Brain metastases which require resection are treated with surgery followed by whole brain radiation therapy or postoperative cavity boost stereotactic radiosurgery (POCBS). Recently a novel strategy using neoadjuvant stereotactic radiosurgery (NaSRS) followed by resection was reported, demonstrating lower rates of postoperative leptomeningeal dissemination (LMD) and symptomatic radiation toxicity compared to a comparative cohort of patients treated with postoperative SRS. To determine if the rate of symptomatic radiation toxicity at 1 yr in patients who receive NaSRS differs significantly from historical rates for patients treated with POCBS. This is a multi-center, non-randomized, open phase II clinical trial. A total of 30 patients with up to 10 brain metastases, at least 1 of which is appropriate for surgical resection, will be enrolled for over 4 yr. All enrolled patients will be assigned to receive NaSRS followed by surgery. This study will clarify whether symptomatic radiation toxicity caused by NaSRS is significantly decreased compared to historical rates associated with POCBS. Secondary endpoints will include 1-yr local control (LC) of the treated lesion, 1-yr rates of LMD, median survival and 2-yr rates of progression-free and overall survival. Tertiary analyses will include correlation between LC and radiation toxicity with pretreatment clinical factors, serum markers, radiomic features, and molecular assessments of the resected tumors. This prospective study will determine the toxicity associated with NaSRS and provide additional quantitative metrics of efficacy for future comparative trials. Copyright © 2019 by the Congress of Neurological Surgeons.