Acute radiation dermatitis among patients with nasopharyngeal carcinoma treated with proton beam therapy- prognostic factors and treatment outcomes

Background: A high incidence of severe acute radiation dermatitis (ARD) has been reported for cancer patients treated by proton beam therapy (PBT). This prospective study investigated the prognostic factors and treatment outcomes of ARD among patients with nasopharyngeal carcinoma (NPC) treated with PBT. Methods Fifty-seven patients with newly diagnosed NPC and treated with PBT were enrolled. ARD was recorded weekly based on the criteria of Common Terminology Criteria for Adverse Events version 4.0 in a prospective fashion at treatment visits (1st to 7th weeks) and 1 week (8th week) and 1 month (11th week) after the completion of PBT. Topical corticosteroid was used when grade 1 ARD appeared, and silver sulfadiazine was added if ARD progressed to grade 2 or more. Results The maximum ARD grade was 1, 2, and 3 in 26 (45.6%), 24 (42.1%), and 7 (12.3%) of the patients, respectively. The peak incidence of grade 2 and 3 ARD was observed during the period of the 6th to 8th weeks. Twenty-four (42.1%) patients received topical corticosteroid alone; 33 (57.9%) patients received the combination of topical corticosteroid and silver sulfadiazine. In the 11th week, most grade 2 and 3 ARD had disappeared and 93.0% of the patients had ARD of grade 1 or lower. In the binary logistic regression model, we identified habitual smoking [odds ratio (OR): 5.2, 95% confidence interval (CI): 1.3–18.8, P  = 0.012] and N2 to N3 nodal status (OR: 4.9, 95% CI: 1.6–15.4, P  = 0.006) as independent predictors of grade 2 and 3 ARD. Conclusion The results show ARD is a major concern for patients with NPC treated with PBT, especially those with habitual smoking or advanced nodal status. Topical corticosteroid and silver sulfadiazine are effective for treating ARD induced by PBT.