Stereotactic reirradiation for local failure of brain metastases following previous radiosurgery: Systematic review and meta-analysis

•Stereotactic radiosurgery (SRS) is an option in patients with brain metastases (BM).•No consensus on optimal salvage modality for local failure in BM after SRS.•Stereotactic reirradiation (SRS2) is an option despite concern for Radionecrosis (RN).•A systematic review was carried out to test efficacy and safety of SRS2.•Eleven studies were included.•Pooled 1-year Local Failure rate was 24 % and median Overall Survival was 14 months.•A pooled crude RN rate of 13 % was reported.•SRS2 is an effective option in patients with recurrent BM following prior SRS. Local failure (LF) following stereotactic radiosurgery (SRS) of brain metastases (BM) may be treated with a second course of SRS (SRS2), though this procedure may increase the risk of symptomatic radionecrosis (RN). A literature search was conducted according to PRISMA to identify studies reporting LF, overall survival (OS) and RN rates following SRS2. Meta-analysis was performed to identify predictors of RN. Analysis included 11 studies (335 patients,389 metastases). Pooled 1-year LF was 24 %(CI95 % 19–30 %): heterogeneity was acceptable (I2 = 21.4 %). Median pooled OS was 14 months (Confidence Interval 95 %, CI95 % 8.8–22.0 months). Cumulative crude RN rate was 13 % (95 %CI 8 %–19 %), with acceptable heterogeneity (I2 = 40.3 %). Subgroup analysis showed higher RN incidence in studies with median patient age ≥59 years (13 % [95 %CI 8 %–19 %] vs 7 %[95 %CI 3 %–12 %], p = 0.004) and lower incidence following prior Whole Brain Radiotherapy (WBRT, 19 %[95 %CI 13 %–25 %] vs 7%[95 %CI 3 %–13 %], p = 0.004). SRS2 is an effective strategy for in-site recurrence of BM previously treated with SRS.