Success of extracorporeal shock wave lithotripsy based on CT texture analysis.

OBJECTIVE: The aims of the study were to evaluate whether computerised tomography texture analysis (CTTA) based on non-contrast computed tomography (NCCT) has predictive value for the success of extracorporeal-shockwave lithotripsy (ESWL) in upper urinary tract stones (UUTS). METHODS: This study included 156 of 356 patients undergoing ESWL for UUTS sized 0.5-2 cm from 2015 to 2019. Patients with congenital kidney anomalies, radiolucent stones, multiple stones, treated for upper urinary tract stones previously and lower pole stones were excluded from study. The number of ESWL sessions of the patients was as follows: 78 (50%) patients had 1 session, 30 (19.2%) patients had 2 sessions and 48 (30.8%) patients had >2 sessions. First- and second-order CTTA properties of patients' UUTS were evaluated using texture analysis software (LIFEx Software). Other clinical features such as Hounsfield Unit (HU), initial stone size, body-mass index (BMI) and skin to stone distance (SSD) was recorded. The patients were divided into two groups according to ESWL success. Cases with residual stones larger than 4 mm were considered failed cases. RESULTS: BMI, the standard deviation of HU, SSD, skewness, kurtosis, entropy and all second-order statistics were found to be statistically different between the two groups except for correlation (P < .05). Multivariate analysis showed longer SSD and four new parameters of CTTA (kurtosis, entropy, dissimilarity and energy by the distribution of pixel grey levels in the UUTS) to be significant predictors for unsuccessful ESWL outcomes. SSD and second-order CTTA properties (dissimilarity and energy) had an area under ROC curve of 0.802, 0.850 and 0.824 at a 95% confidence interval. ESWL success rate in all patients was 76.9%. CONCLUSION: CTTA can help select patients who will undergo ESWL for upper urinary tract stones. Thus, we can reduce treatment costs and ESWL complications by preventing unnecessary ESWL applications.

Influence of 3D-Calculated Parenchymal Volume Loss on Renal Function After Partial Nephrectomy.

Background: Our study aims to evaluate the influence of potential determinants of glomerular filtration rate (GFR) decrease after partial nephrectomy (PN), including renal parenchymal loss and other clinical, tumoral, and surgical factors. Materials and Methods: Eighty-six patients who had undergone PN and for whom preoperative and postoperative computerized tomography scans were available were selected. We calculated the preoperative total kidney volumes, tumor volumes, and postoperative total kidney volumes 1 year after surgery using a three-dimensional (3D) volume segmentation method. Factors that may be potential determinants of percent GFR decrease were also evaluated, including patient age, type of procedure (laparoscopic vs. open), comorbidity index, preoperative GFR, tumor size and volume, RENAL nephrometry score, warm ischemia time, and 3D calculated renal parenchymal loss. Clinical, surgical, and tumor parameters potentially associated with renal parenchymal loss were evaluated. Results: The mean age of the patients was 58 years, the mean tumor diameter was 3.6 cm, and the mean tumor volume was 11.7 cc. The mean percent of renal parenchymal loss was 22.3%, and the mean percent of GFR loss was 17.3%. The renal parenchymal loss was strongly associated with age (r = 0.702, P = .02), Charlson comorbidities index (r = 0.768, P < .001), and RENAL nephrometry score (r = 0.812, P < .001). In multivariate logistic regression analysis, older age, higher Charlson comorbidities index, higher percent renal parenchymal loss, and higher RENAL nephrometry score were independently associated with higher percent of GFR loss. Conclusion: Of all the factors analyzed, RENAL score and Charlson comorbidities index were the most accurate predictors of postoperative parenchymal loss. Also, the percent decrease in GFR at late time points was associated with renal volume preservation and quality of the remnant parenchyma.

Serum procalcitonin levels in prostate cancer: A new biomarker?

BACKGROUND: To examine the role of serum procalcitonin as a biomarker for the detection of prostate cancer in patients with a serum prostate-specific antigen less than 20.0 ng/mL. METHODS: The prospective study included patients with a prostate-specific antigen level of 2-20 ng/mL, who underwent prostate biopsy. Clinical and pathological data such as age, prostate volume, prostate-specific antigen, procalcitonin, and Gleason score were reviewed. All patients were divided into three groups with total prostate-specific antigen level between 2 and 4 ng/mL, 4.1 and 10 ng/mL, and 10.1 and 20 ng/mL. RESULTS: Of 227 patients who underwent biopsy, prostate cancer was diagnosed in 74 (32.6%) patients and the remaining 153 patients had a benign condition. The difference in mean serum procalcitonin values was significantly higher in the prostate cancer compared with the benign group (0.06 ± 0.03 vs 0.04 ± 0.03 ng/mL; p = 0.0001). Using a threshold of 0.045 ng/mL, procalcitonin was 54.1% sensitive and 80.3% specific (area under curve = 0.683). Serum procalcitonin levels were not able to differentiate between prostate cancer patients with prostate-specific antigen level of 2-4, 4.1-10, and 10.1-20 ng/mL. CONCLUSION: Based on this prospective study, procalcitonin can be a novel supplementary biomarker to increase the accuracy of prostate cancer screening.