Chemotherapy and Radiation Therapy in Treating Young Patients With Newly Diagnosed, Previously Untreated, High-Risk Medulloblastoma/PNET

This phase III trial studies different chemotherapy and radiation therapy regimens to compare how well they work in treating young patients with newly diagnosed, previously untreated, high-risk medulloblastoma. Chemotherapy drugs, such as vincristine sulfate, cisplatin, cyclophosphamide, and carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving more than one drug (combination chemotherapy) may kill more tumor cells. Radiation therapy uses high-energy x-rays, particles, or radioactive seeds to kill tumor cells and shrink tumors. Carboplatin may make tumor cells more sensitive to radiation therapy. It is not yet known which chemotherapy and radiation therapy regimen is more effective in treating brain tumors.