Intensive chemotherapy followed by reduced-dose radiotherapy for biopsy-proven CNS germinoma with elevated beta-human chorionic gonadotropin

Abstract

In this study, 10 patients with biopsy-proven germinoma with a beta-human chorionic gonadotropin (β-HCG) level >50 mIU/ml received intensive chemotherapy followed by reduced-dose radiotherapy (RT) to reduce late effects from RT. CSF β-HCG levels were >200 mIU/ml in five patients. After endoscopic or stereotactic biopsy, four cycles of induction chemotherapy were administered prior to RT. A CEB regimen (carboplatin+etoposide+bleomycin) and a CyEB regimen (cyclophosphamide+etoposide+bleomycin) were alternated. No residual tumor remained after induction chemotherapy in six patients, only cystic lesions were present at the primary tumor site in three, and a small solid residual tumor was observed in the remaining patient; however, all these patients had normal β-HCG levels. If complete response was achieved before initiation of RT, 19.5Gy craniospinal RT (CSRT)+10.8Gy local RT was administered to the tumor bed. If residual lesion was suspected, the dose of RT was selected according to the presence/absence of tumor dissemination at diagnosis (19.5Gy CSRT+19.8Gy local RT for localized tumors and 24.0Gy CSRT+16.2Gy local RT for disseminated tumors). Eight patients, including four patients with a β-HCG level >200mIU/ml, received 19.5Gy CSRT. All patients remain disease free at a median follow-up of 58 (range 35-94) months from diagnosis. Our data suggest that pathologically pure germinoma with a significantly elevated β-HCG level might be cured with reduced-dose RT if intensive chemotherapy is provided.