Probe-ablative nephron-sparing surgery: Cryoablation versus radiofrequency ablation

Over the past decade, a number of probe ablative therapies have emerged for the treatment of patients with localized renal tumors. Cryoablation and radiofrequency ablation (RFA) have been studied in the greatest detail. We present the results of 164 laparoscopic cryoablations and 82 percutaneous RFAs performed in our institution and compare them retrospectively in terms of complications, impact on renal function, follow-up imaging, and oncologic outcomes. Comparison of cryotherapy versus RFA revealed that mean tumor size was similar (2.56 cm vs 2.51 cm); however, the cryoablation group had a greater number of anteriorly located tumors (39% vs 10%), as well as fewer central tumors (6% vs 37%) and fewer solitary kidneys (24% vs 49%). Mean thermal treatment time was 19.3 minutes versus 32.2 minutes in the cryoablation and RFA groups, respectively. Radiologic evidence of tumor recurrence or persistence of disease was noted in 3 patients (1.8%) who underwent cryoablation and in 9 (11.1%)who were treated with RFA. All of have been successfully treated with repeat ablation/nephrectomy, or they are currently under observation. Complication rates were minimal in both groups; no significant impact on mean serum creatinine levels was noted. Cancer-specific survival following cryotherapy was 98% at a median follow-up of 3 years and 100% for RFA at 1-year median follow-up. Cryoablation and RFA are developmental nephron-sparing options. Early results are encouraging for both forms of probe ablation in terms of early oncologic control, preservation of renal function, and low complication rates. Longer-term oncologic data are necessary so that the true value of these treatment modalities can be determined.