Post-op RT to 60 Gy/30 fx has been the default for high-risk meningiomas (WHO Grade 2 after STR, any recurrent Grade 2, or any Grade 3) since RTOG 0539, but 5-year PFS has stubbornly hovered in the 40–60% range with predominantly local failures. FIRESTORM is an individual patient-level meta-analysis that pooled 248 high-risk meningioma patients, comparing dose-escalated RT (DE-RT, defined as BED10 ≥79.2 Gy, equivalent to 66 Gy/33 fx) against standard-dose RT. Three-quarters were WHO Grade 2, 75% had STR, and 42% had recurrent disease. The 59 DE-RT patients were treated with one of three regimens: 50 Gy/25 fx photons followed by an 18 Gy/6 fx carbon ion boost (n=33), 70 Gy/35 fx photons alone (n=18), or 66 Gy/33 fx photons alone (n=6). The 189 SD-RT patients received a grab bag including 60 Gy/30 fx, 54 Gy/30 fx, 59.4 Gy/33 fx, and single-fraction SRS (12–18 Gy, 28 cases). At a median follow-up of 67 months, DE-RT was associated with better 5-year PFS (65.8% vs 38.8%). The benefit persisted when SRS cases were excluded and when the SD-RT comparator was restricted to true conventionally fractionated (59.4–60 Gy) regimens. However, no OS difference was observed. Any-grade radionecrosis was higher with DE-RT (33.9% vs 13.2%), but Grade 3+ RN was statistically similar (5.1% vs 3.2%), with the bulk of the toxicity signal coming from the mixed carbon-photon subgroup. | Singh, Int J Radiat Oncol Biol Phys 2026
