Traditional Chinese Medicine for the Prevention of Radiotherapy-Induced Oral Mucositis (RTOM)

This is a multicenter, randomized, controlled, prospective clinical trial designed to observe and evaluate the safety and efficacy of Modified Dahuang Huanglian Xiexin Mouthwash for the prevention of radiotherapy-induced oral mucositis (RTOM). Participants will be randomly assigned to receive either the Modified Dahuang Huanglian Xiexin Mouthwash or Placebo Mouthwash. The study aims to assess the preventative effect on RTOM in patients undergoing radiotherapy.

Inclusion Criteria: 1. Aged 18 to 70 years (inclusive) at the time of screening. 2. Histologically confirmed squamous cell carcinoma of the nasopharynx, oral cavity, or oropharynx. 3. Planned to receive radiotherapy. 4. No prior history of radiotherapy to the head and neck region. 5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 6. Adequate major organ function as defined by the following criteria (within 14 days prior to enrollment, without transfusion support): Hemoglobin (Hb) ≥90 g/L Absolute neutrophil count (ANC)≥1.5×10⁹/L Platelet count (PLT) ≥80×10⁹/L Total bilirubin (BIL) \< 1.25×upper limit of normal (ULN) Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) \< 2.5×ULN Serum creatinine (Cr)≤ULN, or calculated creatinine clearance (Cockcroft-Gault formula) \> 50 mL/min 7. Signed written informed consent prior to any study-related procedures. 8. Judged by the investigator to be able to comply with the study protocol. 9. Negative pregnancy test (for women of childbearing potential) at screening. 10. Willing and able to adhere to scheduled visits, treatment plans, laboratory tests, and other study procedures. Exclusion Criteria: 1. Pre-existing oral mucositis prior to the start of radiotherapy. 2. Prior radiotherapy to the head and neck region. 3. Major surgery within 3 weeks prior to enrollment. 4. Uncontrolled cardiac conditions or symptoms, including but not limited to: New York Heart Association (NYHA) class II or higher heart failure Unstable angina pectoris Myocardial infarction within 1 year prior to enrollment Clinically significant supraventricular or ventricular arrhythmia requiring intervention 5. Use of topical (oral) or systemic corticosteroids within 1 week prior to enrollment. 6. Active infection requiring systemic therapy. 7. Known history of substance abuse, alcohol abuse, or drug addiction. 8. Pregnancy or breastfeeding. 9. Any other condition that, in the investigator's judgment, may interfere with the participant's ability to complete the study or compromise the collection of study data, including but not limited to serious concurrent illness (including psychiatric disorders) requiring concomitant treatment, severely abnormal laboratory values, or unfavorable family or social circumstances.