Association Between Elective Nodal Irradiation and Oncologic Outcomes in Node-Negative Olfactory Neuroblastoma and Sinonasal Squamous Cell Carcinoma: A Propensity-Score Matched Analysis.

Abstract

The association between elective nodal irradiation (ENI) and oncological outcomes in clinically node-negative (cN0) sinonasal squamous cell carcinoma (SCC) and olfactory neuroblastoma (ONB) treated with postoperative chemoradiotherapy remains unclear. We retrospectively analyzed cN0 sinonasal SCC and ONB patients receiving postoperative chemoradiotherapy at a single institution. Propensity score matching was performed to minimize confounding. Survival outcomes were assessed using Kaplan-Meier estimates, and logistic regression identified factors associated with specific failure patterns. Among 62 eligible patients (36 SCC, 26 ONB; median follow-up 44 months), ENI was associated with a lower nodal recurrence rate (4.8% vs. 34.1%; OR 0.10, p = 0.030) but not with overall or recurrence-free survival (p > 0.05). Perineural invasion was independently associated with worse recurrence-free survival. The association between ENI and reduced nodal recurrence appeared more pronounced in ONB. Despite the small sample size, ENI was associated with reduced nodal recurrence but not with improved survival in cN0 sinonasal SCC and ONB.