PD08-03 3D TEXTURE ANALYSIS IN ABDOMINAL CT AIDED BY MACHINE LEARNING CLASSIFIERS PREDICTS SHOCK WAVE LITHOTRIPSY SUCCESS

Three-Dimensional Texture Analysis with Machine Learning Provides Incremental Predictive Information for Successful Shock Wave Lithotripsy in Patients with Kidney Stones

AimThis study aims to evaluate the success rate of Shock Wave Lithotripsy (SWL) in treating kidney stones using the Modulith SLK Inline lithotripter, with a focus on the importance of device efficacy as emphasized in EAU guidelines.Patients and methodsThis retrospective single-center study was conducted between June 2023 and June 2024. Inclusion criteria were adult patients (> 18 years) with radiologically confirmed renal stones smaller than 15 mm in diameter. Exclusion criteria included patients with solitary kidneys, significant renal functional deterioration, skeletal deformities, active urinary tract infections, pregnancy, or coagulopathies. Treatment outcomes were collected and analyzed in detail, considering patients’ demographic characteristics (age, gender) and stone parameters (size, location, and hardness [Hounsfield Unit, HU]). The SWL procedures were performed using the Modulith SLK Inline lithotripter (Storz Medical, Switzerland). The success of SWL was defined as achieving complete stone clearance or the presence of clinically insignificant residual fragments (CIRF) (< 4 mm). This study seeks to provide detailed insights into the optimal use cases of SWL as a non-invasive yet effective treatment option for smaller, more manageable stones.ResultsThe mean age of the 208 patients included in the study was 42.2 ± 12.7 years (18–75), with a male-to-female ratio of 1.9:1. The mean stone size across all patients was 10.3 mm, and the average HU value was 874.0 ± 283.2. Patients who achieved a completely stone-free status had significantly lower HU values (p = 0.049). The overall success rate of SWL was 78.8%, with 164 patients achieving complete stone clearance. When cases with clinically insignificant residual fragments (CIRF, < 4 mm) were included as successful outcomes, the overall success rate increased to 92.3%. This distinction highlights the inclusion of patients with small residual fragments that are deemed clinically irrelevant in the adjusted success rate. In cases with successful outcomes, the mean stone size was 10.3 mm, whereas it was 12.5 mm in patients with residual fragments or treatment failure. A statistically significant relationship was identified between stone size and treatment success rates (p < 0.001). In contrast, stone localization did not have a significant impact on SWL success rates (p = 0.377).ConclusionsSWL has demonstrated its effectiveness in kidney stone treatment with a 78.8% complete stone-free rate using the Modulith SLK Inline lithotripter. Higher success rates were achieved with smaller stones (< 15 mm) and lower HU values. These findings support the significance of advanced lithotripter technology in establishing SWL as a valuable non-invasive option for stones under 15 mm.

ObjectivesTo investigate the effect of furosemide given before shock wave lithotripsy (SWL) in patients with renal stones.MethodsTwo-hundred patients with renal stones measuring 6–20 mm in diameter were prospectively included in...

Kidney Stone Size and Hounsfield Units Predict Successful Shockwave Lithotripsy in Children

To improve outcome prediction of extracorporeal shock wave lithotripsy (SWL) by development of a model based on easily available clinical and radiographical predictors and suitable for daily clinical use. We evaluated predictive factors for SWL success in 517 consecutive patients suffering from urinary calculi who underwent SWL between 2010 and 2018. Analyses included descriptive statistics, receiver operating characteristic statistics and logistic regression. Predictive value was improved by combining parameters using model selection and recursive partitioning. Of the 517 patients, 310 (60.0%) had a successful SWL. Best individual predictor of SWL success was mean attenuation (MAV), with an area under the curve (AUC) of 0.668, and an optimal cutpoint (OC) of 987.5 HU. The best multivariable model, including MAV, stone size, skin to stone distance (SSD), presence of an indwelling stent, and four interaction effects, yielded an AUC of 0.736. Recursive partitioning would categorize patients into three outcome groups with high (76.9%), intermediate (41%) and low (10%) success probability. High probability of SWL success (76.9%) was found for patients with a stone with MAV ≤ 987 HU or with MAV > 987 HU but stone size ≤ 11mm and SSD (45°) ≤ 88mm. A model based on four established predictors, and provided as an Excel®-Tool, can clearly improve prediction of SWL success. In addition, patients can be classified into three defined outcome groups based on simple cutpoint combinations. Both tools improve informed decision-making in daily clinical practice and might reduce failure rates.

