10183- MET-14 SALVAGE SURGERY FOR LOCAL PROGRESSION AFTER RADIATION THERAPY OF BRAIN METASTASES

Abstract Recent advancement in cancer treatments have prolonged survival after the onset of brain metastases (BM), and this trend increases the risk of local progression (LP) after radiotherapy (RT)of BM. Salvage options include surgical resection, re-irradiation and medical therapies, but there is no standard management for this clinical setting. This study aimed to evaluate the outcome of salvage surgery. We performed surgical resection for intracranial metastases in 221 cases in a single institution between Apr 2014 and Mar 2024. Of those, the data of the cases underwent initial surgery after irradiation for BM were extracted. After excluding duplicated cases and those underwent surgery within one month after irradiation, we finally analyzed 49 cases. Overall survival (OS) and local progression free survival (LPFS) were evaluated by Kaplan Meier method. All but two cases had a history of stereotactic radiosurgery/radiotherapy for BM. Histopathological diagnosis of surgical specimens was tumor recurrence in 33 cases and radiation necrosis (RN) in 16 cases. RN cases showed longer duration between radiation and LP, when comparing with recurrent cases (median 42.3. vs. 9.3 months). OS was longer in RN cases than in tumor recurrent cases (median 68.5 vs. 26.9 months). In the recurrent cases, preoperative poor KPS (under 70), active state of extracranial lesions and RPA class were associated with shorter OS. Extent of resection, postoperative chemotherapy and local irradiation did not have significant impact on OS. Twenty cases experienced local recurrence after salvage surgery, and LPFS was 7.0 months. Any of extent of removal, postoperative chemotherapy and RT were not associated with LPFS. Relative long survival after salvage surgery for local failure of BM after irradiation was observed. Salvage surgery should be considered especially in patients with good extracranial control and performance status.