Stereotactic Radiation Therapy With or Without Whole-Brain Radiation Therapy in Treating Patients With Brain Metastases

DISEASE CHARACTERISTICS:

Diagnosis of cerebral metastases meeting the following criteria:

One to three presumed brain metastases

Metastases must be from a histologically confirmed extracerebral site (e.g., lung, breast, prostate)

Histologic confirmation may have been from the primary tumor site, from another metastatic site (e.g., osseous metastasis, adrenal metastasis), or from the metastatic brain lesion(s)
Each lesion must measure less than 3.0 cm by contrast MRI of the brain performed within the past 21 days
Lesions must not be within 5 mm of the optic chiasm or within the brainstem
Eligibility for treatment with gamma knife or linear accelerator-based radiosurgery confirmed by a radiation oncologist
No primary germ cell tumor, small cell carcinoma, or lymphoma
No leptomeningeal metastases
Hormone receptor status not specified

PATIENT CHARACTERISTICS:

Male or female
Menopausal status not specified
ECOG performance status 0-2
Not pregnant
Negative pregnancy test

Fertile patients must use effective contraception

Male patients must continue to use contraception for 3 months after the completion of radiotherapy
No pacemaker or other MRI-incompatible metal in the body
No known allergy to gadolinium

PRIOR CONCURRENT THERAPY:

More than 7 days since prior and no concurrent chemotherapy
No prior cranial radiotherapy
No prior resection of cerebral metastases
Concurrent hormonal agents, steroids, and/or anticonvulsants allowed