Over the last decade, shockwave lithotripsy (SWL) success rates have been correlated with stone density, skin-to-stone distance (SSD), and stone diameter. However, time constraints and the technical challenge of manual measurement often preclude utilization of these parameters. In this study, we describe a scoring system that accurately predicts SWL stone-free rates, is simple to calculate, and can be easily included in the radiology report. Two hundred thirty-five patients who underwent SWL from 2011 to 2014 were evaluated. One hundred thirty-three had available preoperative imaging. Stone density, SSD, ellipsoid stone volume (ESV), and stone-free rates were determined. Receiver operator characteristic (ROC) curves were generated to determine cutoff values for each parameter. The Triple D Score was calculated based upon the number of cutoff values a stone fell below. One hundred forty of the 235 patients (59.5%) who underwent SWL were stone free after single-session treatment. Seventy-six of the 133 (57.1%) patients with available preoperative imaging were stone free. ESV, SSD, and stone density were significant predictors of SWL success. Based upon the ROC curves, cutoffs of <150 μL for ESV, <12 cm for SSD, and <600 HU for stone density were established. A Triple D Score of 0, 1, 2, and 3 correlated with SWL success rates of 21.4%, 41.3%, 78.7%, and 96.1%, respectively. Readily available predictive tools are necessary to enhance SWL cost-effectiveness. The Triple D Score is simple to calculate and can be reported by radiologists. Incorporation of the Triple D Score into preoperative planning may increase the overall SWL success rates.

ObjectivesTo evaluate the success of shock wave lithotripsy (SWL) as monotherapy for solitary renal stones larger than 2cm without ureteral stenting. Hence, if our study result demonstrates acceptable success and safety, we can recommend ESWL as a treatment option for patients with large renal calculi. Subjects and methodsThis is a prospective study conducted in the Department of Urology, Regional Institute of Medical Sciences, Imphal, India, from January 2011 to December 2012. A total of 104 patients aged between 20 and 70 years with solitary large (>2cm) renal stones underwent ESWL using the Dornier Compact Sigma Lithotripter. Stone size was calculated by measuring the largest dimension of the stone in KUB plain films. In each session, 3000–3500 shocks at frequency 60–90min−1 and intensity between 1 and 4 were given. A maximum number of six sessions were given. Successful treatment was defined as complete clearance or residual stones smaller than 4mm on KUB performed 3 months after the first session. ResultsTotal number of patients was 104. The M:F ratio was 1:1.4. The stone size ranged from 21 to 55mm. The overall success rate was 73%. For stones >30mm, the success rate was only 62.2% (n=28). The number of sessions required increased as the stone size increased. The most common complication encountered was haematuria. ConclusionESWL remains the cornerstone of therapy for renal calculi less than 2cm. Our study reveals that multiple sessions were required for solitary renal calculi, with higher rate of ancillary procedures. The success rate of ESWL for both non-staghorn and staghorn calculi with size above 2cm is low, so other treatment modalities like PCNL should be considered as the first treatment option. However, with appropriate patient selection, significant improvements in stone-free rates may be achieved.

ABSTRACTObjectives In this study it is aimed to compare the success and complication rates of SWL and RIRS in treatment of HSK stone disease.Materials and methods In this retrospective study data of 67 patients treated with either SWL (n=44) or RIRS (n=23) for stone disease in HSK between May 2003 to August 2014 was investigated. age, gender, stone size and multiplicity, stone free status, renal colic episodes and complication rates of the SWL and RIRS groups were compared.Results Mean age of the population was 42.5±8.2 (range: 16-78) years and mean stone size was 16.9±4.1 mm. SWL and RIRS groups were similar with regard to demographic characteristics and stone related characteristics. SFR of the SWL and RIRS groups were 47.7%(21/44 patients) and 73.9% (17/23 patients) respectively (p=0.039).Renal colic episodes were observed in 3 and 16 patients in the RIRS and SWL groups respectively (p=0.024). No statistically significant complications were observed between the SWL (8/44 patients) and RIRS (4/23) groups (p=0.936).Conclusions In HSK patients with stone disease, both SWL and RIRS are effective and safe treatment modalities. However RIRS seems to maintain higher SFRs with comparable complication rates.

