New technologies for ablation of small renal tumors: current status.

The diagnostic rate of small, "incidental" tumors which are amenable to local excision or ablation has increased significantly due to widespread use of non-invasive body imaging tests. The role of nephron-sparing tumor-ablative surgery has expanded beyond the traditional circumstances of neoplasms in solitary/functionally solitary kidneys or tumors present bilaterally. Due to technologic advances, possible therapeutic options now include open surgery, laparoscopic, percutaneous and extraciorporeal approaches, in addition to surveillance in some cases. This review will concentrate on the new energy sources available for tumor ablation rather than the different surgical approaches, with a detailed review of renal cryoablation, radiofrequency and high intensity focused ultrasound. The emphasis is on the experimental data and the limited clinical data available to date, and challenges and current limitations of the various modalities.