Safety and quality of cystectomy and pelvic lymph node dissection after neoadjuvant durvalumab and cisplatin/gemcitabine.

OBJECTIVE: To report on the surgical safety and quality of pelvic lymph node dissection (PLND) in patients treated with radical cystectomy (RC) and PLND for muscle-invasive bladder cancer (MIBC) after neoadjuvant chemo-immunotherapy. PATIENTS AND METHODS: The Swiss Group for Clinical Cancer Research (SAKK) 06/17 was an open-label single-arm phase II trial including 61 cisplatin-fit patients with clinical stage (c)T2-T4a cN0-1 operable urothelial MIBC or upper urinary tract cancer. Patients received neoadjuvant cisplatin/gemcitabine and durvalumab followed by surgery. Prospective quality assessment of surgeries was performed via central review of intraoperative photographs. Postoperative complications were assessed using the Clavien-Dindo Classification. Data were analysed descriptively. RESULTS: A total of 50 patients received RC and PLND. All patients received neoadjuvant chemo-immunotherapy. The median (interquartile range) number of lymph nodes removed was 29 (23-38). No intraoperative complications were registered. Grade ≥III postoperative complications were reported in 12 patients (24%). Complete nodal dissection (100%) was performed at the level of the obturator fossa (bilaterally) and of the left external iliac region; in 49 patients (98%) at the internal iliac region and at the right external iliac region; in 39 (78%) and 38 (76%) patients at the right and left presacral level, respectively. CONCLUSION: This study supports the surgical safety of RC and PLND following neoadjuvant chemo-immunotherapy in patients with MIBC. The extent and completeness of protocol-defined PLND varies between patients, highlighting the need to communicate and monitor the surgical template.

The learning curve for robotic-assisted transperineal MRI/US fusion-guided prostate biopsy.

Transperineal fusion prostate biopsy has a considerable learning curve (LC). Robotic-assisted transperineal MRI/Ultrasound fusion-guided biopsy (RA-TP-FBx) may have an easier LC due to automatization. We aimed to assess the LC of RA-TP-FBx and analyze its most difficult steps. We prospectively analyzed cases randomized to a biopsy-naïve urology resident, the chief resident, and an expert urologist in RA-TP-FBx (controls). We also analyzed consecutive cases in the LC of the expert. The LC was defined by procedure time, PCa detection rate (including stratification by PI-RADS), entrustable professional activities (EPA) assessment scores, and the NASA task load index. We collectively performed 246 RA-TP-FBx with the Mona Lisa device. Procedure time for residents decreased steeply from maximum 53 min to minimum 10 min, while the mean procedure time for the expert was 9 min (range 17-5 min). PCa detection for PI-RADS-4 lesions was 57% for the naïve resident, 61% for the chief resident and 62% for the expert. There was also no difference in Pca detection for PI-RADS-4 lesions when comparing the first and second half of the experts' biopsies (p = 0.8). Maximum EPA score was registered after 22 cases. Workload steeply declined. Proficient RA-TP-FBx performance appears feasible after 22 cases regardless of previous experience.

Opportunistic Prostate Cancer Screening with Biparametric Magnetic Resonance Imaging (VISIONING).

BACKGROUND: This study investigates the use of biparametric magnetic resonance imaging (bpMRI) as primary opportunistic screening for prostate cancer (PCa) without using a prostate-specific antigen (PSA) cut-off. OBJECTIVE: The primary endpoint was to assess the efforts and effectiveness of identifying 20 participants with clinically significant prostate cancer (csPCa) using bpMRI. DESIGN, SETTING, AND PARTICIPANTS: Biopsy-naïve men aged over 45 yr were included. All participants underwent 3 Tesla bpMRI, PSA, and digital rectal examination (DRE). Targeted-only biopsy was performed in participants with Prostate Imaging Reporting and Data System (PI-RADS) ≥3. Men with negative bpMRI but suspicious DRE or elevated PSA/PSA density had template biopsies. Preintended protocol adjustments were made after an interim analysis for PI-RADS 3 lesions: no biopsy and follow-up MRI after 6 mo and biopsy only if lesions persisted or upgraded. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Biopsy results underwent a comparison using Fisher's exact test and univariable logistic regression to identify prognostic factors for positive biopsy. RESULTS AND LIMITATIONS: A total of 229 men were enrolled in this study, of whom 79 underwent biopsy. Among these men, 77 displayed suspicious PI-RADS lesions. PCa was detected in 29 participants (12.7%), of whom 21 had csPCa (9.2%). Biparametric MRI detected 21 csPCa cases, while PSA and DRE would have missed 38.1%. Protocol adjustment led to a 54.6% biopsy reduction in PI-RADS 3 lesions. Overall, in this cohort of men with a median PSA value of 1.26 ng/ml, 10.9 bpMRI scans were needed to identify one participant with csPCa. A major limitation of the study is the lack of a control cohort undergoing systematic biopsies. CONCLUSIONS: Opportunistic screening utilising bpMRI as a primary tool has higher sensitivity in detecting csPCa than classical screening methods. PATIENT SUMMARY: Screening with biparametric magnetic resonance imaging (bpMRI) and targeted biopsy identified clinically significant prostate cancer in every 11th man, regardless of the prostate-specific antigen (PSA) levels. Preselecting patients based on PSA >1 ng/ml and a positive family history of prostate cancer, as well as other potential blood tests may further improve the effectiveness of bpMRI in this setting.

