Upfront chemotherapy followed by response adaptive radiotherapy for intracranial germinoma: Prospective multicenter cohort study

Abstract

Purpose: To assess the efficacy of upfront chemotherapy followed by response-adapted reduced-dose/reduced-volume radiotherapy (RT) for intracranial germinoma.

Materials and methods: Ninety-one patients from five institutions were registered in the KSPNO G051/G081 Protocol. Germinomas were classified as solitary or multiple/disseminated diseases, and upfront chemotherapy was administered. For all patients with multiple or disseminated disease, and patients with partial response after chemotherapy, 19.5-24 Gy of craniospinal irradiation plus 10.8-19.8 Gy of tumor bed boost were planned. For patients with complete response (CR), reduced-dose RT (30.6 Gy) was planned, along with a reduced field for solitary lesions.

Results: The median patient age was 14 (range, 3-30) years. Sixty-five patients (71.4%) had a solitary lesion. The median follow-up duration was 67.9 (range, 6.6-119.3) months. Recurrence was not observed in 32 patients in the protocol compliant group. Four patients (4.4%) in the protocol non-compliant group experienced relapse after CR and one patient died of the disease. The 5-year and 7-year overall survival rates were 98.8% and 98.8%, while the corresponding event-free survival rates were 96.6% and 93.8%, respectively. All three patients with basal ganglia germinomas who were treated with local RT experienced recurrence outside the RT field. Among the 23 patients with pineal or suprasellar lesions who received whole-ventricle RT, there was no recurrence.

Conclusions: Currently used upfront chemotherapy followed by reduced-dose, reduced-volume RT appears acceptable, when whole-ventricle RT for pineal or suprasellar tumors and, at minimum, whole-brain RT for basal ganglia/thalamus lesions are applied.

Keywords: Chemotherapy; Craniospinal irradiation; Germinoma; Radiotherapy.