The authors stated that the main drawbacks of this systematic review and meta-analysis lied in the scant level of evidence provided by the design and nature of the non-controlled, and mainly retrospective, studies available, and in their relatively short follow-up. The variable nature and severity of SUI and the different proportion of patients receiving radiation likely explained the high heterogeneity observed. Combining the results of individual studies increased the total number of participants and more participants imply more statistical power. However, combining studies with differences among participants could also reduce statistical power and make real effects more difficult to identify.