Radiofrequency ablation for the treatment of small renal masses: safety and oncologic efficacy.

The successful introduction of radio frequency ablation (RFA) into various surgical fields has fueled the interest of the urological community to study its application in small renal masses (SRM). However, some controversies remain regarding its oncologic efficacy. In this paper, we review the complication rates and highlight local ablative success and long-term oncologic outcomes of recent, larger RFA series. Review of the recent literature (Medline from January 2003 through May 2011 with the terms ("radiofrequency ablation" OR "catheter ablation") AND ("renal cell carcinoma" OR "renal tumor" OR "renal mass" OR "renal cancer" OR "kidney cancer"). Twelve RFA studies including a minimum of 35 treated tumors, and representing 717 patients were identified and analyzed for local ablative success rates and complications. Reported complications were classified according to Dindo-Clavien. Another five studies representing 172 patients were identified to assess long-term oncologic outcomes. Final pathology revealed 82.3% biopsy-proven renal cell carcinomas (RCCs) in 8 of the 12 evaluable RFA studies. Local ablative success rates after a first RFA session ranged from 67% to 100%. However, accepting a 8.8% repeat ablation rate, final success rates were 89.7-100%, with 7 of 12 studies showing final ablative success in >95%. These results demonstrate RFA to achieve adequate local tumor control regardless of histology. Risk of complications was 13.2%. Of complications, 10% were minor (grade I or II), while only 3.2% were major complications (grade ≥III). Five papers were identified describing oncological outcome at a minimum follow-up of 53 months (range 53-61.2). Progression-free survival, cancer-specific survival and overall survival ranged from 79.9 to 93.8%, 98 to 100% and 58.3 to 85%, respectively. This literature review confirms that RFA can deliver durable local tumor control and excellent long-term oncological outcomes. However, in order to achieve this, a repeat ablation rate of 8.8% has to be accepted. Complication rates are low, with 10% grade I-II and only 3.2% grade >III. These observations render RFA an attractive alternative to surgery in an elderly or comorbid population.