Study closed to enrollment

DISEASE CHARACTERISTICS:

• Four or fewer brain metastases (as defined on the pre-operative MRI brain scan) and status post resection of one of the lesions
• Pathology from the resected brain metastasis must be consistent with a non-central nervous system primary site
  • Patients with or without active disease outside the nervous system are eligible (including patients with unknown primaries), as long as the pathology from the brain is consistent with a non-central nervous system primary site
• Any unresected lesions must measure ≤ 3.0 cm in maximal extent on the contrasted MRI brain scan obtained ≤ 35 days prior to pre-registration
  • The metastases size restriction does not apply to the resected brain metastasis; with resected brain metastases only surgical cavity size determines eligibility
• Post-operative MRI confirmed zero, one, two or three unresected lesions
  • Each unresected lesion must measure ≤ 3.0 cm in maximal extent on the contrasted post-operative MRI brain scan
  • The pre-registration, post-operative, brain scan may be used for the randomization scan if obtained ≤ 28 days prior to randomization
    • Note: If there are no unresected brain metastases (i.e., all brain metastases have been resected), a post-operative CT brain scan may be used if obtained ≤ 28 days prior to randomization
• Resection cavity must measure < 5.0 cm in maximal extent on the post-operative MRI (or CT) brain scan obtained ≤ 35 days prior to pre-registration
  • The pre-registration, post-operative brain scan may be used for the planning scan if obtained ≤ 28 days prior to randomization
    • Note: If there are no unresected brain metastases (i.e., all brain metastases have been resected), a post-operative CT brain scan may be used if obtained ≤ 28 days prior to randomization
  • It is permissible for the resection of a dominant brain metastasis to include a smaller "satellite" metastasis as long as the single resection cavity is less than the maximum size requirements
• All standard tumor-staging procedures necessary to define baseline extracranial disease status completed ≤ 42 days prior to pre-registration
• No primary germ cell tumor, small cell carcinoma, or lymphoma
• No widespread definitive leptomeningeal metastasis
• No brain metastasis that is located ≤ 5 mm of the optic chiasm or within the brainstem

PATIENT CHARACTERISTICS:

• ECOG performance status (PS) 0, 1, or 2
• Ability to be treated with either a gamma knife or a linear accelerator-based radiosurgery system
• Willing and able to complete neurocognitive examination without assistance
• Willing and able to complete quality-of-life (QOL) questionnaires by themselves or with assistance
• Willing to provide mandatory blood and urine samples for correlative research purposes
• None of the following:
  • Pregnant or nursing
  • Men or women of childbearing potential who are unwilling to employ adequate contraception through out the study and for men for up to 3 months after completing treatment
• Able to complete a MRI with contrast of the head
• No known allergy to gadolinium

PRIOR CONCURRENT THERAPY:

• No prior cranial radiotherapy
• No planned cytotoxic chemotherapy during the stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT)
• Concurrent hormonal agents, steroids, and/or anticonvulsants allowed