In patients with advanced olfactory neuroblastoma, IMRT and PBRT yielded similar long-term outcomes and rates of grade 2 or higher radiation-related adverse events. Theoretical benefits of PBRT—such as organ sparing—require further study to clarify potential clinical advantages.

Question Does adjuvant proton beam radiotherapy (PBRT) provide equivalent oncologic effectiveness while reducing radiation toxic effects compared with adjuvant intensity-modulated radiotherapy (IMRT) for patients with olfactory neuroblastoma (ONB)?

Findings In this propensity score–matched cohort study of 54 patients, patients treated with adjuvant IMRT and PBRT had similar rates of radiation toxic effects and no statistical difference in overall survival and recurrence-free survival.

Meaning PBRT may not improve overall survival, recurrence-free survival, or radiation toxic effects relative to IMRT for patients with ONB.