Intensity-modulated proton therapy (IMPT) demonstrates superior dose distribution over volumetric-modulated arc therapy (VMAT) for sparing organs-at-risk (OARs) in ipsilateral radiotherapy. To determine a clinical benefit, assessment of patient-reported outcomes (PRO) and physician-reported toxicities alongside a dosimetric analysis is needed.

Plans were analyzed for dosimetric differences. PROs were compared for patients undergoing ipsilateral curative-intent radiotherapy for tonsil and salivary gland cancers with VMAT or IMPT from 2015 to 2020. Physician-reported toxicities were compared.

In 40 patients, IMPT was associated with decreased dose to multiple OARs and less deterioration in the following PROs: pain, swallowing function, dry mouth, sticky saliva, sensory change, cough, speech, feeling ill, and social eating. Physician-reported toxicities demonstrated less oral pain.

IMPT is associated with decreased dose to OARs and less patient-reported acute deterioration in multiple head and neck domains. A strong consideration for IMPT in ipsilateral head and neck patients with cancer is warranted.