How Reliable Is Endoscopic Stone Recognition? A Comparison Between Visual Stone Identification and Formal Stone...

Area of Science:

• Urology
• Nephrology
• Medical Imaging

Background:

• Accurate kidney stone analysis is crucial for preventing recurrence.
• Formal stone analysis methods like X-ray diffraction (XRD) are accurate but time-consuming and costly.
• Endoscopic stone recognition (ESR) offers potential for immediate stone composition assessment.

Purpose of the Study:

• To evaluate the diagnostic accuracy of ESR compared to formal stone analysis.
• To assess the intra-observer agreement of ESR among endourologists.

Main Methods:

• Fifteen endourologists viewed 100 ureteroscopy videos to predict stone composition.
• Diagnostic accuracy was determined by comparing predictions with XRD analysis.
• Intra-observer agreement was assessed by re-reviewing videos after 30 days.

Main Results:

• Median diagnostic accuracy varied significantly by stone type, with cystine (up to 80%) and calcium oxalate dihydrate (up to 75%) showing higher accuracy than others.
• Accuracy for calcium hydroxyphosphate, calcium hydrogen phosphate dihydrate, calcium magnesium phosphate, magnesium ammonium phosphate, and uric acid was generally low (0-40%).
• Intra-observer agreement ranged from 45% to 72%, indicating moderate consistency.

Conclusions:

• The diagnostic accuracy of ESR is limited, with substantial variability depending on stone composition.
• Intra-observer agreement for ESR is below acceptable thresholds, questioning its reliability as a standalone diagnostic tool.
• ESR cannot currently replace formal stone analysis for guiding stone recurrence prevention strategies.