Trial Comparing Stereotactic Body Radiation Therapy to Radiofrequency Ablation for Renal Cell Carcinoma

Inclusion Criteria for SBRT vs. RFA Randomization: * Patients with renal cell carcinoma less than 4 cm in maximum diameter, who are poor surgical candidates are eligible for randomization between SBRT and RFA (Renal cell carcinoma must be pathologically proven). * The primary tumor must be in a location amendable to RFA within the kidney. * Patients must be appropriate candidates for RFA, with platelets ≥50,000/mm3 and an international normalized ratio of 1.5. * Patients must have an ECOG (a measurement of general well being and activities of daily living; scores range from 0 to 5 where 0 represents perfect health) score ≤ 3. * There is no required minimum renal function (patients will be counseled about the possible need for dialysis, if applicable, just as would be the case for radical or partial nephrectomy). * Patients must sign an informed consent form approved for this purpose by the Institutional Review Board (IRB) of the University of Michigan Medical Center indicating that they are aware of the investigational aspects of the treatment and the potential risks. * Ability to understand and the willingness to sign a written informed consent. * If a patient is randomized to the RFA arm, but is deemed not to be an anesthesia candidate, he/she will be placed in the non-randomized SBRT cohort. Inclusion Criteria for non-randomized SBRT arm: * Patients with renal cell carcinoma less than 8 cm in maximum diameter, patients with metastatic RCC who require local palliation or are progressing through systemic disease, patients who are poor surgical candidates and have tumor location not amenable to RFA, or patients who would prefer a noninvasive means of treatment are eligible for the non-randomized SBRT cohort (Renal cell carcinoma must be pathologically proven). * There are no limitations based on location of the primary tumor within the kidney. * Patients must have an ECOG score ≤ 3. * There is no required minimum renal function (patients will be counseled about the possible need for dialysis, if applicable, just as would be the case for radical or partial nephrectomy). * Patients must sign an informed consent form approved for this purpose by the Institutional Review Board (IRB) of the University of Michigan Medical Center indicating that they are aware of the investigational aspects of the treatment and the potential risks. * Ability to understand and the willingness to sign a written informed consent. Exclusion Criteria: * Patients younger than 18 or pregnant women.