In vivo Temperature Assessment during Holmium Laser Enucleation of the Prostate

INTRODUCTION

Holmium laser enucleation of the prostate (HoLEP) has become popular worldwide for the surgical treatment of benign prostate hyperplasia. Holmium laser is considered an ideal transurethral thermomechanical device for enucleating the prostate. Although there is evidence on Ho:YAG laser-related heat generation, the studies mainly investigated ex vivo temperature generation during holmium laser lithotripsy. In this in vivo study, we aimed to assess for the first time the real-time heat generated during HoLEP.

METHODS

Fifteen HoLEP procedures were included. The study was conducted over a time period of 16 months. To investigate the temperature generation, a preoperatively inserted rectal temperature probe and a temperature sensor within a suprapubic bladder catheter were used to record the temperature change during enucleation and coagulation.

RESULTS

The mean values of the temperature change during the laser enucleation and coagulation were -0.35 ± 0.203 K (IQR: 0.23) and +0.14 ± 0.259 K (IQR: 0.3), respectively, in rectal measurements. Temperature differences during laser use and coagulation were <+1 K and <+5 K, respectively, in bladder measurements. We measured no temperature >37.1°C during the procedures and no temperature values considered harmful to the human body.

CONCLUSION

Sufficient irrigation flow rates and irrigation monitoring during HoLEP are obligatory. To prevent a high and uncontrolled temperature rise, the surgeon or operating room staff should pay attention to the irrigation's continuity.

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.

Temperature assessment study of ex vivo holmium laser enucleation of the prostate model

Purpose

There isscarce evidence to date on how temperature develops during holmium laser enucleation of the prostate (HoLEP). We aimed to determine the potential heat generation during HoLEP under ex vivo conditions.

Methods

We developed two experimental setups. Firstly, we simulated HoLEP ex vivo using narrow-neck laboratory bottles mimicking enucleation cavities and a prostate resection trainer. Seven temperature probes were placed at different locations in the experimental setup, and the heat generation was measured separately during laser application. Secondly, we simulated high-frequency current-based coagulation of the vessels using a roller probe.

Results

We observed that the larger the enucleated cavity, the higher the temperature rises, regardless of the irrigation flow rate. The highest temperature difference with an irrigation flow was approximately + 4.5 K for a cavity measuring 100ccm and a 300 ml/min irrigation flow rate. The higher flow rate generates faster removal of the generated heat, thus cooling down the artificial cavity. Furthermore, the temperature differences at different irrigation flow rates (except at 0 ml/min) were consistently below 5 K. Within the resection trainer, the temperature increase with and without irrigation flow was approximately 0.5 K and 3.0 K, respectively. The mean depth of necrosis (1084 ± 176 µm) achieved by the roller probe was significantly greater when using 144 W energy.

Conclusion

Carefully adjusted irrigation and monitoring during HoLEP are crucial when evacuating the thermal energy generated during the procedure. We believe this study of ours provides evidence with the potential to facilitate clinical studies on patient safety.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04041-z.

Data Mining in Urology: Understanding Real-world Treatment Pathways for Lower Urinary Tract Systems via Exploration of Big Data

With an increasing number of novel therapeutic options for lower urinary tract symptoms (LUTS), the spectrum of potential treatment pathways resulting from different combinations of treatment decisions is expanding and evolving. Treatment decisions are frequently made with little or no evidence from randomized controlled trials (RCTs) and thus require evidence from other data sources. Clinical routine data reflect real-world treatment pathways. However, evidence for LUTS from routine data means that heterogeneous pathways need to be simultaneously analyzed for compiling evidence in the absence of RCTs. Statistical multi-state model approaches can provide a powerful framework for achieving this goal. More extensive statistical and methodological efforts in the area of similarity of small data are needed to enable the valid pooling of pathways towards joining evidence. PATIENT SUMMARY: Treatment decisions should rely primarily on evidence from clinical trials. When treatment for which there is limited trial evidence needs to be provided, analysis of results from routine clinical practice can represent valuable complementary evidence, but this requires integration of data from heterogeneous treatment pathways.

Safety and Efficacy of Laser Enucleation of the Prostate in Elderly Patients - A Narrative Review

Benign prostatic hyperplasia (BPH) is a common health condition in aging men resulting in lower urinary tract symptoms (LUTS) and low quality of life (QoL). We aimed to review studies on laser enucleation of the prostate (LEP) due to LUTS in elderly patients (>65 years) comparing different age groups, particularly considering functional outcomes, safety, and perioperative complications. A comprehensive search was conducted using the PubMed-MEDLINE, Web of Science, Wiley Online Library and Cochrane Library databases over the last 10 years until 7 October 2021 with the following search terms solely or in combination: “laser enucleation”, “prostate”, “laser prostatectomy”, “aging”, “elderly patients”, “older patients” and “age”. We identified 12 articles for inclusion in our analysis. Five studies focussed mainly on holmium laser enucleation of the prostate (HoLEP), one compared HoLEP to other laser prostatectomy procedures, two studies examined thulium laser enucleation of the prostate (ThuLEP), and two studies focused on GreenLight laser, one study focussed on potassium-titanyl-phosphate (KTP) laser, and another study compared laser prostatectomy to transurethral resection of the prostate (TURP). These studies showed that LEP improved IPSS, Qmax and QoL compared to baseline regardless of age; no significant difference was reported among age groups. Although ASA scores and anticoagulation/antiplatelet therapy rates are higher in elderly patients, studies revealed no significant difference in perioperative complication rates between age groups. Laser enucleation of the prostate is an effective and safe procedure in elderly patients, resulting in good functional outcomes, low morbidity, and few perioperative complications.

Does the Identification of a Minimum Number of Cases Correlate With Better Adherence to International Guidelines Regarding the Treatment of Penile Cancer? Survey Results of the European PROspective Penile Cancer Study (E-PROPS)

Background

Penile cancer represents a rare malignant disease, whereby a small caseload is associated with the risk of inadequate treatment expertise. Thus, we hypothesized that strict guideline adherence might be considered a potential surrogate for treatment quality. This study investigated the influence of the annual hospital caseload on guideline adherence regarding treatment recommendations for penile cancer.

Methods

In a 2018 survey study, 681 urologists from 45 hospitals in four European countries were queried about six hypothetical case scenarios (CS): local treatment of the primary tumor pTis (CS1) and pT1b (CS2); lymph node surgery inguinal (CS3) and pelvic (CS4); and chemotherapy neoadjuvant (CS5) and adjuvant (CS6). Only the responses from 206 head and senior physicians, as decision makers, were evaluated. The answers were assessed based on the applicable European Association of Urology (EAU) guidelines regarding their correctness. The real hospital caseload was analyzed based on multivariate logistic regression models regarding its effect on guideline adherence.

