettait de detecter l’ensemble des lesions hepatiques. La specificite, la valeur predictive positive et l’exactitude ganglionnaire semblaient superieures en TEP, sans comparaison statistique possible. La TEP detectait l’ensemble des metastases a distance avec des performances optimales permettant d’eviter une therapie ciblee inutile dans 25 % des cas. L’analyse, toutes lesions confondues (hepatiques, ganglionnaires et a distance), retrouvait une exactitude de la TEP significativement superieure a la TDM (0,9 vs 0,58, respectivement ; p

Introduction/materiels Les inhibiteurs de checkpoint (anti-CTLA4 puis anti-PD1) ont considerablement ameliore le pronostic des melanomes metastatiques. Les toxicites auto-immunes accompagnant ces traitements ont ete decrites comme associees a une meilleure reponse. Les dysthyroidies transitoires ou permanentes sont parmi les plus frequentes. Cette etude retrospective monocentrique a pour but (1) d’evaluer la valeur pronostique d’un hypermetabolisme thyroidien sur la survie sans progression (SSP) et la survie globale (SG) sous anti-PD1 et (2) de determiner la valeur predictive de l’hypermetabolisme thyroidien sur la survenue d’une hypothyroidie auto-immune permanente. Ont ete inclus l’ensemble des patients avec un melanome avance ayant debute un traitement par anti-PD1 seul ou en association aux anti-CTLA4 entre janvier 2015 et decembre 2017 au Centre Eugene Marquis de Rennes et ayant beneficie d’une TEP au 18FDG dans les 3 mois precedant le debut des anti-PD1, puis au moins une fois en cours de traitement. Methodes/Resultats/Conclusion Le metabolisme de la thyroide a ete mesure sur l’ensemble des examens effectues par les patients avant et pendant le traitement par anti-PD1 jusqu’a la date des dernieres nouvelles. Un hypermetabolisme de la thyroide etait defini par un ratio SUVmax_thyroide/SUVmax_vasculaire > 2. Les hypothyroidies permanentes, necessitant une opotherapie substitutive, etaient distinguees des hypothyroidies transitoires ne relevant pas d’un traitement specifique. Les courbes de survie (SSP et SG) selon la methode de Kaplan-Meier ont ete comparees selon la methode du log-rank. Au total, 29 patients ont ete inclus. Un total de 4/29 ont presente une hypothyroidie permanente sous anti-PD1. 5/29 ont presente un hypermetabolisme thyroidien lors d’au moins une TEP de suivi. Il n’a pas ete mis en evidence d’association significative entre hypermetabolisme thyroidien et SSP (p = 0,83) ou SG (p = 0,61). Un hypermetabolisme thyroidien en TEP au 18FDG au cours du traitement permettait de predire la survenue d’une hypothyroidie definitive avec une sensibilite de 100 % (4/4), une specificite de 96 % (24/25), une valeur predictive positive de 80 % (4/5) et une valeur predictive negative de 100 % (24/24) La presence d’un hypermetabolisme thyroidien au cours du traitement par anticorps anti-PD1 permet de predire precocement la survenue d’une hypothyroidie auto-immune permanente, mais ne semble pas etre associee a la survie des patients sous immunotherapie.

Fourteen patients with proven prostate cancer who underwent FCH PET/CT and multiparametric MRI were enrolled. FCH PET/CT consisted in a dual phase: early pelvic list-mode acquisition and late whole-body acquisition. FCH PET/CT and multiparametric MRI examinations were registered and tumoral volume-of-interest were drawn on the largest lesion visualized on the apparent diffusion coefficient (ADC) map and projected onto the different multiparametric MR images and FCH PET/CT images. Concerning the FCH uptake, kinetic parameters were extracted with the best model selected using the Akaike information criterion between the one- and two-tissue compartment models with an imaging-derived plasma input function. Other FCH uptake parameters (early SUVmean and late SUVmean) were extracted. Concerning functional parameters derived by MRI scan, cell density (ADC from diffusion weighting imaging) and vessel permeability (KThe one-tissue compartment model for kinetic analysis of PET images was selected. Concerning correlation analysis between PET parameters, KNo significant correlation was found between FCH PET/CT and multiparametric MRI metrics except FCH influx which is moderately linked to the vessel permeability in prostate cancer.

