AbstractLocal recurrence following potentially curative tumor resection is a major problem in patients with gastrointestinal cancer. To augment surgical excision and to avoid the disadvantages of external beam irradiation, intraoperative radiotherapy (IORT) has been applied to primary and recurrent gastrointestinal cancer, both with curative intent and for palliation. There is ample evidence that the combination of radical surgery and IORT can improve local control. Whether this eventually can translate into improved overall survival has not yet been studied in adequately powered randomized and controlled trials. Semin. Surg. Oncol. 20:40–49, 2001. © 2001 Wiley‐Liss, Inc.