Sorafenib-RT in Treating Hepatocellular Carcinoma (SHEP)

Inclusion Criteria: * Patients must have HCC either * confirmed pathologically * diagnosed by showing vascular enhancement of the lesion on at least two imaging techniques * diagnosed by showing vascular enhancement on a single technique if the AFP is over 200, in the setting of cirrhosis or chronic hepatitis B without cirrhosis. Biopsies are mandatory (unless an absolute contraindication exists). * The tumour must be unresectable or medically inoperable * At least 800 cc of non-tumor liver * Patients must be \> 4 weeks since any major surgery. * Patients may have had previous systemic treatment (with at least a 2 week break from systemic therapy to start of radiation therapy. Prior sorafenib or any other targeted therapy with anti-VEGF activity is not permitted. * Child-Pugh Liver score A * Barcelona-Clinic Liver Cancer (BCLC) score A or B or C (BCLC C permitted if ECOG 0-1 and Child Pugh A, with portal invasion) * Age 18 years or older. * Life expectancy of equal to or greater than 3 months. * ECOG performance status 0-1. * Patients must have normal organ and marrow function. * Ability to understand and the willingness to sign a written informed consent document. * Negative pregnancy test for women of child bearing age * If the patient has a history of varices and portal hypertension, elective treatment (e.g. banding) of varices will be performed prior to start of radiation therapy. * The effects of Sorafenib on the developing human fetus are unknown. For this reason women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Exclusion Criteria: * Serious medical conditions that might be aggravated by treatment, including but not limited to: myocardial infarction within 6 months, congestive heart failure, unstable angina, active cardiomyopathy, unstable ventricular arrhythmia, uncontrolled psychotic disorders, serious infections, active peptic ulcer disease, active hepatitis or cerebrovascular disease with previous stroke within the past 12 months. * Patients may not be receiving any other investigational agents concurrently or within 2 weeks of initiation of treatment. * Pregnant women * Patients with immune deficiency * Ascites (on imaging or clinical exam). * Prior liver or upper abdomen radiation therapy. * Resectable hepatocellular carcinoma. * Thrombolytic therapy within 4 weeks, or any concurrent anti-coagulant therapy. * Uncontrolled hypertension * Patients with other active malignancies * History of allergic reactions attributed to compounds of similar chemical or biologic composition to sorafenib. * Patients with active hepatitis or encephalopathy related to liver failure. * Patients with any bleeding or clotting disorder. * Patients with unhealed wounds or ulcers. * Prior sorafenib treatment is not permitted. * Patient with nausea and vomiting refractory to medical therapies, significant prior bowel resection, and inflammatory bowel disease. * Patients with evidence of extrahepatic metastases * Patients on Rifampin, St.John's Wort, Phenytonin, Carbamazepine, Phenobarbital, or chronic use (more than 4 weeks) of dexamethasone.