Adapalene Gel for Acute Radiation-Induced Skin Injury

his study aims to evaluate whether adapalene gel is effective and safe for treating acute radiation-induced skin injury in adults receiving radiotherapy. Researchers will compare adapalene gel with Biafine to determine whether adapalene gel reduces radiation-induced skin injury and improves symptoms. The main questions are: Does adapalene gel reduce the severity of acute radiation-induced skin injury compared with Biafine, and what medical problems or adverse events occur in participants using adapalene gel? Participants will apply adapalene gel or Biafine topically every day throughout the course of radiotherapy, visit the clinic every 5 days for examinations and tests, and record their symptoms and any adverse reactions during use.

Inclusion Criteria: * Informed consent: All subjects must voluntarily participate in the study and sign a written informed consent form that meets the requirements of the ethics committee. * Male or female, aged between 18 and 75 years. * Histologically or cytologically confirmed breast cancer or squamous cell carcinoma of the head and neck. * Planned to receive involved-field radiotherapy (post-breast cancer surgery whole breast/chest wall ± regional lymph node irradiation). Exclusion Criteria: * Patients unable to cooperate with the study: cognitive impairment, severe mental illness, communication disorders, or other reasons (such as extreme anxiety, uncontrollable pain) that prevent understanding and active cooperation with the research process and postoperative care. * Any previous or current illnesses, treatments, or laboratory abnormalities that may confound the study results, affect the subjects' full participation in the study, or involve participation that may not be in the subjects' best interests.