3D voluminometry of urolithiasis as a predictor of success in ureterorenoscopic (URS) treatment

Abstract

AbstractStone burden is a predictor of stone free rate (SFR) after ureterorenoscopy (URS). 2D measurements (X-Ray/CT) may unreliably predict actual stone burden. This study was performed to evaluate 3D measurements as a predictor of SFR after URS compared to 2D measurements. A retrospective study (2008–2019) was performed on patients with a single stone and preoperative CT-scans. Stone size was assessed by three conventional 2D methods and an automated 3D measurement. Primary outcome was SFR after four weeks. Secondary outcomes involved the need for subsequent procedure and complications. 227 patients were included, SFR was 74.9%. 3D measurement correlated significantly with SFR (OR: 0.980). Unfortunately, no predictive value was observed. 3D measurement demonstrated a significant correlation to complications (OR: 0.966). Low interobserver variability (0.891 vs 0.782 respectively) was found in the 2D and 3D measurements. It was concluded that, although 3D voluminometry correlates significantly to SFR and complications, these approach harbors no predictive value.