Finding reliable and easy-to-obtain predictors of severe infectious complications after shock wave lithotripsy (SWL) is a major clinical need, particular in symptom-free hydronephrosis. Therefore, we aim to prospectively investigate the predictive value of Hounsfield units (HU) in renal pelvis urine for the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL. This multi-center prospective study was conducted from June 2020 to December 2023. The HU of renal pelvis urine was measured by non-enhanced computed tomography. The severe infectious complications included systemic inflammatory response syndrome, sepsis, and septic shock. Binary logistic regression models assessed the odds ratios (ORs) and 95% confidence intervals (CIs). Finally, 1,436 patients with ureteral stones were enrolled in this study. 8.9% (128/1,436) of patients experienced severe infectious complications after SWL treatment. After adjusting confounding variables, compared with the patients in the lowest renal pelvis urine density quartile, the OR (95% CI) for the highest quartile was 32.36 (13.32, 78.60). There was a positive linear association between the HU value of renal pelvis urine and the risk of severe infectious complications after SWL (P for trend < 0.001). Furthermore, this association was also observed stratified by age, gender, BMI, stone size, stone location and hydronephrosis grade (all P for interaction > 0.05). Additionally, the nonlinear association employed by restricted cubic splines is not statistically significant (nonlinear P = 0.256). The AUROC and 95%CI of renal pelvis urine density were 0.895 (0.862 to 0.927, P value < 0.001). The cut-off value was 12.0 HU with 78.59% sensitivity and 85.94% specificity. This multi-center prospective study demonstrated a positive linear association between HU in renal pelvis urine and the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL, regardless of age, gender, BMI, stone size, stone location, and hydronephrosis grade. These findings might be helpful in the SWL treatment decision-making process.

Objective:The aim of this study was to evaluate the effectiveness of computed tomography (CT) attenuation values in the characterization of pericardial effusion.Methods:This study consisted of 96 patients with pericardial effusion who underwent pericardiocentesis. For further diagnostic evaluation of pericardial effusion, all the patients were assessed by thorax CT. CT attenuation values were measured from at least 5 different areas of pericardial fluid by specifying the largest region of interest. The average of these measurements was computed and considered as the CT attenuation value of the patient. The patients were classified into two groups: patients with transudative pericardial effusion and those with exudative pericardial effusion.Results:CT attenuation values were significantly higher in patients with exudative pericardial effusion than in those with transudative pericardial effusion [14.85±10.7 Hounsfield unit (HU) vs. 1.13±4.3 HU, p<0.001]. CT attenuation values had a close correlation with the pericardial fluid albumin (r=0.829), protein (r=0.752), and LDH (r=0.708) levels; WBC count (r=0.564); protein ratio (r=0.739); and LDH ratio (r=0.689) as well as the albumin gradient (r=–0.725). A cut-off value of 4.7 HU had 80% sensitivity and 87.7% specificity for the identification of exudative pericardial effusion. In addition, a cut-off value of 6.5 HU had 71.4% sensitivity and 72.3% specificity for the prediction of cardiac tamponade.Conclusion:In patients with pericardial effusion, CT attenuation values seem to be correlated with the characterization parameters of the fluid and may distinguish exudative pericardial effusion from transudative pericardial effusion. This parameter was also found to be a predictor of cardiac tamponade. CT attenuation values can be a useful tool in the clinical evaluation of patients with pericardial effusion.

