Particle beam radiation therapy for sinonasal malignancies: Single institutional experience at the Shanghai Proton and Heavy Ion Center

BACKGROUND: Sinonasal malignancies (SNM) include malignant neoplasms of various histologies that originate from the paranasal sinuses or nasal cavity. This study reported the safety and efficacy of particle‐beam radiation therapy (PBRT) for the treatment of sinonasal malignancies. METHODS AND MATERIALS: One‐hundred‐and‐eleven patients with nonmetastatic sinonasal malignancies received definitive (82.9%) or salvage (31.5%) PBRT. The majority (85.6%) of patients presented with T3/4 disease, and only 19 (17.1%) had R0 or R1 resection. Seventy (63.1%) patients received carbon‐ion radiotherapy (CIRT), 37 received proton radiotherapy (PRT) followed by CIRT boost, and 4 received PRT alone. Prognostic factors were analyzed using Cox regression for univariate and multiple regression. Toxicities were reported using the Common Terminology Criteria for Adverse Events (version 4.03). RESULTS: The median follow‐up was 20.2 months for the entire cohort. The 2‐year local progression‐free survival (LPFS), regional progression‐free survival (RPFS), distant metastasis‐free survival (DMFS), progression‐free survival (PFS), and overall survival (OS) rates were 83%, 97.2%, 85.9%, 66%, and 82%, respectively. Re‐irradiation and large GTV were the significant factors for OS. Melanoma and sarcoma patients had significantly higher distant metastatic rate, and poorer OS and PFS. Late toxicity occurred in 22 (19.8%) patients, but only 4 (3.6%) patients experienced grades 3‐4 late toxicity. CONCLUSIONS: Particle‐beam radiation therapy results in excellent local‐regional control with extremely low serve toxicities for patients with SNM. Sarcoma and melanoma were featured with a greater risk of death from distant dissemination. Patients who underwent re‐irradiation had significantly worse OS. PBRT is feasible and safe in the management of SNM.