S0001 RT and Carmustine With or Without O6BG in Patients With New Glioblastoma Multiforme or Gliosarcoma

RATIONALE: Drugs used in chemotherapy use 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. O6-benzylguanine may help carmustine kill more tumor cells by making tumor cells more sensitive to the drug. It is not yet known whether radiation therapy and carmustine are more effective with or without O6-benzylguanine. PURPOSE: Randomized phase III trial to compare the effectiveness of radiation therapy plus carmustine with or without O6-benzylguanine in treating patients who have newly diagnosed glioblastoma multiforme or gliosarcoma.