Using prostate-specific membrane antigen positron-emission tomography to guide prostate biopsies and stage men at high-risk of prostate cancer.

OBJECTIVE: To assess whether a diagnostic pathway in which prostate-specific membrane antigen (PSMA) positron-emission tomography (PET)/computed tomography (CT) is used as a single imaging modality is feasible to guide targeted biopsy and to detect clinically significant prostate cancer (csPCa) in biopsy-naïve men at high-risk of disease. PATIENTS AND METHODS: A total of 60 men with a prostate-specific antigen (PSA) level of 20-50 ng/mL underwent 18 F-PSMA(DCFPyL)-PET/CT prior to prostate biopsies in this prospective, non-randomised cohort study. Magnetic resonance imaging (MRI) was not performed. Using a 12-segment mapping model of the prostate, PSMA-guided targeted biopsy was performed along with systematic biopsies. The detection rate of PCa and csPCa was assessed for combined systematic and targeted biopsy, and for targeted biopsy only. csPCa was defined as a prostate biopsy with an International Society of Uropathology (ISUP) Grade Group ≥2. RESULTS: Lesions suspicious for PCa in the prostate gland were observed on all PSMA-PET/CTs. A total of 27/60 men (45%) already had metastatic disease on staging 18 F-PSMA(DCFPyL)-PET/CT. Combined PSMA-guided targeted and systematic biopsies detected PCa in 56/60 (93.3%) patients, with 52 of them (92.9%) having csPCa. PSMA-guided targeted biopsy, if performed as a single biopsy modality, identified PCa in 52/60 men (86.7%) and in 27/27 men (100%) men with metastases. CONCLUSIONS: Using the PSMA-driven single imaging modality pathway in biopsy-naïve men at high-risk of PCa, a substantial number of diagnostic MRI scans could be avoided while at the same time obtaining adequate targeting, staging, and detection of csPCa.

3D-Reconstructed Contact Surface Area and Tumour Volume on Magnetic Resonance Imaging Improve the Prediction of Extraprostatic Extension of Prostate Cancer.

This study is to determine whether the volume and contact surface area (CSA) of a tumour with an adjacent prostate capsule on MRI in a three-dimensional (3D) model that can predict side-specific extraprostatic extension (EPE) at radical prostatectomy (RP). Patients with localised prostate cancer (PCa) who underwent robot-assisted RP between July 2015 and March 2021 were included in this retrospective study. MRI-based 3D prostate models incorporating the PCa volume and location were reconstructed. The tumour volume and surface variables were extracted. For the prostate-to-tumour and tumour-to-prostate CSAs, the areas in which the distances were ≤ 1, ≤ 2, ≤ 3, ≤ 4, and ≤ 5 mm were defined, and their surface (cm2) were determined. Differences in prostate sides with and without pathological EPE were analysed. Multivariable logistic regression analysis to find independent predictors of EPE. Overall, 75/302 (25%) prostate sides showed pathological EPE. Prostate sides with EPE had higher cT-stage, higher PSA density, higher percentage of positive biopsy cores, higher biopsy Gleason scores, higher radiological tumour stage, larger tumour volumes, larger prostate CSA, and larger tumour CSA (all p < 0.001). Multivariable logistic regression analysis showed that the radiological tumour stage (p = 0.001), tumour volume (p < 0.001), prostate CSA (p < 0.001), and tumour CSA (p ≤ 0.001) were independent predictors of pathological EPE. A 3D reconstruction of tumour locations in the prostate improves prediction of extraprostatic extension. Tumours with a higher 3D-reconstructed volume, a higher surface area of tumour in contact with the prostate capsule, and higher surface area of prostate capsule in contact with the tumour are at increased risk of side-specific extraprostatic extension.

Automated Detection and Grading of Non-Muscle-Invasive Urothelial Cell Carcinoma of the Bladder.

