Radiation Therapy With or Without Chemotherapy in Treating Patients With Anaplastic Oligodendroglioma

DISEASE CHARACTERISTICS:

• Histologically proven unifocal or multifocal, supratentorial, pure or mixed anaplastic oligodendroglioma

• Prior suspected or proven low-grade glioma allowed if current histologic proof of pure or mixed anaplastic oligodendroglioma

• Tumor must contain an unequivocal (at least 25%) oligodendroglial element and have 2 or more anaplastic features, 1 of which must be frequent mitoses or endothelial proliferation

• For mixed tumors, the non-oligodendroglial element must be astrocytic and the oligodendroglial or astroglial component may be anaplastic

• No evidence of spinal drop metastasis or spread to noncontiguous meninges

• MRI of spine not required for asymptomatic patients and patients not excluded based on pathologic evidence of local meningeal infiltration by underlying tumor

• No tumor that is predominantly located in the posterior fossa (i.e., brainstem or cerebellum)

• No spinal cord tumors

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Karnofsky 60-100%

Life expectancy:

• Not specified

Hematopoietic:

• Absolute granulocyte count at least 1,500/mm^3

• Platelet count at least 150,000/mm^3

Hepatic:

• Bilirubin no greater than 2 times normal

• Serum glutamate oxaloacetate transaminase (SGOT) no greater than 2 times normal

• Alkaline phosphatase no greater than 2 times normal

Renal:

• Creatinine no greater than 1.5 times normal

Pulmonary:

• No chronic lung disease unless diffusion capacity of lung for carbon monoxide (DLCO) is at least 60% predicted

Other:

• No active infection

• No other malignancy within the past 5 years except nonmelanomatous skin cancer or carcinoma in situ of the cervix

• Not pregnant or nursing

• Negative pregnancy test

• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior chemotherapy

Endocrine therapy:

• No concurrent steroids as antiemetics

• Concurrent steroids allowed to control central nervous system (CNS) symptoms due to tumor-associated or radiotherapy-associated cerebral edema

Radiotherapy:

• No prior radiotherapy to brain or head/neck

Surgery:

• Prior surgery allowed