The safety and oncologic efficacy of radio-frequency ablation for the treatment of small renal masses: comprehensive review of the current literature

Abstract

The success 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. This paper reviews the effects of technical factors and tumor/tissue characteristics on treatment success, discuss the evaluation of treatment success by post-treatment imaging and histopathology, and highlight intermediate term oncologic outcomes of recent, larger RFA series. The authors have performed a Medline database search regarding the treatment of SRM by RFA from 2003 through August 2010. To evaluate technical factors and tissue characteristics influencing treatment success, and the evaluation of treatment success by imaging and histopathology, papers were selected when they provided detailed descriptions on one or more of these items. For the analysis of oncologic outcomes, the selection was limited to series that treated a minimum of 20 patients or a minimum follow-up of 48 months and reported effectiveness based on follow-up imaging. Technical evolutions and correct patient/tumor selection produced increasingly higher success rates with RFA. Even though tumor skipping has been described in preclinical studies and early clinical trials, this does not seem to influence efficacy of the procedure. Indeed, a 8.7% retreatment rate exists. However, accepting this potential downside, final ablative success rate is 94.1% at intermediate term follow-up. Complications after RFA are less frequent and more often minor compared to surgical series. The present analysis reveals that RFA achieves a high intermediate-term ablative success rate when accepting an 8.7% re-ablation rate. Complication rates are low and usually minor. Based on this data, RFA represents an attractive minimal invasive treatment for SRM, especially in the growing elderly patient population with multiple comorbidities. Long-term follow-up data are expected to confirm the role of RFA in the treatment of SRM.