Predictors of the Frequency of Ethanol Injections for Renal Cyst Ablation: A Preliminary Study

Abstract

Purpose:To assess the factors facilitating the prediction of the frequency of ethanol injections in successful renal cyst ablation. Materials and Methods:We retrospectively reviewed the computed tomography and ultrasonography scans of 37 renal cysts. Two radiologists evaluated the characteristics of the presenting renal cysts, including size, calcification, septation, and lobulated configuration. Patients were divided into an "above-four" group and "below-three" group, according to the number of ethanol injections. Results: Among the 37 renal cysts, six belonged to the "above-four" group and 31 to the "below-three" group. The mean volume of "above-four" group was 409.48 cc and that of the other group was 301.64 cc. Seven renal cysts included three belonging to the "above-four" group, which showed calcification. Twelve renal cysts presented a multilocular appearance with thin septa, and included a cyst classified under the "above-four" group. Three renal cysts had lobulated configuration, with one of them belonging to the "above-four" group. Conclusion: No significant correlation was found among the different factors in the prediction of the frequency of renal cyst ablation. However, calcification was the most useful parameter for prediction of the number of renal cyst ablations needed.