A Study to See Whether Stereotactic Body RadioTherapy (SBRT) Can Shrink Tumours Within the Liver Safely

Inclusion Criteria: * Pathologically confirmed Colo-rectal Cancer * 1-3 Liver metastasis measurable on Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) * Surgically resected primary disease * Technically/medically inoperable or patient declined surgery * Progression or Stability after at least 1 Line of chemotherapy * Adequate marrow function: Hb \> 80g/L, Platelets \> 100 x 109/L, White blood cell \> 2 x 109/L * Eastern Cooperative Oncology Group (ECOG) status 0-2 * Age \> 18 years * Patient must sign study specific informed consent prior to study entry Exclusion Criteria: * Prior liver radiation, or radiation in close proximity to planned treatment sites * Prior invasive malignancy * Severe, active co-morbidity * Active hepatitis or Child Pugh Score B (9) or worse * Pregnant or nursing women * Extra hepatic disease: Any Bone/Any Brain, 2 or more Lung metastasis * Life expectancy \< 6 mo from any cause * Concurrent chemotherapy * Response to prior chemotherapy with minimal measurable disease in liver