The Optimal Preoperative Radiation Dose to Enhance Overall Survival for Resectable Sinonasal Squamous Cell Carcinoma

Summary: Preoperative radiotherapy has shown promising outcomes in preserving organs and achieving therapeutic effectiveness for patients with resectable sinonasal squamous cell carcinoma (SNSCC). However, there remains no consensus regarding the optimal radiation dose. This study aimed to investigate the optimal preoperative radiotherapy dose for overall survival (OS) for SNSCC patients. The study retrospectively included patients with resectable SNSCC who received preoperative radiotherapy followed by surgery. A P-spline approach explored the nonlinear relationships between preoperative radiotherapy dose and OS. OS was compared among different dose groups using Kaplan-Meier curves and log-rank tests. Univariate and multivariate Cox proportional hazard regression models were used to identify OS-related variables. A total of 96 patients were enrolled. The median follow-up time was 135.06 months. The hazard ratio curve showed that 60-62 Gy was the optimal dose range, according to which patients were divided into three groups: low-dose group ( 62 Gy). The 5-year OS rates were 44.6%, 72.1%, and 52.3% for the low-dose, optimal-dose, and high-dose groups, respectively, with the optimal-dose group having the highest OS (p = 0.02). The multivariate analysis revealed that OS was associated with age, T stage, and radiation dose. Additionally, surgical complications and late toxicity were higher in the high-dose group. The optimal preoperative radiation dose for patients with resectable SNSCC was 60-62 Gy concerning OS. Radiation doses exceeding 62 Gy brought more peri-surgery complications and late toxicities without OS benefit. Qian Liu, MD (Presenting Author) - Cancer Hospital, Chinese Academy of Medical Science; Zeliang Ma (he/him/his), MD (Co-Author) - Cancer Hospital, Chinese Academy of Medical Science; Jingwei Luo, MD (Co-Author) - Cancer Hospital, Chinese Academy of Medical Science