The aim of the study was to compare the kinetic analysis ofSixty-one patients were included. PSA was performed few days before FCH PET/CT. Gleason scoring (GS) was collected from systematic sextant biopsies. FCH PET/CT consisted in a dual phase: early pelvic list-mode acquisition (from 0 to10 min post-injection) and late whole-body acquisition (60 min post-injection). PC volume of interest was drawn using an adaptative thresholding (40% of the maximal uptake) on the late acquisition and projected onto an early static frame of 10 min and each of the 20 reconstructed frames of 30 s. Kinetic analysis was performed using an imaging-derived plasma input function. Early kinetic parameter (K1 as influx) and static parameters (early SUVmean, late SUVmean, and retention index) were extracted and compared to clinicopathological parameters.K1 was significantly, but moderately correlated with early SUVmean (r = 0.57, p 0.001) and late SUVmean (r = 0.43, p 0.001). K1, early SUVmean, and late SUVmean were moderately correlated with PSA level (respectively, r = 0.36, p = 0.004; r = 0.67, p 0.001; r = 0.51, p 0.001). Concerning GS, K1 was higher for patients with GS ≥ 4 + 3 than for patients with GS 4 + 3 (median value 0.409 vs 0.272 minFCH influx index K1 seems to be related to GS and could be a non-invasive tool to gain further information concerning tumor aggressiveness.

International audience; The benefit of radiotherapy (RT) after chemotherapy in limited-stage diffuse large B-cell lymphoma (DLBCL) remains controversial. We conducted a randomized trial in patients with nonbulky limited-stage DLBCL to evaluate the benefit of RT after rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Patients were stratified according to the modified International Prognostic Index, including lactate dehydrogenase, Eastern Cooperative Oncology Group performance status, age, and disease stage. The patients received 4 or 6 consecutive cycles of R-CHOP delivered once every 2 weeks, followed or not by RT at 40 Gy delivered 4 weeks after the last R-CHOP cycle. All patients were evaluated by fluorodeoxyglucose-positron emission tomography scans performed at baseline, after 4 cycles of R-CHOP, and at the end of treatment. The primary objective of the trial was event-free survival (EFS) from randomization. The trial randomly assigned 165 patients in the R-CHOP arm and 169 in the R-CHOP plus RT arm. In an intent-to-treat analysis with a median follow-up of 64 months, 5-year EFS was not statistically significantly different between the 2 arms, with 89% ± 2.9% in the R-CHOP arm vs 92% ± 2.4% in the R-CHOP plus RT arm (hazard ratio, 0.61; 95% confidence interval [CI], 0.3-1.2; = .18). Overall survival was also not different at 92% (95% CI, 89.5%-94.5%) for patients assigned to R-CHOP alone and 96% (95% CI, 94.3%-97.7%) for those assigned to R-CHOP plus RT ( = not significant). R-CHOP alone is not inferior to R-CHOP followed by RT in patients with nonbulky limited-stage DLBCL. This trial was registered at www.clinicaltrials.gov as #NCT00841945.

Nuclear medicine offers several techniques and procedures to image infection, but radiolabelled autologous white blood cells (WBCs) are still the gold standard. These cells are usually labelled with 111In or 99mTc bound to a hydrophobic chelating agent that allows these isotopes to pass through the plasma membrane and enter in the cytoplasm. The most common compound in Europe is HMPAO that efficiently chelates 99mTc. However, up to 20–40% of the complex is released from the cells in the first few hours. The aim of this study was to radiolabel a new compound, (S3CPh)2 (S2CPh)-complex (SSS-complex) with 99mTc and compare its binding kinetics and specificity for WBC with HMPAO. The SSS-complex was labelled with 99mTc and analysed by iTLC and RP-HPLC. In vitro quality controls included a stability assay in serum and saline. Results showed a labelling efficiency of 95 ± 1.2% and 98 ± 1.4% for 99mTc-SSS-complex and 99mTc-HMPAO, respectively (p=ns). 99mTc-SSS-complex was stable in serum and in saline up to 24 h (94 ± 0.1%). Cell labelling experiments showed a higher incorporation of 99mTc-SSS-complex than 99mTc-HMPAO by granulocytes (62.6 ± 17.8% vs 40.5 ± 15%, p=0.05), lymphocytes (59.9 ± 22.2% vs 29.4 ± 13.5%; p=0.03), and platelets (44.4 ± 24% vs 20.5 ± 10.7%; p=ns), but the release of radiopharmaceutical from granulocytes at 1 h was lower for HMPAO than for SSS-complex (10.3 ± 1.9% vs 21.3 ± 1.8%; p=0.001). In conclusion, 99mTc-SSS-complex, although showing high labelling efficiency, radiochemical purity, and stability, is not a valid alternative to 99mTc-HMPAO, for example, in vivo white blood cells labelling because of high lymphocyte and platelet uptake and rapid washout from granulocytes.

