Improved Progression-Free Survival Following Dose-Escalated Versus Standard-Dose Postoperative Radiation Therapy for High-Risk Meningiomas: An International Multicenter Individual Patient-Level Meta-Analysis (FIRESTORM).

PURPOSE: We performed an individual patient-level meta-analysis of high-risk meningiomas to compare the outcomes of dose-escalated radiation therapy (DE-RT) versus standard-dose postoperative radiation therapy (SD-RT).

METHODS AND MATERIALS: A total of 7 institutions participated. DE-RT was defined as treatment with a biologically effective dose of ≥79.2 Gy (equivalent of 66 Gy in 33 fractions). We compared progression-free survival (PFS) with DE-RT versus SD-RT via Kaplan-Meier analysis and log-rank t tests, a Cox proportional hazards multivariable model, and propensity score analyses with inverse probability of treatment weighting (IPTW). We also compared incidences of central nervous system radionecrosis (RN) with DE-RT versus SD-RT.

RESULTS

The analysis included 248 patients with high-risk meningioma (59 received DE-RT and 189 received SD-RT). One hundred and eighty-eight cases (75.8%) were World Health Organization grade 2, and 103 cases (41.5%) were recurrent meningiomas. Extent of resection was subtotal resection in 182 of 248 (75.2%). Three- and 5-year PFS rates were 62.8% (95% CI, 55.8%-69.0%) and 45.0% (95% CI, 37.3%-52.3%), respectively. DE-RT was associated with superior PFS rates (P = .0022), with 3-year (86.4% vs 55.6%) and 5-year (65.8% vs 38.8%) PFS rates favoring DE-RT. On multivariable analysis, DE-RT was associated with superior PFS (hazard ratio, 0.40; 95% CI, 0.24-0.69; P = .001). On IPTW, DE-RT continued to be associated with superior PFS (hazard ratio, 0.45; 95% CI, 0.24-0.83; P = .01). A greater incidence of any grade RN was observed following DE-RT (20 of 59; 33.9%) versus SD-RT (25 of 189; 13.2%) (P = .001) but with similar grade 3 or greater RN events (DE-RT 5.1% vs SD-RT 3.2%).

CONCLUSIONS

DE-RT resulted in superior PFS for patients with high-risk meningiomas over SD-RT without an increase in severe toxicities.