Diagnostic and prognostic value of FDG-PET/CT in recurrent germinal tumor carcinoma

522 Objectives several studies have discussed the performance of FDG-PET/CT for the restaging of patients (pts) with germinal tumor carcinoma (GTC), although with divergent results. However, its prognostic role remains still undefined. The aims of this multicentre retrospective study were to evaluate the accuracy, the effects on treatment decision and the prognostic value of FDG-PET/CT in pts with suspicious of recurrent GTC. Methods data from 114 patients affected by GTC, who underwent 18F-FDG PET/CT for suspicious of recurrent disease were collected. The diagnostic accuracy of visually interpreted FDG-PET/CT was obtained by considering histology (n=17 pts), other diagnostic imaging modalities (i.e. contrast enhanced CT in 89 pts and MRI in 15 pts) and clinical follow-up (n=114 pts). Progression-free survival (PFS) and overall survival (OS) were assessed by using Kaplan-Meier method. The risk of progression (Hazard Ratio-HR) was computed by univariate Cox regression analysis by considering allavailablevariable. Results suspicious of recurrent GTC was confirmed in 47/52 pts with a positive PET/CT scan, respectively in 18 and 29 pts, by histology and other diagnostic imaging modalities/follow-upin. Overall, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of FDG-PET/CT were 88,7%, 91,8%, 90,4%, 90,3%, and 90,3% respectively. FDG-PET/CT findings influenced the therapeutic management in 26 cases (23%). After 2 years of follow-up, PFS was significantly longer in pts with a negative vs. a positive PET/CT scan (95% vs 44%, p Conclusions FDG-PET/CT has a high diagnostic performance in pts with suspicious of recurrent GTC and provided a change in treatment decision in about 25% of cases. Moreover, FDG PET/CT has an important prognostic value in assessing the risk of disease progression and overall survival in this setting of pts.