Arsenic Trioxide and Radiation Therapy in Treating Young Patients With Newly Diagnosed Gliomas

DISEASE CHARACTERISTICS: Diagnosis of 1 of the following: Clinical and neuroradiographic findings consistent with intrinsic pontine glioma Histologically confirmed anaplastic astrocytoma, glioblastoma multiforme, or gliosarcoma Multifocal high-grade gliomas allowed No exophytic tumors No focal lesions No underlying diagnosis of neurofibromatosis No tumors originating in anatomic structures adjacent to the cerebellar peduncle or cervical medullary junction PATIENT CHARACTERISTICS: Age 3 to 21 Performance status Karnofsky 60-100% OR Lansky 60-100% Life expectancy Not specified Hematopoietic Absolute neutrophil count > 1,500/mm^3 Hemoglobin > 10 g/dL Platelet count > 100,000/mm^3 Hepatic Bilirubin < 2.0 mg/dL Alkaline phosphatase < 2.5 times upper limit of normal (ULN) Transaminases < 2.5 times ULN Renal Creatinine < 2.0 times ULN Cardiovascular No second-degree heart block No absolute QTc interval > 500 msec with normal potassium and magnesium levels Other Not pregnant or nursing Negative pregnancy test No other malignancy within the past 5 years except curatively treated basal cell or squamous cell skin cancer or carcinoma in situ No other serious medical illness Able to undergo MRI PRIOR CONCURRENT THERAPY: Biologic therapy More than 28 days since prior biologic therapy No concurrent prophylactic growth factors (e.g., filgrastim [G-CSF] or sargramostim [GM-CSF]) Chemotherapy No prior arsenic trioxide Endocrine therapy Not specified Radiotherapy Not specified Surgery Prior surgery for the brain tumor allowed Other No other prior therapy for the brain tumor More than 28 days since prior investigational drugs or devices No concurrent amphotericin B