Quadruple-D score in the success rate of extracorporeal shock wave lithotripsy of renal stones in pediatric population

Objectives: Evaluation of the validity of the Quadruple-D score in the prediction of success in pediatric stone disease.

Materials and methods: Of the 292 children treated with SWL between 2007 and 2023, a total of 158 children who had adequate follow-up data and evaluated with non-contrast computed tomography before SWL, were included in the study. Parameters were calculated for each of the stone volume (SV), skin-to-stone distance (SSD), stone density (SD) and stone location (SL) variables. Receiver operator characteristic analysis was used to set cut-off values. Quadruple-D scores were calculated, and success rates were determined for each score. Stone-free status was determined as complete clearance after three months of final SWL.

Results: The median age of the study group was 8 (range 1 to 16). One hundred and one of the 158 (64%) children had stone-free status. Mean SV, SSD and SD values were significantly higher in SWL failed group than stone-free group after detecting cutoff values of 150 mm³, 6.7 cm, and 540 HU, respectively. Stone-free rates were detected as 19.6%, 24.7%, 37.2%, 76.2%, and 90.2% with the Quadruple-D scores of 0, 1, 2, 3 and 4 points.

Conclusions: Quadruple-D scoring system can further improve Triple-D scoring system by adding stone position parameter to clarify SFR with a simple and easy calculation. We believe that the Quadruple-D score will have better clinical significance than the Triple-D scoring system in predicting the success of SWL in children.