Evaluation of the Importance of Skin-Stone Distance by Computed Tomography In Predicting Extracorporeal Shock Wave Lithotripsy Stone Free Rate

Abstract

ur study was performed on 50 patients who presented to Urology department on NIUN complaining of renal stones that were amenable for SWL. Skin to stone distance should be measured on NCCT at our radiological department in NIUN. Form the 50 of patients the success rate according to our criteria was 66% and failure rate was 34%. Statistical study on several radiological factor and patient factor revealed the significance of SSD, HU and stone size, while the last two values were significant, the first value was highly significant. It was found that SSD higher than 10.2cm is corresponding to high failure rate. SSD is a significant factor that can predict SWL success rate, can be easily measured by NCCT. SSD should be integrated in scoring system that can apply combined score help to augment predictive power of SWL, reduce cost, and improving of treatment strategies. SSD is not a standard value but the racial factor play a rule in its value.