Accurate grading of non-muscle-invasive urothelial cell carcinoma is of major importance; however, high interobserver variability exists. A fully automated detection and grading network based on deep learning is proposed to enhance reproducibility. A total of 328 transurethral resection specimens from 232 patients were included, and a consensus reading by three specialized pathologists was used. The slides were digitized, and the urothelium was annotated by expert observers. The U-Net-based segmentation network was trained to automatically detect urothelium. This detection was used as input for the classification network. The classification network aimed to grade the tumors according to the World Health Organization grading system adopted in 2004. The automated grading was compared with the consensus and individual grading. The segmentation network resulted in an accurate detection of urothelium. The automated grading shows moderate agreement (κ = 0.48 ± 0.14 SEM) with the consensus reading. The agreement among pathologists ranges between fair (κ = 0.35 ± 0.13 SEM and κ = 0.38 ± 0.11 SEM) and moderate (κ = 0.52 ± 0.13 SEM). The automated classification correctly graded 76% of the low-grade cancers and 71% of the high-grade cancers according to the consensus reading. These results indicate that deep learning can be used for the fully automated detection and grading of urothelial cell carcinoma.

The Predictive Value of Preoperative Negative Prostate Specific Membrane Antigen Positron Emission Tomography Imaging for Lymph Node Metastatic Prostate Cancer.

PURPOSE: We sought to identify a subset of patients in whom an extended pelvic lymph node dissection during robot-assisted laparoscopic radical prostatectomy for localized prostate cancer could be omitted when preoperative prostate specific membrane antigen positron emission tomography showed no lymph node metastatic prostate cancer. MATERIALS AND METHODS: A total of 434 patients who underwent prostate specific membrane antigen positron emission tomography prior to robot-assisted laparoscopic radical prostatectomy and extended pelvic lymph node dissection were retrospectively analyzed. Patients were excluded from analysis when the prostate specific membrane antigen positron emission tomography showed evidence of distant metastases. The primary outcome was whether a negative for metastases prostate specific membrane antigen positron emission tomography was able to correctly rule out pelvic lymp node metastases after extended pelvic lymph node dissection, ie its negative predictive value. RESULTS: Overall sensitivity, specificity, positive predictive value and negative predictive value of prostate specific membrane antigen positron emission tomography for the detection of pelvic lymp node metastases were 37.9%, 94.1%, 64.3% and 84.4%, respectively. The negative predictive value of prostate specific membrane antigen positron emission tomography in patients with intermediate risk prostate cancer was 91.6% (95% CI 86-97), compared to 81.4% (95% CI 77-86) in patients with high risk prostate cancer. When only assessing patients with

Intraoperative Strategies to Reduce Catheter-Related Bladder Discomfort in the Early Postoperative Period after Robot-Assisted Radical Prostatectomy.

PURPOSE: Catheter-related bladder discomfort occurs in up to 63% of patients following robot-assisted radical prostatectomy. The optimal intraoperative anesthesia regime to prevent patients from catheter-related bladder discomfort is unknown. MATERIALS AND METHODS: A prospective cohort analysis was conducted. Patients with biopsy-proven prostate cancer selected for robot-assisted radical prostatectomy were included between January 2017 and April 2020 from a high volume prostate cancer center. Eight different treatment regimens were compared, ie a combination of general anesthesia and a transversus abdominis plane block with either an additional dose of clonidine or an additional dose of ketamine, or perivesical infiltrations (with 20 ml ropivacaine), or periurethral infiltrations (with ropivacaine); or a dorsal penile nerve block (with 20 ml ropivacaine). Multiple logistic regression and linear mixed models were used to analyze differences in catheter-related bladder discomfort and pain (0-10) at the postoperative recovery unit between the treatment protocols. RESULTS: Of the 391 patients included, those with a combination transversus abdominis plane block, perivesical and periurethral block with ropivacaine had the lowest incidence of catheter-related bladder discomfort, clinically relevant and statistically significantly lower compared to our baseline protocol (transversus abdominis plane block only), ie 36% vs 70%, p=0.001. Overall, patients who were treated with periurethral and/or perivesical infiltrations reported a statistically significantly lower incidence of catheter-related bladder discomfort compared to patients who did not receive this local infiltration (46.5% vs 60.7%, p=0.001). CONCLUSIONS: Perivesical and periurethral injections with ropivacaine have the potential to reduce the incidence of early postoperative catheter-related bladder discomfort by up to 49%. Further randomized studies are necessary to determine the optimal treatment regime to prevent early postoperative catheter-related bladder discomfort.

