This is a prospective, open-label, randomized, controlled, multicenter phase II study evaluating the efficacy and safety of Kangfu Spray for the prevention of radiation-induced oral mucositis in patients with histologically confirmed oral malignancies receiving intensity-modulated radiotherapy (IMRT), with or without concurrent platinum-based chemotherapy.
Eligible participants will undergo definitive or postoperative adjuvant IMRT according to multidisciplinary team recommendations. Participants in the experimental group will receive Kangfu Spray prophylactically from the first day of radiotherapy until completion of radiotherapy, in addition to standard oral care. The primary endpoint is the incidence of severe radiation-induced oral mucositis, defined as World Health Organization (WHO) grade 3 or higher. Secondary endpoints include time to onset and duration of severe oral mucositis, incidence and duration of any oral mucositis, oral ulcer and pain scores, radiotherapy interruption, opioid analgesic use, nutritional indicators, quality of life, and safety. Exploratory analyses will evaluate lymphocytes, inflammatory factors, and microbiota in blood and saliva.