• Fully understand and sign the informed consent form;

• Age ≥18 years and \<80 years;

• Good physical condition (WHO performance status score 0-1);

• Pathologically diagnosed with pelvic malignant tumors and received radiotherapy;

• Diagnosed with chronic radiation proctitis after at least 6 months of endoscopic examination following the completion of radiotherapy and ineffective conventional treatment;

• Screening period LENT-SOMA score ≥1;

• Subjects and their spouses or partners have no plans for conception from screening to 6 months after the end of the trial, no plans for sperm or egg donation, and agree to use effective non-pharmacological contraceptive measures during the trial.