# Uncovering New Horizons: Update to Quadruple-D Score to Predict Stone-Free Rate with Advanced Non-invasive Lithotripsy Technology

## TL;DR

A new scoring system called Piezolith Q-D improves predictions of stone-free outcomes after kidney stone treatment with a new lithotripter technology.

## Contribution

The study introduces updated cut-off values and a new scoring system (Piezolith Q-D) for predicting stone-free rates using a newer piezoelectric lithotripter.

## Key findings

- 75% of patients achieved stone-free status after ESWL using the Piezolith 3000 Plus lithotripter.
- Stone density and skin-to-stone distance were the strongest predictors of stone-free outcomes.
- The Piezolith Q-D score showed better predictive accuracy (AUC 84%) compared to the previous Quadruple-D score (AUC 80%).

## Abstract

To evaluate the efficacy of the Quadruple-D scoring system in predicting stone-free rate (SFR) using the newer Generation Piezoelectric lithotripter.

A prospective observational study was conducted from January to December 2023, involving patients who underwent extracorporeal shock wave lithotripsy (ESWL) for renal stones sized 5-20 mm. Evaluation parameters included stone density, skin-to-stone distance (SSD), stone size (ellipsoid stone volume), and location, with Quadruple-D scores calculated based on predetermined cutoffs. Extracorporeal shock wave lithotripsy sessions utilized the “Piezolith 3000 Plus” lithotripter, and SFR was assessed 4 weeks post-procedure. Statistical analysis included Student’s t-test and receiver operating characteristic curve analysis.

Of the 40 eligible patients, 75% achieved stone-free status post-ESWL. Stone density and SSD emerged as leading predictors of SFR, with new cut-off values identified. Comparative analysis demonstrated improved predictive power of the Piezolith Q-D score over the previous Quadruple-D score (AUC: 84% and 80% respectively). Although stone location and size also influenced outcomes, their significance varied in this study.

The Piezolith Q-D score system exhibits promise in predicting SFR post-ESWL with piezoelectric lithotripters. External validation and larger-scale studies are warranted to establish the scoring system’s reliability and applicability across diverse populations.