Aquablation versus HoLEP in patients with benign prostatic hyperplasia: a comparative prospective non-randomized study

PURPOSE

The question of best surgical treatment for lower urinary tract symptoms (LUTS) due to benign prostate hyperplasia (BPH) remains controversial. We compared the outcomes of aquablation and holmium laser enucleation of the prostate ("HoLEP") in a prospective cohort.

METHODS

Patients with BPH underwent aquablation or HoLEP according to their preference between June 2020 and April 2022. Prostate volume ("PV"), laboratory results, postvoid residual volume, uroflowmetry, IPSS, ICIQ-SF, MSHQ-EjD, EES and IIEF were evaluated preoperatively and at three, six and 12 months postoperatively. We also analyzed perioperative characteristics and complications via the Clavien Dindo ("CD") classification.

RESULTS

We included 40 patients, 16 of whom underwent aquablation and 24 HoLEP. Mean age was 67 years (SD 7.4). Baseline characteristics were balanced across groups, except the HoLEP patients' larger PV. IPSS fell from 20.3 (SD 7.1) at baseline to 6.3 (SD 4.2) at 12 months (p < 0.001) without differences between aquablation and HoLEP. HoLEP was associated with shorter operation time (59.5 (SD 18.6) vs. 87.2 (SD 14.8) minutes, p < 0.001) and led to better PV reduction over all timepoints. At three months, aquablation's results were better regarding ejaculatory (p = 0.02, MSHQ-EjD) and continence function (p < 0.001, ICIQ-SF). Beyond three months, erectile, ejaculatory, continence function and LUTS reduction did not differ significantly between aquablation and HoLEP. CD ≥ grade 3b complications were noted in six patients in aquablation group while only one in HoLEP group (p =  < 0.01).

CONCLUSIONS

While aquablation revealed temporary benefits regarding ejaculation and continence at three months, HoLEP was superior concerning operation time, the safety profile and volumetric results.

Primary results of patients with genitourinary malignancies presented at a Molecular Tumor Board

PURPOSE

Personalized medicine poses great opportunities and challenges. While therapeutic landscape markedly expands, descriptions about status, clinical implementation and real-world benefits of precision oncology and molecular tumor boards (MTB) remain sparse, particularly in the field of genitourinary (GU) cancer. Hence, this study characterized urological MTB cases to better understand the potential role of MTB in uro-oncology.

METHODS

We analyzed patients with complete data sets being reviewed at an MTB from January 2019 to October 2022, focusing on results of molecular analysis and treatment recommendations.

RESULTS

We evaluated 102 patients with GU cancer with a mean patient age of 61.7 years. Prostate cancer (PCa) was the most frequent entity with 52.9% (54/102), followed by bladder cancer (18.6%, 19/102) and renal cell carcinoma (14.7%, 15/102). On average, case presentation at MTB took place 54.9 months after initial diagnosis and after 2.7 previous lines of therapy. During the study period 49.0% (50/102) of patients deceased. Additional MTB-based treatment recommendations were achieved in a majority of 68.6% (70/102) of patients, with a recommendation for targeted therapy in 64.3% (45/70) of these patients. Only 6.7% (3/45) of patients - due to different reasons - received the recommended MTB-based therapy tough, with 33% (1/3) of patients reaching disease control. Throughout the MTB study period, GU cancer case presentations and treatment recommendations increased, while the time interval between initial presentation and final therapy recommendation were decreasing over time.

CONCLUSION

Presentation of uro-oncological patients at the MTB is a highly valuable measure for clinical decision-making. Prospectively, earlier presentation of patients at the MTB and changing legislative issues regarding comprehensive molecular testing and targeted treatment approval might further improve patients' benefits from comprehensive molecular diagnostics.

Prospective Multicenter Validation of the Stockholm3 Test in a Central European Cohort

BACKGROUND

It has been shown that the Stockholm3 test decreases overdetection of prostate cancer (PCa) while retaining the ability to detect clinically significant PCa (csPCa) in a Swedish population. However, the test includes potentially population-specific testing of single-nucleotide polymorphisms and has yet not been validated outside Scandinavia.

OBJECTIVE

To assess the performance of the Stockholm3 test in discriminating csPCa in a Central European cohort undergoing prostate biopsy (PBx).

DESIGN, SETTING, AND PARTICIPANTS

This prospective multicenter validation study was conducted from August 2020 to September 2022 at two centers in Switzerland and one center in Germany. The study involved 342 men undiagnosed with PCa who were scheduled for PBx after prostate-specific antigen (PSA) testing and subsequent magnetic resonance imaging (MRI) of the prostate. Before PBx, participants had a blood sample taken for Stockholm3 testing.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the accuracy of the Stockholm3 test in detecting csPCa (International Society of Urological Pathology grade group [GG] ≥2) according to the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity, and the clinical consequences of using the model.

RESULTS AND LIMITATIONS

The Stockholm3 test with a cutoff of 11% for csPCa detection had sensitivity of 92.3% (95% confidence interval [CI] 86.9-95.9%), specificity of 32.6% (95% CI 26.0-39.8%), a positive predictive value of 53.2% (95% CI 47.0-59.2%), and a negative predictive value of 83.6% (95% CI 73-91.2%). It showed superior discrimination for csPCa (AUC 0.77, 95% CI 0.72-0.82) in comparison to PSA (AUC 0.66, 95% CI 0.61-0.72; p < 0.001). Using a Stockholm3 cutoff of 11%, PBx could have been omitted for 73 men (21.0%), and 12/154 (8%) csPCa and 2/72 (2.8%) GG >2 cases would have been missed. Limitations include population selection bias.

CONCLUSIONS

Our results show favorable clinical outcomes for the blood-based Stockholm3 biomarker test in a Central European patient cohort.

PATIENT SUMMARY

The Stockholm3 blood test shows better accuracy in predicting prostate cancer than the more common PSA (prostate-specific antigen) test.

A Machine Learning Framework Reduces the Manual Workload for Systematic Reviews of the Diagnostic Performance of Prostate Magnetic Resonance Imaging

Prostate magnetic resonance imaging has become the imaging standard for prostate cancer in various clinical settings, with interpretation standardized according to the Prostate Imaging Reporting and Data System (PI-RADS). Each year, hundreds of scientific studies that report on the diagnostic performance of PI-RADS are published. To keep up with this ever-increasing evidence base, systematic reviews and meta-analyses are essential. As systematic reviews are highly resource-intensive, we investigated whether a machine learning framework can reduce the manual workload and speed up the screening process (title and abstract). We used search results from a living systematic review of the diagnostic performance of PI-RADS (1585 studies, of which 482 were potentially eligible after screening). A naïve Bayesian classifier was implemented in an active learning environment for classification of the titles and abstracts. Our outcome variable was the percentage of studies that can be excluded after 95% of relevant studies have been identified by the classifier (work saved over sampling: WSS@95%). In simulation runs of the entire screening process (controlling for classifier initiation and the frequency of classifier updating), we obtained a WSS@95% value of 28% (standard error of the mean ±0.1%). Applied prospectively, our classification framework would translate into a significant reduction in manual screening effort.

Patient summary

Systematic reviews of scientific evidence are labor-intensive and take a lot of time. For example, many studies on prostate cancer diagnosis via MRI (magnetic resonance imaging) are published every year. We describe the use of machine learning to reduce the manual workload in screening search results. For a review of MRI for prostate cancer diagnosis, this approach reduced the screening workload by about 28%.

