SRS can accomplish destruction of a defined intracranial target through precise targeting of a high dose of radiation with a sharp dose fall off at the target boundaries and minimal damage to surrounding tissue. Brain metastases are well suited for SRS as they are often small, radiographically well-circumscribed, pseudo-spherical tumors that are non-infiltrative, and they are often located at the gray-white junction, where toxicity to critical structures is minimal. SRS toxicity is low (<5%).