Topical Betamethasone Valerate As a Prophylactic Agent to Prevent Acute Radiation Dermatitis in Head and Neck Malignancies: A Randomized, Open-Label, Phase 3 Trial.

PURPOSE: We assessed the role of topical betamethasone as a prophylactic agent in patients receiving radiation for head and neck malignancies. METHODS AND MATERIALS: This randomized, open-label, phase 3 trial was completed at a single research institute. Patients receiving curative radiation for head and neck cancer were randomized into 2 groups of 75 patients each by computer-generated permuted block random assignment. Patients in the test arm applied 0.1% topical betamethasone valerate cream once a day, after radiation. Patients in the control arm received best supportive care. The Radiation Therapy Oncology Group acute toxicity grading scale was used to assess radiation dermatitis after every fifth fraction until completion and at 2 weeks after treatment. Primary outcome in both arms was the proportion of patients who developed grade 2 and 3 acute skin reaction. The trial is registered at the Central Trial Registry of India (CTRI/2017/04/008298). RESULTS: Between April 15, 2017, and October 30, 2018,150 patients were randomized into the study, with 75 patients in each arm. Fourteen patients in the test arm and 15 patients in the control arm did not complete the intended treatment. Per the intention-to-treat analysis, 25 of 75 patients (33.3%) and 38 of 75 patients (50.7%) developed grade 2 or greater radiation dermatitis in the test and control arms, respectively (absolute difference, 17.4%; 95% confidence interval, 4%-30%; P = .032). Fifteen of 75 patients (20%) developed grade 3 reactions in the test arm compared with 18 of 75 patients (24%) in the control arm (absolute difference, 4%; 95% confidence interval, 7%-15%; P = .554). CONCLUSION: Although prophylactic use of betamethasone significantly reduced the composite outcome of the proportion of patients developing grade 2 and grade 3 radiation dermatitis, it did not reduce the proportion of patients developing the clinically significant outcome of grade 3 radiation dermatitis.