The CyberKnife system has been cleared by the U.S. Food and Drug Administration (FDA) to treat lesions, tumors and conditions anywhere in the body when radiation treatment is indicated. In order to treat tumors during the respiratory cycle (vs. increasing the margin of treatment around the tumor to compensate for movement or requiring the patient to breath hold during the delivery of each beam), the Synchrony™ option, a system option that enables dynamic radiosurgery during respiration, will be used. The purpose of this study is to determine a tolerable dose of radiation delivered by the CyberKnife in two groups of patients with hepatocellular carcinoma (HCC).Group 1: Patients with HCC and Childs A cirrhosis, and patients with colorectal liver metastases. Group 2: Patients with Childs B cirrhosis. Patients will be irradiated with radiation doses using the CyberKnife system in 3-5 radiation fractions using guidance from fiducials placed by interventional radiology. Treatments will be delivered with standard CyberKnife procedures to account for respiratory motion and set up variations. The fiducial location will be the prime determinant of the delivery site and respiratory motion and fiducial markers will be placed via percutaneous approach by interventional radiology.