The Efficacy and Safety of Intrasphincteric Botulinum Toxin-A Injections in Patients with Non-Spinal Cord Injury-Related Detrusor Sphincter Dyssynergia: A Retrospective Study.

Botulinum toxin-A (BoNT-A) injections into the external urethral sphincter are an established therapeutic procedure for reducing bladder outlet obstruction in patients with detrusor sphincter dyssynergia (DSD) due to spinal cord injury (SCI). Given the paucity of data on patients with DSD but without SCI, we aimed to assess the efficacy of intrasphincteric BoNT-A injections in this cohort. For this retrospective study, we screened all patients who underwent their first intrasphincteric BoNT-A injection at our institution between 2015 and 2021. The inclusion criteria were patients aged 18 years or older with neurogenic detrusor overactivity (NDO) and DSD with a maximum detrusor pressure (Pdetmax) of >40 cmH2O, confirmed via video-urodynamic studies (VUDS). The primary outcome was a reduction in Pdetmax and detrusor overactivity leak point pressure (DOLPP) during NDO-associated urinary incontinence posttreatment. The secondary outcome was a reduction in patients relying on indwelling urinary catheters posttreatment. We included 13 eligible patients (all male, median age 31 years, with different underlying neurological disorders, except SCI). All underwent intrasphincteric BoNT-A injections with either 100 (n = 7) or 150 (n = 6) units, respectively. Pdetmax during voiding was significantly reduced posttreatment (median 105 vs. 54 cmH2O, p = 0.006), whereas DOLPP remained unchanged (i.e., median 50 cmH2O). While seven patients relied on indwelling urinary catheters pre-treatment, all were catheter-free posttreatment. Intrasphincteric BoNT-A injections in patients with non-SCI related DSD appear feasible for reducing bladder outlet obstruction to a certain degree in this cohort and subsequently for reducing the rate of indwelling catheters.

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.

Prevalence of Unfavorable Video-Urodynamic Findings and Clinical Implications in Patients with Minimally Conscious State/Unresponsive Wakefulness Syndrome: A Retrospective Descriptive Analysis.

The aim of this retrospective exploratory study was to investigate the prevalence of unfavorable findings during video-urodynamic studies (VUDS) in patients with minimally conscious state (MCS)/unresponsive wakefulness syndrome (UWS) and whether management of the lower urinary tract (LUT) was adjusted accordingly. A retrospective chart review was conducted to screen for patients diagnosed with MCS/UWS at our rehabilitation center between 2011 and 2020. Patients 18 years or older were included and underwent baseline VUDS after being diagnosed with MCS/UWS. We analyzed urodynamic parameters and subsequent changes in LUT management in this cohort. In total, 32 patients (7 females, 25 males, median age 37 years) with MCS/UWS were included for analysis. While at least one unfavorable VUDS finding (i.e., neurogenic detrusor overactivity [NDO], detrusor sphincter dyssynergia {DSD, high maximum detrusor pressure during storage phase [>40 cmH2O], low-compliance bladder [<20 mL/cmH2O], and vesico-uretero-renal reflux [VUR]) was found in each patient, NDO (78.1%, 25/32) and DSD (68.8%, 22/32) were the two most frequent unfavorable VUDS findings. Following baseline VUDS, new LUT treatment options were established in 56.3% (18/32) of all patients. In addition, bladder-emptying methods were changed in 46.9% (15/32) of all patients, resulting in fewer patients relying on indwelling catheters. Our retrospective exploratory study revealed a high prevalence of NDO and DSD in patients with MCS/UWS, illustrating the importance of VUDS to adapt LUT management in this cohort accordingly.

