Intraoperative radiotherapy in the multimodality approach to gastric cancer.

It is difficult to conclude a clear benefit from the addition of IORT to the multimodality treatment of gastric cancer based on the studies available. Only three prospective randomized trials have been published and each varies in the approach of combining adjuvant and neoadjuvant chemotherapy and EBRT with IORT. With a complex degree of confounding factors in these and other retrospective series, it also remains difficult to identify a decrease in local recurrence rates, or an improvement in overall patient survival rates attributable to the use of IORT. Several series, however, have identified patient subsets--specifically, patients who have advanced disease with serosal extension or node-positive disease--who may be more likely to benefit from the addition of IORT to gastric resection. Finally, there is no evidence in prospective or retrospective series that there is an increased patient risk or inferior outcome caused by the addition of IORT. Limited evidence of a possible benefit in advanced disease and no evidence of a disadvantage to the use of IORT have promoted continued use and investigation in the multimodality treatment of an aggressive disease. Continued efforts in prospective randomized trials should be promoted to further delineate the efficacy of IORT and EBRT in the treatment of gastric cancer, especially in light of recently published data [30], where concurrent chemotherapy has been reported to increase survival rates in high-risk patients.