This study aimed to compare the historical incidence rate of severe oral mucositis (OM) in head and neck cancer patients undergoing definitive concurrent chemoradiation therapy (CRT) versus a prospective cohort of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) treated with prophylactic photobiomodulation therapy (PBMT).

This US-based, institutional, single-arm, phase Ⅱ prospective clinical trial was initiated in 50 patients (age ≥ 18 years, Karnofsky Performance Scale Index > 60, with locally advanced HNSCC (excluding oral cavity) receiving definitive or adjuvant radiation therapy (RT) with concurrent platinum-based chemotherapy (CT). PBMT was delivered three times per week throughout RT utilizing both an intraoral as well extraoral delivery system. Primary outcome measure was incidence of severe OM utilizing both the National Cancer Institute Common Toxicity Criteria, version 4.0 (NCI-CTCAE) Grade ≥3 and the World Health Organization Mucositis Grading Scale (WHO) Grade ≥3 versus historical controls; secondary outcome measures included time to onset of severe OM following therapy initiation.

At baseline, all patients included in final analysis ( = 47) had OM Grade 0. Average RT and CT dose was (66.3 ± 5.1) Gy and (486.1 ± 106.8) mg/m, respectively. Severe OM was observed in 11 of 47 patients (23%, confidence interval: 12, 38). OM toxicity grade trended upward during treatment, reaching a maximum at 7 weeks (WHO: 1.8 vs. NCI-CTCAE: 1.7). Subsequently, OM grade returned to baseline 3 months following completion of RT. The mean time to onset of severe OM was (35 ± 12) days. The mean time to resolution of severe OM was (37 ± 37) days.

Compared to historical outcomes, PBMT aides in decreasing severe OM in patients with locally advanced HNSCC. PBMT represents a minimally invasive, prophylactic intervention to decrease OM as a major treatment-related side effect.