Prostate Specific Membrane Antigen Positron Emission Tomography/Computerized Tomography in the Evaluation of Initial Response in Candidates Who Underwent Salvage Radiation Therapy after Radical Prostatectomy for Prostate Cancer.

PURPOSE: We assessed predictors of short-term oncologic outcomes of patients who underwent salvage radiation therapy for biochemical recurrence after robot-assisted laparoscopic radical prostatectomy without evidence of metastases on prostate specific membrane antigen positron emission tomography/computerized tomography. MATERIALS AND METHODS: We retrospectively analyzed 194 patients with biochemical recurrence after robot-assisted laparoscopic radical prostatectomy who underwent prostate specific membrane antigen positron emission tomography/computerized tomography prior to salvage radiation therapy. Patients with lymph node or distant metastases on restaging imaging or at the time of extended pelvic lymph node dissection during robot-assisted laparoscopic radical prostatectomy were excluded, as were patients who received androgen deprivation therapy during or prior to salvage radiation therapy. A multivariable logistic regression analysis was performed to assess predictors of treatment response, defined as prostate specific antigen value ≤0.1 ng/ml after salvage radiation therapy. RESULTS: Overall treatment response after salvage radiation therapy was 75% (146/194 patients). On multivariable analysis, prostate specific antigen value at initiation of salvage radiation therapy (OR 0.42, 95% CI 0.27-0.62, p <0.001), pathological T stage (pT3a vs pT2 OR 0.28, 95% CI 0.11-0.69, p=0.006; pT3b vs pT2 OR 0.26, 95% CI 0.09-0.71, p=0.009) and local recurrent disease on imaging (OR 5.53, 95% CI 1.96-18.52, p=0.003) were predictors of treatment response. CONCLUSIONS: Salvage radiation therapy in patients without evidence of metastases on prostate specific membrane antigen positron emission tomography/computerized tomography showed a good overall treatment response of 75%. Higher treatment response rates were observed in patients with lower prostate specific antigen values at initiation of salvage radiation therapy, those with local recurrent disease on imaging and those with lower pathological T stage (pT2 vs pT3a/b).

Management impact of 18F-DCFPyL PET/CT in hormone-sensitive prostate cancer patients with biochemical recurrence after definitive treatment: a multicenter retrospective study.

PURPOSE: The aim of this study was to investigate whether an early, accurate identification of disease using 18F-DCFPyL PET/CT imaging resulted in a change of decision on treatment management, for individual patients with biochemically recurrent (BCR), hormone-sensitive prostate cancer. METHODS: In this retrospective study, a total of 253 patients with BCR who underwent restaging 18F-DCFPyL PET/CT were assessed. Two urologists specialized in uro-oncology were asked to formulate a preferred treatment for each patient before and after knowing the results of the 18F-DCFPyL PET/CT. RESULTS: Out of 253 patients, 191 (75%) underwent robot-assisted radical prostatectomy (RARP) as primary therapy, and 62 (25%) external beam radiation therapy (EBRT). In 103/253 cases (40.7%), a preferred treatment change based on the 18F-DCFPyL PET/CT findings was reported. In patients post-RARP, a positive 18F-DCFPyL PET/CT (OR 6.21; 95%CI 2.78-13.8; p < 0.001) and positive pathological lymph node status (pN1) (OR 2.96; 95%CI 1.15-7.60; p = 0.024) were significant predictors for an intended change of management, whereas a positive surgical margin (OR 0.42; 95%CI 0.20-0.88; p = 0.022) was inversely associated with an intended change of management. CONCLUSION: In this study, we found a significant impact of 18F-DCFPyL PET/CT on the intended management of patients with biochemically recurrent hormone-sensitive prostate cancer. A positive 18F-DCFPyL PET/CT scan, positive pathological lymph node status, and a negative surgical margin status were significantly associated with increased odds of having a change of management based on 18F-DCFPyL PET/CT findings.

