2797 - Optimal Preoperative Radiotherapy Dose for Sinonasal Squamous Cell Carcinoma
Presenter(s)
Q. Liu1, and J. Luo2; 1Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 2Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
Purpose/Objective(s): Preoperative radiotherapy has demonstrated promising results in organ preservation and therapeutic effectiveness for patients with resectable sinonasal squamous cell carcinoma (SNSCC). However, the optimal radiation dose remains undefined. This study aimed to investigate the optimal preoperative radiotherapy dose for overall survival (OS) for SNSCC patients.
Materials/Methods: 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. Survival curves were generated using the Kaplan-Meier method and compared using log-rank tests. Univariate and multivariate Cox proportional hazard regression models were employed to identify variables associated with OS.
Results: 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 categorized into three groups: low-dose (<60 Gy), optimal-dose (60–62 Gy), and high-dose (>62 Gy) groups. The 5-year OS rates were 44.6% for the low-dose group, 72.1% for the optimal-dose group, and 52.3% for the high-dose group, with the optimal-dose group showing the highest OS (p = 0.02). Multivariate analysis showed that OS was associated with age, T stage, and radiation dose. Furthermore, the high-dose group experienced higher rates of surgical complications and late toxicity.
Conclusion: For patients with resectable SNSCC, The optimal preoperative radiation dose was determined to be 60–62 Gy for improving OS. Doses above 62 Gy resulted in increased peri-surgery complications and late toxicities without providing additional OS benefits.