Efficacy and Safety of Percutaneous Cryoablation for Stage 1A/B Renal Cell Carcinoma: Results of a Prospective, Single-Arm, 5-Year Study

Abstract
Purpose Percutaneous cryoablation is gaining in popularity as a viable treatment option for renal cell carcinoma (RCC). We present the 5-year oncologic outcomes of a prospective trial. Methods Over a 5-year period, we treated 134 consecutive patients with biopsy-proven RCC with CT-guided percutaneous cryoablation. All were treated while under conscious sedation. Technical objective was for the ice ball to cover the lesion plus a 5-mm margin. Hydro- or air dissection was utilized to aid in technical success as needed. Efficacy was defined as the lack of enhancement and/or enlargement of a previously enhancing lesion on follow-up imaging. Safety was assessed by the common terminology criteria for adverse events (CTCAE), version 4.0. Results The 1-, 2-, 3-, 4-, and 5-year efficacy of percutaneous cryoablation for RCC was 99.2, 99.2, 98.9, 98.5, and 97.0 %, respectively. Median tumor size was 2.8 ± 1.4 cm. All-cause mortality during the study period was 3 (none from RCC), yielding an overall 5-year survival of 97.8 %. The cancer-specific 5-year survival was 100 %. No patient developed metastatic disease during the follow-up period. The overall significant CTCAE version 4.0 complication rate was 6 %, with the most frequent being transfusion-requiring hemorrhage, at 1.6 %. There was one 30-day mortality unrelated to the procedure. Conclusion CT-guided percutaneous cryoablation for renal cancer offers very high efficacy, approaching that of the gold standard, with a more favorable safety profile.