Inclusion Criteria:

- Histopathologically confirmed WHO grade IV astrocytoma (GBM), tumor can be supra- or
infra-tentorial in location but not located in the brain stem.

- Solitary or multifocal tumor.

- Tumor can be biopsied or resected, either totally or sub-totally.

- A pre-radiation therapy brain MRI is mandatory. Patients with contraindications for
MRI scanning are ineligible for this study.

- Surgical cavity or surgical cavity + T1 enhancing residual tumor ≤ 6 cm in the
largest diameter on the pre-radiation therapy MRI. In the case of multifocal tumor,
the combined largest diameter of T1 enhancing tumor + surgical cavity ≤ 6 cm.

- Placement of bis-chloronitrosourea (BCNU) wafers at the time of surgery is allowed.

- Age > 18 years at time of registration.

- Estimated survival of at least 3 months.

- Zubrod Performance Scale of 0-2 (Karnofsky performance scale ≥ 60).

- Hgb > 9 gm; absolute neutrophil count (ANC) > 1500/ul; platelets > 100,000;
Creatinine < 1.5 times the upper limit of laboratory normal value; Bilirubin < 2
times the upper limit of laboratory normal value; serum glutamate pyruvate
transaminase (SGPT) or serum glutamate oxaloacetate transaminase (SGOT) < 3 times the
upper limit of laboratory normal value.

- Patients cannot be treated on any other clinical protocols within 30 days prior to
study entry or during participation in the study.

- Patients must sign study-specific informed consent form prior to registration.

- Men and women and members of all ethnic groups are eligible for this trial.

- No active connective tissue disorders, such as active lupus or scleroderma.

- Radiation therapy and chemotherapy must start within 8 weeks of tumor resection or
biopsy

Exclusion Criteria:

- prior temozolomide chemotherapy.

- prior brain irradiation.

- evidence of severe or uncontrolled psychiatric or systemic disease (e.g., unstable or
uncompensated respiratory, cardiac, hepatic, or renal disease) that would interfere
with study protocol as judged by the investigator.

- Acquired Immune Deficiency (HIV (+)/AIDS)

- pregnant women or breast feeding women. Women of childbearing potential must
practice medically approved contraceptive precautions. Men should be counseled and
agreeable to follow acceptable birth control methods.

- concurrent active malignancy at other sites.

- frequent vomiting of medical condition which could interfere with oral medication
intake (e.g. partial bowel obstruction).