A systematic review on mutation markers for bladder cancer diagnosis in urine.

OBJECTIVES: To systematically summarise the available evidence on urinary bladder cancer (BC) mutation markers. Gene mutations are expected to provide novel biomarkers for urinary BC diagnosis. To date, evidence on urinary BC mutation markers has not proven sufficient to be adopted by clinical guidelines. In the present systematic review, diagnostic accuracy of urinary mutation analysis is separately assessed for primary BC diagnosis (BC detection) and for follow-up of BC patients (BC surveillance). METHODS: A literature search (PubMed, Embase.com and Wiley/Cochrane Library) and systematic review was performed up to 31 October 2019. As studies were too heterogeneous, no quantitative analysis could be performed. RESULTS: In total, 25 studies were summarised by qualitative analysis. For BC detection, diagnostic accuracy differed considerably for single mutation markers (sensitivity 1-85%, specificity 84-100%), and for marker panels (sensitivity 50-94%, specificity 43-97%). Similarly, for BC surveillance, diagnostic accuracy was highly variable for single mutation markers (sensitivity 0-85%, specificity 66-100%), and for marker panels (sensitivity 51-84%, specificity 66-96%). CONCLUSION: Urinary mutation analysis showed to be a promising diagnostic tool for non-invasive BC diagnosis. Nonetheless, we observed substantial differences in diagnostic accuracy of urinary BC mutation markers among publications. To translate the data summarised in the present review to future clinical practice, heterogeneity in research design, BC population, mutation analysis technique and urinary DNA should be considered. Eventual clinical implementation of urinary BC mutation markers can only be achieved by collecting more and stronger evidence. Combining different molecular assays might overcome current shortcomings of urinary mutation analysis.

Genital Gender-Affirming Surgery Without Urethral Lengthening in Transgender Men-A Clinical Follow-Up Study on the Surgical and Urological Outcomes and Patient Satisfaction.

BACKGROUND: Genital gender-affirming surgery (gGAS) with urethral lengthening (UL) in transgender men is associated with high urological complication and reoperation rates. Since 2009, we offer gGAS without UL to avoid these complications. AIM: The aim of this study was to assess what portion of the transgender men opted for gGAS without UL and to assess functional, surgical outcomes, and patient satisfaction after gGAS without UL. MATERIAL AND METHODS: Retrospective data were collected from patients' charts. The International Prostate Symptom Score, uroflowmetry, and 24-hour frequency voiding chart were used to assess voiding, and a self-constructed semistructured questionnaire was used to assess patient-reported outcomes. Transgender men who underwent gGAS without UL between January 2009 and January 2018 were included, and 56 transgender men were approached to complete the patient-reported outcome measurement. The simple statistical analysis combined with the Mann-Whitney U test and the Wilcoxon signed-rank test was used. OUTCOMES: 68 transgender men were included. Median follow-up time was 24 (6-129) months. Uroflowmetry and the International Prostate Symptom Score were completed by 44 transgender men, whereas 13 completed the frequency voiding chart preoperatively and postoperatively, respectively. The patient-reported outcome measurement was completed by 40 of 56 (71%) transgender men. RESULT: Postoperative surgical and urological complications occurred in 9 of 68 (13%) and 8 of 68 (12%) patients, respectively. Storage and voiding function remained unchanged. The median quality of life because of urinary symptoms was scored as "pleased." Sexual functioning and voiding were scored satisfactory and very satisfactory in 18 of 40 (45%) and 21 of 40 (53%) patients, respectively. The number of patients satisfied with the penis and neoscrotum was 25 of 40 (63%) and 26 of 40 (65%), respectively. Increased self-esteem was reported by 32 of 40 (80%), 32 of 40 (80%) would undergo the surgery again, and 28 of 40 (70%) would recommend it to others. CLINICAL IMPLICATIONS: gGAS without UL should be part of the surgical armamentarium in centers performing gender-affirming surgery. STRENGTHS AND LIMITATIONS: Strengths of this study comprise the number of patients, the completeness of data, incorporation of patient-reported outcomes, and description of a relatively new surgical approach that may be well-suitable for a subgroup of transgender men. Limitations are the retrospective study design and the lack of validated questionnaires. CONCLUSION: gGAS without UL shows good surgical and urological outcomes. After extensive counseling, the majority of this selective group of patients shows favorable patient-reported outcomes. Pigot GLS, Al-Tamimi M, Nieuwenhuijzen JA, et al. Genital Gender-Affirming Surgery Without Urethral Lengthening in Transgender Men-A Clinical Follow-Up Study on the Surgical and Urological Outcomes and Patient Satisfaction. J Sex Med 2020;17:2478-2487.