Results

The median annual hospital caseload was 6 (interquartile range (IQR) 3–9). Recommendations for CS1–6 were correct in 79%, 66%, 39%, 27%, 28%, and 28%, respectively. The probability of a guideline-adherent recommendation increased with each patient treated per year in a clinic for CS1, CS2, CS3, and CS6 by 16%, 7.8%, 7.2%, and 9.5%, respectively (each p < 0.05); CS4 and CS5 were not influenced by caseload. A caseload threshold with a higher guideline adherence for all endpoints could not be perceived. The type of hospital care (academic vs. non-academic) did not affect guideline adherence in any scenario.

Conclusions

Guideline adherence for most treatment recommendations increases with growing annual penile cancer caseload. Thus, the results of our study call for a stronger centralization of diagnosis and treatment strategies regarding penile cancer.

In vitro fragmentation performance of a novel, pulsed Thulium solid-state laser compared to a Thulium fibre laser and standard Ho:YAG laser

The aim of this work was to compare the fragmentation efficiency of a novel, pulsed Thulium solid-state laser (p-Tm:YAG) to that of a chopped Thulium fibre laser (TFL) and a pulsed Holmium solid-state laser (Ho:YAG). During the fragmentation process, we used a silicone mould to fixate the hemispherical stone models under water in a jar filled with room-temperature water. Each laser device registered the total energy applied to the stone model to determine fragmentation efficiency. Our study examined laser settings with single pulse energies ranging from 0.6 to 6 J and pulse frequencies ranging from 5 to 15 Hz. Similar laser settings were applied to explicitly compare the fragmentation efficiency of all three devices. We experimented with additional laser settings to see which of the three devices would perform best. The fragmentation performance of the three laser devices differed statistically significantly (p < 0.05). The average total energy required to fragment the stone model was 345.96 J for Ho:YAG, 372.43 J for p-Tm:YAG and 483.90 J for TFL. To fragment the stone models, both Ho:YAG and p-Tm:YAG needed similar total energy (p = 0.97). TFL’s fragmentation efficiency is significantly lower than that of Ho:YAG and p-Tm:YAG. Furthermore, we found the novel p-Tm:YAG’s fragmentation efficiency to closely resemble that of Ho:YAG. The fragmentation efficiency is thought to be influenced by the pulse duration. TFL’s shortest possible pulse duration was considerably longer than that of Ho:YAG and p-Tm:YAG, resulting in Ho:YAG and p-Tm:YAG exhibiting better fragmenting efficiency.

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.

Dusting Efficiency of a Novel Pulsed Thulium:Yttrium Aluminum Garnet Laser vs a Thulium Fiber Laser

Background: Holmium:yttrium aluminum garnet laser (Ho:YAG) is still considered the gold standard in laser lithotripsy. There is a large body of literature comparing the capabilities of Ho:YAG and thulium fiber lasers (TFLs). The novel, pulsed thulium:yttrium aluminum garnet laser (p-Tm:YAG) evaluation model has only been compared with Ho:YAG in terms of its dusting performance to date. It was this study's aim to compare the p-Tm:YAG's dusting efficiency with that of a chopped TFL. Materials and Methods: During the laser ablation procedure, while the laser device was emitting light, the laser fiber was spiraled across the surface of a uniform kidney stone model via software. We relied on the stone model's difference in weight before and after the dusting procedure to assess the dusting efficiency and assessed each laser device's dusting efficiency at various preset laser configurations and laser fiber-motion speeds. We compared both laser devices' laser configurations, which were identical in pulse energy and frequency, while keeping in mind that the pulse duration differed significantly. In addition, we tested each laser device's capability. Results: The average ablated weight across all laser configurations was 0.61 g (standard deviation [SD] = 0.44 g) for p-Tm:YAG and 0.76 g (SD = 0.51 g) for TFL. After statistical analysis, we found no significant difference in ablated weight between the laser devices (U = 1715.5, p-value = 0.11). The maximum permissible frequency configuration for TFL was 1600 Hz, which resulted in the worst overall dusting output. Conclusions: We observed that the p-Tm:YAG's dusting efficiency resembled that of TFL in the identical pulse energy and frequency laser configurations. The ablation efficiency did not seem to be affected by the laser devices' differences in pulse duration. Slower laser fiber-motion speeds resulted in more efficient ablation. When using the maximum preset frequency and power configuration, TFL's dusting efficiency appeared to be inefficient.

Thermal effects of thulium: YAG laser treatment of the prostate-an in vitro study

PURPOSE

To objectively determine whether there is potential thermal tissue damage during Tm:YAG laser-based LUTS treatment.

METHODS

Our experimental model was comprised of a prostatic resection trainer placed in a 37 °C water bath. In a hollowed-out central area simulating the urethral lumen, we placed a RigiFib 800 fibre, irrigation inflow regulated with a digital pump, and a type K thermocouple. A second thermocouple was inserted 0.5/1 cm adjacently and protected with an aluminum barrier to prevent it from urethral fluid. We investigated continuous and intermittent 120 W and 80 W laser application with various irrigation rates in eight measurement sessions lasting up to 14 min. Thermal measurements were recorded continuously and in real-time using MatLab. All experiments were repeated five times to balance out variations.

RESULTS

Continuous laser application at 120 W and 125 ml/min caused a urethral ∆T of ~ 15 K and a parenchymal temperature increase of up to 7 K. With 50 ml/min irrigation, a urethral and parenchymal ∆T of 30 K and 15 K were reached, respectively. Subsequently and in absence of laser application, prostatic parenchyma needed over 16 min to reach baseline body temperature. At 80 W lower temperature increases were reached compared to similar irrigation but higher power.

CONCLUSIONS

We showed that potentially harming temperatures can be reached, especially during high laser power and low irrigation. The heat generation can also be conveyed to the prostate parenchyma and deeper structures, potentially affecting the neurovascular bundles. Further clinical studies with intracorporal temperature measurement are necessary to further investigate this potentially harming surgical adverse effect.

Soft Urinary Bladder Phantom for Endoscopic Training

Bladder cancer (BC) is the main disease in the urinary tract with a high recurrence rate and it is diagnosed by cystoscopy (CY). To train the CY procedures, a realistic bladder phantom with correct anatomy and physiological properties is highly required. Here, we report a soft bladder phantom (FlexBlad) that mimics many important features of a human bladder. Under filling, it shows a large volume expansion of more than 300% with a tunable compliance in the range of 12.2 ± 2.8 - 32.7 ± 5.4 mL cmH2O-1 by engineering the thickness of the bladder wall. By 3D printing and multi-step molding, detailed anatomical structures are represented on the inner bladder wall, including sub-millimeter blood vessels and reconfigurable bladder tumors. Endoscopic inspection and tumor biopsy were successfully performed. A multi-center study was carried out, where two groups of urologists with different experience levels executed consecutive CYs in the phantom and filled in questionnaires. The learning curves reveal that the FlexBlad has a positive effect in the endourological training across different skill levels. The statistical results validate the usability of the phantom as a valuable educational tool, and the dynamic feature expands its use as a versatile endoscopic training platform.

