Particle Therapy in the Multimodal Treatment for Locally Advanced Malignancies of the Nasal Cavity and Paranasal Sinus-Single Institute Experience.

Purpose: Particle therapy with protons or carbon ions is a promising method for treating locally advanced nasal cavity and paranasal sinus carcinomas (NPSC). This study evaluates the clinical outcomes and toxicities of patients treated with carbon ion radiation therapy with a boost (CIRT-B) at our institution. Methods and Materials: Patients with NPSC who received combined treatment with CIRT-B and intensity modulated radiation therapy were considered. Local control (LC) and survival rates were estimated using Kaplan-Meier survival analysis and proportional hazards models. Results: Between 2016 and 2023, a total of 66 patients were included in the analysis. Of these, 53 patients (80%) received primary radiation therapy as their first-line treatment, while 13 patients (20%) underwent salvage reirradiation for recurrent disease. The median total dose administered in the upfront radiation therapy group was 74 Gy (range, 70-78 Gy relative biological effectiveness), whereas the median total dose in the salvage radiation therapy group was 45 Gy (range, 39-51 Gy relative biological effectiveness). The median duration of LC was 21 months in both the upfront and salvage groups. The overall median LC across all patients was 14 months. The 2-year LC rate was 73% for the upfront radiation therapy group and 52% for the salvage radiation therapy group, with a statistically significant difference ( Conclusions: CIRT-B combined with photon radiation therapy is an effective and safe treatment for advanced NPSC in both primary and salvage settings.