Value of a Marker Lesion in Non-Muscle-Invasive Bladder Cancer Patients Treated with Interleukin-2 Instillations: A Randomized Controlled Multicentre Trial.

PURPOSE: To compare the effect of intravesical interleukin-2 (IL-2) instillations with and without a marker lesion on time to recurrence (TTR) in non-muscle-invasive bladder cancer (NMIBC) patients. METHODS: A prospective randomized, controlled trial was conducted. Patients with multiple non-muscle-invasive tumours were randomized for a complete or incomplete transurethral resection (TURBT), followed by 3 IL-2 instillations. The primary end point was TTR. RESULTS: These are the results of an interim analysis, which was performed due to slow accrual after which the study was closed prematurely. Twenty-eight patients were randomized of which 17 were eligible on an intention-to-treat basis. Median TTR or last follow-up was 3 months (interquartile range [IQR] 3-10 months) for the complete and 4 months (IQR 3-8 months) for the incomplete TURBT group. The TTR between the 2 groups did not differ significantly (log-rank, p = 0.54). -Conclusions: These data do not support the hypothesis that a marker lesion enhances the therapeutic effect of IL-2 instillations in patients with NMIBC.

The effect of timing of an immediate instillation of mitomycin C after transurethral resection in 941 patients with non-muscle-invasive bladder cancer.

OBJECTIVE: To investigate whether the timing of an immediate instillation of mitomycin C (on the day of transurethral resection of bladder tumour [TURBT] or 1 day later) has an impact on time to recurrence of non-muscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS: All patients with NMIBC who were enrolled in a prospective trial between 1998 and 2003, and treated with an early mitomycin C instillation (on the day of TURBT or 1 day later), were selected. Statistical analysis was performed with Kaplan-Meier curves and multivariable Cox regression. RESULTS: Administering an instillation of mitomycin C on the day of TURBT or 1 day later did not show a statistically significant difference in time to recurrence in a univariable model (log-rank P = 0.99). After correcting for the number of scheduled adjuvant instillations, no statistically significant difference could be detected either: hazard ratio 1.05 (95% confidence interval 0.81-1.35, P = 0.74). CONCLUSION: These data do not support the hypothesis that a very early instillation (on the day of TURBT) of mitomycin C decreases the risk of recurrence as compared with an early instillation (1 day after TURBT).

The World Health Organization 1973 classification system for grade is an important prognosticator in T1 non-muscle-invasive bladder cancer.

