Demir M. et al., 2025: Evaluating shear wave elastography as a predictor of extracorporeal shock wave lithotripsy outcomes in children.

Mehmet Demir, İsmail Yağmur, Osman Dere, İbrahim Halil Albayrak, Abdulhakim Şengel
Urolithiasis. 2025 Jun 25;53(1):126. doi: 10.1007/s00240-025-01796-z

Abstract

The aim of this study was to demonstrate the utility of Shear Wave Elastography (SWE) in predicting the success of extracorporeal shock wave lithotripsy (ESWL) in pediatric patients. A total of 102 patients < 18 years of age with a diagnosis of kidney stones underwent ESWL between May 2021 and December 2023. SWE measurements of the stones were performed in all patients prior to ESWL. The subjects were divided into two groups: those who responded to ESWL and those who did not. Age, gender, stone location, stone size, body mass index (BMI), Hounsfield Unit (HU), and stone SWE values were compared between the groups. Among the 102 patients included in the study, 78 exhibited a positive response to ESWL. In the responder group, the SWE, HU, and stone size values were significantly lower than the non-responder group (p < 0.05). SWE exhibited significant efficacy in discriminating between responders and non-responders [area under the curve (AUC): 0.979 & p = 0.000]. A SWE cutoff value of 13.70 kPa was identified for patient differentiation [AUC:0.929 & p = 0.000]. SWE appears to be an effective method for predicting the success of ESWL in pediatric patients and may serve as an alternative parameter to HU for pre-treatment evaluation.

Comment Hans-Göran Tiselius

Shear wave elastography for estimation of stone hardness is a valuable novelty in clinical evaluation of children before SWL. Every attempt to avoid CT in this patient group is of value.
Unfortunately, the authors provided no information on stone composition, but they showed that there was a good correlation between elastography and HU.
I am insufficiently informed about the ELMED lithotripter and the analgesic method applied by the authors, but it is surprising that that only 30% of the children were satisfactorily treated with only one session.
The notation that children with higher BMI were more successfully treated is also surprising even though the difference was small. That observation might indicate some problem with shock wave transfer in smaller and thinner children.
The reviewer is not convinced of the need of detailed predictive procedures before SWL, because of the many unknown factors such as operator skill, collaboration with the child and stone composition. Nevertheless, the authors should be complemented for this radiation-free determination of stone hardness.

Hans-Göran Tiselius