Background and purpose: The introduction of radiofrequency ablation (RFA) into other fields of surgery has fueled the interest to study its application in small renal masses (SRM). Some controversies remain, however, regarding its oncologic efficacy. We review technical factors and tissue characteristics that influence 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.
Materials and methods: A search of the MEDLINE database regarding the treatment of SRM by RFA was performed from 2003 through August 2009. For the purpose of describing technical factors and tissue characteristics that influence treatment success and the evaluation of treatment success by imaging and histopathology, articles were selected when they provided detailed descriptions of one or more of these items. For the analysis of oncologic outcomes, the selection was limited to series in which a minimum of 20 patients were treated and that provided effectiveness based on follow-up imaging.
Results: Technical evolutions and correct patient/tumor selection have led to increasingly higher success rates being achieved by RFA. Even though tumor skipping has been described in preclinical studies and early clinical studies, this does not seem to influence final success. Indeed, a 8.6% re-treatment rate has to be taken into account. Accepting this, the final ablative success rate is 93.8% at intermediate-term follow-up. Complications after RFA are less frequent and more often minor compared with surgical series.
Conclusions: The present analysis reveals that RFA achieves a high intermediate-term ablative success rate when accepting a 8.6% reablation rate. Complication rates are low and mostly minor. Those facts render RFA an attractive minimally 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 management of SRM.