RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells.

PURPOSE: Phase II trial to study the effectiveness of radiation therapy in treating patients with newly diagnosed brain metastases from kidney cancer, melanoma, or sarcoma.

OBJECTIVES:

• Evaluate whether the delivery of stereotactic radiosurgery without conventional whole brain radiotherapy is feasible in patients with 1-3 newly diagnosed brain metastases from renal cell carcinoma, melanoma, or sarcoma.
• Determine the 3-, 6-, and 12-month radiographic and neurologic intracranial patterns of progression (i.e., original lesions vs new lesions) in patients treated with this regimen.

OUTLINE: This is a multicenter study. Patients are stratified according to maximum tumor diameter (2 cm vs greater than 2 cm to 3 cm vs greater than 3 cm to 4 cm).

Patients undergo stereotactic radiosurgery at an assigned dose according to tumor diameter. Patients undergo MRI or CT scan at 3, 6, and 12 months after treatment or until disease progression.

All other therapies are allowed after stereotactic radiosurgery except external beam whole brain radiotherapy or resection of brain metastases, unless there is documented progression or unrelenting mass effect that necessitates craniotomy.

Patients are followed every 3 months for 2 years.

PROJECTED ACCRUAL: A total of 36 patients will be accrued for this study within 7.2 months.

DISEASE CHARACTERISTICS:

• Histologically confirmed renal cell carcinoma, melanoma, or sarcoma with 1-3 newly diagnosed intraparenchymal brain metastases based on contrast-enhanced MRI (CT scan acceptable if patients have a medical contraindication to MRI)
• No lesion greater than 4.0 cm in diameter and, if multiple lesions are present, no more than one greater than 3.0 cm in diameter
• No limitation on the extent of extracranial metastatic disease
• No metastases in the brain stem, midbrain, pons, or medulla
• No leptomeningeal metastases documented by MRI or CSF evaluation
• No metastases within 10 mm of optic nerve or chiasm
• No history of multiple liver metastases

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• At least 3 months

Hematopoietic:

• Absolute neutrophil count greater than 1,000/mm^3
• Platelet count greater than 50,000/mm^3
• Hemoglobin greater than 8 g/dL

Hepatic:

• Not specified

Renal:

• Not specified

Other:

• No major medical illness
• No psychoses
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• Prior chemotherapy allowed
• Systemic chemotherapy may be continued at the discretion of investigator after completion of radiosurgery

Endocrine therapy:

• Not specified

Radiotherapy:

• No prior cranial radiotherapy
• Prior or concurrent radiotherapy to noncranial sites allowed

Surgery:

• No prior surgical resection for brain metastases
• Prior stereotactic biopsy for diagnostic purposes allowed