RADT-40. EFFICACY AND SAFETY OF STEREOTACTIC RADIOSURGERY IN PATIENTS WITH LARGE-VOLUME MENINGIOMAS ≥ 10 CM³: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Large-volume intracranial meningiomas (LVMs) pose significant surgical challenges and are associated with increased morbidity despite advances in neurosurgical techniques. While stereotactic radiosurgery (SRS) is an established treatment for small- to medium-sized meningiomas, its efficacy and safety profile in LVMs (≥10 cm³) remain uncertain. We performed a systematic review and meta-analysis evaluating the efficacy and safety of SRS in patients with LVMs. PubMed, Embase, Web of Science, and Cochrane databases were searched for studies reporting outcomes of SRS in LVMs. Heterogeneity was assessed using the I² statistic, and pooled estimates were calculated using a random-effects model. Fifteen studies comprising 1,093 patients were included, of whom 955 (87%) presented with meningiomas measuring ≥10 cm³. The median follow-up duration across studies was 55 months (range of medians: 22–106 months). The overall tumor control rate was 91.2% (95% CI: 87.7–93.8%). Subgroup analyses demonstrated higher tumor control rates with hypofractionated SRS (94.9%; 95% CI: 90.8–97.2%) compared to single-session (89.0%; 95% CI: 83.6–92.7%) and staged SRS (82.6%; 95% CI: 68.9–91.1%). Progression-free survival at 3 and 5 years was 91.3% (95% CI: 84.6–95.2%) and 90.6% (95% CI: 82.2–95.3%), respectively. Adverse radiation effects occurred in 15.9% (95% CI: 7.8–29.9%), and symptomatic peritumoral edema in 4.7% (95% CI: 1.6–13.1%). Overall, a favorable clinical outcome was observed in 90.5% (95% CI: 81.9–95.3%). In patients with large-volume meningiomas, SRS is associated with high tumor control rates and an acceptable safety profile. Hypofractionated SRS demonstrates superior tumor control compared to single-session and staged approaches. Further prospective randomized trials are warranted to validate these findings and optimize treatment protocols.