Acute Radiation Enteritis

Research Objective and Principle: Through a randomized controlled study, evaluate the effectiveness of dexamethasone in improving radiation-induced rectal injury in rectal cancer patients undergoing pelvic radiotherapy, thereby providing evidence for treatment options in patients at risk of radiation-induced rectal injury and aiming for adoption in international guidelines. Primary Objective: Improvement rate of radiation-induced rectal injury. Secondary Objectives: Severity of radiation-induced rectal injury, completion rate of pelvic radiotherapy, safety of dexamethasone enema, quality of life, pathological complete response (pCR) rate. Study Design: Prospective, single-center, randomized controlled study. Study Population and Expected Enrollment: Patients with rectal cancer undergoing conventional pelvic radiotherapy, expecting to enroll 40 patients. Trial Duration: From February 2026 to February 2028. Intervention: Experimental Group: Patients will receive enema (dexamethasone 1 mL + normal saline to total 30 mL) once daily from day 10 of radiotherapy until radiotherapy completion. Control Group: Patients will receive enema (dexamethasone 1 mL + normal saline to total 30 mL) once daily from the occurrence of radiation-induced rectal injury until radiotherapy completion. Statistical Hypothesis: Based on previous reports, the incidence of acute radiation-induced rectal injury is 86%, and it is expected that the experimental group can reduce it to 40%. The sample size was estimated using a formula designed to compare 2 proportions, with a set at 0.05 and a power of 80%. The study aimed to enroll at least 36 patients. Considering a dropout rate of 10%, at least 40 patients need to be included.

Research Objective and Principle: To evaluate the effectiveness of Bergmann enema in preventing acute radiation-induced rectal injury in patients with rectal cancer, thereby providing a basis for treatment options for potential radiation-induced rectal injury patients, aiming for adoption by international guidelines. Primary Objective: Incidence of grade 2 or higher radiation-induced rectal injury. Secondary Objectives: Severity of radiation-induced rectal injury, completion rate of short-course radiotherapy, safety of Bergmann enema, quality of life, pathological complete response (pCR) rate. Study Design: Prospective, single-center, single-arm study. Study Population and Expected Enrollment: Patients with rectal cancer undergoing short-course radiotherapy, expecting to enroll 40 patients. Trial Duration: From December 2025 to December 2026. Intervention: Patients will receive Bergmann enema (30 ml) once daily from the start of radiotherapy until the 10th day after the end of radiotherapy. Statistical Hypothesis: Based on previous reports, the incidence of acute radiation-induced rectal injury is 80%, and it is expected that Bergmann enema preventive treatment can reduce it to 50%. The sample size was estimated using a formula designed to calculate single-group rate, with a set at 0.05 and a power of 80%. The study aimed to enroll at least 36 patients. Considering a dropout rate of 10%, at least 40 patients need to be included.

Preclinical data indicate that rifaximin could be repurposed as a novel strategy for preventing and reducing the severity of gastrointestinal damage, particularly diarrhea, that results from pelvic irradiation. So, The aim of the work is to investigate the impact of Rifaximin on the incidence and severity of radiotherapy-induced diarrhea in cancer patients undergoing pelvic irradiation with or without chemotherapy.