Toxicity and Patient Reported Quality of Life after PSMA-PET and mpMRT-Based Focal Dose Escalated Definitive Radiotherapy in Prostate Cancer Patients: 2-Year Follow-Up of the HypoFocal Phase II Trial

PURPOSE/OBJECTIVE(S)

The prospective, 2-armed non-randomized HypoFocal phase II trial investigates the safety and feasibility of focal dose escalated external beam radiotherapy (EBRT) and high-dose-rate brachytherapy (HDR-BT) for prostate cancer (PCa) patients based on PSMA-PET and multiparametric MRI. This approach improves tumor coverage and thus putatively treatment effectiveness but leads to larger boost volumes. Here we present toxicity and patient reported quality of life (QoL) results after 2 years follow-up (FU) MATERIALS/METHODS: Patients with intermediate- or high-risk PCa and cN0/cM0 stage were included. Patients in arm A received 60 Gy in 20 fractions to the prostate with an integrated boost of up to 75 Gy. Patients in arm B received one session HDR-BT with 15 Gy to the prostate and a boost of up to 19 Gy, followed by EBRT of 44 Gy in 20 fractions. Boost volumes were defined by PSMA-PET and mpMRI based on validated approaches. Genitourinary (GU) and gastrointestinal (GI) toxicity (CTCAE v5.0) and QoL with IPSS and EORTC questionnaires (QLQ30 and PR25) were assessed.

RESULTS

Fifty patients were treated in both arms in two centers (Freiburg and Berlin). Table 1 shows patients characteristics. In arm, A grade 2 GU and GI toxicity rates after 2 years were 8% and 4%. There were no grade 3 GU toxicities. Two patients experienced grade 3 GI toxicities due to multifactorial causes. In Arm B grade 2 GU and GI toxicity rates after 2 years were 17% and 0%. No grade 3 toxicities were observed in arm B. Toxicities were not statistically significantly different between baseline and 2y FU (p>0.055). QoL analysis was performed with patients with available questionnaires at baseline and 2y FU (12-15 in Arm A and 13-15 in Arm B). Only bowel function (p = 0.0005, median 4 vs 25 points) in Arm A and sexual- (p = 0.016, median 25 vs 50 points) and bowel function (p = 0.004, median 0 vs 8 points) and dyspnea (p = 0.031, median 0 vs 0 points) in Arm B decreased significantly after 2 year FU. Other QoL items were not significantly different. Bowel symptoms were significantly worse in Arm A compared to Arm B (p = 0.003). Median PSA values after 2 years were 0.23 ng/ml in Arm A and 0.33 ng/ml in Arm B.

CONCLUSION

Despite large boost volumes, the 2 years FU of the HypoFocal-Phase II trials shows no significantly increased GU and GU toxicities compared to baseline symptoms. Patients reported about a good QoL but increased bowel symptoms after 2 years, particularly if treated with EBRT only. Implementation of PSMA-PET into focal dose escalated radiotherapy approaches appears safe and feasible. However, radioproctitis demands careful management. The current PSA values suggest a highly effective therapy, but longer FU is needed to evaluate oncological outcomes. The HypoFocal-SBRT phase III trial will evaluate the PSMA-PET and mpMRI-based focal dose escalated SBRT.

[Novel hormone treatment for advanced prostate cancer]

The systemic treatment of advanced prostate cancer (PCa) has undergone an absolute revolution in the past decade. Numerous new substances have been approved for all stages of advanced disease and treatment has been increasingly intensified. The focus continues to be on substances with an effect on the androgen receptor axis. In this review, approved treatment options for metastatic hormone-sensitive PCa (mHSPC), non-metastatic castration-refractory PCa (nmCRPC) and metastatic castration-refractory PCa (mCRPC) are summarized. A special focus is on novel hormone therapeutic agents. Based on recent trial data, potential triple combinations for mHSPC as well as treatment sequence options and novel targeted agents for mCRPC are also highlighted.

Prediction of upgrade to clinically significant prostate cancer in patients under active surveillance: performance of a fully automated AI-algorithm for lesion detection and classification

BACKGROUND

Multiparametric MRI (MpMRI) improves the detection of aggressive prostate cancer (PCa) subtypes. As cases of active surveillance (AS) increase and tumor progression triggers definitive treatment, we evaluated whether an AI-driven algorithm can detect clinically significant PCa (csPCa) in patients under AS.

METHODS

Consecutive patients under AS who received mpMRI (PI-RADSv2.1 protocol) and subsequent MR-guided ultrasound fusion (targeted and extensive systematic) biopsy between 2017 and 2020 were retrospectively analyzed. Diagnostic performance of an automated clinically certified AI-driven algorithm was evaluated on both lesion and patient level regarding the detection of csPCa.

RESULTS

Analysis of 56 patients resulted in 93 target lesions. Patient level sensitivity and specificity of the AI algorithm was 92.5%/31% for the detection of ISUP ≥ 1 and 96.4%/25% for the detection of ISUP ≥ 2, respectively. The only case of csPCa missed by the AI harbored only 1/47 Gleason 7a core (systematic biopsy; previous and subsequent biopsies rendered non-csPCa).

CONCLUSIONS

AI-augmented lesion detection and PI-RADS scoring is a robust tool to detect progression to clinically significant PCa in patients under AS. Integration in the clinical workflow can serve as reassurance for the reader and streamline reporting, hence improve efficiency and diagnostic confidence. This article is protected by copyright. All rights reserved.

Prediction of significant prostate cancer in equivocal MRI lesions: A high-volume international multicenter study

311

Background: The decision of performing prostate biopsy in men with equivocal findings in prostate magnetic resonance imaging (MRI) is challenging as they have a low but still relevant risk of harboring significant prostate cancer (sPC). Objective: To identify clinical predictors of sPC in men with equivocal findings in prostate MRI. Secondly, we aimed to analyze the hypothetical effect of incorporating prostate-specific antigen density (PSAD) into biopsy decision. Methods: We analysed a retrospective multinational cohort from 10 academic centers comprising 1476 men who underwent combined prostate biopsy (MRI-targeted plus systematic) between 02/2012 – 04/2021 due to an equivocal lesion found in prostate MRI (Prostate Imaging Reporting and Data System 3). Primary outcome was the detection of sPC (ISUP ≥ 2) in combined biopsy. Regression analysis was performed to identify predictors for this outcome. Descriptive statistics were applied to evaluate the hypothetical effect of involving PSAD into biopsy decision. Results: 273/1476 (18.5%) men were diagnosed with sPC by combined biopsy. MRI-targeted biopsy diagnosed less sPC as compared to combined strategy: 183/1476 (12.4%) vs. 273/1476 (18.5%), p<0.01. Regression analysis confirmed age (OR 1.10 [95% CI: 1.05 – 1.15]; p < 0.001), prior negative biopsy (OR 0.46 [0.24 – 0.89]; p = 0.022) and PSAD (p<0.001) as independent predictors for sPC. Applying a PSAD cut-off of 0.15 for biopsy decision, 817/1398 (58.4%) of the biopsy procedures would have been avoided at the cost of missing sPC in 91 (6.5%) men. Limitations were the retrospective design, heterogeneity of the study cohort due to the long inclusion period and a missing central revision of MRI. Conclusions: Age, previous biopsy status and PSAD were found independent predictors of sPC in men with equivocal prostate MRI. Implementation of PSAD into biopsy decision can avoid a large proportion of unnecessary biopsies. Clinical parameters such as PSAD need validation in a prospective setting.

Individualized Decision Making in Transperineal Prostate Biopsy: Should All Men Undergo an Additional Systematic Biopsy?

Background: In prostate cancer (PC) diagnosis, additional systematic biopsy (SB) is recommended to complement MRI-targeted biopsy (TB) to address the limited sensitivity of TB alone. The combination of TB+SB is beneficial for diagnosing additional significant PC (sPC) but harmful in terms of the additional diagnosis of indolent PC (iPC), morbidity, and resource expenditures. We aimed to investigate the benefit of additional SB and to identify predictors for this outcome. Methods: We analyzed the frequency of upgrading to sPC by additional SB in a retrospective single-center cohort of 1043 men. Regression analysis (RA) was performed to identify predictors for this outcome. Reclassification rates of ISUP grade groups between prostate biopsy and a subsequent radical prostatectomy were assessed. Results: Additional SB led to upgrading to sPC in 98/1043 men (9.4%) and to the additional diagnosis of iPC in 71/1043 (6.8%). In RA, men harboring a PI-RADS 2-4 lesion were more likely to have TB results upgraded by SB (p < 0.01) compared to PI-RADS 5 men. When analyzing reclassification rates, additional SB reduced the upgrading to sPC from 43/214 (20.1%) to 8/214 (3.7%). In the PI-RADS 5 subgroup, this difference decreased: 4/87 (4.7%) with TB only vs. 1/87 (1.2%) with TB+SB. Conclusion: Men with a PI-RADS 5 lesion may obviate additional SB.

