Recommandations pour la réalisation d’un examen de tomographie par émission de positons aux ligands de l’antigène membranaire spécifique de la prostate

International audienceProstate-specific membrane antigen targeting positron emission tomography (PSMA-PET) is nowadays widely used for the management of patients with prostate cancer during natural history of the disease. Several radiopharmaceuticals labeled with Gallium-68 and Fluor-18 are now available in France, some of which have obtained marketing authorization in various indications. Patient preparation and image acquisition protocols differ from one radiopharmaceutical to another. The objective of this article is to provide practical guidelines regarding PET-PSMA protocols, for radiopharmaceuticals labeled with Gallium-68 or Fluor-18, to facilitate implementation in clinical routine in nuclear medicine departments in France.La tomographie par émission de positons aux ligands de l’antigène membranaire spécifique de la prostate (TEP-PSMA) est de plus en plus utilisée en France pour la prise en charge de patients porteurs de cancer de la prostate. Plusieurs radiopharmaceutiques marqués au Gallium-68 et au Fluor-18 sont désormais disponibles en France, dont certains ont obtenu une autorisation de mise sur le marché dans diverses indications. La préparation des patients et les protocoles d’acquisition des images diffèrent d’un radiopharmaceutique à l’autre. L’objectif de cet article est de fournir des recommandations pratiques concernant les protocoles de réalisation des examens par TEP-PSMA marqués au Gallium-68 et au Fluor-18, pour faciliter l’implémentation en routine clinique dans les services de médecine nucléaire en France

Tomographie par émission de positons aux ligands de l’antigène membranaire spécifique de la prostate (TEP-PSMA) dans le cancer de la prostate : classification PSMA-RADS et critères PROMISE

International audienceProstate-specific membrane antigen targeting positron emission tomography (PSMA-PET) is nowadays widely used for the management of patients with prostate cancer during natural history of the disease. PSMA is not specific to prostate tissue, many benign and malignant diseases unrelated to prostate cancer are frequently found on PSMA-PET examinations, leading to false positives results and potentially to inadequate patient management. Various interpretation criteria have been proposed within classifications in order to standardize and homogenize PSMA-PET interpretation. This article describes, on the one hand the PSMA-RADS classification, and on the other hand the PROMISE criteria

Voxel-based identification of local recurrence sub-regions from pre-treatment PET/CT for locally advanced head and neck cancers

International audienceBackground - Overall, 40% of patients with a locally advanced head and neck cancer (LAHNC) treated by chemoradiotherapy (CRT) present local recurrence within 2 years after the treatment. The aims of this study were to characterize voxel-wise the sub-regions where tumor recurrence appear and to predict their location from pre-treatment F-fluorodeoxyglucose (FDG) positron emission tomography (PET) images. Materials and methods - Twenty-six patients with local failure after treatment were included in this study. Local recurrence volume was identified by co-registering pre-treatment and recurrent PET/CT images using a customized rigid registration algorithm. A large set of voxel-wise features were extracted from pre-treatment PET to train a random forest model allowing to predict local recurrence at the voxel level. Results - Out of 26 expert-assessed registrations, 15 provided enough accuracy to identify recurrence volumes and were included for further analysis. Recurrence volume represented on average 23% of the initial tumor volume. The MTV with a threshold of 50% of SUVmax plus a 3D margin of 10 mm covered on average 89.8% of the recurrence and 96.9% of the initial tumor. SUV and MTV alone were not sufficient to identify the area of recurrence. Using a random forest model, 15 parameters, combining radiomics and spatial location, were identified, allowing to predict the recurrence sub-regions with a median area under the receiver operating curve of 0.71 (range 0.14-0.91). Conclusion - As opposed to regional comparisons which do not bring enough evidence for accurate prediction of recurrence volume, a voxel-wise analysis of FDG-uptake features suggested a potential to predict recurrence with enough accuracy to consider tailoring CRT by dose escalation within likely radioresistant regions

Characterization of recurrence origin using pre-treatment PET/CT for head and neck cancers

International audienc

Assessment of Glioma Aggressiveness Using Dynamic FDOPA PET/CT

International audienc

Impact of Point-Spread Function Reconstruction on Dynamic and Static FDOPA PET/CT Quantitative Parameters in Glioma

International audienceMeeting AbstractOP-066

Baseline [(18)F]FDG PET features are associated with survival and toxicity in patients treated with CAR T cells for large B cell lymphoma

International audiencePURPOSE: Chimeric antigen receptor (CAR) T cells have established themselves as an effective treatment for refractory or relapsed large B cell lymphoma (LBCL). Recently, the sDmax, which corresponds to the distance separating the two farthest lesions standardized by the patient’s body surface area, has appeared as a prognostic factor in LBCL. This study aimed to identify [(18)F]FDG-PET biomarkers associated with prognosis and predictive of adverse events in patients treated with CAR T cells. METHODS: Patients were retrospectively included from two different university hospitals. They were being treated with CAR T cells for LBCL and underwent [(18)F]FDG-PET just before CAR T cell infusion. Lesions were segmented semi-automatically with a threshold of 41% of the maximal uptake. In addition to clinico-biological features, sDmax, total metabolic tumor volume (TMTV), SUVmax, and uptake intensity of healthy lymphoid organs and liver were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The occurrence of adverse events, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), was reported. RESULTS: Fifty-six patients were included. The median follow-up was 9.7 months. Multivariate analysis showed that TMTV (cut-off of 36 mL) was an independent prognostic factor for PFS (p < 0.001) and that sDmax (cut-off of 0.15 m(-1)) was an independent prognostic factor for OS (p = 0.008). Concerning the occurrence of adverse events, a C-reactive protein level > 35 mg/L (p = 0.006) and a liver SUVmean > 2.5 (p = 0.027) before CAR T cells were associated with grade 2 to 4 CRS and a spleen SUVmean > 1.9 with grade 2 to 4 ICANS. CONCLUSION: TMTV and sDmax had independent prognostic values, respectively, on PFS and OS. Regarding adverse events, the mean liver and spleen uptakes were associated with the occurrence of grade 2 to 4 CRS and ICANS, respectively. Integrating these biomarkers into the clinical workflow could be useful for early adaptation of patients management

Value of 18F-FDG PET/CT for therapeutic assessment of patients with polymyalgia rheumatica receiving tocilizumab as first-line treatment

International audienc