Differences in Immunologic Response to Cryoablation Versus Radiofrequency Ablation in the Treatment of Renal Cell Carcinoma

The purpose of this study is to compare changes in the body's self-defense (immune response) after two different treatments for small kidney tumors: 1) Cryoablation (freezing) therapy in which the tumor and a margin of normal kidney tissue are frozen and thawed twice with a needle probe and 2) radiofrequency ablation (RFA) in which radiofrequency energy delivered through a needle probe is used to heat tissue and thereby destroy a tumor.