An observational study on the predictability of the Triple-D score in the success rate of extracorporeal shock wave lithotripsy in renal stones 1 – 2 cm in diameter

Abstract

Introduction: Evaluation of Triple-D scoring system to assess the stone free rate in individuals who were given extracorporeal shock wave lithotripsy (ESWL) for renal stones measuring 10-20 mm in diameter. Materials and methods: The study subjects were 120 patients who presented to the urological outpatient department with complaints of renal stones. Systemic Random Sampling technique was applied to select study subjects for study population with a Sampling Interval of 2. Prior to ESWL, Triple-D scoring comprising of three CT based metrics - stone dimension (volume), stone density (HU) and skin-to-stone distance (SSD) was done prior to ESWL as described by Tran et al. The score ranged from 0 (worst) to 3 (best). Treatment efficacy was studied by plain abdominal radiography three weeks after ESWL. Complete clearance was considered the “stone free status”. Results: In the study population, stone dimension, stone density and stone location were positive predictors of stone free rate after ESWL whereas age, sex and BMI of the patients, laterality of the stone and skin to stone distance were not. The area under the curve (AUC) of Triple-D scoring system was 0.598.Conclusion: Triple-D scoring system has been successfully validated as the SFR showed a parallel increase with every positive component. &nbsp