Radiography of the distal colon and rectum after irradiation of carcinoma of the cervix.

High dose therapeutic irradiation for carcinoma of the cervix, usually delivered using a combination of external and intracavitary sources, may damage the rectum, sigmoid, distal small bowel, vagina, and urinary bladder. A pretreatment barium enema is valuable for baseline comparison should symptoms developing after treatment necessitate radiographic evaluation of the colon and rectum. Included in this review are a summary of radiation therapy techniques for carcinoma of the cervix, the radiation tolerance of normal pelvic structures, and the histopathology of changes in the bowel following irradiation. The spectrum of radiographic manifestations of radiation effect on the rectum and sigmoid is presented and contrasted with changes secondary to recurrent or persistent tumor. Gradations of symmetrical volume loss characterize radiation change, whereas mass effect, asymmetrical narrowing of the colon lumen, or fixation are more typical of tumor recurrence.