Outcomes and prognostic factors of major salivary gland tumors treated with proton beam radiation therapy

Background: Proton beam radiation therapy (PBRT) has dosimetric advantages compared to photon radiation therapy for the treatment of major salivary gland tumors (MSGTs).

Methods: Patients with non-metastatic MSGTs treated at a single proton therapy center from October 2013 to October 2018 were retrospectively reviewed.

Results: Sixty-eight patients with MSGTs were included and the most common site and histology were the parotid gland (75.0%) and adenoid cystic carcinoma (22.1%), respectively. The 3-year rates of locoregional control, progression-free survival, and overall survival were 95.1% (95% CI: 89.9%-100.0%), 80.7% (70.2%-92.7%), and 96.1% (95% CI: 90.9%-100.0%), respectively.

Conclusion: In a large cohort of MSGTs treated with PBRT, the rates of locoregional control were high in short-term follow-up and treatment was well tolerated.