SBRT of Metastases Following Neo-adjuvant Treatment for Colorectal Cancer With Synchronous Liver Metastases

This will be a phase II feasibility trial to evaluate ablative radiation for the management of colorectal cancer with potentially resectable/ablatabale synchronous oligo-metastases. In this study, following completion of the neo-adjuvant component of treatment, patients will be re-staged (as is the current standard of care) and can then proceed for SBRT to the liver lesion. Patients who may have responded very well to the systemic treatment with no-residual disease on re-staging imaging, will use pre-treatment imaging for target delineation. The advantage of SBRT is in the minimally invasive approach to treatment that may be associated with lower morbidity, better quality of life and post treatment morbidity, as well as being significantly less expensive. The planned course of the neo-adjuvant component of treatment for this study will reflect the NCCN (National Comprehensive Cancer Network) guidelines and will treat rectal cancer patients with a short course of radiation followed by 6-9 cycles of a combination chemotherapy regimen. For the colon cancer group of patients, all patients will receive 6-9 cycles (2-3 months) of neo-adjuvant systemic chemotherapy as per current standard of care. Patients with non-progressive disease at that point, will have SBRT for the metastatic lesion followed by surgery for the primary rectal cancer.