Introduction La radionecrose est une complication frequente de la radiotherapie stereotaxique des metastases cerebrales. Lors de la surveillance par IRM, l’apparition d’une prise de contraste en zone irradiee ne permet pas toujours de distinguer une radionecrose d’une progression tumorale. L’objectif de cette etude est d’evaluer les performances diagnostiques de la TEP au 18-FDG avec seconde acquisition tardive pour differencier la progression tumorale et radionecrose, en comparant les analyses visuelles et quantitatives. Methodes Pour cette etude monocentrique, ont ete inclus retrospectivement les patients ayant ete traites par radiotherapie stereotaxique pour des metastases cerebrales et presentant une prise de contraste douteuse a l’imagerie morphologique lors de la surveillance. La TEP au 18-FDG comportait deux temps d’acquisition, respectivement a 1 h et 4 h30 apres injection du traceur. Une lesion etait consideree comme evocatrice de progression en analyse visuelle si son metabolisme etait superieur a celui du cortex sain sur les images acquises tardivement (6 sur une echelle validee de 1 a 6) ; en analyse quantitative en cas d’index [(L2/SG2)–(L1/SG1)]/(L1/SG1) > 0,25, (ou L1 et L2 sont les SUVmax de la lesion, et SG1 et SG2 les SUVmax de la substance grise saine, respectivement aux temps precoces et tardives, comme publie en 2011). Ces resultats etaient compares aux analyses anatomopathologiques des lesions lorsqu’elles etaient disponibles, a un suivi IRM d’au moins 6 mois sinon. Les exactitudes diagnostiques et les AUC des analyses visuelles et quantitatives ont ete comparees. Resultats Dix-huit lesions ont ete analysees, chez 16 patients (10 cancers primitifs pulmonaires, 4 mammaires, 2 colorectaux, 1 melanome et 1 UCNT). Sept lesions etaient des progressions (dont 6 prouvees histologiquement). Les sensibilites, specificites et exactitudes diagnostiques etaient respectivement de 71 %, 82 % et 78 % pour l’analyse visuelle au temps tardif et 71 %, 91 % et 83 % pour l’analyse quantitative. Il n’a pas ete mis en evidence de difference significative ni entre les exactitudes diagnostiques (p = 1,0), ni les AUC des analyses visuelles (AUC = 0,86) et quantitatives (AUC = 0,87) (p = 0,81). Conclusion La TEP au 18-FDG avec seconde acquisition tardive permet de distinguer la progression tumorale et radionecrose cerebrale en cas de doute a l’imagerie morphologique, avec une exactitude diagnostique de 83 % en analyse quantitative, sans difference significative avec l’analyse visuelle.

Objectifs Le syndrome de Richter est un syndrome rare qui consiste au developpement d’un lymphome agressif (le plus souvent un lymphome B diffus a grandes cellules (DLBCL)) chez les patients atteints d’une leucemie lymphoide chronique (LLC). Ce syndrome represente un veritable challenge clinique compte tenu de son pronostic tres reserve. Le caractere clonal du DLBCL identique a la LLC sous-jacente est le principal facteur de mauvais pronostic. Extrait de la TEP au 18FDG, le volume metabolique tumoral total (TMTV) est un parametre pronostique deja connu du DLBCL de novo, du lymphome de Hodgkin et du lymphome folliculaire. L’objectif est d’etudier ici son interet pronostique dans la transformation en DLBCL de la LLC, plus simple a rechercher que le caractere clonal. Materiels et methodes Vingt-quatre patients d’âge median de 72 ans atteints d’un DLBCL compliquant une LLC et ayant beneficie d’une TEP au 18FDG au moment du syndrome de Richter entre janvier 2012 et avril 2018 ont ete analyses retrospectivement. La survie globale a ete calculee par methode de Kaplan–Meier. Pour identifier les facteurs associes a la survie globale, nous avons compare les courbes de survie selon le log-rank test apres binarisation des parametres quantitatifs par extraction d’un cut-off par courbe ROC des parametres demographiques (âge et sexe), cliniques (performans status et score IPI), biologiques (LDH et plaquettes), la presence ou non d’un traitement de la LLC au prealable et les parametres extraits de la TEP au 18FDG (score d’Ann Arbor, caractere bulky ou non, SUVmax, SUVmean et TMTV). Le TMTV a ete mesure par segmentation des SUV des masses tumorales ganglionnaires et extra-ganglionnaires, avec un seuil a 41 % du SUVmax de chaque lesion. Resultats Le delai de suivi median etait de 16 mois avec une survie globale de 75 %. Seuls les taux de plaquettes, de LDH, le score IPI et le TMTV etaient predictifs de la survie globale (respectivement p = 0,001 ; p = 0,001 ; p = 0,0048 ; p = 0,0043) avec respectivement un cut-off de 134000/mm3, 827 UI/L, score 2 et 50 cm3. En analyse multivariee, aucun parametre n’etait significativement associe a la survie globale. Conclusion Un TMTV > 50 cm3 mesure par TEP au 18FDG au moment de la transformation en DLBCL de la LLC serait associe a une survie globale plus faible. Ces resultats sont a confirmer avec un plus grand nombre de patients.