Living systematic review and meta-analysis of the prostate MRI diagnostic test with Prostate Imaging Reporting and Data System (PI-RADS) assessment for the detection of prostate cancer: study protocol

INTRODUCTION

The Prostate Imaging Reporting and Data System (PI-RADS) standardises reporting of prostate MRI for the detection of clinically significant prostate cancer. We provide the protocol of a planned living systematic review and meta-analysis for (1) diagnostic accuracy (sensitivity and specificity), (2) cancer detection rates of assessment categories and (3) inter-reader agreement.

METHODS AND ANALYSIS

Retrospective and prospective studies reporting on at least one of the outcomes of interest are included. Each step that requires literature evaluation and data extraction is performed by two independent reviewers. Since PI-RADS is intended as a living document itself, a 12-month update cycle of the systematic review and meta-analysis is planned.This protocol is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Protocols statement. The search strategies including databases, study eligibility criteria, index and reference test definitions, outcome definitions and data analysis processes are detailed. A full list of extracted data items is provided.Summary estimates of sensitivity and specificity (for PI-RADS ≥3 and PI-RADS ≥4 considered positive) are derived with bivariate binomial models. Summary estimates of cancer detection rates are calculated with random intercept logistic regression models for single proportions. Summary estimates of inter-reader agreement are derived with random effects models.

ETHICS AND DISSEMINATION

No original patient data are collected, ethical review board approval, therefore, is not necessary. Results are published in peer-reviewed, open-access scientific journals. We make the collected data accessible as supplemental material to guarantee transparency of results.

PROSPERO REGISTRATION NUMBER

CRD42022343931.

[Image-guided biopsy of the prostate gland]

The recommendations on carrying out a multiparametric magnetic resonance imaging (mpMRI) for the primary diagnostics and during active surveillance of prostate cancer, include as a consequence an image-guided sampling from conspicuous areas. In doing so, the information on the localization provided by mpMRI is used for a targeted biopsy of the area suspected of being a tumor. The targeted sampling is mainly performed under sonographic control and after fusion of MRI and ultrasound but can also be (mostly in special cases) carried out directly in the MRI scanner. In an ultrasound-guided biopsy, it is vital to coregister the MR images with the ultrasound images (segmentation of the contour of the prostate and registration of suspect findings). This coregistration can either be carried out cognitively (transfer by the person performing the biopsy alone) or software based. Each method shows specific advantages and disadvantages in the prioritization between diagnostic accuracy and resource expenditure.

The maximum standardized uptake value in patients with recurrent or persistent prostate cancer after radical prostatectomy and PSMA-PET-guided salvage radiotherapy-a multicenter retrospective analysis

Purpose

This study aims to evaluate the association of the maximum standardized uptake value (SUVmax) in positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET) prior to salvage radiotherapy (sRT) on biochemical recurrence free survival (BRFS) in a large multicenter cohort.

Methods

Patients who underwent ⁶⁸ Ga-PSMA11-PET prior to sRT were enrolled in four high-volume centers in this retrospective multicenter study. Only patients with PET-positive local recurrence (LR) and/or nodal recurrence (NR) within the pelvis were included. Patients were treated with intensity-modulated-sRT to the prostatic fossa and elective lymphatics in case of nodal disease. Dose escalation was delivered to PET-positive LR and NR. Androgen deprivation therapy was administered at the discretion of the treating physician. LR and NR were manually delineated and SUVmax was extracted for LR and NR. Cox-regression was performed to analyze the impact of clinical parameters and the SUVmax-derived values on BRFS.

Results

Two hundred thirty-five patients with a median follow-up (FU) of 24 months were included in the final cohort. Two-year and 4-year BRFS for all patients were 68% and 56%. The presence of LR was associated with favorable BRFS (p = 0.016). Presence of NR was associated with unfavorable BRFS (p = 0.007). While there was a trend for SUVmax values ≥ median (p = 0.071), SUVmax values ≥ 75% quartile in LR were significantly associated with unfavorable BRFS (p = 0.022, HR: 2.1, 95%CI 1.1–4.6). SUVmax value in NR was not significantly associated with BRFS. SUVmax in LR stayed significant in multivariate analysis (p = 0.030). Sensitivity analysis with patients for who had a FU of > 12 months (n = 197) confirmed these results.

Conclusion

The non-invasive biomarker SUVmax can prognosticate outcome in patients undergoing sRT and recurrence confined to the prostatic fossa in PSMA-PET. Its addition might contribute to improve risk stratification of patients with recurrent PCa and to guide personalized treatment decisions in terms of treatment intensification or de-intensification.

This article is part of the Topical Collection on Oncology—Genitourinary.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-022-05931-5.

Intraindividual Comparison Between [18F] PSMA-1007 PET/CT and Multiparametric MRI for Radiotherapy Planning in Primary Prostate Cancer Patients

Introduction

Accurate detection and segmentation of the intraprostatic gross tumor volume (GTV) is pivotal for radiotherapy (RT) in primary prostate cancer (PCa) since it influences focal therapy target volumes and the patients’ cT stage. The study aimed to compare the performance of multiparametric resonance imaging (mpMRI) with [¹⁸F] PSMA-1007 positron emission tomography (PET) for intraprostatic GTV detection as well as delineation and to evaluate their respective influence on RT concepts.

Materials and Methods

In total, 93 patients from two German University Hospitals with [¹⁸F] PSMA-1007-PET/CT and MRI (Freiburg) or [¹⁸F] PSMA-1007-PET/MRI (Dresden) were retrospectively enrolled. Validated contouring techniques were applied for GTV-PET and -MRI segmentation. Absolute tumor volume and cT status were determined for each imaging method. The PCa distribution from histopathological reports based on biopsy cores and surgery specimen was used as reference in terms of laterality (unilateral vs. bilateral).

Results

In the Freiburg cohort (n = 84), mpMRI and PET detected in median 2 (range: 1–5) and 3 (range: 1–8) GTVs, respectively (p < 0.01). The median GTV-MRI was significantly smaller than the GTV-PET, measuring 2.05 vs. 3.65 ml (p = 0.0005). PET had a statistically significant higher concordance in laterality with surgery specimen compared to mpMRI (p = 0.04) and biopsy (p < 0.01), respectively. PSMA PET led to more cT2c and cT3b stages, whereas cT3a stage was more pronounced in mpMRI. Based on the cT stage derived from mpMRI and PET information, 21 and 23 as well as 59 and 60 patients, respectively, were intermediate- and high-risk according to the National Comprehensive Cancer Network (NCCN) v1.2022 criteria. In the Dresden cohort (n = 9), similar results were observed.

Conclusion

Intraprostatic GTV segmentation based on [18F] PSMA-1007 PET results in more and larger GTVs compared to mpMRI. This influences focal RT target volumes and cT stage definition, but not the NCCN risk group.

Similarity of competing risks models with constant intensities in an application to clinical healthcare pathways involving prostate cancer surgery

The recent availability of routine medical data, especially in a university-clinical context, may enable the discovery of typical healthcare pathways, that is, typical temporal sequences of clinical interventions or hospital readmissions. However, such pathways are heterogeneous in a large provider such as a university hospital, and it is important to identify similar care pathways that can still be considered typical pathways. We understand the pathway as a temporal process with possible transitions from a single initial treatment state to hospital readmission of different types, which constitutes a competing risks setting. In this article, we propose a multi-state model-based approach to uncover pathway similarity between two groups of individuals. We describe a new bootstrap procedure for testing the similarity of constant transition intensities from two competing risk models. In a large simulation study, we investigate the performance of our similarity approach with respect to different sample sizes and different similarity thresholds. The studies are motivated by an application from urological clinical routine and we show how the results can be transferred to the application example.

