iii. Diagnosis of leptomeningeal disease. iv. Prior history of radiation therapy involving the brain. v. Chemotherapy (including oral agents and targeted agents) or immunotherapy given within 14 days of SRS. Hormonal therapy is permitted. For Her2+ breast cancer patients, anti-Her2 therapy cannot be given within 14 days of SRS. Patients who are scheduled to receive trastuzumab emtansine after SRS cannot be enrolled.