Semi-ResMass Study: Residual masses after salvage chemotherapy in men with pure seminoma—A multicenter retrospective analysis.

420 Background: Only scarce data exist on the management of residual masses in men who have received two lines of chemotherapy for advanced seminoma. Due to the lack of data, the role of PET scanning, surgery and other additional treatments is controversial in these men. Methods: Data from men with pure seminoma and residual masses after salvage chemotherapy were retrospectively collected from 10 high-volume centers in 3 European countries. We analyzed the clinical management of residual masses (imaging, surgery, pathological data, and additional treatment modalities) and long-term outcomes. Residual mass was defined as a lesion of ≥1 cm after two lines of platin-based chemotherapy. Result…