SRS Compared With FSRS for Treatment of Intact Metastatic Brain Disease, FRACTIONATE Trial

Inclusion Criteria: * Age \>= 18 years old * Presence of presumed brain metastases from an extra-cerebral tumor site (e.g. lung, breast, prostate, etc.) * Note: Dural based metastases (e.g. commonly seen in breast cancer) are eligible * Size of brain metastases * At least one intact metastasis (not previously treated with radiosurgery) must measure \>= 2.0 cm and =\< 4.0 cm in maximal extent on the contrasted pre-treatment magnetic resonance imaging (MRI) brain scan obtained =\< 28 days prior to registration * If the largest lesion measures \>= 2.0 to =\< 4.0 cm in maximal extent the patient will be randomized * Able to undergo contrast enhanced MRI brain * Negative urine or serum pregnancy test completed =\< 7 days prior to registration, for women of childbearing potential only * Patient is willing and able to provide written informed consent or have a legally Authorized Representative (LAR) who is responsible for the care and well-being of the potential study participant provide consent. * Karnofsky performance status (KPS) \>= 50 * Eastern Cooperative Oncology Group (ECOG) performance score of (PS) \>= 2 * Past radiosurgery or resection is allowed as long as no definitive evidence of progression in these locations * Note: Repeat radiosurgery to the same location/lesion is not allowed on this protocol Exclusion Criteria: * Any patient who has received previous whole brain radiation * Any brain metastasis that is located in the brainstem measuring \>= 2.0 cm in…