Proton, Carbon ion, Newly-diagnosed, Major salivary gland carcinoma, Initial clinical outcomes, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282

Abstract Background Major salivary gland tumors (MSGTs) are rare and pose significant treatment challenges. This study investigates the efficacy and safety of particle beam radiotherapy (PBRT) for patients with newly-diagnosed MSGTs. Methods We conducted a retrospective analysis of 82 patients treated at the Shanghai Proton and Heavy Ion Center (SPHIC) between August 2015 and March 2022. The cohort received various radiotherapy regimens based on surgical history and pathological risk factors. We evaluated survival outcomes, treatment toxicity, and potential prognostic factors. Results Our findings revealed promising 3-year survival rates: 94.3% for overall survival (OS), 81.3% for progression-free survival (PFS), 97.2% for locoregional control (LRC), and 82.6% for distant metastasis-free survival (DMFS). Acute and late toxicities were generally mild to moderate, with a favorable safety profile. Distant metastasis was the primary mode of treatment failure, emphasizing the need for early risk assessment. Conclusion As a potentially safe and efficient treatment option for newly-diagnosed MSGTs, proton and carbon ion radiation offers an excellent alternative for traditional methods. More investigation is required to determine the long-term results and relative efficacy of various treatment modality for major salivary gland cancer when compared to photon therapy.