Radiosurgery Before Surgery for the Treatment of Brain Metastases

PRIMARY OBJECTIVE: I. To determine the safety of pre-operative stereotactic radiosurgery (SRS) followed by surgery for brain metastasis. SECONDARY OBJECTIVES: I. To evaluate the immune niche in brain metastasis following SRS in the presence of low or high dose dexamethasone. II. To evaluate the impact of pre-operative SRS on survival outcomes. OUTLINE: Patients are assigned to 1 of 2 arms. ARM A: Patients undergo SRS to the brain metastasis for 1-3 fractions over 1-5 days. Patients also receive low dose dexamethasone orally (PO) or intravenously (IV) for 2-21 days until the day of surgical resection. Patients then undergo surgical resection. ARM B: Patients undergo SRS to the brain metastasis for 1-3 fractions over 1-5 days. Patients also receive high dose dexamethasone PO or IV for 2-21 days until the day of surgical resection. Patients then undergo surgical resection. After completion of study intervention, patients are followed up for 120 days, and then every 12 weeks thereafter.