Stereotactic Body Radiotherapy (SBRT) and Sorafenib in Patients With Metastatic, Recurrent, or Unresectable Renal Cell Cancer (RCC)

Inclusion Criteria: * Age \> 18 years old * Zubrod Performance Status 0 or 1 * Adequate bone marrow, liver and renal function as assessed by the following: * Hemoglobin \> 9.0 g/dl * Absolute neutrophil count (ANC) \> 1,500/mm3 * Platelet count \> 100,000/mm3 * Total bilirubin \< 1.5 times institutional upper limit of normal (ULN) * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) \< 2.5 times the institutional ULN * Creatinine \< 1.5 times institutional ULN * Histologically or cytologically confirmed renal cell carcinoma, which is metastatic, unresectable or recurrent. * Life expectancy \> 6 months * Local recurrence or progression of primary lesion or progression, or symptomatic progression in extra-cranial, extra-pulmonary metastases while on sorafenib * Measurable disease * Bone metastases must have a tissue component measurable by imaging. * No untreated brain metastases * Resolution of pre-existing toxicity from prior therapy excluding alopecia and taste alteration. * Willingness and ability to comply with continuing sorafenib, visits, treatment plans, laboratory tests and study procedures. * All treated lesions must comply with SBRT dose constraints * More than 28 days since any prior systemic or local therapy for this cancer, including investigational agents and surgical procedures exclusive of sorafenib * Women of childbearing potential and men must agree to use adequate contraception (barrier method of birth control) * Women of childbearing potential must have a negative serum pregnancy test performed within 7 days prior to the start of treatment. * Ability to understand and the willingness to sign a written informed consent. * Prothrombin time(PT) and partial thromboplastin time (PTT) within normal limits. Exclusion Criteria: * Lesion in remaining (solo) kidney * Contraindications to radiotherapy or prior radiotherapy overlapping current site(s) of disease. * Cardiac disease: Congestive heart failure. Patients must not have unstable angina (anginal symptoms at rest) or new onset angina (began within the last 3 months) or myocardial infarction within the past 6 months. * Cardiac ventricular arrhythmias requiring anti-arrhythmic therapy. * Uncontrolled hypertension defined as systolic blood pressure \> 150 mmHg or diastolic pressure \> 90 mmHg, despite optimal medical management. * Known human immunodeficiency virus (HIV) infection or chronic Hepatitis B or C. * Active clinically serious infection * Thrombolic or embolic events such as a cerebrovascular accident including transient ischemic attacks within the past 6 months. * Pulmonary hemorrhage/bleeding event within 4 weeks of first dose of study drug. * Any other hemorrhage/bleeding event within 4 weeks of first dose of study drug. * Serious non-healing wound, ulcer, or bone fracture. * Evidence or history of bleeding problems * Major surgery, open biopsy or significant traumatic injury within 4 weeks of first study drug. * Use of St. John's Wort or rifampin (rifampicin). * Known or suspected allergy to sorafenib or any agent given in the course of this trial. * Any condition that impairs patient's ability to swallow whole pills. * Any malabsorption problem.