Gastrointestinal Complications (PDQ®): Supportive care - Health Professional Information [NCI] - Radiation Enteritis
The initial signs and symptoms occur 6 to 18 months after radiation therapy. Radiologic findings include submucosal thickening, single or multiple stenoses, adhesions, and sinus or fistula formation. Microscopic findings include villi that are fibrotic or may be lost altogether. Ulceration is common, varying from simple loss of epithelial layers to ulcers that may penetrate to different depths of the intestinal wall, even to the serosa. Lymphatic tissue is often atrophic or absent. The submucosa is severely diseased. Arterioles and small arteries show profound changes, with hyalinization of the entire wall thickness. The muscularis is often distorted or focally replaced by fibrosis.
The diagnosis of chronic radiation enteritis may be difficult to make. Clinically and radiologically recurrent tumor needs to be ruled out. Because of the possible latency of the illness, it is essential that the physician obtain a detailed history of the patient's radiation therapy course. It is often advisable to include the radiation therapy physician in the continued management of the patient's care.
Medical management of the patient's symptoms (which are similar to symptoms of acute radiation enteritis) is indicated, with surgical management reserved for severe damage.[Level of evidence: I] Fewer than 2% of the 5% to 15% of patients who received abdominal or pelvic radiation will require surgical intervention.
The timing and choice of surgical techniques remains somewhat controversial. A lower operative mortality (21% vs. 10%) and incidence of anatomic dehiscence (36% vs. 6%) have been reported with intestinal bypass as compared with resection.[Level of evidence: II] Those who favor resection point out that the removal of diseased bowel decreases the mortality rate for resection and is comparable to the bypass procedure. All agree that simple lysis of adhesions is inadequate and that fistulas require bypass.
Surgery is undertaken only after careful assessment of the patient's clinical condition and extent of radiation damage because wound healing is often delayed, necessitating prolonged parenteral feeding after surgery. Even after apparently successful operations, symptoms may persist in a significant proportion of patients.