# Lithotripsy literature database Reviewer's Choice ## Xu H. et al., 2024: The Association Between Stone Heterogenicity and the Success of Shock Wave Lithotripsy for High Density Upper Urinary Tract Stones: A Muti-Center Prospective Cohort. Hanfeng Xu, Junlong Liu, Zheming Li, Chengshan Ge, Hongqiang Guo, Shiyu Song, Zhenhua Li, Song Bai Urology. 2024 Nov 20:S0090-4295(24)00970-1. [doi: 10.1016/j.urology.2024.10.069](https://pubmed.ncbi.nlm.nih.gov/39577810/) ## Abstract Objective: To prospectively investigate the predictive value of radiological stone heterogenicity for the success of shock-wave lithotripsy (SWL) in patients with high-density upper urinary tract stones. Methods: This multi-center prospective study was conducted from June 2020 to December 2023. The radiological stone density index measured by computed tomography (CT) included the mean, standard deviation (SD), and coefficient variation (CV) of the Hounsfield Unit value of stones. The success was defined as no evidence of clinically significant stone fragments (≥4 mm) on a plain X-ray and ultrasound of the upper urinary tract 1 month after SWL. Binary logistic regression models were used to assess the odds ratios (ORs) and 95% confidence intervals (CIs). Results: Finally, 533 patients with high-density upper urinary tract stones were enrolled in this study. There were 68.5% (379/533) patients experienced success after SWL treatment. After adjusted confounding variables, compared with the patients in the lowest quartile of stone density index, the odds ratios (95% CI) for the extreme quartile was 1.42 (0.71, 2.81, P for trend = .443), .03 (.01, .09, P for trend <.001), and .02 (.01, .07, P for trend <.001) for MSD, SD, and CV, respectively. Furthermore, this linear association was confirmed only for SD and CV regardless of gender, body mass index, stone size, and stone location. Conclusion: This multi-center prospective study demonstrated a positive association between the stone heterogenicity and the success of SWL in patients with high-density upper urinary tract stones regardless of gender, body mass index, stone size, and stone location. However, this association was not observed in mean stone density. ## Comment Peter Alken Congratulation! I was often annoyed by the never-ending series of contradictory publications about the stone density measured by CT and the different response to ESWL, without any explanation for the different results being given. The present publication seems to put an end to that story. My annoyance partially anchors on the fact that more than 20 years ago publications (1) of Williams et al. had shown that CT techniques allow to see the inner structure of stones much as we had seen it in pre-CT-times by simply sectioning the stones in half. For those not familiar with such views a recently published paper on the microstructure of stones offers a quick glance into the inside of stones (2). Williams et al. concluded “These results open up new possibilities for determining the relationship of stone structure and fragility for shock wave lithotripsy.” This was confirmed in later publications of the same group (3), Williams et al. (4), and others(5). However, the decisive step into practice is only made now, by the present paper. It is the simplicity of the solution that reads so brilliantly. I hope it will be confirmed by further studies. 1 Williams JC Jr, Paterson RF, Kopecky KK, Lingeman JE, McAteer JA. High resolution detection of internal structure of renal calculi by helical computerized tomography. J Urol. 2002 Jan;167(1):322-6. PMID: 11743350. 2 Barannyk K, et al. Features of the morphogenesis of oxalate and urate urinary stones in urolithiasis patients from heavely industrialized region. Wiad Lek. 2024;77(9):1672-1679. doi: 10.36740/WLek/191325. PMID: 39548991. Free Full Text 3 Zarse CA, et al. CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro. Urol Res. 2007 Aug;35(4):201-6. doi: 10.1007/s00240-007-0104-6. Epub 2007 Jun 13. PMID: 17565491; PMCID: PMC2408919. Free Full Text 4 Ferrero A, et al. Quantitative Prediction of Stone Fragility From Routine Dual Energy CT: Ex vivo proof of Feasibility. Acad Radiol. 2016 Dec;23(12):1545-1552. doi: 10.1016/j.acra.2016.07.016. Epub 2016 Oct 4. PMID: 27717761; PMCID: PMC5111401. Free Full Text 5 Moen T, et al. Robustness of Textural Features to Predict Stone Fragility Across Computed Tomography Acquisition and Reconstruction Parameters. Acad Radiol. 2019 Jul;26(7):885-892. doi: 10.1016/j.acra.2018.08.010. Epub 2018 Oct 2. PMID: 30287145; PMCID: PMC6443511. Free Full Text Peter Alken Details Written by: Peter Alken Hits: 1615 - [ SWL Featured ](https://www.storzmedical.com/en/component/tags/tag/swl-featured/)