Radiographic Parameters on Noncontrast Computerized Tomography Predictive of Shock Wave Lithotripsy Success

Purpose: Accurate prediction of shock wave lithotripsy success for given patient and radiographic parameters will lead to improved selection of patients for shock wave lithotripsy vs more invasive treatment. In this study we determined which radiographic parameters are the most predictive of shock wave lithotripsy success, and present a method to incorporate these into current and future models based on nonradiographic parameters.Materials and Methods: A retrospective case-control study was performed to determine average, maximum and standard deviation of stone attenuation values, stone size and skin-to-stone distance on preoperative noncontrast computerized tomography for 220 patients successfully treated with shock wave lithotripsy and 105 patients in whom shock wave lithotripsy failed.Results: Average stone attenuation is the best independent predictor of shock wave lithotripsy success as determined by the Student t test (p <0.0001) and receiver operating characteristic curves. Odds and likelihood rati...