Radiation Therapy, Arsenic Trioxide, and Temozolomide in Treating Patients With Newly Diagnosed High-Grade Glioma

DISEASE CHARACTERISTICS:

* Newly diagnosed grade III or IV glioma including any of the following:

  * Glioblastoma
  * Anaplastic astrocytoma
  * Gliosarcoma
  * Anaplastic oligodendroglioma
  * Anaplastic oligoastrocytoma
* Measurable or nonmeasurable disease
* No more than 5 weeks since prior brain surgery

  * Recovered from surgery, post- operative infection, and other complications
* Preoperatively and postoperatively diagnostic contrast-enhanced MRI or CT scan of the brain performed prior to radiation therapy

  * Patients diagnosed by stereotactic biopsy do not require the postoperative scan

PATIENT CHARACTERISTICS:

* Karnofsky performance status ≥ 60%
* Absolute neutrophil count ≥ 1,500/mm\^3
* Platelet count ≥ 100,000/mm\^3
* Serum creatinine ≤ 1.5 times upper limit of normal (ULN)
* Total bilirubin ≤ 2.0 mg/dL
* AST ≤ 4.0 times ULN
* No prolonged QT interval \> 460 milliseconds on baseline electrocardiogram in the presence of normal serum potassium and magnesium
* No uncontrolled electrolyte imbalance (i.e., sodium \< 132 mmol/L, potassium \< 3.5 mEq/dL, magnesium \< 1.7 mg/dL)
* No history of torsades de pointes type of ventricular arrhythmia
* Negative pregnancy test
* Not pregnant or nursing
* Fertile patients must use effective contraception
* No medical or psychiatric illness that, in the investigator's opinion, could potentially preclude the completion of study therapy
* No HIV positivity
* No active connective tissue disorders (e.g., lupus or scleroderma) that, in the investigator's opinion, may put the patient at high risk for radiation toxicity

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* No prior brain radiotherapy or chemotherapy for brain tumor
* Concurrent corticosteroids to control cerebral edema allowed provided dose is stable or decreasing for the past 5 days
* No concurrent or plan to receive drugs that are known to prolong the QT interval
* No prior radiation to the head or neck (except for T1 glottic cancer) resulting in overlap of radiation fields