Intraoperative radiotherapy in the treatment of gastrointestinal malignancies

Intraoperative radiotherapy (IORT) is a technique that allows delivery of a single high dose of radiation to a target volume during surgery. Where conventional external beam radiation therapy (EBRT) is limited by the normal tissue tolerance of abdominal and pelvic organs, IORT has an advantage that surrounding organs can be shielded or moved. This approach permits delivery of a biologically potent dose of radiation with minimal toxicity. Many gastrointestinal malignancies are characterized by high rates of local failure, thus IORT has been investigated as a means to improve local control either alone or as part of a combined modality approach. In pancreatic, gastric and rectal cancers, available data suggest that the addition of IORT consistently improves local control. The effect on survival has been variable in these cancers with a significant competing risk of distant failure. As EBRT techniques improve, the utility of IORT will need to be further validated in prospective trials.