Risk Factors for Biochemical Recurrence After PSMA-PET-Guided Definitive Radiotherapy in Patients With De Novo Lymph Node-Positive Prostate Cancer

Introduction

The National Comprehensive Cancer Network recommends external beam radiotherapy (EBRT) combined with androgen deprivation therapy (ADT) as the preferred treatment option for newly diagnosed node-positive (cN1) prostate cancer (PCa) patients. However, implementation of positron emission tomography targeting prostate-specific membrane antigen (PSMA-PET) in the staging of primary PCa patients has a significant impact on RT treatment concepts. This study aims to evaluate outcomes and their respective risk factors on patients with PSMA-PET-based cN1 and/or cM1a PCa receiving primary RT and ADT.

Methods

Forty-eight patients with cN0 and/or cM1a PCa staged by [¹⁸F]PSMA-1007-PET (n = 19) or [⁶⁸Ga]PSMA-11-PET (n = 29) were retrospectively included. All patients received EBRT to the pelvis ± boost to positive nodes, followed by boost to the prostate. The impact of different PET-derived characteristics such as maximum standard uptake value (SUVmax) and number of PET-positive lymph nodes on biochemical recurrence-free survival (BRFS) (Phoenix criteria) and metastasis-free survival (MFS) was determined using Kaplan–Meier and Cox proportional hazard regression analyses.

Results

Median follow-up was 24 months. Median initial serum prostate-specific antigen was 20.2 ng/ml (IQR 10.2–54.2). Most patients had cT stage ≥ 3 (63%) and ISUP grade ≥ 3 (85%). Median dose to the prostate, elective nodes, and PET-positive nodes was 75 Gy, 45 Gy, and 55 Gy, respectively. Ninety percent of patients received ADT with a median duration of 9 months (IQR 6–18). In univariate analysis, cM1a stage (p = 0.03), number of >2 pelvic nodes (p = 0.01), number of >1 abdominal node (p = 0.02), and SUVmax values ≥ median (8.1 g/ml for ⁶⁸Ga-PSMA-11 and 7.9 g/ml for ¹⁸F-PSMA-1007) extracted from lymph nodes were significantly associated with unfavorable BRFS, but classical clinicopathological features were not. Number of >2 pelvic nodes (n = 0.03), number of >1 abdominal node (p = 0.03), and SUVmax values ≥ median extracted from lymph nodes were associated with unfavorable MFS. In multivariate analysis, number of >2 pelvic lymph nodes was significantly associated with unfavorable BRFS (HR 5.2, p = 0.01) and SUVmax values ≥ median extracted from lymph nodes had unfavorable MFS (HR 6.3, p = 0.02).

Conclusion

More than 2 PET-positive pelvic lymph nodes are associated with unfavorable BRFS, and high SUVmax values are associated with unfavorable MFS. Thus, the number of PET-positive lymph nodes and the SUVmax value might be relevant prognosticators to identify patients with favorable outcomes.

Salvage radiotherapy (SRT) in combination with pembrolizumab in patients with PSA persistence or biochemical recurrence after radical prostatectomy due to prostate cancer

TPS212

Background: Goal of our study is to evaluate the efficacy and safety of immunotherapy in combination with standard salvage radiation therapy (SRT) in patients with biochemical recurrence (BCR) or prostate-specific antigen (PSA) persistence after radical prostatectomy (RP). The combination of immunotherapy (IO) with radiation therapy might provide a clinical benefit to patients with recurrent prostate cancer due to an induction of increased activity of the immune system against cancerous tissue (abscopal effect). Primary endpoint is complete biochemical response (PSA level below detection level) 60 weeks after start of trial treatment, which further defines prognosis of patients. Further explorative endpoints like radiographic progression-free survival, PSA-nadir level and time to PSA-nadir, time to initiation of subsequent therapy (secondary ADT or NHA) and quality of life as well as adverse events will be evaluated. Methods: The trial is as a phase II, open-label, single arm monocenter trial which evaluates the combination of pembrolizumab as study medication in combination with SRT. Pembrolizumab will be administered in a three-weekly scheme up to one year of treatment. A concomitant ADT is administered in high-risk patients only (PSA > 0.7ng/ml or cN+ in imaging studies). All patients will be staged with PSMA PET-CT, if applicable. Additionally, blood and urine samples will be collected for correlative biomarker studies. A total of 49 patients are planned to be enrolled in this explorative study within 2 years. INCLUSION CRITERIA (excerpt) Histologically confirmed diagnosis of an adenocarcinoma of the prostate and a BCR or PSA persistence after RP. Histology of the RP specimen needs to fulfill the following criteria: adenocarcinoma of the prostate, Gleason score 7-10; pNX or pN0 or pN1 (max. 2 lymph nodes involved). Imaging within 30 days prior to study inclusion is mandatory (([68Ga] or [18F] PSMA PET-CT as standard imaging modality, alternatively CT abdomen and full-body bone scan). PSA value between ≥0.2 and ≤1.0 ng/ml, measured at least six weeks postoperatively. EXCLUSION CRITERIA (excerpt) Prior-therapy with an anti-PD-1, anti-PD-L1, or anti PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g., CTLA-4, OX 40, CD137). Prior systemic anti-cancer therapy including investigational agents within 4 weeks prior to registration (like neo-adjuvant androgen deprivation therapy (ADT), secondary hormone ablation or taxan-based chemotherapy). Distant metastases or suspicious lymph nodes outside the lower pelvis in imaging with PSMA PET-CT (patients with PET positive bone lesions that are morphologically not clearly suspicious of metastases and would not change clinical practice can be included). Clinical trial information: NCT04931979.

More Than Detection of Adenocarcinoma - Indications and Findings in Prostate MRI in Benign Prostatic Disorders

BACKGROUND

 Multiparametric MRI of the prostate has become a fundamental tool in the diagnostic pathway for prostate cancer and is recommended before (or after negative) biopsy to guide biopsy and increase accuracy, as a staging examination (high-risk setting), and prior to inclusion into active surveillance. Despite this main field of application, prostate MRI can be utilized to obtain information in a variety of benign disorders of the prostate.

METHODS

 Systematic bibliographical research with extraction of studies, national (German) as well as international guidelines (EAU, AUA), and consensus reports on MRI of benign disorders of the prostate was performed. Indications and imaging findings of prostate MRI were identified for a) imaging the enlarged prostate, b) prostate MRI in prostatic artery embolization, c) imaging in prostatitis and d) imaging in congenital anomalies.

RESULTS AND CONCLUSIONS

 Different phenotypes of the enlarged prostate that partly correlate with severity of symptoms are discussed. We provide an overview of the different types of prostatitis and possible imaging findings, highlighting abscesses as a severe complication. The most common congenital anomalies of the prostate are utricular cysts, whereas anomalies like aplasia, hypoplasia, and ectopia are rare disorders. Knowledge of indications for imaging and imaging appearance of these conditions may improve patient care and enhance differential diagnosis.

KEY POINTS

  · Current guidelines do not implement indications for mpMRI apart from prostate carcinoma.. · MRI can distinguish different anatomical phenotypes of prostatic enlargement.. · Prostatic artery embolization represents a valuable treatment option in cases of symptomatic benign prostatic enlargement.. · Different forms of prostatitis exist and may mimic prostate carcinoma in MRI.. · MRI can be used to evaluate anatomical prostate anomalies..

CITATION FORMAT

· Oerther B, Sigle A, Franiel T et al. More Than Detection of Adenocarcinoma - Indications and Findings in Prostate MRI in Benign Prostatic Disorders. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1719-1463.

