Testing Longer Duration Radiation Therapy Versus the Usual Radiation Therapy in Patients With Cancer That Has Spread to the Brain

Inclusion Criteria: * Pathologically (histologically or cytologically) proven diagnosis of one of the following solid tumor malignancies within 5 years prior to registration: * Non-small cell lung cancer * Melanoma * Breast cancer * Renal cell carcinoma * Gastrointestinal cancer * If the original histologic proof of malignancy is greater than 5 years, then more recent pathologic confirmation (e.g., from a systemic site or brain metastasis) or unequivocal imaging confirmation of extracranial metastatic disease (e.g. CT of the chest/abdomen/pelvis, positron emission tomography \[PET\]/CT, etc.) is required * Patients must have at least 1 and up to 8 total intact brain metastases detected on a contrast-enhanced MRI performed ≤ 21 days prior to registration * At least 1 of the up to 8 lesions must be a study eligible lesion, defined as lesion with a maximum diameter as measured on any orthogonal plane (axial, sagittal, coronal) of ≥ 1.0 cm and ≤ 3.0 cm * All brain metastases must be located outside of the brainstem and ≥ 5 mm from the optic nerves or optic chiasm and ≤ 3.0 cm in maximum dimension * Note: brainstem metastases per the MRI within 21 days of registration are an exclusion criterion; however, if the MRI used for treatment planning performed within 7 days of SRS/FSRS reveals a brainstem metastasis, the patient remains eligible if the patient is considered an appropriate radiosurgery candidate per the local investigator * Patients must have a diagnosis-s…