Introduction:Shockwave-lithotripsy (SWL) provides a noninvasive and effective option for the management of ureteric calculi. Several factors may affect the success of SWL. Identification of these predictive factors will both increase the efficacy and decrease the cost. This study was designed to identify factors affecting the outcome of SWL for ureteral stones.Materials and Methods:This study was conducted from March 2012 to November 2014 in patients with solitary ureteric calculi who were managed with SWL. Data were analyzed to identify clinical and radiological factors associated with treatment outcome. Success after SWL was described as complete stone clearance or clinically insignificant residual fragments <3 mm at 3 months after SWL.Results:A total of 110 patients with ureteric calculi were divided into two groups depending on the outcome of SWL, Group A (successful - 76%) and Group B (failed - 24%). Stone size, Skin to stone distance (SSD), secondary signs of obstruction, and presence of double J (DJ) Stent, all were significantly associated with the outcome of SWL on univariate analysis. On multivariate analysis, stone size, hounsfield unit, SSD, and DJ stent were the independent factors affecting the outcome of SWL. On Receptor-Operator Characteristic curve analysis, a cutoff value of 8.2 mm for the stone size was found which best predicts a successful outcome, with a sensitivity of 54% and specificity of 96%.Conclusion:The findings of this study suggest that Stone size, SSD, the presence of DJ stent, and stone attenuation values are the significant factors that influence the outcome of SWL in patients with ureteral stones.

Re: Patel SR, Nakada SY: Quantification of Preoperative Stone Burden for Ureteroscopy and Shock Wave Lithotripsy: Current State and Future Recommendations (Urology 2011;78:282-285)

BackgroundWe evaluated malignancy according to the characteristics of pericardial fluid in symptomatic Japanese patients undergoing pericardiocentesis and computed tomography (CT).MethodsThis was a retrospective, single-center, observational study of 125 symptomatic patients undergoing pericardiocentesis. The patients were classified into two groups: a malignancy group and a non-malignancy group, according to the primary disease and cytology of the pericardial effusion (PE). We compared the pericardial fluid sample and CT measurements between both groups.ResultsAll patients were diagnosed as having exudative PE by Light’s criteria. PE with malignant cells was demonstrated in 76.8% of the malignancy group patients. Pericardial to serum lactate dehydrogenase (LDH) ratio > 0.6, as one of Light’s criteria, was associated with malignancy (p = 0.017). Lower serum brain natriuretic peptide (BNP) concentration was also associated with malignancy (BNP: 126.9 ± 89.8 pg/ml vs 409.2 ± 97.7 pg/ml, malignancy vs non-malignancy groups, respectively; p = 0.037). A significant difference was observed in pericardial fluid glucose level between the malignancy and non-malignancy groups (pericardial fluid glucose: 78.24 ± 48.29 mg/dl vs 98.41 ± 44.85, respectively; p = 0.048). Moreover, CT attenuation values (Hounsfield units (HU)) tended to be higher in the malignancy group vs the non-malignancy group (22.7 [interquartile range (IQR), 17.4–26.0] vs 17.4 [IQR, 13.7–26.4], respectively; p = 0.08). The sensitivity and specificity of pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were 40.9% and 89.6%, respectively, in the malignancy group. The positive- and negative predictive values of pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were 85.7% and 50.0%, respectively, in the malignancy group. Pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were cutoff values associated with malignancy (p = 0.012).ConclusionsLower pericardial fluid glucose level with higher CT attenuation values may suggest malignancy-related PE.

Objective: To evaluate the success of extracorporeal shock wave lithotripsy (ESWL) in the treatment of ureteric calculi and determine the factors which influence outcome. Patients and methods: A retrospective audit of patients with a single ureteric stone receiving ESWL was performed. Success was defined as complete stone clearance on post-treatment imaging. Patient demographics and stone characteristics were correlated to ESWL outcome. Results: 108 patients met the inclusion criteria for this study. The mean age of the patients was 52.5 years (range 24–89 years). 80% (86/108) of patients were male. Stone sizes varied from 4 to 19 mm (mean 7.92 mm). The overall ESWL success rate for ureteric stones was 79%. Treatment was more effective for smaller ( p = 0.003) and more located stones ( p = 0.035). Stone size correlated with number of treatments required ( p =0.005). A JJ stent in situ at the time of ESWL reduced the success rate ( p = 0.002). Conclusions: Stone size, site in the ureter, and the presence of a JJ stent were predictors of ESWL success. Our study from a District General Hospital in the UK demonstrates that ESWL may be used with high efficacy to treat ureteric stones.

The role of stress waves and cavitation in stone comminution in shock wave lithotripsy