Predicting Stone-free Status based on Quadruple-D and Triple-D Scores after Extracorporeal Shock-Wave Lithotripsy and Comparing With Broad-Spectrum Population.

Purpose: To compare the Triple-D and Quadruple-D scores in predicting the success of shock-wave lithotripsy (SWL).

Material And Methods: We retrospectively reviewed a total of 328 patients who had undergone SWL for stones with an average size of 10-15 mm in the renal pelvis, lower, middle, and upper calyces at the Urology Clinic of Kartal Dr. Lütfi Kırdar City Hospital between 2021 and 2023. Patients were divided into two groups - stone-free and residual - based on pre-and post-SWL imaging. Age, gender, stone location, ellipsoid stone volume (ESV) and side (right/left), stone density (SD), stone-skin distance (SSD), body-mass index (BMI), Triple-D score (TrD-S), and Quadruple-D score (QrD-S) values were recorded and compared. For TrD-S, SV <150 mm, SD <600 Hounsfield (HU), and SSD <12 cm were scored in the range of 0-3. For QrD-S, lower calyx localization was scored as "0", and pelvis, middle calyx, and upper calyx stones were scored as "1" in the range of 0-4.

Results: Of a total of 328 patients, 219 (66.8%) were stone-free, 109 (33.2%) had residual stones, 211 were male, and 117 were female. Of the stones, 149 were located in the lower calyx, 118 in the middle calyx, 55 in the renal pelvis, and 6 in the upper calyx. ESV was 95.5 and 120 µ/L in the two groups, (p:0.001). Cutoff values of TrD-S and QrD-S were 1.5 and 2.5, and area under the curve (AUC) values were 0.65 and 0.67, respectively, (p:0.001).

Conclusions: The Quadruple-D score is at least as successful as the Triple-D score in predicting SWL success.