GammaTile for Recurrent High-Grade Meningioma: Outcomes from a Multicenter Analysis

Abstract Purpose GammaTile (GT), a form of brachytherapy utilizing cesium-131 seeds in a bioresorbable collagen tile, has gained popularity for recurrent intracranial tumors including high-grade meningioma. This study reports early experience utilizing GT in recurrent high-grade meningioma with a focus on perioperative safety and clinical applications. Methods The STaRT Registry (NCT04427384) was queried for patients receiving GT for WHO Grade II-III meningiomas from January 2021 to January 2026. Patient demographics, procedure details, overall survival, recurrence, and adverse events (AEs) were analyzed. Results Forty-nine tumors from 44 patients (mean age 58 years, SD ± 14.7) across 20 institutions were included. Prior radiation included fractionated stereotactic radiosurgery (SRS) in 20 patients (45%), single fraction SRS in 15 (34%), and whole-brain radiotherapy in one (2%). Median tumor diameter was 4.4cm (range 2.5–5.8). Gross total resection was achieved in 35 tumors (71%). One- and two-year overall survival (OS) were 86% and 54%, respectively. Karnofsky Performance Scale (KPS) < 80 was associated with shorter median OS (p = 0.019). Median time to local failure was 18 months, and tumor diameter < 3 cm was associated with local control (p = 0.013, 95% CI 0.031–0.661). Two patients (5%) developed asymptomatic adverse radiation effects (AREs), managed conservatively. Five AEs (11%) were reported, all CTCAE grade 3, with re-operations for surgical site infection. Three patients (7%) died from neurologic causes and five (11%) from systemic causes. Conclusion GT for recurrent high-grade meningioma demonstrates favorable local control and safety, with low AREs. Greater survival and local control were associated with higher KPS and smaller tumor size, respectively.