Low-energy electronic intraoperative radiotherapy for pT3 locally advanced colon cancer: a single-institution retrospective analysis

Abstract Background Patients with locally advanced colon cancer (LACC) treated with surgery had a high risk of local recurrence. The outcomes can vary significantly among patients with pT3 disease. This study was undertaken to assess whether low-energy electronic intraoperative radiotherapy (eIORT) can achieve promising results comparing with electron beam IORT (IOERT) and whether specific subgroups of patients with pT3 colon cancer may benefit from eIORT. Methods We retrospectively reviewed 44 patients with pT3 LACC treated with eIORT. Clinicopathologic characteristics were analyzed to identify patients that could potentially benefit from eIORT. Kaplan-Meier survival analysis was used to assess overall survival (OS) and progression free survival (PFS). The log-rank test was used for the subgroup comparison. Results The median follow-up of patients was 20.5 months (range, 6.1–38.8 months). At the time of analysis, 38 (86%) were alive and 6 (14%) had died of their disease. The 3-year Kaplan-Meier of PFS and OS for the entire cohort were 82.8% and 82.1%, respectively. At median follow-up, no in-field failure within the eIORT field had occurred. Locoregional and distant failure had occurred in 2 (5%) patients each. The rate of perioperative 30-day mortality was 0% and morbidity rate was 11%. Five patients experienced 7 complications, including 4 early complications (30-d) and three late complications (>30 days) leading early and late morbidity rates of 9% and 7%, respectively. Conclusion Low-energy eIORT can be considered as part of management in pT3 LACC.