Questioning the value of fluorodeoxyglucose positron emission tomography for residual lesions after chemotherapy for metastatic seminoma: Results of an International Global Germ Cell Cancer Group Registry

Richard Cathomas, Dirk Klingbiel, Brandon Bernard, Anja Lorch, Xavier Garcia del Muro, Franco Morelli, Ugo De Giorgi, Mikhail Fedyanin, Christoph Oing, Hege Sagstuen Haugnes, Marcus Hentrich, Christian Fankhauser, Silke Gillessen, Jörg Beyer

Research output: Contribution to journalArticlepeer-review

Abstract

Purpose Residual lesions after chemotherapy are frequent in metastatic seminoma. Watchful waiting is recommended for lesions, < 3 cm as well as for fluorodeoxyglucose (FDG) positron emission tomography (PET)–negative lesions ≥ 3 cm. Information on the optimal management of PET-positive residual lesions ≥ 3 cm is lacking. Patients and Methods We retrospectively identified 90 patients with metastatic seminoma with PET-positive residual lesions after chemotherapy. Patients with elevated α-fetoprotein or nonseminomatous histology were excluded. We analyzed the post-PET management and its impact on relapse and survival and calculated the positive predictive value (PPV) for PET. Results Median follow-up time was 29 months (interquartile range [IQR], 10 to 62 months). Median diameter of the largest residual mass was 4.9 cm (range, 1.1 to 14 cm), with masses located in the retroperitoneum (77%), pelvis (16%), mediastinum (17%), and/or lung (3%). Median time from the last day of chemotherapy to PET was 6.9 weeks (IQR, 4.4 to 9.9 weeks). Post-PET management included repeated imaging in 51 patients (57%), resection in 26 patients (29%), biopsy in nine patients (10%) and radiotherapy in four patients (4%). Histology of the resected specimen was necrosis in 21 patients (81%) and vital seminoma in five patients (19%). No biopsy revealed vital seminoma. Relapse or progression occurred in 15 patients (17%) after a median of 3.7 months (IQR, 2.5 to 4.9 months) and was found in 11 (22%) of 51 patients on repeated imaging, in two (8%) of 26 patients after resection, and in two (22%) of nine patients after biopsy. All but one patient who experienced relapse were successfully treated with salvage therapy. The PPV for FDG-PET was 23%. Conclusion FDG-PET has a low PPV for vital tumor in residual lesions after chemotherapy in patients with metastatic seminoma. This cautions against clinical decisions based on PET positivity alone.

Original languageEnglish
Pages (from-to)3381-3387
Number of pages7
JournalJournal of Clinical Oncology
Volume36
Issue number34
DOIs
Publication statusPublished - Dec 1 2018

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Fingerprint Dive into the research topics of 'Questioning the value of fluorodeoxyglucose positron emission tomography for residual lesions after chemotherapy for metastatic seminoma: Results of an International Global Germ Cell Cancer Group Registry'. Together they form a unique fingerprint.

Cite this