Stereotactic radiosurgery for treatment of brain metastases

Brain metastases are the most common intracranial malignancy. Incidence of brain metastases has risen as systemic therapies have improved and patients with metastatic disease live longer. Whole-brain radiation therapy, for many years, has been the standard treatment approach. Stereotactic radiosurgery has become an increasingly popular option because of its relatively short, convenient, and noninvasive treatment course. Although recently published data have renewed interest in use of whole-brain radiation therapy or systemic therapies for control of micrometastatic disease, stereotactic radiosurgery continues to be an important modality, capable of delivering ablative doses of radiation for long-term control of macroscopic disease. The purpose of this review is to explore the different paradigms for incorporation of stereotactic radiosurgery into management of brain metastases. Current uses for stereotactic radiosurgery include delivery as a boost with whole-brain radiation therapy; alone for patients with a limited number of brain metastases; in pre- or postoperative settings; and in combination with systemic, targeted, and immune-based therapies. Mature prospective data on use of stereotactic radiosurgery in combination with whole-brain radiation therapy is available; however, prospective, randomized data on stereotactic radiosurgery for patients with a greater number of brain metastases, its use in pre- and postoperative settings, and its use in combination with systemic therapies are limited. Data from ongoing and future studies are needed to define the appropriate use of stereotactic radiosurgery in these settings.