International audience; See an invited perspective on this article on page 1043.This multicenter phase II study investigated a selective radiotherapy dose increase to tumor areas with significant (18)F-misonidazole ((18)F-FMISO) uptake in patients with non-small cell lung carcinoma (NSCLC). Methods: Eligible patients had locally advanced NSCLC and no contraindication to concomitant chemoradiotherapy. The (18)F-FMISO uptake on PET/CT was assessed by trained experts. If there was no uptake, 66 Gy were delivered. In (18)F-FMISO-positive patients, the contours of the hypoxic area were transferred to the radiation oncologist. It was necessary for the radiotherapy dose to be as high as possible while fulfilling dose-limiting constraints for the spinal cord and lungs. The primary endpoint was tumor response (complete response plus partial response) at 3 mo. The secondary endpoints were toxicity, disease-free survival (DFS), and overall survival at 1 y. The target sample size was set to demonstrate a response rate of 40% or more (bilateral α = 0.05, power 1-β = 0.95). Results: Seventy-nine patients were preincluded, 54 were included, and 34 were (18)F-FMISO-positive, 24 of whom received escalated doses of up to 86 Gy. The response rate at 3 mo was 31 of 54 (57%; 95% confidence interval [CI], 43%-71%) using RECIST 1.1 (17/34 responders in the (18)F-FMISO-positive group). DFS and overall survival at 1 y were 0.86 (95% CI, 0.77-0.96) and 0.63 (95% CI, 0.49-0.74), respectively. DFS was longer in the (18)F-FMISO-negative patients (P = 0.004). The radiotherapy dose was not associated with DFS when adjusting for the (18)F-FMISO status. One toxic death (66 Gy) and 1 case of grade 4 pneumonitis (>66 Gy) were reported. Conclusion: Our approach results in a response rate of 40% or more, with acceptable toxicity. (18)F-FMISO uptake in NSCLC patients is strongly associated with poor prognosis features that could not be reversed by radiotherapy doses up to 86 Gy.

The ability to predict tumor recurrence after chemoradiotherapy of locally advanced cervical cancer is a crucial clinical issue to intensify the treatment of the most high-risk patients. The objective of this study was to investigate tumor metabolism characteristics extracted from pre- and per-treatment

International audience; PURPOSE: In the context of oropharyngeal cancer treated with definitive radiotherapy, the aim of this retrospective study was to identify the best threshold value to compute metabolic tumor volume (MTV) and/or total lesion glycolysis to predict local-regional control (LRC) and disease-free survival. METHODS: One hundred twenty patients with a locally advanced oropharyngeal cancer from 2 different institutions treated with definitive radiotherapy underwent FDG PET/CT before treatment. Various MTVs and total lesion glycolysis were defined based on 2 segmentation methods: (i) an absolute threshold of SUV (0-20 g/mL) or (ii) a relative threshold for SUVmax (0%-100%). The parameters' predictive capabilities for disease-free survival and LRC were assessed using the Harrell C-index and Cox regression model. RESULTS: Relative thresholds between 40% and 68% and absolute threshold between 5.5 and 7 had a similar predictive value for LRC (C-index = 0.65 and 0.64, respectively). Metabolic tumor volume had a higher predictive value than gross tumor volume (C-index = 0.61) and SUVmax (C-index = 0.54). Metabolic tumor volume computed with a relative threshold of 51% of SUVmax was the best predictor of disease-free survival (hazard ratio, 1.23 [per 10 mL], P = 0.009) and LRC (hazard ratio: 1.22 [per 10 mL], P = 0.02). CONCLUSIONS: The use of different thresholds within a reasonable range (between 5.5 and 7 for an absolute threshold and between 40% and 68% for a relative threshold) seems to have no major impact on the predictive value of MTV. This parameter may be used to identify patient with a high risk of recurrence and who may benefit from treatment intensification.