Real-world data and treatment patterns of patients with lower urinary tract symptoms due to benign prostatic hyperplasia in Germany: an observational study using health insurance claims data

PURPOSE

Benign prostatic hyperplasia (BPH) is associated with lower urinary tract symptoms (LUTS), representing one of the most common urological conditions. However, insights into the actual healthcare of this patient cohort in Germany are scarce. We aimed to retrospectively analyse management patterns of patients with LUTS in Germany using health insurance claims databases.

METHODS

A retrospective, longitudinal cohort analysis was conducted obtaining claims data from the German InGef health insurance database containing approximately five million member-records from over 60 nationwide statutory health insurances. First, a cross-sectional prevalence analysis was performed on all individuals with a diagnosis on LUTS (ICD-10 GM N40) in 2018. Second, a longitudinal analysis of individuals with either a newly started BPH medication or initial BPH surgery who were indexed in 2014 and followed-up for 4 years.

RESULTS

In 2018, 132,386 (6.7%) prevalent BPH patients were identified from 1,979,916 continuously insured males. A potential overcoding bias could not be assessed which may influence the outpatient sector estimation. 10,361 (0.7%) patients were identified with incident BPH medication and 1768 (0.1%) patients with incident BPH surgery out of 1,575,604 males (2013-2018). Alpha-blockers were the drug of choice (95.6%) in the first year. Half of patients received specific BPH medications four years after index, while almost 98% of initial BPH surgeries were performed within the inpatient setting. TURP was the most frequent surgical intervention (76%).

CONCLUSIONS

A widespread diffusion of alternative individualized minimally invasive approaches in the outpatient sector might address pharmacotherapy discontinuation and patient-access barriers to other treatments.

Role of Radiomics in the Prediction of Muscle-invasive Bladder Cancer: A Systematic Review and Meta-analysis

CONTEXT

Radiomics is a field of science that aims to develop improved methods of medical image analysis by extracting a large number of quantitative features. New data have emerged on the successful application of radiomics and machine-learning techniques to the prediction of muscle-invasive bladder cancer (MIBC).

OBJECTIVE

To systematically review the diagnostic performance of radiomic techniques in predicting MIBC.

EVIDENCE ACQUISITION

The literature search for relevant studies up to July 2020 was performed in the PubMed and EMBASE databases by two independent reviewers. The meta-analysis was inducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Inclusion criteria comprised studies that evaluated the diagnostic accuracy of radiomic models in predicting MIBC and used pathological examination as the reference standard. For bias assessment, Quality Assessment of Diagnostic Accuracy Studies-2 and Radiomic Quality Score were used. Weighted summary proportions were used to calculate pooled sensitivity and specificity. A linear mixed model was implemented to calculate the hierarchical summary receiver-operating characteristic (HSROC). Meta-regression analyses were performed to explore heterogeneity.

EVIDENCE SYNTHESIS

Eight studies with a total of 860 patients were included. The summary estimates for sensitivity and specificity in predicting MIBC were 82% (95% confidence interval [CI]: 77-86%) and 81% (95% CI: 76-85%), respectively. The area under HSROC was 0.88. There were no relevant heterogeneity in diagnostic accuracy measures (I² = 33% and 41% for sensitivity and specificity, respectively), which was confirmed by a subsequent meta-regression analysis.

CONCLUSIONS

Radiomics shows high diagnostic performance in predicting MIBC. Despite differences in approaches, radiomic models were relatively homogeneous in their diagnostic accuracy. With further improvements, radiomics has the potential to become a useful adjunct in clinical management of bladder cancer.

PATIENT SUMMARY

Rapidly evolving imaging analysis methods using artificial intelligence algorithms, called radiomics, show high diagnostic performance in predicting muscle-invasive bladder cancer.

Laser enucleation for prostates larger than 100 mL: Comparison of HoLEP and ThuLEP

Recently, with the advancements in laser technology, Holmium laser enucleation of the prostate (HoLEP) and Thulium laser enucleation of the prostate (ThuLEP) have come to the fore in the surgical treatment of benign prostatic hyperplasia (BPH). We aimed to evaluate and compare the outcomes of HoLEP and ThuLEP in patients with >100 ml prostate volume. Patients who underwent HoLEP and ThuLEP between July 2017 and March 2020 were reviewed retrospectively. The patients were divided into two groups as HoLEP (Group 1, n = 121) and ThuLEP (Group 2, n = 104). Perioperative parameters, functional outcomes, continence status, intra and post-operative complications were compared between groups in the post-operative 1st and 6th month. No significant difference was found in terms of total laser energy (TLE), morcellation efficiency (ME), enucleated tissue weight (ETW), complication rates (CR) and continence status of patients between both groups (p > .05). In favour of ThuLEP group, there were statistically significant differences regarding total operation time (TOT), laser efficiency (LE), enucleation time (ET) and enucleation efficiency (EE) between groups (p ≤ .05). HoLEP and ThuLEP can be used safely and effectively in prostates larger than 100 ml.

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.

Mixed reality applications in urology: Requirements and future potential

Background

Mixed reality (MR), the computer-supported augmentation of a real environment with virtual elements, becomes ever more relevant in the medical domain, especially in urology, ranging from education and training over surgeries. We aimed to review existing MR technologies and their applications in urology.

Methods

A non-systematic review of current literature was performed using the PubMed-Medline database using the medical subject headings (MeSH) term “mixed reality”, combined with one of the following terms: “virtual reality”, “augmented reality”, ‘’urology’’ and “augmented virtuality”. The relevant studies were utilized.

Results

MR applications such as MR guided systems, immersive VR headsets, AR models, MR-simulated ureteroscopy and smart glasses have enormous potential in education, training and surgical interventions of urology. Medical students, urology residents and inexperienced urologists can gain experience thanks to MR technologies. MR applications are also used in patient education before interventions.

Conclusions

For surgical support, the achievable accuracy is often not sufficient. The main challenges are the non-rigid nature of the genitourinary organs, intraoperative data acquisition, online and multimodal registration and calibration of devices. However, the progress made in recent years is tremendous in all respects and the gap is constantly shrinking.

∙

MR, including AV and AR, is an intriguing technology with tremendous potential in urology field.

∙The main challenges lie in intraoperative data acquisition, online and multimodal registration and calibration of devices and data, appropriate display hardware, as well as cooperative devices and tools in the operation theatres.

