Risk-adapted meningioma management leans on grade, extent of resection, and recurrence status. RTOG 0539 prospectively stratified 165 patients into three cohorts. Low-risk patients (grade 1 after GTR/STR, n=60) were observed, intermediate-risk patients (recurrent grade 1 or newly diagnosed grade 2 after GTR, n=52) received 54 Gy in 30 fractions, and high-risk patients (grade 2 after STR, any grade 3, or recurrent grade 2/3, n=53) received 60 Gy in 30 fractions. With a median follow-up beyond 11 years, 10-year PFS/OS were 85%/94% for low risk, 72%/85% for intermediate risk, and a sobering 43%/51% for high risk. Recurrent disease (HR 2.86) and STR (HR 3.38) independent predictors of worse OS. The tell: recurrent grade 1 patients did worse than upfront grade 2 with 10-year OS of 67% vs 91%, suggesting molecularly aggressive biology lurking under benign histology. Grade 3+ adverse effects were 9.6% and 15.1% in the treatment arms. | Kotecha, J Clin Oncol 2026