[Learning from coding data-surgical treatment of benign prostatic syndrome : Big data for BPS]

Benign prostatic syndrome (BPS) is one of the most common urological diseases. Currently, there are numerous surgical methods to treat BPS. The digitalisation of medicine enables new study approaches in healthcare research using digital data from individual treatment pathways. In the present work, BPS-specific longitudinal trend analyses were performed. Treatment-related figures, both with regard to the therapy methods and predefined patient cohorts, could be examined after validating the datasets. This meant that information on relevant characteristics of surgical BPS treatment could be read and calculations made that reflect the overall impact of these processes. In the future, it is expected that increasingly comprehensive, higher-quality digital datasets on different clinical pictures will be available for analytical purposes. Intensification of research projects in this field is desirable. The results thus obtained enable further optimisation steps of certain treatment actions and provide important key figures for the strategy development of a medical facility.

Incidental prostate cancer after holmium laser enucleation of the prostate-A narrative review

Prostate cancer can be detected incidentally after surgical therapy for benign prostatic obstruction such as holmium laser enucleation of the prostate (HoLEP), thus called incidental prostate cancer (iPCa). We aimed to review the studies on iPCa detected after HoLEP and investigate its prevalence. A detailed search of original articles was conducted via the PubMed-MEDLINE, Web of Science, Wiley Online Library and Cochrane Library databases in the last 10 years up to 1 May 2021 with the following search string solely or in combination: "prostate cancer", "prostate carcinoma", "holmium laser enucleation of the prostate" and "HoLEP". We identified 19 articles to include in our analysis and divided them into six main categories: HoLEP versus open prostatectomy and/or transurethral resection of the prostate in terms of iPCa, oncological and functional outcomes, the role of imaging modalities in detecting iPCa, predictive factors of iPCa, the role of prostate-specific antigen kinetics in detecting iPCa and the management of iPCa after HoLEP. We found that the iPCa after HoLEP rate ranges from 5.64% to 23.3%. Functional and oncological outcomes were reported to be encouraging. Oncological treatment options are available in a wide range.

Cancer detection rates of the PI-RADSv2.1 assessment categories: systematic review and meta-analysis on lesion level and patient level

BACKGROUND

The Prostate Imaging Reporting and Data System, version 2.1 (PI-RADSv2.1) standardizes reporting of multiparametric MRI of the prostate. Assigned assessment categories are a risk stratification algorithm, higher categories indicate a higher probability of clinically significant cancer compared to lower categories. PI-RADSv2.1 does not define these probabilities numerically. We conduct a systematic review and meta-analysis to determine the cancer detection rates (CDR) of the PI-RADSv2.1 assessment categories on lesion level and patient level.

METHODS

Two independent reviewers screen a systematic PubMed and Cochrane CENTRAL search for relevant articles (primary outcome: clinically significant cancer, index test: prostate MRI reading according to PI-RADSv2.1, reference standard: histopathology). We perform meta-analyses of proportions with random-effects models for the CDR of the PI-RADSv2.1 assessment categories for clinically significant cancer. We perform subgroup analysis according to lesion localization to test for differences of CDR between peripheral zone lesions and transition zone lesions.

RESULTS

A total of 17 articles meet the inclusion criteria and data is independently extracted by two reviewers. Lesion level analysis includes 1946 lesions, patient level analysis includes 1268 patients. On lesion level analysis, CDR are 2% (95% confidence interval: 0-8%) for PI-RADS 1, 4% (1-9%) for PI-RADS 2, 20% (13-27%) for PI-RADS 3, 52% (43-61%) for PI-RADS 4, 89% (76-97%) for PI-RADS 5. On patient level analysis, CDR are 6% (0-20%) for PI-RADS 1, 9% (5-13%) for PI-RADS 2, 16% (7-27%) for PI-RADS 3, 59% (39-78%) for PI-RADS 4, 85% (73-94%) for PI-RADS 5. Higher categories are significantly associated with higher CDR (P < 0.001, univariate meta-regression), no systematic difference of CDR between peripheral zone lesions and transition zone lesions is identified in subgroup analysis.

CONCLUSIONS

Our estimates of CDR demonstrate that PI-RADSv2.1 stratifies lesions and patients as intended. Our results might serve as an initial evidence base to discuss management strategies linked to assessment categories.

Evaluation of the Ginsburg Scheme: Where Is Significant Prostate Cancer Missed?

Simple Summary

Systematic biopsy according to the Ginsburg scheme is widely used to complement MRI-targeted biopsy for the diagnosis of prostate cancer. This is the first study to evaluate the distribution of cancerous lesions that were missed by the Ginsburg scheme. We found that significant prostate cancer lesions were missed in 3.6% of patients. The majority of the missed lesions (17/39, 43.6%) were localized within the anterior region of the prostate. Complementing the Ginsburg scheme by adding biopsy cores to this region may be considered in certain patients who were extensively pre-biopsied without a conclusive diagnosis or when targeted biopsy was not possible. Moreover, based on Ginsburg scheme sectors and newly defined blind sectors, we developed a new sector map of the prostate that can be applied to focal therapy planning and for the follow-up management of patients under active surveillance.

Abstract

Background: Systematic biopsy (SB) according to the Ginsburg scheme (GBS) is widely used to complement MRI-targeted biopsy (MR-TB) for optimizing the diagnosis of clinically significant prostate cancer (sPCa). Knowledge of the GBS’s blind sectors where sPCa is missed is crucial to improve biopsy strategies. Methods: We analyzed cancer detection rates in 1084 patients that underwent MR-TB and SB. Cancerous lesions that were missed or underestimated by GBS were re-localized onto a prostate map encompassing Ginsburg sectors and blind-sectors (anterior, central, basodorsal and basoventral). Logistic regression analysis (LRA) and prostatic configuration analysis were applied to identify predictors for missing sPCa with the GBS. Results: GBS missed sPCa in 39 patients (39/1084, 3.6%). In 27 cases (27/39, 69.2%), sPCa was missed within a blind sector, with 17/39 lesions localized in the anterior region (43.6%). Neither LRA nor prostatic configuration analysis identified predictors for missing sPCa with the GBS. Conclusions: This is the first study to analyze the distribution of sPCa missed by the GBS. GBS misses sPCa in few men only, with the majority localized in the anterior region. Adding blind sectors to GBS defined a new sector map of the prostate suited for reporting histopathological biopsy results.

Influence of Urethra Sparing on Tumor Control Probability and Normal Tissue Complication Probability in Focal Dose Escalated Hypofractionated Radiotherapy: A Planning Study Based on Histopathology Reference

Purpose

Multiparametric magnetic resonance tomography (mpMRI) and prostate specific membrane antigen positron emission tomography (PSMA-PET/CT) are used to guide focal radiotherapy (RT) dose escalation concepts. Besides improvements of treatment effectiveness, maintenance of a good quality of life is essential. Therefore, this planning study investigates whether urethral sparing in moderately hypofractionated RT with focal RT dose escalation influences tumour control probability (TCP) and normal tissue complication probability (NTCP).

Patients and Methods

10 patients with primary prostate cancer (PCa), who underwent 68Ga PSMA-PET/CT and mpMRI followed by radical prostatectomy were enrolled. Intraprostatic tumour volumes (gross tumor volume, GTV) based on both imaging techniques (GTV-MRI and -PET) were contoured manually using validated contouring techniques and GTV-Union was created by summing both. For each patient three IMRT plans were generated with 60 Gy to the whole prostate and a simultaneous integrated boost up to 70 Gy to GTV-Union in 20 fractions by (Plan 1) not respecting and (Plan 2) respecting dose constraints for urethra as well as (Plan 3) respecting dose constraints for planning organ at risk volume for urethra (PRV = urethra + 2mm expansion). NTCP for urethra was calculated applying a Lyman-Kutcher-Burman model. TCP-Histo was calculated based on PCa distribution in co-registered histology (GTV-Histo). Complication free tumour control probability (P+) was calculated. Furthermore, the intrafractional movement was considered.