∙Medical experts should feel encouraged to experience MR solutions and to communicate their specific needs and effects they aim at.

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.

Role of Stone Heterogeneity Index in Determining Success of Shock Wave Lithotripsy in Urinary Calculi

INTRODUCTION

Various stone factors can affect the outcome of shock wave lithotripsy (SWL). A novel factor called the stone heterogeneity index (SHI) may have an impact on stone free rates. The objective of this study was to assess the role of SHI in SWL outcomes.

METHODS

Patients' medical records were reviewed for the collection of data variables. They were subjected to SWL, using an electromagnetic lithotripter machine (Storz Modulith SLX-MX). Computation of mean stone density (mean value of the Hounsfield units) and SHI was accomplished by generating elliptical regions of interest on the computed tomography (CT) scan images. Grouping was performed on the basis of stone free and failure outcomes. Relevant statistical tests were applied for continuous and categorical variables. P ≤ 0.05 was considered statistically significant.

RESULTS

Overall, 385 subjects were included having a mean age of 38.4 ± 14.7 years. The cohort comprised 276 (71.7%) males and 109 (28.3%) female patients. A total of 234 (60.8%) patients were rendered successful (stone free after one session) while 151 (39.2%) of the patients were declared to have failed the SWL procedure. Stone length, stone density, and SHI values were 13.7 ± 7.6 mm, 935 ± 404, and 201 ± 107, respectively. The stone density, SHI, and stone length were significantly different between the two groups (p-values of 0.001, 0.02, and 0.04, respectively).

CONCLUSIONS

SHI can be a helpful CT scan-based parameter to assess stone fragility. It can help clinicians in the judicious selection of patients before implementing SWL procedure.

RELEVANCE FOR PATIENTS

Non-contrast CT-based stone parameters have been found to be effective for predictions of outcomes. SHI can be a helping tool to better predict SWL success rates when treating the renal stones.

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.

Endourological Training Using 3D-Printed Bladder Phantoms: Development and Prospective Evaluation

Background: To create and evaluate a realistic, anatomically accurate, and user-friendly bladder phantom for reproducible endourological training purposes and endoscope mastery. Materials and Methods: The anatomy of full bladders was mapped from human computed tomography datasets. After a 3D model development process, content evidence and response process evidence (RPE) of the phantom were evaluated using the system usability scale (SUS), 5-point Likert scale questionnaires, and task execution of experienced urologists (U) and endoscopy-naive medical students (MS) in two training sessions (first vs second). Required validation cohort sizes (1:10) of the evaluating urologists (n = 12) and students (n = 115) were precalculated. Time measurements were recorded. Students were additionally evaluated by a validated global psychomotor assessment score (GPSS). Group comparisons were calculated by the Mann-Whitney U test. All tests were two sided with p < 0.05 considered statistically significant. Results: Content evidence was assessed by urologists with an "excellent" SUS score of 89.4 ± 5.9 and an average "agreement" of ≥4 pts in the Likert scale questionnaires. RPE was assessed by intra- and intergroup time comparison for the execution of endoscopic tasks (cystoscopy [CY], guidewire insertion, and tumor biopsy). For CY, U: first 17.6 ± 4.4 seconds vs second 12.4 ± 2.0 seconds, p = 0.002; MS: first 56.6 ± 28.2 seconds vs second 28.6 ± 14.7 seconds, p < 0.001; U vs MS: first U 17.6 ± 4.4 seconds vs first MS 56.6 ± 28.2 seconds, p < 0.001, second U 12.4 ± 2.0 seconds vs second MS 28.6 ± 14.7 seconds, p < 0.001. Significant time differences were documented for all tasks and sessions (p < 0.001). Additionally, significant GPSS differences were recorded between the sessions (GPSS: first 20.4 ± 5.1 pts vs second 24.7 ± 4.0 pts, p < 0.001). Conclusions: Our low-fidelity 3D-printed bladder, called BladCap, is an easy-to-assemble, inexpensive, and robust phantom. We present data, which establish construct validity to support use as a clinical training device.

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.

Functional Outcomes after Local Salvage Therapies for Radiation-Recurrent Prostate Cancer Patients: A Systematic Review

PURPOSE

To assess the rate and severity of functional outcomes after salvage therapy for radiation recurrent prostate cancer.

METHODS

This systematic review of the MEDLINE/PubMed database yielded 35 studies, evaluating salvage radical prostatectomy (RP), brachytherapy (BT), high-intensity focal ultrasound (HIFU) and cryotherapy (CT) after failure of primary radiation therapy. Data on pre- and post-salvage rates and severity of functional outcomes (urinary incontinence, erectile dysfunction, and lower urinary tract symptoms) were collected from each study.

RESULTS

The rates of severe urinary incontinence ranged from 28-88%, 4.5-42%, 0-6.5%, 2.4-8% post salvage RP, HIFU, CT and BT, respectively. The rates of erectile dysfunction were relatively high reaching as much as 90%, 94.6%, 100%, 62% following RP, HIFU, CT and BT, respectively. Nonetheless, the high pre-salvage rates of ED preclude accurate estimation of the effect of salvage therapy. There was an increase in the median IPSS following salvage HIFU, BT and CT ranging from 2.5-3.4, 3.5-12, and 2, respectively. Extended follow-up showed a return-to-baseline IPSS in a salvage BT study. The reported data suffer from selection, reporting, publication and period of study biases, making inter-study comparisons inappropriate.

CONCLUSIONS

local salvage therapies for radiation recurrent PCa affect continence, lower urinary tract symptoms and sexual functions. The use of local salvage therapies may be warranted in the setting of local disease control, but each individual decision must be made with the informed patient in a shared decision working process.

Retropulsion force in laser lithotripsy-an in vitro study comparing a Holmium device to a novel pulsed solid-state Thulium laser

PURPOSE

To investigate retropulsion forces generated by two laser lithotripsy devices, a standard Ho:YAG and a new pulsed solid-state Thulium laser device.

MATERIALS AND METHODS

Two different Dornier laser devices were assessed: a Medilas H Solvo 35 and a pulsed solid-state Thulium laser evaluation model (Dornier MedTech Laser GmbH, Wessling, Germany). We used a 37 °C water bath; temperature was monitored with a thermocouple/data-logger. Representative sets of settings were examined for both devices, including short and long pulse lengths where applicable. For each setting, ten force values were recorded by a low-force precision piezo sensor whereby the laser fibre was either brought into contact with the sensor or placed at a 3 mm distance.

