Byung Ki Lee

Prevalence and Clinical Features of Detrusor Underactivity among Elderly with Lower Urinary Tract Symptoms: A Comparison between Men and Women

Purpose To identify the prevalence and clinical features of detrusor underactivity (DU) in elderly men and women presenting with lower urinary tract symptoms (LUTS). Materials and Methods We reviewed 1,179 patients aged over 65 years who had undergone a urodynamic study for LUTS with no neurological or anatomical conditions. DU was defined as a bladder contractility index <100 and a maximal flow rate (Qmax) ≤12 ml/s combined with a detrusor pressure at Qmax ≤10 cmH2O for men and women, respectively. Results Of the patients, 40.2% of men and 13.3% of women were classified as having DU (p<0.001). Types of clinical symptoms were not significantly different between patients with and without DU. In men, whereas the prevalence of bladder outlet obstruction (BOO) was constant across the age spectrum, the prevalence of DU and detrusor overactivity (DO) increased with age, and 46.5% of men with DU also had DO or BOO. In women, the prevalence of DU also increased with age, and the trend was more remarkable in women aged over 70 years. DU was accompanied by DO or urodynamic stress urinary incontinence (USUI) in 72.6% of the women with DU. Women with DU were found to have lower cystometric capacity and exhibited a greater incidence of reduced compliance than did women without DU. Conclusions DU was a common mechanism underlying LUTS in the elderly population, especially in men. One half of the men and three quarters of the women with DU also had other pathologies such as DO, BOO, or USUI.

Seoul National University Renal Stone Complexity Score for Predicting Stone-Free Rate after Percutaneous Nephrolithotomy

Objectives Currently, no standardized method is available to predict success rate after percutaneous nephrolithotomy. We devised and validated the Seoul National University Renal Stone Complexity (S-ReSC) scoring system for predicting the stone-free rate after single-tract percutaneous nephrolithotomy (sPCNL). Patients and Methods The data of 155 consecutive patients who underwent sPCNL were retrospectively analyzed. Preoperative computed tomography images were reviewed. The S-ReSC score was assigned from 1 to 9 based on the number of sites involved in the renal pelvis (#1), superior and inferior major calyceal groups (#2–3), and anterior and posterior minor calyceal groups of the superior (#4–5), middle (#6–7), and inferior calyx (#8–9). The inter- and intra-observer agreements were accessed using the weighted kappa (κ). The stone-free rate and complication rate were evaluated according to the S-ReSC score. The predictive accuracy of the S-ReSC score was assessed using the area under the receiver operating characteristic curve (AUC). Results The overall SFR was 72.3%. The mean S-ReSC score was 3.15±2.1. The weighted kappas for the inter- and intra-observer agreements were 0.832 and 0.982, respectively. The SFRs in low (1 and 2), medium (3 and 4), and high (5 or higher) S-ReSC scores were 96.0%, 69.0%, and 28.9%, respectively (p<0.001). The predictive accuracy was very high (AUC 0.860). After adjusting for other variables, the S-ReSC score was still a significant predictor of the SFR by multiple logistic regression. The complication rates were increased to low (18.7%), medium (28.6%), and high (34.2%) (p = 0.166). Conclusions The S-ReSC scoring system is easy to use and reproducible. This score accurately predicts the stone-free rate after sPCNL. Furthermore, this score represents the complexity of surgery.

Prostate-specific antigen vs prostate-specific antigen density as a predictor of upgrading in men diagnosed with Gleason 6 prostate cancer by contemporary multicore prostate biopsy

Study Type – Diagnostic (validating cohort)

Women with pure stress urinary incontinence symptoms assessed by the initial standard evaluation including measurement of post‐void residual volume and a stress test: Are urodynamic studies still needed?

