Late Radiation Injury of the Large Intestine

Late radiation injury of the colon and rectum after radiotherapy for a pelvic malignancy is a not uncommon complication. Although the colonoscopic appearance of radiation injury is well known, few reports have focused on the progression of radiation proctocolitis. The colonoscopic examinations of 103 patients with late radiation injuries were reviewed. The radiotherapy had originally been administered for carcinoma of the uterine cervix (79 patients), prostate (13), uterine corpus (3), ovaries (3), urinary bladder (2), vagina (2), and pelvic metastasis of breast cancer (1). In 31 patients, changes in colonoscopic appearance were followed-up. Anal bleeding was the major initial symptom, with more than half experiencing bleeding within 2 years of radiotherapy. Lesions were limited to the rectum and sigmoid colon. The incidence of late radiation injury, according to cancer site, was calculated to be 3.8% for the cervix uteri, 5.1% for the prostate, 0.60% for the corpus uteri, 0.80% for the ovary and 0.35% for the bladder. Seventeen patients underwent colostomy. Between eight and 37 years after radiotherapy, six patients developed a second colorectal cancer. As to radiation injury, two response types, bleeding and stricture, occurred. Virtually no resolution of the strictures was observed in this series. The grade of radiation injury did not correlate with radiotherapy dosage.