BackgroundTo evaluate the impact of postoperative radiotherapy (PORT) on survival in olfactory neuroblastoma (ONB) patients with different stages. MethodsPatients with ONB were selected in the Surveillance, Epidemiology, and End Results (SEER) database during 2004–2016. Survival analyses were performed using Kaplan Meier (K-M) method, Cox regression analysis, and competing risk model. ResultsA total of 513 patients were included in the study. Univariate and multivariate analysis results demonstrated that PORT was not an independent prognostic factor for overall survival (OS) of patients with modified Kadish stage A and B (p=0.699 and p=0.248, respectively). For C and D cases, patients who underwent PORT had significantly better OS than those who did not undergo PORT (p=0.03 and p< 0.0001, respectively). K-M curves illustrated that the 5- and 10-year OS rates according to radiotherapy (PORT vs. non-PORT) were 70.4% vs. 85.3% and 56.8% vs. 68.2% in stage C, respectively. For stage D patients, the 5-year OS rates were 42.6% and 70.7%, and 10-year OS rates were 29.5% and 53.4% in the PORT and non-PORT groups, respectively. The competitive risk model revealed that the 5-year cancer-specific cumulative mortality incidence decreased by 26.6% and the 10-year mortality incidence by 41.4% in patients with stage C who were treated using PORT; meanwhile, for patients with stage D who were treated with PORT, the 5- and 10-year mortality incidence reduced by 35.3% and 42.6%, respectively. Chemotherapy was not related to the prognosis of ONB (all p> 0.05).ConclusionsOur results indicate that PORT improved survival outcomes in ONB patients with modified Kadish stage C and D. However, for modified Kadish stage A and B cases, PORT may not affect survival. Chemotherapy was not recommended for ONB patients until more studies determine the role of chemotherapy.