Feasibility of ipsilateral elective neck irradiation of levels Ib and II without level III in patients with node‐negative sinonasal squamous cell carcinoma

The necessity of level III irradiation in patients with node-negative advanced sinonasal squamous cell carcinoma (SNSCC) is unclear.Seventy-eight patients with advanced SNSCC were included. Survival rates were estimated and compared between treatment groups.Twenty-five patients received ipsilateral levels Ib and II irradiation (group 1) and 53 patients received ipsilateral levels Ib and II plus level III irradiation (group 2). The median follow-up time was 75.56 months. Five-year survival rates (regional relapse-free survival, overall survival, local relapse-free survival, and distant metastasis-free survival) were similar between groups 1 and 2 (all p > 0.05). Irradiation doses to the thyroid and larynx were significantly lower in group 1 than in group 2.Ipsilateral irradiation of levels Ib and II neck provides similar regional control and results as irradiation of these levels plus level III, with lower irradiation doses to normal neck tissue, in patients with node-negative advanced SNSCC.