A Systematic Review of the Quality of Evidence of Ablative Therapy for Small Renal Masses

Purpose: We critically assessed the methodological and reporting quality of published studies of ablative techniques for small renal masses. Materials and Methods: We performed a systematic PubMed (R) and EMBASE (R) literature search from January 1966 to March 2010 to identify all full text, original research publications on ablative therapy for renal masses. Six reviewers working independently in 3 teams performed duplicate data abstraction using Strengthening the Reporting of Observational Studies in Epidemiology criteria, which were pilot tested in a separate sample. Results: A total of 117 original research publications published in a 15-year period (1995 to 2009) met eligibility criteria. No randomized, controlled trials were identified. All studies were observational and 88.9% had 1 arm with no comparison group. Median sample size was 18 patients (IQR 5.5, 40.0) and 53.8% of studies included 20 or fewer patients. Median followup was 14.0 months (IQR 8.0, 23.8) and only 19.7% of studies had an average followup of greater than 24 months. Of the studies 20.5% mentioned the number of operators involved and only 6.0% provided information on their experience level. Of the studies 66.7% addressed the recurrence rate. Disease specific and overall survival was reported in only 15.4% and 16.2% of studies, respectively. Conclusions: The published literature on the therapeutic efficacy of ablative therapy for renal masses is largely limited to uncontrolled, 1-arm observational studies. In the absence of higher quality evidence ablative therapy outside research studies should be limited to select patients who are not candidates for surgical intervention.