Results

Median overlap of GTV-Union and PRV-Urethra was 1.6% (IQR 0-7%). Median minimum distance of GTV-Histo to urethra was 3.6 mm (IQR 2 - 7 mm) and of GTV-Union to urethra was 1.8 mm (IQR 0.0 - 5.0 mm). The respective prescription doses and dose constraints were reached in all plans. Urethra-sparing in Plans 2 and 3 reached significantly lower NTCP-Urethra (p = 0.002) without significantly affecting TCP-GTV-Histo (p = p > 0.28), NTCP-Bladder (p > 0.85) or NTCP-Rectum (p = 0.85), resulting in better P+ (p = 0.006). Simulation of intrafractional movement yielded even higher P+ values for Plans 2 and 3 compared to Plan 1.

Conclusion

Urethral sparing may increase the therapeutic ratio and should be implemented in focal RT dose escalation concepts.

Morcellation After Endoscopic Enucleation of the Prostate: Efficiency and Safety of Currently Available Devices

CONTEXT

Although several studies have compared different morcellators and enucleation techniques for the management of benign prostatic hyperplasia (BPH), there is sparse literature on morcellation, so further experimental and clinical research is required for its optimization.

OBJECTIVE

To critically appraise the contemporary literature on prostate morcellation and to evaluate the safety and efficiency of currently available morcellators for endoscopic enucleation of the prostate (EEP) in the context of BPH.

EVIDENCE ACQUISITION

A comprehensive review of the English and French literature relevant to prostate morcellation was performed using the PubMed-MEDLINE, Cochrane Library, Web of Science, and Wiley Online Library database from 1998 to 2020 using PICOS (patient population, intervention, comparison, outcome, and study design) criteria.

EVIDENCE SYNTHESIS

We retrieved 26 studies involving 5652 patients treated with a morcellator that were eligible for data extraction and analysis. The mean patient age was 67.4 (range 61.4-72.8) yr. The weighted mean efficiency of Piranha, VersaCut, and DrillCut morcellators was 5.29, 3.95, and 5.3 g/min, respectively. Several approaches, such as en bloc, two-lobe, inverse, and improved techniques, may increase morcellation efficiency and safety. The lowest weighted mean rate of bladder wall injury was 1.24% for Piranha, followed by 1.98% for DrillCut, and 5.23% for VersaCut, while the VersaCut morcellator had the lowest weighted mean rate of device malfunction at 0.74%, compared to 2.07% for Piranha and 7.86% for DrillCut.

CONCLUSIONS

All three morcellators are efficient and safe for prostatic morcellation after EEP. Further development of devices and techniques may improve the efficiency and safety profile of morcellation. To increase safety, surgeon expertise, technical equipment, and patient characteristics should be considered. Therefore, interdisciplinary exchange of knowledge and further technological innovations are strongly encouraged.

PATIENT SUMMARY

We reviewed the safety and efficacy of devices called morcellators. These devices cut tissue into small pieces that are easier to remove from the body, and are used during laser surgery for benign enlargement of the prostate. Three morcellators are currently available on the market and are comparable in safety and efficacy.

Artificial Intelligence in Magnetic Resonance Imaging-based Prostate Cancer Diagnosis: Where Do We Stand in 2021?

CONTEXT

Men suspected of harboring prostate cancer (PCa) increasingly undergo multiparametric magnetic resonance imaging (mpMRI) and mpMRI-guided biopsy. The potential of mpMRI coupled to artificial intelligence (AI) methods to detect and classify PCa before decision-making requires investigation.

OBJECTIVE

To review the literature for studies addressing the diagnostic performance of combined mpMRI and AI approaches to detect and classify PCa, and to provide selection criteria for relevant articles having clinical significance.

EVIDENCE ACQUISITION

We performed a nonsystematic search of the English language literature using the PubMed-MEDLINE database up to October 30, 2020. We included all original studies addressing the diagnostic accuracy of mpMRI and AI to detect and classify PCa with histopathological analysis as a reference standard.

EVIDENCE SYNTHESIS

Eleven studies assessed AI and mpMRI approaches for PCa detection and classification based on a ground truth that referred to the entire prostate either with radical prostatectomy specimens (RPS) or relocalization of positive systematic and/or targeted biopsy. Seven studies retrospectively annotated cancerous lesions onto mpMRI identified in whole-mount sections from RPS, three studies used a backward projection of histological prostate biopsy information, and one study used a combined cohort of both approaches. All studies cross-validated their data sets; only four used a test set and one a multisite validation scheme. Performance metrics for lesion detection ranged from 87.9% to 92% at a threshold specificity of 50%. The lesion classification accuracy of the algorithms was comparable to that of the Prostate Imaging-Reporting and Data System.

CONCLUSIONS

For an algorithm to be implemented into radiological workflows and to be clinically applicable, it must be trained with a ground truth labeling that reflects histopathological information for the entire prostate and it must be externally validated. Lesion detection and classification performance metrics are promising but require prospective implementation and external validation for clinical significance.

PATIENT SUMMARY

We reviewed the literature for studies on prostate cancer detection and classification using magnetic resonance imaging (MRI) and artificial intelligence algorithms. The main application is in supporting radiologists in interpreting MRI scans and improving the diagnostic performance, so that fewer unnecessary biopsies are carried out.

Safety and side effects of transperineal prostate biopsy without antibiotic prophylaxis

STUDY AIMS

To investigate safety and side effects of transperineal prostate biopsy without antibiotic prophylaxis. Secondary aim was to identify whether the number of cores influenced the occurrence of complications.

PATIENTS AND METHODS

A cohort of 184 patients undergoing perineal prostate biopsy without antibiotic prophylaxis from 2015 to 2017 was analyzed retrospectively. On average, 41 cores were taken via two perineal skin punctures. Demographic and clinical data were obtained from patients´ electronic medical records. Binary logistic regression was performed to identify predictors for complications with the following covariates: age, prostate specific antigen (PSA), prostate volume, Prostate Imaging Reporting and Data System score, history of prostatitis, therapeutic anticoagulation, risk factors for urinary tract infection, surgery duration, and the number of biopsy cores. Furthermore, we calculated chi-squared tests with post hoc analyses for differences in the occurrence of complications between quartiles of the above-mentioned parameters.

RESULTS

The overall complication rate was 10.8% (20/185). Out of 20, 19 (95 %) complications were ≤ grade 2 according to the Clavien-Dindo classification. There were two cases of afebrile urinary tract infection, and no patient developed fever or sepsis. Acute urinary retention was reported in 10 patients (5.4 %). The total number of cores was not associated to infectious complications or acute urinary retention rates.

CONCLUSIONS

Transperineal prostate biopsy without antibiotic prophylaxis is a safe procedure. Neither postoperative fever nor sepsis occurred. An increased number of cores through two skin punctures was not associated with more complications.

99mTc-labelled PSMA ligand for radio-guided surgery in nodal metastatic prostate cancer: proof of principle

Purpose

Intraoperative identification of prostate cancer (PCa) lymph node (LN) metastases (LNM) detected by preoperative PSMA PET/CT may be facilitated by PSMA radio-guided surgery (RGS) with use of a γ-probe. Earlier we demonstrated excellent performance of the ¹¹¹In-labelled PSMA ligand DKFZ-617 ([¹¹¹In]In-PSMA-617) in RGS for ex situ distinction of LN vs LNM at lymphadenectomy (LA) at a single LN level. In comparison with indium-111, technetium-99m has better physical properties for γ-probe measurements, better availability and lower radiation exposure for patients and medical personnel. Against this background, we evaluated the uptake of ^99mTc-PSMA-I&S ligand at the level of single LN and its power to discriminate between unaffected LN and LNM.

