Induction chemotherapy followed by low-dose involved-field radiotherapy for intracranial germ cell tumors

Abstract

Purpose: To investigate the efficacy of chemotherapy followed by low-dose involved-field radiotherapy for the treatment of intracranial germ cell tumors (GCTs).

Patients and methods: Thirty-three patients with GCTs, including 16 pure germinomas, 11 human chorionic gonadotropin-beta (HCG-beta)-secreting germinomas, three mixed GCTs composed of immature teratomas plus germinomas (IMT/G), and three highly malignant mixed GCTs, were treated. Etoposide and cisplatin (EP) were used for the treatment of solitary pure germinomas, and ifosfamide, cisplatin, and etoposide (ICE) were used for the treatment of other GCTs. The dose schedule was 24 Gy for germinomas and 40 to 54 Gy for other GCTs. An involved-field set-up was used except for highly malignant GCTs, in which craniospinal irradiation was used. The median follow-up was 58 months (range, 18 to 102 months).

Results: Disease-related, overall, and relapse-free survival rates at 5 years were 100%, 93%, and 69% for all patients, 100%, 100%, and 86% for patients with pure germinomas, and 100%, 75%, and 44% for patients with HCG-beta-secreting germinomas, respectively. All six patients with nongerminomatous GCTs were alive at the last follow-up. All eight relapses (one pure germinoma, five HCG-beta-secreting germinomas, and two IMT/G), except one in a course of salvage treatment, were salvaged and free of disease at the last follow-up. No decline was observed in the full-scale, verbal, or performance intelligence quotient at 12 to 51 months after the treatment in 11 patients.

Conclusion: Our results support an excellent prognosis after EP and ICE regimens followed by radiotherapy. Dose and volume can be reduced to 24 Gy in 12 fractions and involve a field set-up after EP chemotherapy for the treatment of pure germinomas.