Study on Biomarkers of Radiation-Induced Intestinal Injury

1. Enroll eligible patients and obtain written informed consent.
2. Collect clinical data.
3. Sample collection and biomarker assessment: Peripheral blood, urine, and stool samples will be collected from patients before the initiation of radiotherapy and after the start of radiotherapy, followed by multi-omics analyses.
4. Patient follow-up: Patients will be followed during radiotherapy, within 1 month after completion of treatment, and every 3 months thereafter; after 1 year, follow-up will be conducted every 6 months. Patients' symptoms, laboratory tests, and examination results will be recorded. Radiation-induced intestinal injury and its grading will be assessed according to the Radiation Therapy Oncology Group (RTOG) criteria. In addition, treatments and outcomes after the occurrence of radiation-induced intestinal injury will be documented.

The primary endpoint is radiation-induced intestinal injury, and the secondary endpoint is overall survival. 5. Data integration: Clinical data, previous research findings, and biomarkers measured from patient samples will be integrated to identify biomarkers of radiation-induced intestinal injury and to develop a predictive model using bioinformatics approaches.