Methods

Six patients with PCa with the suspicion of LNM on preoperative PSMA-PET/CT underwent [^99mTc]Tc-PSMA-I&S RGS (4 salvage LA, 2 primary LA) with intravenous injection of [^99mTc]Tc-PSMA-I&S 24 h prior to surgery. Resected samples were isolated manually aiming at the level of single LN. Uptake measurements were done ex situ with a high-purity germanium detector. Receiver operating characteristic (ROC) analysis was performed based on [^99mTc]Tc-PSMA-I&S uptake expressed as lean body mass standard uptake value (SUL).

Results

Separation of the tissue samples from 73 subregions resulted in 498 single samples. After final histopathology 356 LN, 160 LNM und 11 non-nodal PCa samples were identified. Median SUL of tumor-free samples (0.26) and samples with cancer (3.5) was significantly different (p < 0.0001). ROC analysis revealed an area under the curve (AUC) of 0.917 (95% CI 0.89–0.95). Using a SUL cutoff of 1.1, sensitivity, specificity, positive predictive value, and negative predictive values were 76.6%, 94.4%, 89.4% and 86.9%.

Conclusion

Ex situ analysis of [^99mTc]Tc-PSMA-I&S uptake at single LN level showed good diagnostic performance for the ex situ distinction of tumor-bearing vs tumor-free LN during RGS.

SRGAP1 Controls Small Rho GTPases To Regulate Podocyte Foot Process Maintenance

BACKGROUND

Previous research demonstrated that small Rho GTPases, modulators of the actin cytoskeleton, are drivers of podocyte foot-process effacement in glomerular diseases, such as FSGS. However, a comprehensive understanding of the regulatory networks of small Rho GTPases in podocytes is lacking.

METHODS

We conducted an analysis of podocyte transcriptome and proteome datasets for Rho GTPases; mapped in vivo, podocyte-specific Rho GTPase affinity networks; and examined conditional knockout mice and murine disease models targeting Srgap1. To evaluate podocyte foot-process morphology, we used super-resolution microscopy and electron microscopy; in situ proximity ligation assays were used to determine the subcellular localization of the small GTPase-activating protein SRGAP1. We performed functional analysis of CRISPR/Cas9-generated SRGAP1 knockout podocytes in two-dimensional and three-dimensional cultures and quantitative interaction proteomics.

RESULTS

We demonstrated SRGAP1 localization to podocyte foot processes in vivo and to cellular protrusions in vitro. Srgap1^fl/fl*Six2Cre but not Srgap1^fl/fl*hNPHS2Cre knockout mice developed an FSGS-like phenotype at adulthood. Podocyte-specific deletion of Srgap1 by hNPHS2Cre resulted in increased susceptibility to doxorubicin-induced nephropathy. Detailed analysis demonstrated significant effacement of podocyte foot processes. Furthermore, SRGAP1-knockout podocytes showed excessive protrusion formation and disinhibition of the small Rho GTPase machinery in vitro. Evaluation of a SRGAP1-dependent interactome revealed the involvement of SRGAP1 with protrusive and contractile actin networks. Analysis of glomerular biopsy specimens translated these findings toward human disease by displaying a pronounced redistribution of SRGAP1 in FSGS.

CONCLUSIONS

SRGAP1, a podocyte-specific RhoGAP, controls podocyte foot-process architecture by limiting the activity of protrusive, branched actin networks. Therefore, elucidating the complex regulatory small Rho GTPase affinity network points to novel targets for potentially precise intervention in glomerular diseases.

Is There an Oncological Benefit of Performing Bilateral Pelvic Lymph Node Dissection in Patients with Penile Cancer and Inguinal Lymph Node Metastasis?

We aim to review the literature for studies investigating the oncological outcomes of patients with penile cancer (PC) undergoing bilateral pelvic lymph node dissection (PLND) in the presence of inguinal lymph node metastasis (LNM) who are at risk of harboring pelvic metastasis. A search of English language literature was performed using the PubMed-MEDLINE database up to 3 December 2020 to identify articles addressing bilateral PLND in PC patients. Eight articles investigating bilateral PLND met our inclusion criteria. Patients with pelvic LNM have a dismal prognosis and, therefore, PLND has an important role in both the staging and treatment of PC patients. Ipsilateral PLND is recommended in the presence of ≥2 positive inguinal nodes and/or extranodal extension (ENE). Significant survival improvements were observed with a higher pelvic lymph node yield, in patients with pN2 disease, and in men treated with bilateral PLND as opposed to ipsilateral PLND. Nevertheless, the role of bilateral PLND for unilateral inguinal LNM remains unclear. Although the EAU guidelines state that pelvic nodal disease does not occur without ipsilateral inguinal LNM, metastatic spread from one inguinal side to the contralateral pelvic side has been reported in a number of studies. Further studies are needed to clarify the disseminative pattern of LNM, in order to establish PLND templates according to patients’ risk profiles and to investigate the benefit of performing bilateral PLND for unilateral inguinal disease.

[Robotics and intraoperative navigation]

Urology has always been closely linked to technological progress. In the last few decades, we have witnessed increasing implementation of various technologies and innovations in subdisciplines of urology. While conventional laparoscopy is increasingly being replaced by robot-assisted procedures and the introduction of new robotic systems from various manufactures will continue for years, the field of endourolgy is still not dominated by robotic systems. However, new systems (e.g., autonomous, robot-controlled aquablation of the prostate) are becoming increasingly popular and numerous development projects will also probably change clinical care in coming years. In addition, further advancements in the combination of robotics with intraoperative navigation through the integration of imaging and augmented-reality (AR) and virtual reality (VR) technology can be expected. This combination of navigation and robotic technology is already being used successfully in prostate biopsy.

Comparison of Manual and Semi-Automatic [18F]PSMA-1007 PET Based Contouring Techniques for Intraprostatic Tumor Delineation in Patients With Primary Prostate Cancer and Validation With Histopathology as Standard of Reference

PURPOSE

Accurate contouring of intraprostatic gross tumor volume (GTV) is pivotal for successful delivery of focal therapies and for biopsy guidance in patients with primary prostate cancer (PCa). Contouring of GTVs, using 18-Fluor labeled tracer prostate specific membrane antigen positron emission tomography ([18F]PSMA-1007/PET) has not been examined yet.

PATIENTS AND METHODS

Ten Patients with primary PCa who underwent [18F]PSMA-1007 PET followed by radical prostatectomy were prospectively enrolled. Coregistered histopathological gross tumor volume (GTV-Histo) was used as standard of reference. PSMA-PET images were contoured on two ways: (1) manual contouring with PET scaling SUVmin-max: 0-10 was performed by three teams with different levels of experience. Team 1 repeated contouring at a different time point, resulting in n = 4 manual contours. (2) Semi-automatic contouring approaches using SUVmax thresholds of 20-50% were performed. Interobserver agreement was assessed for manual contouring by calculating the Dice Similarity Coefficient (DSC) and for all approaches sensitivity, specificity were calculated by dividing the prostate in each CT slice into four equal quadrants under consideration of histopathology as standard of reference.

RESULTS

Manual contouring yielded an excellent interobserver agreement with a median DSC of 0.90 (range 0.87-0.94). Volumes derived from scaling SUVmin-max 0-10 showed no statistically significant difference from GTV-Histo and high sensitivities (median 87%, range 84-90%) and specificities (median 96%, range 96-100%). GTVs using semi-automatic segmentation applying a threshold of 20-40% of SUVmax showed no significant difference in absolute volumes to GTV-Histo, GTV-SUV50% was significantly smaller. Best performing semi-automatic contour (GTV-SUV20%) achieved high sensitivity (median 93%) and specificity (median 96%). There was no statistically significant difference to SUVmin-max 0-10.

CONCLUSION

Manual contouring with PET scaling SUVmin-max 0-10 and semi-automatic contouring applying a threshold of 20% of SUVmax achieved high sensitivities and very high specificities and are recommended for [18F]PSMA-1007 PET based focal therapy approaches. Providing high specificities, semi-automatic approaches applying thresholds of 30-40% of SUVmax are recommend for biopsy guidance.

