DISEASE CHARACTERISTICS:

• Histologically confirmed supratentorial glioblastoma multiforme (with areas of necrosis) by surgical biopsy or excision within 4 weeks of study
• Tumor and/or any associated edema limited to one hemisphere and unifocal
• No gross invasion of a ventricular surface
• Tumor accessible
• No other astrocytoma
• No multifocal or recurrent malignant glioma
• No disease below the tentorium or beyond the cranial vault

PATIENT CHARACTERISTICS:

Age:

• Adult

Performance status:

• Zubrod 0-1

Life expectancy:

• At least 8 weeks

Hematopoietic:

• Hemoglobin at least 10 g/dL (transfusion allowed)
• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than 2.0 mg/dL
• SGOT or SGPT no greater than 2 times normal

Renal:

• BUN no greater than 25 mg/dL
• Creatinine no greater than 1.5 mg/dL

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No hypersensitive or idiosyncratic reaction to bleomycin
• No other prior malignancies within the past 2 years except nonmelanomatous skin cancer or carcinoma in situ of the cervix or urinary bladder
• No other major medical illness or psychiatric impairment that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior chemotherapy for glioblastoma multiforme
• No prior radiosensitizer for glioblastoma multiforme

Endocrine therapy:

• Not specified

Radiotherapy:

• No prior radiotherapy to the head or neck resulting in overlapping radiotherapy fields

Surgery:

• See Disease Characteristics
• Recovered from prior surgery