RESULTS

The mean retropulsion forces resulting from the new Tm:YAG device were significantly lower than those of the Ho:YAG device under all pulse energy and frequency settings, ranging between 0.92 and 19.60 N for Thulium and 8.09-39.67 N for Holmium. The contact setups yielded lower forces than the distance setups. The forces increased with increasing pulse energy settings while shorter pulse lengths led to 12-44% higher retropulsive force in the 2.0 J/5 Hz comparisons.

CONCLUSION

The Tm:YAG device not only significantly generated lower retropulsion forces in all comparisons to Holmium at corresponding settings but also offers adjustment options to achieve lower energy pulses and longer pulse durations to produce even lower retropulsion. These advantages are a promising add-on to laser lithotripsy procedures and may be highly relevant for improving laser lithotripsy performance.

Gas Bubble Anatomy During Laser Lithotripsy: An Experimental In Vitro Study of a Pulsed Solid-State Tm:YAG and Ho:YAG Device

Purpose: To examine gas bubbles generated by two laser lithotripsy devices, a pulsed thulium solid-state laser and a holmium:yttrium-aluminum-garnet (Ho:YAG) device, and their possible effects in lithotripsy. Materials and Methods: We investigated two Dornier laser devices, a Medilas H Solvo 35 and a pulsed solid-state thulium laser evaluation model (Dornier MedTech Laser GmbH, Wessling, Germany). Our setup consisted of a water-filled glass tank heated to 37/60/70°C. Different laser power/frequency settings and short/long pulses were examined for both laser devices. We analyzed the impact of degraded, cut, and broken fibers on gas bubble anatomy. Furthermore, high-speed recordings of BegoStone ablation were analyzed. For all recordings, we used a Photron Nova S12 camera. Results: These two devices produced differently shaped gas bubbles under different fiber conditions, temperatures, power settings, and short and long pulse settings, which explain the differing repulsive force and pressure values. Inside the gas bubble, a cone was visible whose angle correlates with the protruding jet. We observed turbulences and swirls moving back and forth the fiber tip. During fragmentation, sparks are generated that demonstrate the photothermal effect, and we recorded stone fragments being pulled toward the fiber. Both devices showed comparable results with differences mainly due to pulse lengths. Conclusion: The shapes of the vapor bubbles formed during laser lithotripsy depend on several factors. Excessive transoperative fiber cleavage seems to be unnecessary. Due to the large gas bubbles observed and because of the amount of potential pressure generated, only low energies should be applied in the ureter.

Temperature Assessment of a Novel Pulsed Thulium Solid-State Laser Compared with a Holmium:Yttrium-Aluminum-Garnet Laser

Purpose: To compare a novel Thulium laser device with the commonly used Holmium:Yttrium-Aluminum-Garnet (Ho:YAG) laser in terms of the in vitro temperatures generated. Methods: Our study investigated and compared an evaluation model of a solid-state Thulium laser with a Medilas H Solvo 35 Holmium laser device, both by Dornier (Dornier MedTech Laser GmbH, Wessling, Germany). Our in vitro model consisted of a 20 mL test tube placed in a 37°C water bath. Constant irrigation was set at 50 mL/minute with a Reglo Z Digital pump (Cole Parmer, Chicago, IL). Four hundred micrometers of Dornier laser fibers were used. The temperature was measured with a type K thermocouple and a real-time data logger from Pico (PICO Technology, Cambridgeshire, United Kingdom). Power settings between 2 and 30 W were investigated. Each measurement lasted 120 seconds and was repeated five times. The data were evaluated by MATLAB^® (The Mathworks, Inc., Natick, MA). Results: The resulting temperatures were directly proportional to the power supplied. When comparing Holmium with Thulium, we observed maximum deviations of ≤0.82 K in temperatures at 120 seconds. The highest investigated laser power of 30 W yielded maximum temperatures differing by 6.7 K from the initial value. Out of the five comparisons, Thulium showed marginally yet significantly lower end temperatures in four cases and slightly lower cumulative equivalent minutes at 43°C (CEM₄₃) values in three cases. Conclusion: The Thulium laser resembles the Holmium device in the temperatures generated during in vitro application. An increase in laser power, thus, leads to equivalent increases in temperature that are largely independent of frequency, pulse duration, and single pulse energy. Pulsed Thulium:Yttrium-Aluminum-Garnet (Tm:YAG), Ho:YAG, and Thulium fiber laser seem to share a similar risk profile for patients in terms of temperature development. Intrarenal power outputs exceeding 10 W during clinical application should be compensated by ensuring sufficient irrigation.

Laser procedures in the treatment of BPH: a bibliometric study

Purpose

To perform a bibliometric analysis of lased-based BPH treatment publications and to obtain an understanding of the publication trends over time.

Materials and methods

The Medline database was searched for articles in English language regarding laser-based BPH therapy up to 2018. Matching articles were assigned to at least one of the following categories: Ho:YAG, Tm:YAG, green light, diode, Nd:YAG laser and review articles. The laser categories were analysed using bibliometric procedures regarding citation rate, authors, country of origin and journal of publication. Moreover, the articles on laser BPH therapy included in the EAU, AUA and JUA guidelines were analysed to evaluate the most influential articles.

Results

In total, 982 articles were included: 317 articles were assigned to green light, 283 to Ho:YAG, 101 to Tm:YAG, 74 to Nd:YAG and 39 to diode lasers. The publication rate for Nd:YAG laser has declined, but continues to grow for Ho:YAG and Tm:YAG lasers. We found a positive correlation between number of authors and year of publication (R = 0.3, p < 0.001*). Articles on Ho:YAG lasers are cited the most (mean 23.0 ± 37.1). Asia has contributed the most articles. Mostly, countries with high health and research and development (R&D) expenditures influenced the guidelines regarding laser-based approaches. Yet, after adjustment of all search results to GDP, health and R&D expenditure, India and China were the most prolific countries.

Conclusion

Laser-based approaches for BPH treatment are increasing but have not been implemented worldwide. Asia’s contribution should be acknowledged. An inflationary trend regarding the number of authors per article is confirmed.

