Inclusion Criteria

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