Standard radiation with temozolomide for glioblastoma multiforme caps at 60 Gy, with prior dose-escalation efforts falling flat. But those in-field failures continue to taunt! Enter the phase 2 trial NRG-BN001 asking whether a gross tumor simultaneous integrated boost to 75 Gy could improve survival—first with photons (spoiler: nope), and now with protons. Among 193 randomized patients, proton SIB to 75 Gy eeked out an advantage in median survival (22 → 22.8 months, HR 0.81) and survival at 3 years (25% → 30%). The benefit held across MGMT and RPA strata, and the theory behind protons being uniquely equipped to achieve this is it carries less risk of inducing grade 3+ lymphopenia (here it was 23% 60 Gy photons versus 17% with 75 Gy protons) and/or neurotoxicity (grade 4 was ≤5%). | Mehta, ASTRO 2025