The significance of preoperative urodynamic studies in women with a “clinically‐defined pure stress urinary incontinence (SUI) symptom” has been debated in recent years. We evaluated changes of reliability of pure SUI symptoms for prediction of pure urodynamic SUI (USUI) when the assessment of post‐void residual (PVR) volume and a stress test, designated as the initial standard evaluation in the NICE and AUA guidelines, were added to the process for the diagnosis of pure SUI symptoms.

Mobile Application-Based Seoul National University Prostate Cancer Risk Calculator: Development, Validation, and Comparative Analysis with Two Western Risk Calculators in Korean Men

Objectives We developed a mobile application-based Seoul National University Prostate Cancer Risk Calculator (SNUPC-RC) that predicts the probability of prostate cancer (PC) at the initial prostate biopsy in a Korean cohort. Additionally, the application was validated and subjected to head-to-head comparisons with internet-based Western risk calculators in a validation cohort. Here, we describe its development and validation. Patients and Methods As a retrospective study, consecutive men who underwent initial prostate biopsy with more than 12 cores at a tertiary center were included. In the development stage, 3,482 cases from May 2003 through November 2010 were analyzed. Clinical variables were evaluated, and the final prediction model was developed using the logistic regression model. In the validation stage, 1,112 cases from December 2010 through June 2012 were used. SNUPC-RC was compared with the European Randomized Study of Screening for PC Risk Calculator (ERSPC-RC) and the Prostate Cancer Prevention Trial Risk Calculator (PCPT-RC). The predictive accuracy was assessed using the area under the receiver operating characteristic curve (AUC). The clinical value was evaluated using decision curve analysis. Results PC was diagnosed in 1,240 (35.6%) and 417 (37.5%) men in the development and validation cohorts, respectively. Age, prostate-specific antigen level, prostate size, and abnormality on digital rectal examination or transrectal ultrasonography were significant factors of PC and were included in the final model. The predictive accuracy in the development cohort was 0.786. In the validation cohort, AUC was significantly higher for the SNUPC-RC (0.811) than for ERSPC-RC (0.768, p<0.001) and PCPT-RC (0.704, p<0.001). Decision curve analysis also showed higher net benefits with SNUPC-RC than with the other calculators. Conclusions SNUPC-RC has a higher predictive accuracy and clinical benefit than Western risk calculators. Furthermore, it is easy to use because it is available as a mobile application for smart devices.

Chronic Lower Urinary Tract Symptoms in Young Men Without Symptoms of Chronic Prostatitis: Urodynamic Analyses in 308 Men Aged 50 Years or Younger

Purpose We investigated the etiologies of lower urinary tract symptoms (LUTS) and compared urodynamic characteristics between different diagnostic groups in young men with chronic LUTS. Materials and Methods We reviewed the medical records of 308 men aged 18 to 50 years who had undergone a urodynamic study for chronic LUTS (≥6 months) without symptoms suggestive of chronic prostatitis. Results The mens mean age was 40.4 (±10.1) years and their mean duration of symptoms was 38.8 (±49.2) months. Urodynamic evaluation demonstrated voiding phase dysfunction in 62.1% of cases (primary bladder neck dysfunction [PBND] in 26.0%, dysfunctional voiding [DV] in 23.4%, and detrusor underactivity [DU]/acontractile detrusor [AD] in 12.7%) and a single storage phase dysfunction in 36.4% of cases (detrusor overactivity [DO] in 13.3%, small cystometric capacity in 17.9%, and reduced bladder sensation in 5.2%). Most of the demographic characteristics and clinical symptoms did not differ between these diagnostic groups. Whereas 53.9% of patients with voiding dysfunction had concomitant storage dysfunction, 69.6% of those with storage dysfunction had concomitant voiding dysfunction. Men with DV or DU/AD exhibited lower maximum cystometric capacity than did those with normal urodynamics. Low bladder compliance was most frequent among patients with PBND (10.0%, p=0.025). In storage dysfunctions, men with DO exhibited higher detrusor pressure during voiding than did those with other storage dysfunctions (p<0.01). Conclusions Because clinical symptoms are not useful for predicting the specific urodynamic etiology of LUTS in this population, urodynamic investigation can help to make an accurate diagnosis and, potentially, to guide appropriate treatment.

