Sevim M. et al., 2023: Could twinkling artifact be a parameter in predicting the success of shock wave lithotripsy? A prospective study.
Sevim M, Alkis O, Kartal İG, Kazan HO, Sonmez OY, Korkmaz M, Aras B.
Department of Urology, Kutahya Health Sciences University, Faculty of Medicine, Kutahya, Turkey.
Department of Radiology, Kutahya Health Sciences University, Faculty of Medicine, Kutahya, Turkey.
Abstract
Introduction: It is important to predict success before the treatment of urolithiasis. We aimed to predict the success of shock wave lithotripsy (SWL) by comparing twinkling artifact (TA) revealed through colour Doppler ultrasonography (CDUS) with stone density in non-contrast computed tomography (NCCT).
Material and methods: Eighty patients who underwent SWL between January 2021 and January 2022 were included in the study. Patients with stones of 5-20 mm in the renal pelvis and proximal ureter at NCCT were included. Patients' demographics, Hounsfield units (HU) in NCCT, and TA grades in CDUS were recorded. The stone-free rate after SWL, additional treatments, overall success rates, and the association between TA and success rates were evaluated.
Results: The mean age was 47.41 ±15.08 years. The mean BMI was 24.49 ±3.67 kg/m2. Twenty-three (28.8%) patients were TA grade 0, 33 (41.2%) patients were grade 1, and 24 (30%) were grade 2. The mean HU of TA grades 0, 1, and 2 of stones were 628 ±107, 864 ±123, and 1166 ±292, respectively. The HU increased along with the increase in the TA grade of the stone (p <0.01). The mean number of SWL sessions was 2.26 ±0.75 in patients with TA grade 0, and 2.92 ±0.40 in patients with TA grade 2. The mean number of SWL sessions increased along with the increase in TA grade (p <0.01). The stone-free rate decreased as the TA grade increased. Stone diameter and TA were the only predictors of SWL success.
Conclusions: We think that TA may be useful in predicting SWL success.
Cent European J Urol. 2023;76(3):227-232. doi: 10.5173/ceju.2023.20. Epub 2023 Aug 26. PMID: 38045786 FREE PMC ARTICLE
Comments 1
The authors of this article have studied, in a limited number of patients, how twinkling artifacts (TA) can be used to predict outcome of SWL. Twinkling artifacts are optical properties of stones possible to identify in NCCT examinations.
The results showed that TA increased with stone density (HU) and is one method to roughly predict stone composition when no stone fragments are available for analysis. It is not mentioned in the report how easy or difficult it is to measure TA, but the variable results in the literature indicate that the method might be associated with some difficulties.
The TA was graded 0, 1 and 2 and there was a relationship between TA and stone density with mean HU-values of 628, 864 and 1166, respectively. The required number of SWL sessions increased with TA and HU. Inasmuch as TA reflects stone composition, the assumption was that Grade 0 represented COD and CaP whereas Grade 2 reflects cystine, and COM. High TA was associated with significantly increased requirement of number of SWL sessions.
Most certainly TA does not come naturally to clinically active urologists, but it seems likely that TA can be used to predict stone composition and how much SWL-energy that will be necessary for stone disintegration.
It is indeed highly interesting to learn more about TA and SWL-results and therefore it seems of interest to develop a standard method for TA-measurement in many patients as an estimate of stone hardness and stone composition in the case stone composition is unknown. It remains to be shown, however, if measurement of TA is superior to that of HU.
Hans-Göran Tiselius