Arsenic Trioxide, Temozolomide, and Radiation Therapy in Treating Patients With Malignant Glioma That Has Been Removed By Surgery

DISEASE CHARACTERISTICS: Histologically confirmed supratentorial malignant glioma of 1 of the following types: Glioblastoma multiforme Gliosarcoma Anaplastic astrocytoma Anaplastic oligodendroglioma Anaplastic mixed gliomas Anaplastic gliomas not otherwise specified Has undergone surgical resection of tumor Patients with biopsy only are eligible Evaluable or measurable disease following resection of recurrent tumor is not mandated for entry into the study No brain metastases PATIENT CHARACTERISTICS: Karnofsky performance status 60-100% Life expectancy > 3 months WBC > 3,000/mm^3 Absolute neutrophil count > 2,000/mm^3 Platelet count > 100,000/mm^3 Hemoglobin > 10 g/dL (eligibility level for hemoglobin may be reached by transfusion) Creatinine ≤ 1.5 mg/dL Bilirubin ≤ 2 mg/dL Transaminases ≤ 2 times the upper limit of normal Serum potassium* > 4.0 mEq/dL Serum magnesium* > 1.8 mg/dL NOTE: *If these serum electrolytes are below the specified limits on the baseline laboratory tests, supplemental electrolytes should be administered to bring the serum concentrations to these levels before administering arsenic trioxide Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 3 months after completion of study treatment No second-degree heart block QT interval ≤ 460 msec No other malignancy within the past 3 years except curatively treated carcinoma in situ or basal cell carcinoma of the skin Patients who cannot undergo MRI are not eligible for this study No other serious concurrent infection or other medical illness that would jeopardize the ability of the patient to receive the therapy in this protocol with reasonable safety PRIOR CONCURRENT THERAPY: See Disease Characteristics Patients must have recovered from the effects of surgery prior to the start of treatment (10-14 days minimum) and be maintained on a stable corticosteroid regimen for 5 days Concurrent glucocorticoid therapy allowed at the smallest effective dose Patients must be on non-enzyme-inducing anti-convulsants to minimize any drug reaction No prior radiation therapy, chemotherapy, immunotherapy, therapy with biologic agents (including immunotoxins, immunoconjugates, antisense agents, peptide receptor antagonists, interferons, interleukins, tumor-infiltrating lymphocytes, lymphokine-activated killer cells, or gene therapy), or hormonal therapy for their brain tumor