Prostate cancer detection rate in patients with fluctuating prostate-specific antigen levels on the repeat prostate biopsy

Purpose: To evaluate whether the risk of prostate cancer was different according to the pattern of fluctuation in prostate-specific antigen (PSA) levels in patients undergoing repeat transrectal ultrasound-guided prostate biopsy (TRUS-Bx). Methods: From March 2003 to December 2012, 492 patients underwent repeat TRUS-Bx. The patients were stratified into 3 groups based on the PSA fluctuation pattern: group 1 (continuous elevation of PSA, n=169), group 2 (PSA fluctuation with PSA velocity [PSAV]≥1.0 ng/mL/yr, n=123), and group 3 (PSA fluctuation with PSAV<1.0 ng/mL/yr, n=200). Results: Prostate cancer was detected in 112 of 492 patients (22.8%) in the repeat biopsy set. According to the PSA fluctuation pattern, prostate cancer detection rates at repeat TRUS-Bx were 29.6% (50/169) for patients with continuously increasing PSA, 30.1% (37/123) for PSA fluctuation with PSAV ≥1.0 ng/mL/yr, and 12.5% (25/200) for PSA fluctuation with PSAV <1.0 ng/mL/yr. Multivariate analysis showed that PSA fluctuation pattern and high grade prostatic intraepithelial neoplasia at initial TRUS-Bx were the predictive parameters for positive repeat biopsies. Among the 96 patients (85.7%) who underwent radical prostatectomy, no significant differences in pathologic outcomes were found according to the PSA fluctuation pattern. Conclusions: The current study shows that the risk of prostate cancer at repeat TRUS-Bx was higher in men with a fluctuating PSA level and PSAV≥1.0 ng/mL/yr than in those with a fluctuating PSA level and PSAV<1.0 ng/mL/yr.

Targeted therapy after complete resection of metastatic lesions in metastatic renal cell carcinoma

To evaluate the efficacy of targeted therapy after complete resection of metastatic lesions in patients with metastatic renal cell carcinoma.

Combination of clinical characteristics and transrectal ultrasound-guided biopsy to predict lobes without significant cancer: application in patient selection for hemiablative focal therapy.

Purpose: A major limitation of performing hemiablative focal therapy (FT) for prostate cancer (PCa) is the possibility of accompanying significant cancer in the contralateral side of the prostate that is missed on prostate biopsy. We attempted to verify whether clinical and biopsy-related parameters can be used to predict the absence of significant cancer in the prostate lobe. Methods: We assumed that hemiablative FT could be performed in patients with low-risk PCa, with unilateral tumors as assessed by transrectal ultrasound-guided biopsy. We evaluated 214 patients who had undergone radical prostatectomy (RP) and fulfilled the eligibility criteria. Seemingly preserved lobes, defined by the absence of cancer on biopsy, were classified as lobes with no cancer (LNC), lobes with insignificant cancer (LIC), and lobes with significant cancer (LSC) according to RP pathology. Cases with an estimated tumor volume of <0.5 mL, a Gleason score of <7, and organ confinement without Gleason pattern 4 were classified as LIC. Univariate and multivariate logistic regression analyses were performed to identify predictors for LSC. Predictive accuracies of the multivariate models were assessed using receiver operating characteristic curve-derived areas under the curve. Results: Of 214 evaluated lobes, 45 (21.0%), 62, (29.0%), and 107 (50.0%) were classified as LNC, LIC, and LSC, respectively. Among the clinical and biopsy-related parameters, prostate-specific antigen density and prostate volume were identified as significant predictors for LSC in univariate regression analysis. However, multivariate analysis did not identify an independent predictor. Predictive accuracies of the multivariate models did not exceed 70.4%. Conclusions: Conventional parameters have limited value in predicting LSC in patients who are candidates for hemiablative FT.