Initial experience with AI Pathway Companion: Evaluation of dashboard-enhanced clinical decision making in prostate cancer screening.

PURPOSE: Rising complexity of patients and the consideration of heterogeneous information from various IT systems challenge the decision-making process of urological oncologists. Siemens AI Pathway Companion is a decision support tool that provides physicians with comprehensive patient information from various systems. In the present study, we examined the impact of providing organized patient information in comprehensive dashboards on information quality, effectiveness, and satisfaction of physicians in the clinical decision-making process. METHODS: Ten urologists in our department performed the entire diagnostic workup to treatment decision for 10 patients in the prostate cancer screening setting. Expenditure of time, information quality, and user satisfaction during the decision-making process with AI Pathway Companion were recorded and compared to the current workflow. RESULTS: A significant reduction in the physician's expenditure of time for the decision-making process by -59.9% (p < 0,001) was found using the software. System usage showed a high positive effect on evaluated information quality parameters completeness (Cohen's d of 2.36), format (6.15), understandability (2.64), as well as user satisfaction (4.94). CONCLUSION: The software demonstrated that comprehensive organization of information improves physician's effectiveness and satisfaction in the clinical decision-making process. Further development is needed to map more complex patient pathways, such as the follow-up treatment of prostate cancer.

Somatic Features of Response and Relapse in Non-muscle-invasive Bladder Cancer Treated with Bacillus Calmette-Guérin Immunotherapy.

BACKGROUND: High-risk non-muscle-invasive bladder cancer (NMIBC) is treated with bacillus Calmette-Guérin (BCG), but relapse is common. Improvement of patient outcomes requires better understanding of links between BCG resistance and genomic driver alterations. OBJECTIVE: To validate the prognostic impact of common genomic alterations in NMIBC pretreatment and define somatic changes present in post-BCG relapses. DESIGN, SETTING, AND PARTICIPANTS: We retrieved tumour tissues and outcomes for 90 patients with BCG-naive NMIBC initiating BCG monotherapy. Post-BCG tissue was available from 34 patients. All tissues underwent targeted sequencing of tumour and matched normal. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Associations between clinical outcomes and genomics were determined using Cox proportional hazard models. RESULTS AND LIMITATIONS: Of the patients, 58% were relapse free at data cut-off, 24% had NMIBC recurrence, and 18% experienced muscle-invasive progression. The risk of relapse was associated with ARID1A mutation (hazard ratio [HR] = 2.00; p = 0.04) and CCNE1 amplification (HR = 2.61; p = 0.02). Pre- and post-BCG tumours shared truncal driver alterations, with mutations in TERT and chromatin remodelling genes particularly conserved. However, shifts in somatic profiles were common and clinically relevant alterations in FGFR3, PIK3CA, TSC1, and TP53 were temporally variable, despite apparent clonal prevalence at one time point. Limitations include the difficulty of resolving the relative impact of BCG therapy versus surgery on genomics at relapse and biopsy bias. CONCLUSIONS: Somatic hypermutation and alterations in CCNE1 and ARID1A should be incorporated into future models predicting NMIBC BCG outcomes. Changes in tumour genomics over time highlight the importance of recent biopsy when considering targeted therapies, and suggest that relapse after BCG is due to persisting and evolving precursor populations. PATIENT SUMMARY: Changes in key cancer genes can predict bladder cancer relapse after treatment with bacillus Calmette-Guérin. Relapses after treatment can be driven by large-scale genetic changes within the cancer. These genetic changes help us understand how superficial bladder cancer can progress to be treatment resistant.

Toward a Platform for Structured Data Acquisition in Oncology: A Pilot Study on Prostate Cancer Screening.

INTRODUCTION: Physicians spend an ever-rising amount of time to collect relevant information from highly variable medical reports and integrate them into the patient's health condition. OBJECTIVES: We compared synoptic reporting based on data elements to narrative reporting in order to evaluate its capabilities to collect and integrate clinical information. METHODS: We developed a novel system to align medical reporting to data integration requirements and tested it in prostate cancer screening. We compared expenditure of time, data quality, and user satisfaction for data acquisition, integration, and evaluation. RESULTS: In a total of 26 sessions, 2 urologists, 2 radiologists, and 2 pathologists conducted the diagnostic work-up for prostate cancer screening with both narrative reporting and the novel system. The novel system led to a significantly reduced time for collection and integration of patient information (91%, p < 0.001), reporting in radiology (44%, p < 0.001) and pathology (33%, p = 0.154). The system usage showed a high positive effect on evaluated data quality parameters completeness, format, understandability, as well as user satisfaction. CONCLUSION: This study provides evidence that synoptic reporting based on data elements is effectively reducing time for collection and integration of patient information. Further research is needed to assess the system's impact for different patient journeys.

