RATIONALE: Drugs used in chemotherapy work in different ways to stop tumor cells from dividing so they stop growing or die. Giving a chemotherapy drug before surgery may shrink the tumor so that it is no longer present by conventional imaging and tumor markers from serum and cerebrospinal fluid. Radiation therapy uses high-energy x-rays to damage tumor cells. Peripheral stem cell transplantation may allow the doctor to give higher doses of chemotherapy drugs and kill more tumor cells. Combining different types of therapy may kill more tumor cells.