Surgery Followed by Radiation Therapy in Treating Patients With Newly Diagnosed Glioblastoma Multiforme

DISEASE CHARACTERISTICS: Clinically suspected supratentorial grade IV glioblastoma multiforme Candidate for maximal surgical resection of tumor mass Expected residual enhancing tumor must be within the expected brachytherapy treatment volume Resection must not be expected to result in a new permanent neurologic deficit No clearly multi-focal disease (2 or more separate foci of contrast-enhancing tumor not all within the expected brachytherapy prescription volume by MRI) No enhancing tumor greater than 1 cm beyond the midline by MRI No grossly or radiographically apparent leptomeningeal spread and/or ventricular invasion outside the anticipated radiation treatment volume No marked edema by MRI with significant shift that is not anticipated to be corrected by resection PATIENT CHARACTERISTICS: Age 18 and over Performance status Karnofsky 60-100% Life expectancy Not specified Hematopoietic Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Hepatic Not specified Renal Creatinine no greater than 1.7 mg/dL BUN no greater than 2 times upper limit of normal Cardiovascular No uncontrolled hypertension No unstable angina pectoris No uncontrolled cardiac dysrhythmia Other Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Mini mental state exam score at least 15 No other concurrent medical illness that would preclude study participation No concurrent serious infection No other malignancy within the past 5 years except curatively treated carcinoma in situ of the cervix or nonmelanoma skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy No immunotherapy prior to, during, or within 90 days after brachytherapy No biologic therapy with any of the following prior to, during, or within 90 days after brachytherapy : Immunotoxins Immunoconjugates Antiangiogenesis compounds Peptide receptor antagonists Interferons Interleukins Tumor-infiltrating lymphocytes Lymphokine-activated killer cells Gene therapy Antisense agents Chemotherapy No chemotherapy or polifeprosan 20 with carmustine implant (Gliadel wafers) prior to, during, or within 90 days after brachytherapy Endocrine therapy No hormonal therapy prior to, during, or within 90 days after brachytherapy Concurrent corticosteroids to improve quality of life allowed Radiotherapy No other radiotherapy prior to, during, or within 90 days after brachytherapy Surgery See Disease Characteristics No radiosurgery prior to, during, or within 90 days after brachytherapy Other No other investigational agents directed at the brain tumor prior to, during, or within 90 days after brachytherapy Concurrent noncytotoxic therapy to improve quality of life allowed