Adjuvant chemoradiotherapy with or without intraoperative radiotherapy for the treatment of resectable locally advanced gastric adenocarcinoma.

Purpose: To document the long-term efficacy of intraoperative electron radiotherapy (IOERT) followed by concurrent chemotherapy and external-beam radiotherapy (EBRT) in the management of locally advanced gastric cancer. Materials and methods: A total of 97 consecutive patients with T3/4 or N+ gastric adenocarcinoma were enrolled. Fifty-one patients received adjuvant chemoradiotherapy (EBRT group) and 46 received IOERT (dose range, 12-15 Gy) followed by chemoradiotherapy (EBRT + IOERT group). Results: The 5-year locoregional control rates were 50% and 35% in the two groups with or without IOERT, respectively (p = 0.04). Two patients had recurrence within the IOERT field in the EBRT + IOERT group and 14 patients recurred in the same area in the EBRT group (p = 0.02). Multivariate analyses revealed that adjuvant IOERT was an independent prognosticator for both local-regional control (p = 0.02) and disease-free survival (p = 0.05). G3/4 late toxicity was observed in 5 patients in the EBRT + IOERT group, but none in the EBRT group (p = 0.02). Conclusions: Higher radiation dose may contribute to the improvement of local control, especially in the field encompassed by IOERT. The addition of IOERT to surgery and adjuvant chemoradiation deserves further investigation in a randomized trial. (C) 2011 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 102 (2012) 51-55