Topical Periplaneta Americana-Derived Meilian Fuxin Liquid for Radiation Dermatitis

Inclusion Criteria: 1. Age and Gender: Patients aged 18 to 80 years (inclusive of boundary values), regardless of gender. 2. Diagnosis and Treatment: Patients with head and neck cancer (including nasopharyngeal carcinoma) who have been confirmed by histopathology and require radical radiotherapy or postoperative adjuvant radiotherapy. 3. Performance Status: Patients with an ECOG Performance Status score of 0 to 2. 4. Consent: Patients who voluntarily agree to participate in this study and sign the informed consent form. Exclusion Criteria: 1. Prior Radiotherapy: Patients with a history of prior radiotherapy to the target area. 2. Baseline Skin Condition: Baseline skin condition in the treatment area that may interfere with efficacy assessment (e.g., presence of open wounds, infection, rash, psoriasis, etc.). 3. Systemic Diseases: Presence of connective tissue diseases or other systemic dermatoses. 4. Known Allergies: Known allergy to any component of the investigational product (Meilian Fuxin Solution). 5. Prior Clinical Research: Participation in other interventional clinical studies within the past 3 months and use of any investigational drugs or devices. 6. Investigator Discretion: Subjects judged by the investigator to be unsuitable for participation in this clinical study.