Therapy-Refractory Matrix Staghorn in a Kidney Transplant Recipient: Endoscopic Percutaneous Morcellation as a Novel Treatment Option

Background: Urolithiasis of transplant kidneys usually encompasses a challenging clinical situation due to specific anatomical conditions and the patients' immunological status. In this case report, we describe the treatment of a rare Proteus mirabilis matrix staghorn stone applying percutaneous nephrolithotomy in combination with matrix stone extraction by morcellation while utilizing endo-urological equipment designed for transurethral prostate surgery. Case Presentation: We present the case of a 44-year-old Caucasian woman who had undergone a post-mortal kidney transplant at age 37. After recurrent urinary tract infections, symptomatic obstructions of the transplant ureter, and multiple surgical interventions (73 Double-J stent and nephrostomy placements and three ureter re-implantations), permanent percutaneous nephrostomy drainage was established 6 years after her kidney transplantation. The patient was referred to our department due to recurrent dysfunction of the nephrostomy tube caused by blockage due to stone-matrix material and a staghorn calculus in the transplant kidney's collecting system. Microbiological examination of the stone material retrieved from the nephrostomy tube revealed massive P. mirabilis contamination. In this work, we present a novel percutaneous technique of matrix stone removal by relying on endoscopic equipment usually employed during prostate surgery by urologists. Conclusion: Percutaneous matrix stone morcellation is a technically challenging but feasible method that might be considered as a salvage treatment strategy in situations described earlier and in highly selective cases. However, for this extremely rare stone entity and individual clinical presentations, matrix stone morcellation seems to be a reasonable alternative before considering more radical interventions such as open nephrolithotomy. Selection criteria are a very soft stone, large-caliber percutaneous access to the collecting system, and enough space in the collecting system to execute morcellation.

Application of artificial neural networks for automated analysis of cystoscopic images: a review of the current status and future prospects

BACKGROUND

Optimal detection and surveillance of bladder cancer (BCa) rely primarily on the cystoscopic visualization of bladder lesions. AI-assisted cystoscopy may improve image recognition and accelerate data acquisition.

OBJECTIVE

To provide a comprehensive review of machine learning (ML), deep learning (DL) and convolutional neural network (CNN) applications in cystoscopic image recognition.

EVIDENCE ACQUISITION

A detailed search of original articles was performed using the PubMed-MEDLINE database to identify recent English literature relevant to ML, DL and CNN applications in cystoscopic image recognition.

EVIDENCE SYNTHESIS

In total, two articles and one conference abstract were identified addressing the application of AI methods in cystoscopic image recognition. These investigations showed accuracies exceeding 90% for tumor detection; however, future work is necessary to incorporate these methods into AI-aided cystoscopy and compared to other tumor visualization tools. Furthermore, we present results from the RaVeNNA-4pi consortium initiative which has extracted 4200 frames from 62 videos, analyzed them with the U-Net network and achieved an average dice score of 0.67. Improvements in its precision can be achieved by augmenting the video/frame database.

CONCLUSION

AI-aided cystoscopy has the potential to outperform urologists at recognizing and classifying bladder lesions. To ensure their real-life implementation, however, these algorithms require external validation to generalize their results across other data sets.

Automatic speech recognition in the operating room - An essential contemporary tool or a redundant gadget? A survey evaluation among physicians in form of a qualitative study

Introduction

For decades, automatic speech recognition (ASR) has been the subject of research and its range of applications broadened. Presently, ASR among physicians is mainly used to convert speech into text but not to implement instructions in the operating room (OR). This study aimed to evaluate physicians of different surgical professions on their personal experience and posture towards ASR.

Methods

A 16-item survey was distributed electronically to hospitals and outpatient clinics in southern Germany addressing physicians on the potential applications of ASR in the OR.

Results

The survey was responded by 185 of 2693 physicians (response rate: 6.9%) with a mean age of 41.8 ± 9.8 years. ASR is desirable in the OR regardless of the field of speciality (93.7%). While only 2.7% have used ASR, 87.9% evaluate its future potential as high. 91.0% of those working in a university hospital would consider testing ASR, while 67.5% of those in non-university hospitals and practices (p = 0.001). 90.1% of responders of strictly surgical specialities see potential in ASR while 73.7% in non-surgical specialities evaluate its future potential as high (p = 0.01). 58.3% of those over the age of 60 consider the use of ASR without a headset to be imaginable, while 96.3% among those under the age of 60. There were no statistically significant differences regarding sex and professional position.

Conclusion

Foreseeably, ASR is anticipated to be integrated into ORs and valued at a high market potential. Our study provides information about physicians’ individual preferences from various surgical disciplines regarding ASR.

•

ASR is a desirable tool in the OR regardless of the field of speciality.

•

While 90.1% interviewees from surgical specialities see potential in ASR and 73.7% from non-surgical specialities assess its future potential as high.

•

There were no statistically significant differences regarding sex and professional position.

•

For an ASR system to be implemented in the OR, it needs to be sophisticated and updatable since there are still several technical requirements to be fulfilled.

•

Foreseeably, ASR is anticipated to be integrated into the OR and valued at a high market potential.

In Vitro Dusting Performance of a New Solid State Thulium Laser Compared to Holmium Laser Lithotripsy

Purpose: To examine the dusting performance of a novel solid state Thulium laser device compared to a standard holmium:yttrium-aluminum-garnet (Ho:YAG) device. Methods: This study compares a Dornier Medilas H Solvo 35 with an evaluation model of a pulsed solid state thulium:yttrium-aluminum-garnet (Tm:YAG) laser (Dornier MedTech Laser GmbH, Wessling, Germany). The in vitro model consisted of a mold with irrigated water at 37°C. For 2-9 minutes, laser fibers were guided by an xy-plotter in spirals over BegoStones. Stone mass was measured before and after laser application. Comparisons to Ho:YAG and further Tm:YAG investigations were performed. Results: Identical settings with similar pulse durations yielded a significant 14% advantage for Ho:YAG in slow fiber speeds and a tendency toward 15% higher efficiency of Tm:YAG in fast fiber speeds. Increased pulse duration in Tm:YAG led significantly to 32%-54% higher ablation rates in comparison to Tm:YAG in both setups. Ablated mass loss range is 102-1107 mg for slow fiber speeds and 22-528 mg for fast speeds. Mass loss is proportional to pulse energy, frequency, and pulse duration, whereas pulse energy defines the penetration depth into the model stones. Frequency characterizes the ablation homogeneity and possible working speeds. Conclusion: Tm:YAG is significantly more efficient when longer pulse durations are used. Identical settings revealed a strong connection to fiber movement speeds. In addition, the Tm:YAG device enables a broader range of settings with the possibility of minimal pulse energy of 100 mJ for low retropulsion and fine dusting with possible frequencies ≤200 Hz.

First results of computer-enhanced optical diagnosis of bladder cancer

Bladder cancer is the sixth leading cancer cause worldwide. Non-muscle invasive tumors can be diagnosed and treated endoscopically. Based on biopsies alone, pathologists cannot determine the spatial organization of specimens, their relationship with each other, or their complete removal. To extend white light cystoscopy as the gold standard for bladder cancer detection, diagnosis and removal of small or flat lesions, new image-based technologies have been investigated. These include a stereo-cystoscope for improved orientation and navigation, computation of 2D and 3D panoramic images for extended visualization and documentation, as well as label-free fiber-based fluorescence-lifetime imaging (FLIM) and Raman-spectroscopy in combination with statistical data analysis. Combining all these technologies, cystoscopy can will be further enhanced to include new diagnostic possibilities.

