Long‐term recurrence risk and temporal dynamics after resection of intracranial meningiomas: A multicenter cohort study with up to 15 years of follow‐up

BACKGROUND: Meningiomas are the most common primary intracranial tumors, accounting for approximately one third of central nervous system neoplasms. Although most are benign, recurrence remains a clinical concern, particularly in cases of subtotal resection (STR) where complete tumor removal is not feasible due to involvement of critical structures. Adjuvant Gamma Knife radiosurgery (GKRS) is often considered in these patients, yet the long-term effectiveness of GKRS and the temporal dynamics of recurrence beyond 10 years are not well characterized. METHODS: In this multicenter retrospective cohort study, 949 adult patients who underwent surgical resection for intracranial meningiomas between 2009 and 2017 at two tertiary centers in China were followed through 2024. The primary exposure was extent of resection (gross total resection vs subtotal resection [STR]) and postoperative GKRS. The primary outcome was recurrence-free survival (RFS); secondary outcomes included overall survival, annualized recurrence risk, and biomarker-based stratification. Analyses included Cox models and competing-risk approaches. RESULTS: Median follow-up for RFS was 8.8 years. The 15-year RFS rate was 79.2% (95% CI, 74.2-84.6). In STR cases, a second recurrence peak emerged at 7 to 10 years. GKRS was associated with lower recurrence risk (hazard ratio = 0.50; 95% CI, 0.27-0.90), especially in convexity tumors. Ki-67 > 5% and progesterone receptor negativity showed nonsignificant trends toward higher recurrence. CONCLUSIONS: In this large cohort with extended follow-up, STR patients exhibited a second recurrence peak at 7 to 10 years postoperatively. Adjuvant GKRS showed long-term benefit, supporting its selective use and long-term surveillance beyond 10 years.