PRIOR CONCURRENT THERAPY: Biologic therapy: No prior immunotherapy or biologic agents (e.g., immunotoxins, immunoconjugates, antisense, peptide receptor antagonists, interferons, interleukins, lymphokine activated killer cells, tumor infiltrating lymphocytes, or gene therapy) for brain tumor Chemotherapy: No prior chemotherapy for brain tumor Endocrine therapy: No prior hormonal therapy for brain tumor Prior glucocorticoids allowed Maintenance 5 day stable corticosteroid regimen required postsurgery Radiotherapy: No prior radiotherapy for brain tumor Surgery: Prior surgery for brain tumor allowed if recovered from the immediate post operative period