Prospective Analysis of the Safety and Efficacy of Percutaneous Cryoablation for pT1NxMx Biopsy-Proven Renal Cell Carcinoma

Abstract

Our objective was to determine the efficacy and safety of image-guided, percutaneous cryoablation for American Joint Committee on Cancer pT1ANxMx and pT1BNxMx biopsy-proven renal cell carcinoma (RCC). Computed tomography (CT)-guided, percutaneous cryoablation was used to treat 117 renal lesions in 113 consecutive patients with pT1NxMx RCC. All 117 ablations were included in the safety analysis, and complications were categorized according to Common Terminology Criteria for Adverse Events version 3.0 (CTCAE v3.0). Eighty-one lesions were biopsy-proven RCC and were included in the efficacy analysis. Technical success was defined as the "ice-ball" covering the entire lesion plus a minimum 5-mm margin. Efficacy was defined as complete lack of enhancement and continuous decrease in size on subsequent follow-up imaging studies. Technical success was 100%, with 15% of ablations requiring air or saline injection to prevent nontarget ablation. We recorded a 7% rate of clinically significant complications (CTCAE category≥2) and 0% mortality. Renal function was not adversely affected. Seventy percent of patients were discharged to home on the same day. Efficacy was 98.7% for a median follow-up of 67 weeks (range 7-172). For the subgroup of patients that reached a median follow-up of 2 (n=59) and 3 years (n=13), efficacy was 98.3 and 92.3%, respectively. Cancer specific survival was 100%. CT-guided, percutaneous cryoablation has an excellent safety and efficacy profile for stage T1A and T1B RCC; however, longer follow-up is needed to compare it with other nephron-sparing surgical treatments. It is a great option for nonsurgical patients, those in whom renal function cannot be further sacrificed, and those at risk for metachronous lesions.