OBJECTIVES: To compare the prognostic value of the World Health Organization (WHO) 1973 and 2004 classification systems for grade in T1 bladder cancer (T1-BC), as both are currently recommended in international guidelines. PATIENTS AND METHODS: Three uro-pathologists re-revised slides of 601 primary (first diagnosis) T1-BCs, initially managed conservatively (bacille Calmette-Guérin) in four hospitals. Grade was defined according to WHO1973 (Grade 1-3) and WHO2004 (low-grade [LG] and high-grade [HG]). This resulted in a lack of Grade 1 tumours, 188 (31%) Grade 2, and 413 (69%) Grade 3 tumours. There were 47 LG (8%) vs 554 (92%) HG tumours. We determined the prognostic value for progression-free survival (PFS) and cancer-specific survival (CSS) in Cox-regression models and corrected for age, sex, multiplicity, size and concomitant carcinoma in situ. RESULTS: At a median follow-up of 5.9 years, 148 patients showed progression and 94 died from BC. The WHO1973 Grade 3 was negatively associated with PFS (hazard ratio [HR] 2.1) and CSS (HR 3.4), whilst WHO2004 grade was not prognostic. On multivariable analysis, WHO1973 grade was the only prognostic factor for progression (HR 2.0). Grade 3 tumours (HR 3.0), older age (HR 1.03) and tumour size >3 cm (HR 1.8) were all independently associated with worse CSS. CONCLUSION: The WHO1973 classification system for grade has strong prognostic value in T1-BC, compared to the WHO2004 system. Our present results suggest that WHO1973 grade cannot be replaced by the WHO2004 classification in non-muscle-invasive BC guidelines.

Development of a patient decision aid for the treatment of localised prostate cancer: a participatory design approach.

AIMS AND OBJECTIVES: To develop a patient decision aid and to prepare an overview of requirements for implementation. BACKGROUND: We developed a decision aid that fits the preferences of patients and health care professionals to ensure adequate uptake in clinical practice. DESIGN: A participatory design approach was used to acquire insight into preferences regarding the content and design of a decision aid and into barriers and aspects of the decision aid that facilitate implementation in clinical practice. METHODS: Three focus group interviews with patients, their partners and health care professionals were conducted. A prototype of the decision aid was developed and presented to patients (n = 14) and health care professionals (n = 13) in semi-structured interviews. Patients (n = 5) participated in a usability study. Data were analysed by two independent coders. RESULTS: Health care professionals considered medical information on treatments and side effects as the most important aspect to be included in the decision aid. Patients also focused on nonmedical considerations, such as location. Both expected the decision aid to support patients in making a treatment choice. According to health care professionals, the oncology nurse was the most suitable to discuss the decision aid with patients, while some patients preferred to discuss the patient decision aid with the urologist. The main barrier to implementation of the decision aid was said to be the expectation that it is time and money consuming, while the incorporation of the decision aid into clinical guidelines and basing the content on these guidelines, would promote implementation. CONCLUSIONS: By using a participatory design approach a patient decision aid was designed to meet patients' and health care professionals' needs. Insight was also gained on requirements for implementation. RELEVANCE TO CLINICAL PRACTICE: Wide-scale implementation of decision aids is desirable. An overview is provided of requirements for implementation to successfully incorporate a decision aid into clinical practice.

Prostate sparing cystectomy for bladder cancer: 20-year single center experience.

PURPOSE: We evaluated long-term oncologic and functional results after prostate sparing cystectomy for bladder cancer. MATERIALS AND METHODS: A total of 120 patients with cT1-4N0-3 bladder cancer were treated with prostate sparing cystectomy between 1994 and 2013, of whom 110 had a followup of 2 years or greater and were eligible for analysis. To rule out tumor in the bladder neck, prostatic urethra or prostate cancer all patients underwent preoperative transurethral biopsy of the bladder neck and prostatic urethra, prostate specific antigen measurement and transrectal ultrasound with biopsies. We assessed oncologic outcomes (disease specific and recurrence-free survival), recurrence rates, prostate cancer and functional results (continence, voiding, and erectile and ejaculatory function). RESULTS: Mean patient ± SD age was 56.2 ± 8.3 years and median followup was 77.0 months (IQR 57-116). Two and 5-year disease specific survival rates were 76.2% and 66.5%, 2 and 5-year recurrence-free survival rates were 71.2% and 66.6%, and distant and local recurrence rates were 34.2% and 10.0%, respectively. One local recurrence was in the remnant prostatic urothelium. Prostate cancer was diagnosed in 2.7% of cases. Complete daytime and nighttime continence was achieved in 96.2% and 81.9% of patients, and erectile function and antegrade ejaculation were intact in 89.7% and 35.5%, respectively. CONCLUSIONS: Our long-term data show that prostate sparing cystectomy is an oncologically safe procedure with excellent functional results in a subset of carefully selected patients with bladder cancer without evidence of urothelial carcinoma in the prostatic urethra/bladder neck and no prostate cancer.

