DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed supratentorial pure or mixed anaplastic oligodendroglioma

  • Unifocal or multifocal disease
  • Prior suspected or proven low-grade glioma eligible provided biopsy reveals pure or mixed anaplastic oligodendroglioma that has not been previously treated with radiotherapy and/or chemotherapy
• No equivocal oligodendroglial element
• No tumors predominantly located in the posterior fossa (i.e., brainstem or cerebellum)
• No spinal cord tumors
• No evidence of spinal drop metastasis or spread to noncontiguous meninges

PATIENT CHARACTERISTICS:

Age:

• 18 to 65

Performance status:

• Zubrod 0-1

Life expectancy:

• More than 12 weeks

Hematopoietic:

• Absolute granulocyte count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 10 g/dL

Hepatic:

• Bilirubin no greater than 2 times normal
• AST no greater than 3 times normal
• Alkaline phosphatase no greater than 2 times normal

Renal:

• Creatinine no greater than 1.5 times normal

Other:

• No active infection
• No other medical problems that would preclude study participation
• No other malignancy within the past 3 years except carcinoma in situ of the cervix or nonmelanoma skin cancer
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• No prior chemotherapy for this malignancy
• No prior temozolomide

Endocrine therapy:

• Not specified

Radiotherapy:

• See Disease Characteristics
• No prior radiotherapy to the brain, head, or neck

Surgery:

• At least 14 days since prior surgery requiring general anesthesia