Role of radiation therapy in gastrointestinal cancer.

The intradiation techniques in the last several decades has resulted in a wider application of radiation therapy to the treatment of gastrointestinal cancer. Controlled and uncontrolled clinical trials have shown benefit for preoperative and/or postoperative irradiation in carcinoma of the rectum and rectosigmoid. Endocavitary radiation techniques have been employed successfully in early, accessible rectal cancers as an alternative to abdominal perineal resection. High-dose external beam irradiation with and without concomitant chemotherapy has produced encouraging results in locally advanced, unresectable pancreatic carcinoma. Benefit for radiotherapy in locally advanced gastric carcinoma has been demonstrated as well. In carcinoma of the esophagus, radiotherapy has resulted in long-term control in selected patients and also has been employed with modest success in combination with surgery. Interstitial radiation techniques, intraoperative electron beam therapy, and fast neutrons, heavy charged particles, and other forms of high linear energy transfer radiation are being investigated and may eventually find greater application.