Radiation-Induced Skin Fibrosis

This phase I, open-label, single-arm, non-randomized clinical trial uses a "3+3" dose-escalation design to evaluate the safety, tolerability, and preliminary efficacy of intradermal delivery of complement factor H (CFH) fragment (human, 860-1231aa) via ice microneedles for the prevention of radiation-induced skin fibrosis in patients with head and neck squamous cell carcinoma (excluding nasopharyngeal carcinoma) receiving postoperative adjuvant radiotherapy. The main questions are: 1. The safety profile, including dose-limiting toxicities (DLTs) within 28 days after the first dose, adverse events, and tolerability. 2.Preliminary efficacy, assessed by changes in irradiated skin thickness, palpation of fibrotic area, CTCAE grade ≤2 fibrosis rate, and quality of life. Participants receive CFH ice microneedle patches twice weekly for a total of 8 doses (starting at 0.5 mg, escalating to 1.0 mg and 2.0 mg), applied to the skin area to be irradiated.