Single Fraction Stereotactic Radiosurgery Compared With Fractionated Stereotactic Radiosurgery in Treating Patients With Resected Metastatic Brain Disease

Inclusion Criteria: PRE-REGISTRATION: * 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. * Three or fewer (i.e. 0 to 3) unresected brain metastases (as defined on the post operative magnetic resonance imaging \[MRI\]) at the time of screening. o Note: Dural based metastases (e.g. commonly seen in breast cancer) are eligible. * Unresected lesions must measure \< 4.0 cm in maximal extent on the contrasted post-operative treatment MRI brain scan. The unresected lesions will be treated with SRS as outlined in the treatment section of the concept. o Note: The metastases size restriction does not apply to the resected brain metastasis. * One brain metastasis must be completely (gross total resection) resected =\< 30 days prior to pre-registration. o NOTE: May not have had resection of more than one brain metastasis. * The resected brain metastasis must measure 2 cm or larger on the pre-operative MRI. * Resection cavity must measure \< 5.0 cm in maximal extent and the resection must be complete (gross total resection) on the post-operative MRI obtained =\< 30 days prior to pre-registration. * Karnofsky performance status of \>= 60. * For women of childbearing potential only, a negative u…