Intraoperative electron radiotherapy as a component of salvage therapy for patients with colorectal cancer and advanced nodal metastases

Abstract

Purpose To define the survival rates and relapse patterns in patients with isolated advanced nodal metastases secondary to colorectal cancer, treated with curative intent using aggressive combined-modality treatment. Methods and materials Forty-eight patients with isolated advanced lymph node metastases secondary to colorectal cancer received intraoperative radiotherapy as part of curative-intent treatment. Forty-seven patients also received external beam radiotherapy (EBRT). Chemotherapy was delivered concomitantly with EBRT in 35 patients. The median intraoperative radiotherapy dose was 1250 cGy. End points included local failure within the EBRT field, central failure within the intraoperative radiotherapy field, distant metastases, survival, and toxicity. Results The median survival time and 5-year survival rate were 35 months and 34%, respectively. At 3 years, the local control and central control rates were 81% and 93%, respectively. Macroscopically complete resection and colonic primary site were predictors of survival and disease control. The median survival time and 5-year survival rate in patients with colonic primary sites and macroscopically complete resection were 53 months and 49%, respectively. Intraoperative radiotherapy–related neuropathy occurred in 3 patients and ureteral fibrosis in 1. Conclusion With aggressive combined-modality therapy that includes intraoperative radiotherapy, long-term survival is achievable in colorectal cancer patients presenting with nodal relapse or advanced nodal disease. Survival and disease control rates are highest in those without gross residual disease.