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.
METHODS AND MATERIALS
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).
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 dis-ease-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).
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 fur-ther investigation in a randomized trial.