International audience; A 75-year-old man with a history of prostate cancer was referred to our department to perform F-choline (FCH) PET/CT. FCH PET/CT showed a markedly increased uptake in the right temporoparietal junction brain. Three weeks earlier, acute ischemic stroke was diagnosed in the right temporoparietal junction brain on diffusion-weighted sequence and thrombosis in a distal branch of the right middle cerebral artery on MR angiography. Choline precursors promote repair and growth of cell membranes in neurologic diseases, so FCH PET/CT uptake could be explained by repair processes during early outcome of acute ischemic stroke.

Introduction et but de l’etude La majorite de ces recidives apres radiotherapie des tumeurs ORL se situe dans le site tumoral initial. Cependant, la sous-region precise a l’origine de la recidive reste a identifier pour un eventuel complement d’irradiation. L’objectif de cette etude etait de predire sur la tomographie par emission de positrons (TEP) pretherapeutique les voxels de la sous-region tumorale a l’origine de la recidive. Materiel et methodes Les dossiers de 26 patients pris en charge par chimioradiotherapie pour un cancer de la sphere ORL localement evolue et ayant ete atteints d’une recidive tumorale ont ete analyses. Apres delineation de la recidive sur la TEP post-therapeutique, un recalage rigide a ete realise avec la TEP pretherapeutique. L’union entre le volume de recidive et la tumeur initiale a ete definie sur la TEP pretherapeutique comme etant le volume a l’origine de la recidive. Une analyse radiomique a ete realisee sur la TEP pretherapeutique pour generer, par random forest avec validation croisee par leave one out, un modele de prediction de la recidive a l’echelle du voxel. Resultats et analyse statistique Apres un recalage personnalise, le resultat a ete juge satisfaisant pour 16 patients dont les dossiers ont ete finalement analyses. Le volume de recidive couvrait en moyenne 23 % du volume tumoral macroscopique. Les parametres de la TEP classiques (standard uptake value [SUV], volume tumoral metabolique, glycolyse lesionnelle totale) ne permettaient pas d’identifier le volume initial a l’origine de la recidive. L’association de 15 parametres de textures de la TEP et de la scanographie a permis d’identifier la sous-region a l’origine de la recidive avec une AUC (aire sous la courbe) mediane de 0,71 (0,14–0,91). Conclusion Une analyse des caracteristiques de la TEP prenant en compte l’information spatiale de relation entre les differents voxels de la tumeur initiale permet de predire la localisation de la recidive. Une validation plus large de cette approche pourrait conduire a une escalade de dose tres ciblee dans la sous-region tumorale a haut risque de recidive.

Introduction et but de l’etude L’objectif de cette etude etait de developper et d’evaluer une signature radiomique en utilisant l’imagerie tomographique par emission de positons (TEP/TDM) chez des patients atteints d’un cancer du poumon non a petites cellules traites par irradiation stereotaxique. Materiel et methodes Il s’agit d’une etude retrospective multicentrique portant sur 87 patients atteints d’un atteints d’un cancer du poumon non a petites cellules de stade T1-T2 traite dans quatre centres du Grand Ouest. Les patients des trois premiers centres (n = 27, 29 et 8) constituaient le groupe d’apprentissage, et ceux du quatrieme (n = 23) le groupe de validation. Le critere d’evaluation principal etait le controle local. En tout, 184 parametres radiomiques ont ete extraits (92 de chaque modalite) et sept parametres cliniques, histologiques et therapeutiques ont ete consideres. En raison des differents scanographes et protocoles d’acquisition des institutions, nous avons utilise la methode ComBat pour harmoniser les parametres de texture. Resultats et analyse statistique En analyse unifactorielle, deux parametres issus de la TEP et deux de la scanographie etaient significativement predictifs du controle local, a l’inverse des variables cliniques. Le meilleur modele predictif du groupe d’apprentissage etait obtenu en associant deux parametres TEP (IC2 et strength), avec une sensibilite de 100 % et une specificite de 88 %, et un hazard ratio indefini (p Conclusion Notre etude a permis d’identifier deux parametres de textures derives de la TEP/scanographie comme facteurs predictifs independants associes a la recidive locale chez les patients atteints d’un cancer du poumon non a petites cellules traites par irradiation stereotaxique. Ce modele merite d’etre confirme sur une cohorte plus consequente et pourrait etre utilise en clinique pour guider une eventuelle escalade de dose.