The purpose of this study is to investigate the safety and effects of IMM 101 in combination with a single targeted dose of radiation in patients with metastatic colorectal cancer in whom chemotherapy or other treatment has not been effective. Administration of radiation (using the CyberKnife) to the target tumour growth in the liver results in the release of tumour material. IMM-101 may help the immune system to react to the tumour material released from the damaged tumour, and so have a beneficial effect in slowing down the rate of growth of other tumour growths in the liver and other organs.