Etoposide Plus Radiation Therapy Followed by Combination Chemotherapy in Treating Children With Newly Diagnosed Advanced Medulloblastoma

OBJECTIVES: * Assess the response rate and toxicity of oral etoposide and radiotherapy in children with newly diagnosed high stage medulloblastoma. * Compare the response rate and toxicity of these patients to historical control patients registered on POG #9031. * Estimate the 2-year event-free survival and overall survival of these patients. * Evaluate the toxicity of dose intensive chemotherapy with oral etoposide, cisplatin, cyclophosphamide, and vincristine following craniospinal irradiation in these patients. OUTLINE: Patients begin treatment within 1 month of surgery. Patients receive 6 weeks of radiotherapy to the head and spine, with boosts to the posterior fossa and to sites of metastasis. Patients also receive 2 courses of oral etoposide once daily for 3 weeks concurrent with and immediately following radiotherapy (weeks 1-3 and 5-7). Patients then receive adjuvant chemotherapy consisting of cisplatin IV once every 4 weeks for 3 courses beginning on week 11, oral etoposide daily for 21 days every 4 weeks for 3 courses (weeks 11, 15, and 19), cyclophosphamide IV on days 1 and 2 with filgrastim (G-CSF) SQ daily for at least 10 days every 4 weeks for 8 courses (weeks 23-51), and vincristine IV on days 1, 8, and 15 every 4 weeks for 8 courses (weeks 23-51). Patients are followed every 3 months for 1 year, every 4 months for 1 year, every 6 months for 1 year, and annually thereafter. PROJECTED ACCRUAL: A total of 48 patients will be accrued for this study within about 2 years.