18F-Fluorodeoxyglucose positron emission tomography in the management of patients with thymic epithelial tumors
Menée sur 56 patients atteints d'une tumeur épithéliale du thymus non résécable et de stade III ou IV selon la classification de Masaoka, cette étude évalue l'intérêt d'une tomographie numérique par émission de positrons à base de fluorodésoxyglucose (18F) pour surveiller, en mesurant la réponse métabolique précoce, l'efficacité d'un traitement et identifier les différences histologiques entre les patients
Purpose: There is limited data regarding the role of 18F-Fluorodeoxyglucose positron emission tomography ([18F]-FDG PET) imaging in management of patients with thymic epithelial tumors (TET). The primary objective of this study was to assess the usefulness of early [18F]-FDG PET to monitor treatment efficacy and its correlation with Response Evaluation Criteria in Solid Tumors (RECIST) in patients with TETs. Experimental Design: [18F]-FDG PET/CT scans were performed at baseline and after six weeks of treatment in patients enrolled in two phase II and one phase I/II clinical trials. Based on data from other solid tumors, metabolic response was defined as a reduction of [18F]-FDG uptake by more than 30% as assessed by average standardized uptake values (SUV) of up to five most metabolically active lesions. Results: Fifty six patients with unresectable Masaoka stage III or IV TETs were included. There was a close correlation between early metabolic response and subsequent best response using RECIST (P <0.0001 to 0.0003): sensitivity and specificity for prediction of best response were 95% and 100% respectively. Metabolic responders had significantly longer progression-free survival (median 11.5 vs. 4.6 months, P = 0.044) and a trend towards longer overall survival (median 31.8 vs. 18.4 months, P = 0.14) than non-responders. [18F]-FDG uptake was significantly higher in thymic carcinoma compared with thymoma (P= 0.0004 to 0.0010). Conclusions: In patients with advanced TETs, early metabolic response closely correlates with outcome of therapy. [18F]-FDG PET may be used to monitor treatment efficacy and assess histological differences in patients with advanced TETs.
Clinical Cancer Research , résumé, 2013