Prostate cancer patient-derived organoids: detailed outcome from a prospective cohort of 81 clinical specimens.

Patient-derived organoids (PDOs) represent promising preclinical models in various tumor types. In the context of prostate cancer (PCa), however, their establishment has been hampered by poor success rates, which impedes their broad use for translational research applications. Along with the necessity to improve culture conditions, there is a need to identify factors influencing outcomes and to determine how to assess success versus failure in organoid generation. In the present study, we report our unbiased efforts to generate PDOs from a cohort of 81 PCa specimens with diverse pathological and clinical features. We comprehensively analyzed histological features of each enrolled sample (Gleason score, tumor content, proliferation index) and correlated them with organoid growth patterns. We identified improved culture conditions favoring the generation of PCa organoids, yet no specific intrinsic tumor feature was broadly associated with sustained organoid growth. In addition, we performed phenotypic and molecular characterization of tumor-organoid pairs using immunohistochemistry, immunofluorescence, fluorescence in situ hybridization, and targeted sequencing. Morphological and immunohistochemical profiles of whole organoids altogether provided a fast readout to identify the most promising ones. Notably, primary samples were associated with an initial take-rate of 83% (n = 60/72) in culture, with maintenance of cancer cells displaying common PCa alterations, such as PTEN loss and ERG overexpression. These cancer organoids were, however, progressively overgrown by organoids with a benign-like phenotype. Finally, out of nine metastasis samples, we generated a novel organoid model derived from a hormone-naïve lung metastasis, which displays alterations in the PI3K/Akt and Wnt/ß-catenin pathways and responds to androgen deprivation. Taken together, our comprehensive study explores determinants of outcome and highlights the opportunities and challenges associated with the establishment of stable tumor organoid lines derived from PCa patients. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Revisiting DCE-MRI: Classification of Prostate Tissue Using Descriptive Signal Enhancement Features Derived From DCE-MRI Acquisition With High Spatiotemporal Resolution.

METHODS: A retrospective study (from January 2016 to July 2019) including 75 subjects (mean, 65 years; 46-80 years) with 2.5-second temporal resolution DCE-MRI and PIRADS 4 or 5 lesions was performed. Fifty-four subjects had biopsy-proven prostate cancer (Gleason 6, 15; Gleason 7, 20; Gleason 8, 13; Gleason 9, 6), whereas 21 subjects had negative MRI/ultrasound fusion-guided biopsies. Voxel-wise analysis of contrast signal enhancement was performed for all time points using custom-developed software, including automatic arterial input function detection. Seven descriptive parameter maps were calculated: normalized maximum signal intensity, time to start, time to maximum, time-to-maximum slope, and maximum slope with normalization on maximum signal and the arterial input function (SMN1, SMN2). The parameters were compared with ADC using multiparametric machine-learning models to determine classification accuracy. A Wilcoxon test was used for the hypothesis test and the Spearman coefficient for correlation. RESULTS: There were significant differences (P < 0.05) for all 7 DCE-derived parameters between the normal peripheral zone versus PIRADS 4 or 5 lesions and the biopsy-positive versus biopsy-negative lesions. Multiparametric analysis showed better performance when combining ADC + DCE as input (accuracy/sensitivity/specificity, 97%/93%/100%) relative to ADC alone (accuracy/sensitivity/specificity, 94%/95%/95%) and to DCE alone (accuracy/sensitivity/specificity, 78%/79%/77%) in differentiating the normal peripheral zone from PIRADS lesions, biopsy-positive versus biopsy-negative lesions (accuracy/sensitivity/specificity, 68%/33%/81%), and Gleason 6 versus ≥7 prostate cancer (accuracy/sensitivity/specificity, 69%/60%/72%). CONCLUSIONS: Descriptive perfusion characteristics derived from high-resolution DCE-MRI using model-free computations show significant differences between normal and cancerous tissue but do not reach the accuracy achieved with solely ADC-based classification. Combining ADC with DCE-based input features improved classification accuracy for PIRADS lesions, discrimination of biopsy-positive versus biopsy-negative lesions, and differentiation between Gleason 6 versus Gleason ≥7 lesions.

