Objective
Aim of this study is analysing the pooled results of Intra-Operative Electron beam Radiotherapy (IOERT) containing mulitmodality treatment of locally recurrent rectal cancer (LRRC) of two major treatment centers.
Methods and Materials
Five hundred sixty five patients with LRRC who underwent multimodality-treatment up to 2010 were studied. The preferred treatment was preoperative chemo-radiotherapy, surgery and IOERT. In Uni-and multivariate analyses risk factors for local re-recurrence, distant metastasis free survival, relapse free survival, cancer-specific survival and overall survival were studied.
Results
Two hundred fifty one patients (44%) underwent a radical (R0) resection. In patients who had no preoperative treatment the R0 resection rate was 26%, and this was 43% and 50% for patients who respectively received preoperative re-(chemo)-irradiation or full-course radiotherapy (p<0.0001). After uni-and multivariate analysis it was found that all oncologic prameters were influenced by preoperative treatment and radicality of the resection. Patients who were re-irradiated had a similar outcome compared to patients, who were radio-therapy naive and could undergo full-course treatment, except the chance of local re-recurrence was higher for re-irradiated patients. Waiting -time between preoperative radiotherapy and IOERT was inversely correlated with the chance of local re-recurrence, and positively correlated with the chance of a R0 resection.
Conclusion
R0 resection is the most important factor influencing oncologic parameters in treatment of LRRC. Preoperative (chemo)-radiotherapy increases the chance of achieving radical resections and improves oncologic outcomes. Short waiting-times between preoperative treatment and IOERT improves the effectiveness of IOERT to reduce the cance of a local re-recurrence.