Background: According to GLOBOCAN 2022 statistics, colorectal cancer has become the third most common cancer disease worldwide, and also the second leading cause of death. The incidence rate of rectal cancer is particularly prominent. Radiotherapy is one of the important methods for comprehensive treatment of rectal cancer, but the radiation damage caused by radiotherapy cannot be ignored. During radiotherapy for rectal cancer, the skin of the anal canal will be damaged by radiation, resulting in acute radiation dermatitis, which is characterized by redness, pain, and ulcers. The main symptom of patients is anal pain. As the radiation dose accumulates, the skin damage to the anal canal becomes increasingly severe, and the patient's anal pain becomes more severe, which seriously affects the patient's quality of life. Mepilex Lite Dressings can absorb the exudate, keep it moist, promote the healing of radioactive dermatitis, and relieve pain. However, when inserting into the anal canal, the patient reported significant pain that was difficult to tolerate. Therefore, indomethacin suppositories were administered rectally before inserting the dressing, which has been proven to have a reliable analgesic effect by research. In summary, the main objective of this study is to determine the effectiveness of Mepilex Lite Dressings combined with indomethacin suppositories in the treatment of acute radiation dermatitis of anal canal skin in patients with rectal cancer undergoing radiotherapy.

Method: The research plan will be a prospective randomized controlled trial. Participants were randomly divided into an experimental group (n=137) and a control group (n=137) using a simple randomization method. The control group received indomethacin suppositories and routine nursing measures, while the experimental group received the same treatment as the control group and received insertion of Meipile Lite Dressing into the anal canal. The primary outcome measure was the effective rate of treatment for acute radiation dermatitis of the anal canal skin on the 14th day after intervention, and the secondary outcome measure was the effective rate of treatment for acute radiation dermatitis of the anal canal skin on the 7th and 21st days after intervention. At the same time, a questionnaire survey was conducted using the Digital Pain Assessment Scale, Anxiety and Depression Scale, Pittsburgh Sleep Quality Index, and Skin Disease Patient Quality of Life Scale at baseline and on the 7th, 14th, and 21st days after intervention.

Rectal cancer is a common type of cancer, and radiotherapy is an important treatment method, which is of great significance for the treatment of rectal cancer. But the adverse reactions of radiotherapy also make patients feel extremely painful. The common adverse reactions of radiotherapy for rectal cancer mainly include radiation enteritis, clinically manifested as diarrhea, abdominal pain, urgency, anal pain, etc. Among them, anal pain is very painful for patients. In clinical practice, anal pain is usually considered a normal adverse reaction of radiotherapy, and is only treated with medication to alleviate pain. After the efficacy of the medication, patients may experience pain again, especially during defecation, which seriously affects their quality of life.

Through physical examination, it was found that the tissues inside the patient's anus had been damaged or even ulcerated. This area is the anatomical anal canal, from the dentate line to the anal margin. This area is covered with non-keratinized stratified squamous epithelium and is an unnatulated skin that is extremely sensitive to pain and other conditions. As the radiation dose accumulates, the anal canal skin is continuously irradiated and damaged, resulting in acute radiation dermatitis of the anal canal skin. Therefore, the patient complains of significant pain.

In order to alleviate patients' anal pain and ensure the successful completion of radiotherapy, it was found that the mepilex lite dressings was effective in the treatment of radiation dermatitis after consulting the literature, but as far as we know, it has not been applied to the treatment of anal canal skin radiation dermatitis. Therefore, this study is a bold attempt to insert mepilex lite dressings into the anal canal to verify its effectiveness in treating anal canal skin radiation dermatitis, and whether it can reduce pain and improve the quality of life of patients.

Inclusion criteria

1. Confirmed rectal cancer by histopathological diagnosis;
2. Individuals with clear indications for radiotherapy;
3. Individuals who receive radiation therapy for the first time and develop grade 2 or higher acute radiation dermatitis after receiving radiation therapy;
4. Age ≥ 18 years old;
5. Those who voluntarily participate in this study and sign the informed consent form.

Exclusion criteria

1. Individuals with allergic constitution and allergies to the drugs and materials used in this study;
2. Those who withdraw or interrupt radiotherapy midway;
3. Individuals with mental illness, emotional instability, or inability to express their own feelings;
4. Individuals with various comorbidities such as serious cardiovascular and cerebrovascular diseases, digestive system diseases, hematological diseases, and infectious diseases;
5. Physical condition score (Eastern Cooperative Oncology Group, ECOG) >3 points;
6. Individuals suffering from anal fissures and other diseases that cause skin damage to the anal canal;
7. Individuals with an artificial anus.

The study protocol, data generated in later studies will be published in the form of a paper

1. The study protocol and informed consent were published at the time of clinical trial approval.
2. The statistical analysis plan and clinical study report will be published following publication of the paper, approximately December 1, 2027.
3. The above information is valid for 3 years after publication.

Everyone can access it via ClinicalTrials.gov or by email directly to 15863788372@163.com.All individuals may access the study protocol, statistical analysis plan, and informed consent forms.