An Intergroup Pilot Study of Concurrent Carboplatin, Vincristine and Radiotherapy Followed by Adjuvant Chemotherapy in Patients With Newly Diagnosed High-Risk Central Nervous System Embryonal Tumors

OBJECTIVES: Determine the feasible dose and duration of carboplatin combined with craniospinal and local radiotherapy and adjuvant chemotherapy in children with newly diagnosed, high-risk CNS embryonal tumors (Phase I completed as of 11-25-03). Determine the feasibility of administering cyclophosphamide and vincristine with or without cisplatin after concurrent carboplatin, vincristine, and radiotherapy in these patients. Determine the overall and individual toxicity rates of this regimen in these patients. Determine the complete response rate in patients treated with this regimen. Obtain preliminary estimates of event-free survival of patients treated with this regimen. Determine the prognostic significance of enhancing tumor after completion of radiotherapy on event-free survival of these patients. OUTLINE: This is a pilot, dose-escalation study of carboplatin. (Phase I completed as of 11-25-03.) Within 31 days of definitive surgery, all patients receive vincristine IV weekly for 6 weeks and carboplatin IV over 15-20 minutes (after completion of vincristine infusion) 5 days a week for 6 weeks. Patients undergo radiotherapy (1-4 hours after carboplatin infusion) 5 days a week for 6 weeks. Cohorts of 6-12 patients receive escalating doses of carboplatin until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which no more than 3 of 12 patients experience dose-limiting toxicity. (Phase I completed as of 11-25-03.) At 6 weeks after completion of radiotherapy, patients are assigned to arm II for adjuvant/maintenance chemotherapy. (Arm I closed to accrual as of 11-25-03.) Arm I (closed to accrual as of 11-25-03): Patients receive cyclophosphamide IV over 1 hour on days 0 and 1, vincristine IV on days 0 and 7, and filgrastim (G-CSF) IV or subcutaneously (SC) beginning on day 2 and continuing for at least 10 days until blood counts recover. Arm II: Patients receive cyclophosphamide IV over 1 hour on days 1 and 2, vincristine IV on days 0 and 7, cisplatin IV over 6 hours on day 0, and G-CSF IV or SC beginning on day 3 and continuing for at least 10 days until blood counts recover. In both arms, adjuvant/maintenance chemotherapy repeats every 4 weeks for 6 courses. Patients are followed every 3 months for 8 months, every 4 months for 1 year, every 6 months for 2 years, and then annually thereafter. PROJECTED ACCRUAL: A total of 162 patients will be accrued for this study.