Preclinical and Clinical Evaluation of a Novel, Variable-View, Rigid Endoscope for Female Cystoscopy

OBJECTIVE

To evaluate the preclinical and clinical performance of the pivoting lens rigid Endocameleon (ECAM) endoscope in white light cystoscopy (WLC).

MATERIALS AND METHODS

Preclinical evaluation was performed ex vivo in CT-based, anatomically accurate and validated bladder phantoms. Six defined tasks with objective endpoints were compared between ECAM-WLC and rigid WLC (30° view angle, rWLC) in 30 interventions. Subsequently, the comparison was transferred to in vivo n = 21 interventions. A validated usability score (System Usability Scale, SUS) as well as physician and patient-related outcomes were assessed using Likert-scale-based questionnaires. Intra- and postinterventional complications were recorded according to the Clavien-Dindo classification.

RESULTS

The ex vivo evaluation showed a significant superiority of ECAM-WLC in 4 of 6 endoscopic tasks. Noteworthy is the lower pressure on the bladder neck due to the endoscopesalteration of the endoscope (4/60 vs 17/60, P <.0001) and a more precise imaging of all bladder regions (22/30 vs 30/30, P = .046), including the anterior wall (0/30 vs 28/30, P <.0001). In vivo, surgeons rated the ECAM-WLC with an "excellent" SUS of 86.79%, also expressing that ECAM-WLC would enhance bladder surface visualization (4.52/5.0 ± 0.51), with a preferred use for ECAM-WLC during their next cystoscopy (4.62 ± 0.50). Patients reported ECAM-WLC to be less painful (4.5/5.0 ± 0.84) compared to rWLC. No intervention-related complications were observed.

CONCLUSION

ECAM-WLC is a safe and accessible procedure that could improve conventional diagnostic WLC by combination of the advantages of fWLC and rWLC.

Use of Artificial Intelligence for Medical Literature Search: Randomized Controlled Trial Using the Hackathon Format

Background

Mapping out the research landscape around a project is often time consuming and difficult.

Objective

This study evaluates a commercial artificial intelligence (AI) search engine (IRIS.AI) for its applicability in an automated literature search on a specific medical topic.

Methods

To evaluate the AI search engine in a standardized manner, the concept of a science hackathon was applied. Three groups of researchers were tasked with performing a literature search on a clearly defined scientific project. All participants had a high level of expertise for this specific field of research. Two groups were given access to the AI search engine IRIS.AI. All groups were given the same amount of time for their search and were instructed to document their results. Search results were summarized and ranked according to a predetermined scoring system.

Results

The final scoring awarded 49 and 39 points out of 60 to AI groups 1 and 2, respectively, and the control group received 46 points. A total of 20 scientific studies with high relevance were identified, and 5 highly relevant studies (“spot on”) were reported by each group.

Conclusions

AI technology is a promising approach to facilitate literature searches and the management of medical libraries. In this study, however, the application of AI technology lead to a more focused literature search without a significant improvement in the number of results.

Current Standards in the Endoscopic Management of Bladder Cancer: A Survey Evaluation among Urologists in German-Speaking Countries

INTRODUCTION

To assess the current diagnostic, treatment, and documentation strategies for bladder cancer (BC) in German-speaking countries.

MATERIALS AND METHODS

A 14-item web-based survey was distributed among members of the German, Austrian, and Swiss Associations of Urology, addressing physicians who perform cystoscopies and transurethral resection of bladder tumors (TURB).

RESULTS

The survey was responded to by 308 of 5,564 urologists with a mean age of 49.5 years (response rate: 5.5%). The majority of participants (57.3%) practice in an outpatient setting. White light cystoscopy only is used by 60.2%, with additional photodynamic diagnosis and narrow band imaging by 36.8 and 12.5%, respectively. Endoscopic findings are documented in written form by 93.5%, followed by image capture (33.7%) and a central data archive (20.8%). Inpatient hospital urologists document cystoscopic findings by freehand drawing (21.4 vs. 11.4%, p = 0.017), and with a fixed bladder scheme (31.3 vs. 7.4%, <0.05) significantly more frequently. Cystoscopic findings are mainly conveyed to other health professionals in written form (77.4%), and significantly more often by inpatient urologists (p < 0.05).

CONCLUSIONS

Significant differences exist in the approach to documenting and communicating cystoscopic BC findings. Accurate graphic documentation of lesions, visualization of the mucosa's totality, and meticulous consultation of previous surgical reports require improvements to reduce recurrence and progression rates.

Adherence to European Association of Urology and National Comprehensive Cancer Network Guidelines Criteria for Inguinal and Pelvic Lymph Node Dissection in Penile Cancer Patients-A Survey Assessment in German-speaking Countries on Behalf of the European Prospective Penile Cancer Study Group

BACKGROUND

Urologists' adherence to European Association of Urology and National Comprehensive Cancer Network guideline recommendations to perform inguinal (ILND) and pelvic (PLND) lymph node dissection in penile cancer (PC) patients is not known.

OBJECTIVE

To assess a German-speaking European cohort of urologists based on their criteria to perform ILND and PLND in PC patients.

DESIGN, SETTING, AND PARTICIPANTS

A 14-item survey addressing general issues of PC treatment was developed and sent to 45 clinical centers in Germany (n = 34), Austria (n = 8), Switzerland (n = 2), and Italy (n = 1).

INTERVENTION

Two of the 14 questions assessed the criteria to perform ILND and ipsilateral PLND.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Correct responses for ILND and PLND criteria were assessed. Based on a multivariate logistic-regression-model, criteria independently predicting guideline adherence were identified.

RESULTS AND LIMITATIONS

In total, 557 urologists participated in the survey, of whom 43.5%, 19.3%, and 37.2% were residents in training, certified, and in leading positions, respectively. ILND and PLND criteria were correctly identified by 35.2% and 23.9%, respectively. Of the participants, 23.3% used external sources for survey completion. The use of auxiliary tools (odds ratio [OR] 1.57; p[_bootstrapped] = 0.028) and participants outside of Germany (OR 0.56; p[_bootstrapped] = 0.006) were predictors of ILND guideline adherence. The number of PC patients treated yearly (p = 0.012; OR 1.06) and the use of auxiliary tools (p < 0.001; OR 5.88) were predictors of PLND adherence. Department size, healthcare status, professional status, and responsibility for PC surgery did not predict endpoints. Limitations include sample size and results in comparison with retrospective studies.

CONCLUSIONS

Our results demonstrate overall suboptimal knowledge of the correct indications to perform ILND and PLND in PC patients among the surveyed urologists. We propose that governments and healthcare providers should be encouraged to centralize PC management.