Development of an in vitro model to measure bioactivity of botulinum neurotoxin A in rat bladder muscle strips.

BACKGROUND: Botulinum toxin A (BoNT-A) is a new treatment modality in various causes of bladder dysfunction; like neurogenic detrusor overactivity and overactive bladder. The best technique of administrating BoNT-A in patients is unknown. A validated in vitro model could be used to investigate newer intravesical administration techniques of BoNT-A. In this study, we describe the development and validation of in vitro model to measure inhibitory effects of BoNT-A on bladder strip contractions. METHODS: Rat bladder strips were mounted in organ baths filled with Krebs' solution. The strips were stimulated chemically (80 mM potassium chloride, 1 µM carbachol) and electrically (Electrical Field Stimulation (EFS) 100 shocks, 50 V, 20 Hz, every 3 minutes). The viability of the strips was measured by carbachol stimulation at the beginning and at the end of the experiments. The strips were incubated in various concentrations of BoNT-A (0.03, 0.2, 0.3 nM). Controls were incubated in Krebs' solution only. The inhibition of strip contraction induced by EFS was measured. These measurements were statistically analyzed with a log-logistic model representing diffusion. RESULTS: All strips remained viable during the experiments. Inhibition of strip contraction was observed after incubation with 0.3 nM BoNT-A. The measurements fitted to a log-logistic model describing diffusion of BoNT-A in the bladder strip. The parameters of the log-logistic model representing diffusion were significant for 0.3 nM BoNT-A. Incubation with 0.2 nM BoNT-A showed insignificant results for 2 out of 3 runs. Incubation with 0.03 nM BoNT-A did not result in significant inhibition of strip contractions. CONCLUSIONS: An in vitro model was developed and validated in which the inhibitory effect of low concentrations of BoNT-A on bladder strip contractions can be measured.

The Impact of Omitting Contralateral Systematic Biopsy on the Surgical Planning of Patients with a Unilateral Suspicious Lesion on Magnetic Resonance Imaging Undergoing Robot-assisted Radical Prostatectomy for Prostate Cancer.

Background and objective: A combined approach of magnetic resonance imaging (MRI)-targeted biopsy (TBx) and bilateral systematic biopsy (SBx) is advised in patients who have an increased risk of prostate cancer (PCa). The diagnostic gain of SBx in detecting PCa for treatment planning of patients undergoing robot-assisted radical prostatectomy (RARP) is unknown. This study aims to determine the impact of omitting contralateral SBx on the surgical planning of patients undergoing RARP in terms of nerve-sparing surgery (NSS) and extended pelvic lymph node dissection (ePLND). Methods: Case files from 80 men with biopsy-proven PCa were studied. All men had a unilateral suspicious lesion on MRI, and underwent TBx and bilateral SBx. Case files were presented to five urologists for the surgical planning of RARP. Each case file was presented randomly using two different sets of information: (1) results of TBx + bilateral SBx, and (2) results of TBx + ipsilateral SBx. The urologists assessed whether they would perform NSS and/or ePLND. Key findings and limitations: A change in the surgical plan concerning NSS on the contralateral side was observed in 9.0% (95% confidence interval [CI] 6.4-12.2) of cases. Additionally, the indication for ePLND changed in 5.3% (95% CI 3.3-7.9) of cases. Interobserver agreement based on Fleiss' kappa changed from 0.44 to 0.15 for the indication of NSS and from 0.84 to 0.83 for the indication of ePLND. Conclusions and clinical implications: In our series, the diagnostic information obtained from contralateral SBx has limited impact on the surgical planning of patients with a unilateral suspicious lesion on MRI scheduled to undergo RARP. Patient summary: In patients with one-sided prostate cancer on magnetic resonance imaging, omitting biopsies on the other side rarely changed the surgical plan with respect to nerve-sparing surgery and the indication to perform extended lymph node dissection.