Isotropic Expansion of the Intraprostatic Gross Tumor Volume of Primary Prostate Cancer Patients Defined in MRI-A Correlation Study With Whole Mount Histopathological Information as Reference

Introduction

An accurate delineation of the intraprostatic gross tumor volume (GTV) is of importance for focal treatment in patients with primary prostate cancer (PCa). Multiparametric MRI (mpMRI) is the standard of care for lesion detection but has been shown to underestimate GTV. This study investigated how far the GTV has to be expanded in MRI in order to reach concordance with the histopathological reference and whether this strategy is practicable in clinical routine.

Patients and Methods

Twenty-two patients with planned prostatectomy and preceded 3 Tesla mpMRI were prospectively examined. After surgery, PCa contours delineated on histopathological slides (GTV-Histo) were superimposed on MRI using ex-vivo imaging as support for co-registration. According to the PI-RADSv2 classification, GTV was manually delineated in MRI (GTV-MRI) by two experts in consensus. For volumetric analysis, we compared GTV-MRI and GTV-Histo. Subsequently, we isotropically enlarged GTV-MRI in 1 mm increments within the prostate and also compared those with GTV-Histo regarding the absolute volumes. For evaluating the spatial accuracy, we considered the coverage ratio of GTV-Histo, the Sørensen–Dice coefficient (DSC), as well as the contact with the urethra.

Results

In 19 of 22 patients MRI underestimated the intraprostatic tumor volume compared to histopathological reference: median GTV-Histo (4.7 cm³, IQR: 2.5–18.8) was significantly (p<0.001) lager than median GTV-MRI (2.6 cm³, IQR: 1.2–6.9). A median expansion of 1 mm (range: 0–4 mm) adjusted the initial GTV-MRI to at least the volume of GTV-Histo (GTV^exp-MRI). Original GTV-MRI and expansion with 1, 2, 3, and 4 mm covered in median 39% (IQR: 2%–78%), 62% (10%–91%), 70% (15%–95%), 80% (21–100), 87% (25%–100%) of GTV-Histo, respectively. Best DSC (median: 0.54) between GTV-Histo and GTV-MRI was achieved by median expansion of 2 mm. The urethra was covered by initial GTVs-MRI in eight patients (36%). After applying an expansion with 2 mm the urethra was covered in one more patient by GTV-MRI.

Conclusion

Using histopathology as reference, we demonstrated that MRI underestimates intraprostatic tumor volume. A 2 mm–expansion may improve accurate GTV-delineation while respecting the balance between histological tumor coverage and overtreatment.

Intraprostatic Tumor Segmentation on PSMA PET Images in Patients with Primary Prostate Cancer with a Convolutional Neural Network

Accurate delineation of the intraprostatic gross tumor volume (GTV) is a prerequisite for treatment approaches in patients with primary prostate cancer (PCa). Prostate-specific membrane antigen PET (PSMA PET) may outperform MRI in GTV detection. However, visual GTV delineation underlies interobserver heterogeneity and is time consuming. The aim of this study was to develop a convolutional neural network (CNN) for automated segmentation of intraprostatic tumor (GTV-CNN) in PSMA PET. Methods: The CNN (3D U-Net) was trained on the ⁶⁸Ga-PSMA PET images of 152 patients from 2 different institutions, and the training labels were generated manually using a validated technique. The CNN was tested on 2 independent internal (cohort 1: ⁶⁸Ga-PSMA PET, n = 18 and cohort 2: ¹⁸F-PSMA PET, n = 19) and 1 external (cohort 3: ⁶⁸Ga-PSMA PET, n = 20) test datasets. Accordance between manual contours and GTV-CNN was assessed with the Dice-Sørensen coefficient (DSC). Sensitivity and specificity were calculated for the 2 internal test datasets (cohort 1: n = 18, cohort 2: n = 11) using whole-mount histology. Results: The median DSCs for cohorts 1-3 were 0.84 (range: 0.32-0.95), 0.81 (range: 0.28-0.93), and 0.83 (range: 0.32-0.93), respectively. Sensitivities and specificities for the GTV-CNN were comparable with manual expert contours: 0.98 and 0.76 (cohort 1) and 1 and 0.57 (cohort 2), respectively. Computation time was around 6 s for a standard dataset. Conclusion: The application of a CNN for automated contouring of intraprostatic GTV in ⁶⁸Ga-PSMA and ¹⁸F-PSMA PET images resulted in a high concordance with expert contours and in high sensitivities and specificities in comparison with histology as a reference. This robust, accurate and fast technique may be implemented for treatment concepts in primary prostate cancer. The trained model and the study's source code are available in an open source repository.

Retrospective Evaluation of the Clinical Values of Minimally Invasive Marsupialization of Symptomatic Giant Renal Cysts

Background: To evaluate the indication and benefit of minimally invasive laparoscopic marsupialization (MIS) of symptomatic giant renal cysts. Materials and Methods: Sixty-four consecutive patients who underwent MIS for large renal cysts (Bosniak I; 4 × 5-16 × 12 cm) by one surgeon were included in the study. Presenting symptoms were renal pain (100%), associated with hypertension (28%), renal dysfunction (4.7%), hematuria (4.7%), ureteropelvic junction obstruction (UPJO) (7.8%), ipsilateral urolithiasis (4.7%), polycystic kidney (6.3%), adrenal cyst (1.6%), and retroperitoneal cysts (1.6%). Seven patients with peripelvic cysts and previous retroperitoneal operations were treated by a laparoscopic approach; all other patients underwent retroperitoneoscopic marsupialization. Single-port retroperitoneoscopy was performed in 4 patients. Follow-up included clinical examination, abdominal ultrasound, and computed tomography scan. Postoperative radiologic success was defined as a minimum of 50% in size reduction and no recurrence. Results: Mean patients' age was 46 (21-65) years. All procedures were successfully completed without conversion or revision. Mean operative time was 55 (40-85) minutes with a mean hospital stay of 3 days. All patients underwent uneventful postoperative recovery. Observed minor complications (transitory fever/pain) were found in 4 patients during the first postoperative month. Median follow-up was 12 months (10 months-2 years). About 98.5% of patients reported of no relevant postoperative pain. A relief from UPJO and hematuria was achieved in 100% of patients. Ten patients with known hypertensive disease (55.6%) had a significant reduction of mean blood pressure resulting in a reduction of antihypertensive medication. Ureterorenoscopic stone extractions were performed successfully afterward. No cyst recurrences were detected during the follow-up period. Conclusion: Treatment indications for symptomatic renal cysts could include not only symptoms but also associated diseases like UPJO and hypertension. Retroperitoneoscopic MIS may be curative for these cyst-associated pathologies. The feasibility, safety and efficacy of these techniques could be demonstrated.

ARP3 Controls the Podocyte Architecture at the Kidney Filtration Barrier

Podocytes, highly specialized epithelial cells, build the outer part of the kidney filtration barrier and withstand high mechanical forces through a complex network of cellular protrusions. Here, we show that Arp2/3-dependent actin polymerization controls actomyosin contractility and focal adhesion maturation of podocyte protrusions and thereby regulates formation, maintenance, and capacity to adapt to mechanical requirements of the filtration barrier. We find that N-WASP-Arp2/3 define the development of complex arborized podocyte protrusions in vitro and in vivo. Loss of dendritic actin networks results in a pronounced activation of the actomyosin cytoskeleton and the generation of over-maturated but less efficient adhesion, leading to detachment of podocytes. Our data provide a model to explain podocyte protrusion morphology and their mechanical stability based on a tripartite relationship between actin polymerization, contractility, and adhesion.

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ARP3-dependent actin assembly is required for podocyte process formation

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Arp2/3 thereby links process formation, podocyte adhesion and mechano-adaptation

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Arp2/3 function is regulated by a reciprocal interplay with actomyosin