Re: Cryoablation vs. radiofrequency ablation for small renal masses.

RATIONALE AND OBJECTIVES Cancer of the kidney is the third most common cancer of the urinary tract, and renal cell carcinoma is the most lethal of all genitourinary tumors. The incidental discovery of renal cell carcinoma has increased with increased use of cross-sectional imaging. Concomitantly, minimally invasive ablative technologies, including image-guided cryoablation, radiofrequency ablation, and others, have evolved as therapeutic options for small renal masses. MATERIALS AND METHODS Between 2006 and 2009, 111 patients (age range, 31-91 years; mean age, 70 years) underwent percutaneous computed tomography-guided thermal ablation for suspected renal cell carcinoma at two major academic centers. Outcomes data were retrospectively collected and analyzed to compare recurrence rates for patients undergoing radiofrequency ablation (n = 41) versus cryoablation (n = 70). RESULTS There were four cases of suspicious enhancement on follow-up computed tomography or magnetic resonance imaging in each group, with cumulative imaging recurrence rates of 11% and 7% for radiofrequency ablation and cryoablation, respectively. Log rank test analysis revealed no significant difference between rates of imaging recurrence between the two groups (P = .6044). CONCLUSIONS These results suggest that the use of cryoablative technology will result in similar outcomes compared with radiofrequency ablation.