Metastatic brain disease is a focal disease, and focal control of the tumor is paramount to patient survival. The approach in the past has been to treat metastatic brain disease as a whole brain disease with whole brain radiation (WBR). Because of poor local control of tumor growth when treated solely by WBR, brain metastases in the past were rapidly lethal. Therefore, patients with brain metastases did not benefit from many advances in cancer therapy (immuno therapy, chemo therapy, conformal radiotherapy, etc.) because these therapies do no effectively reach brain metastases and individuals died quickly from neurological progression.