Could the twinkling artifact be a parameter in predicting the success of SWL? A prospective study Predicting the success of SWL with the TA

Introduction: It is important to determine the factors to predict success before the treatment decision in urolithiasis. In this study, we aimed to predict the success of shock wave lithotripsy (SWL) by comparing the twinkling artifact (TA) revealed through color doppler ultrasonography (CDUS) with the stone density in non-contrast computed tomography (NCCT). Material and method: 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 the study. Age, gender, stone size, hydronephrosis grade, body mass index (BMI), Hounsfield unit (HU) in NCCT, and TA grades in CDUS of the patients 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/m 2 . Twenty three (28.8%) patients were TA grade 0, 33 (41.2%) patients were grade 1, and 24 (30%) patients were grade 2. The mean HU of TA grades 0, 1, and 2 of stones were 628 ± 107, 864 ± 123, and 1166 ± 292, respectively. 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). Stone-free rate following SWL decreased as TA grade increased. Stone diameter and TA were the only predictors of SWL success. Conclusion SWL is an important treatment option in the treatment of urolithiasis. We think that TA may be useful in predicting SWL success.