Chemotherapy Combined With Radiation Therapy for Newly Diagnosed CNS AT/RT

RATIONALE: Drugs used in chemotherapy work in different ways to stop tumor cells from dividing so they stop growing or die. Radiation therapy uses high-energy x-rays to damage tumor cells. Giving more than one chemotherapy drug with radiation therapy may kill more tumor cells. PURPOSE: This phase II trial is studying how well giving intrathecal and systemic combination chemotherapy together with radiation therapy works in treating young patients with newly diagnosed central nervous system (CNS) atypical teratoid/rhabdoid tumors.