PATIENT SUMMARY

The management of inguinal and pelvic lymph nodes is crucial for the survival of penile cancer patients. Disease rarity mandates referral to clinical practice guidelines for appropriate treatment selection.

Soft Phantom for the Training of Renal Calculi Diagnostics and Lithotripsy

Organ models are important for medical training and surgical planning. With the fast development of additive fabrication technologies, including 3D printing, the fabrication of 3D organ phantoms with precise anatomical features becomes possible. Here, we develop the first high-resolution kidney phantom based on soft material assembly, by combining 3D printing and polymer molding techniques. The phantom exhibits both the detailed anatomy of a human kidney and the elasticity of soft tissues. The phantom assembly can be separated into two parts on the coronal plane, thus large renal calculi are readily placed at any desired location of the calyx. With our sealing method, the assembled phantom withstands a hydraulic pressure that is four times the normal intrarenal pressure, thus it allows the simulation of medical procedures under realistic pressure conditions. The medical diagnostics of the renal calculi is performed by multiple imaging modalities, including X-ray, ultrasound imaging and endoscopy. The endoscopic lithotripsy is also successfully performed on the phantom. The use of a multifunctional soft phantom assembly thus shows great promise for the simulation of minimally invasive medical procedures under realistic conditions.

Development of a prognostic model for survival time prediction in castration-resistant prostate cancer patients

BACKGROUND

To identify predictors of survival in patients treated with docetaxel chemotherapy for castration-resistant prostate cancer (CRPC).

METHODS

We retrospectively analyzed clinical data from 186 patients who underwent docetaxel chemotherapy for CRPC from 2005 to 2016 at a single center. Pretreatment baseline variables including demographic and clinicopathological data were reviewed. Disease progression was defined by imaging and/or consecutive prostate-specific antigen (PSA) elevation. The systemic immune-inflammation index (SII), the modified Glasgow Prognostic Score (mGPS), and the neutrophil-lymphocyte ratio (NLR) were calculated. Univariable and multivariable Cox proportional hazards regression analyses reporting hazard ratios assessed the risk for disease progression and overall survival (OS). A survival nomogram was constructed.

RESULTS

Most patients (n = 139, 74.7%) completed at least 6 cycles of docetaxel chemotherapy. 156 patients (82.9%) experienced disease progression during the studied period. Only mGPS was independently associated with disease progression in a multivariable model (P < 0.01). During the studied period, 98 patients (52.1%) died. The built survival nomogram included statistically significant variables for OS in univariable analysis: hemoglobin, PSA, alkaline phosphatase (AP), lactate dehydrogenase, SII, neutrophil-lymphocyte ratio, mGPS, and site of metastases; and had a concordance index of 0.703. At decision curve analysis, the nomogram led to superior outcomes for any decision associated with a threshold probability of above 40%. In multivariable analysis, only AP (P = 0.02), hemoglobin and PSA (P < 0.01, respectively) remained associated with OS.

CONCLUSIONS

PSA, AP, and hemoglobin are independent prognosticators for OS. Although mGPS is a promising marker for tumor progression and SII is a plausible prognostic marker for OS, valid integration of inflammatory indices into a prognostic model requires validation studies. Predictive and prognostic biomarkers are desperately needed to guide physicians in treatment counseling given the heterogeneous nature of CRPC and the plethora of effective therapies.

Assessment of body composition in the advanced stage of castration-resistant prostate cancer: special focus on sarcopenia

PURPOSE

To assess the prevalence of sarcopenia and whether body composition parameters are associated with disease progression and overall survival (OS) in castration-resistant prostate cancer (CRPC) patients.

MATERIALS AND METHODS

This single-centre retrospective study evaluated data of 186 consecutive patients who underwent chemohormonal therapy between 2005 and 2016 as first-line systemic treatment for CRPC. Skeletal muscle and fat indices were determined using computerized tomography data before initiation of chemotherapy. Sarcopenia was defined as SMI of <55 cm²/m². Visceral-to-subcutaneous fat ratio and skeletal muscle volume were calculated with body composition specific areas. Harrell's concordance index was used for predictive accuracy.

RESULTS

A total of 154 (82.8%) patients met the criteria for sarcopenia; 139 (74.7%) individuals completed at least six cycles of docetaxel. Within a median follow-up of 24.1 months, age (HR 1.03, 95% CI 1.01-1.06, p = 0.02), high PSA (1.55, 95% CI 1.07-2.25, p = 0.02) and low skeletal muscle volume (HR 1.61, 95% CI 1.10-2.35, p = 0.02) were the only independent prognostic factor for tumor progression. Overall, 93 (50%) patients died during the follow-up period. The established prognosticator, the prechemotherapy presence of liver metastases (HR 1.32, 95% CI 1.08-1.61, p < 0.01) was associated with shorter OS. Moreover, we noted that patients with an elevated visceral-to-subcutaneous fat ratio tended to have a shorter OS (p = 0.06).

CONCLUSION

The large majority of men with CRPC suffers from sarcopenia. In our cohort, low skeletal muscle volume was an independent adverse prognosticator for progression of disease. We could not detect a statistically significant body composition parameter for OS, although patients with a high proportion of visceral fat had a trend for shorter OS. However, we suggest that body composition parameters determined by CT data can provide useful objective prognostic factors that may support tailored treatment decision-making.

Current and future applications of machine and deep learning in urology: a review of the literature on urolithiasis, renal cell carcinoma, and bladder and prostate cancer

PURPOSE

The purpose of the study was to provide a comprehensive review of recent machine learning (ML) and deep learning (DL) applications in urological practice. Numerous studies have reported their use in the medical care of various urological disorders; however, no critical analysis has been made to date.

METHODS

A detailed search of original articles was performed using the PubMed MEDLINE database to identify recent English literature relevant to ML and DL applications in the fields of urolithiasis, renal cell carcinoma (RCC), bladder cancer (BCa), and prostate cancer (PCa).

RESULTS

In total, 43 articles were included addressing these four subfields. The most common ML and DL application in urolithiasis is in the prediction of endourologic surgical outcomes. The main area of research involving ML and DL in RCC concerns the differentiation between benign and malignant small renal masses, Fuhrman nuclear grade prediction, and gene expression-based molecular signatures. BCa studies employ radiomics and texture feature analysis for the distinction between low- and high-grade tumors, address accurate image-based cytology, and use algorithms to predict treatment response, tumor recurrence, and patient survival. PCa studies aim at developing algorithms for Gleason score prediction, MRI computer-aided diagnosis, and surgical outcomes and biochemical recurrence prediction. Studies consistently found the superiority of these methods over traditional statistical methods.

CONCLUSIONS

The continuous incorporation of clinical data, further ML and DL algorithm retraining, and generalizability of models will augment the prediction accuracy and enhance individualized medicine.