Efficacy, safety, and perioperative outcomes of holmium laser enucleation of the prostate-a comparison of patients with lower urinary tract symptoms and urinary retention.

Holmium laser enucleation of the prostate (HoLEP) is a valid treatment option to relieve bladder outlet obstruction in patients with large prostate volumes (PV). Its efficacy, tolerability, and safety are comparable to the ones of other laser treatments of the prostate and resection techniques. However, safety and efficacy of HoLEP have not been compared between patients with and without preoperative urinary retention. We included 350 patients (mean age 71.2 years) who had undergone HoLEP due to lower urinary tract symptoms (LUTS) or urinary retention caused by prostatic hyperplasia. We evaluated the differences in peri- and postoperative outcomes and complications between patients with and patients without preoperative urinary retention. The mean PV was 115 cm3. PV was > 100 cm3 in 61.9% and < 100 cm3 in 38.1% of the patients. Perioperative complications occurred in 23 patients (6.6%), 15 of which (4.3%) required operative revision. We found no significant differences in terms of complication rates between patients with PV > 100 cm3 and patients with PV < 100 cm3. Mean catheterization-duration was 3.3 days. Preoperatively, 140 patients (40%) had a suprapubic or transurethral indwelling catheter; they did not differ from patients without preoperative catheter regarding postoperative catheter removal success rate, early postoperative complications, and functional outcomes. Prostate cancer was diagnosed in 43 patients (12.3%). Median postoperative PSA-decline was 6.1 ug/l (89.8% drop). HoLEP is a safe and effective treatment for patients with LUTS or urinary retention and large PV. PV > 100 cm3 was not associated with higher complication rates or successful catheter-removal. Furthermore, functional outcomes were independent of preoperative catheterization.

High Mortality of Non-Fournier Necrotizing Fasciitis With Enterobacteriales: Time to Rethink Classification?

This cohort study describes mortality predictors of necrotizing fasciitis (NF). Higher age, chronic kidney disease, and higher Charlson score increased the mortality rate. Mortality was >3 times higher in monomicrobial gram-negative NF than in type I or type II NF. Highest mortality was found with Enterobacteriales in non-Fournier NF.

Insulin-like growth factor II mRNA binding protein 3 (IMP3) is overexpressed in prostate cancer and correlates with higher Gleason scores.

BACKGROUND: The oncofetal protein insulin-like growth factor II mRNA binding protein 3 (IMP3) is an important factor for cell-migration and adhesion in malignancies. Recent studies have shown a remarkable overexpression of IMP3 in different human malignant neoplasms and also revealed it as an important prognostic marker in some tumor entities. To our knowledge, IMP3 expression has not been investigated in prostate carcinomas so far. METHODS: Immunohistochemical stainings for IMP3 were performed on tissue microarray (TMA) organized samples from 507 patients: 31 normal prostate tissues, 425 primary carcinomas and 51 prostate cancer metastases or castration-resistant prostate cancers (CRPC). IMP3 immunoreactivity was semiquantitatively scored and correlated with clinical-pathologic parameters including survival. RESULTS: IMP3 is significantly stronger expressed in prostate carcinomas compared to normal prostate tissues (p < 0.0001), but did not show significant correlation with the pT-stage, the proliferation index (MIB1), preoperative serum PSA level and the margin status. Only a weak and slightly significant correlation was found with the Gleason score and IMP3 expression failed to show prognostic significance in clinico-pathological correlation-analyses. CONCLUSIONS: Although IMP3 is overexpressed in a significant proportion of prostate cancer cases, which might be of importance for novel therapeutic approaches, it does not appear to possess any immediate diagnostic or prognostic value, limiting its potential as a tissue biomarker for prostate cancer. These results might be corroborated by the fact, that two independent tumor cohorts were separately reviewed.

Photoselective vaporization of the prostate: the basel experience after 108 procedures.

OBJECTIVES: This study aims to investigate safety and efficacy of 80 watt high-power potassium titanyl phosphate (KTP) laser vaporization of the prostate in men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). METHODS: 108 patients underwent 80W KTP laser vaporization. Functional follow-up included measurement of maximum urinary flow rate (Qmax), postvoid residual volume (Vres) and International Prostate Symptom Score (IPSS) within a 12 months period. RESULTS: The average prostate volume was 52.2+/-24.3 ml and the preoperative PSA value was 3.6+/-3.6 ng/dl. Mean operation time was 54.5+/-25.0 min. Qmax increased highly significantly (p<0.001) by 111% (+7.9 ml/s) at discharge, 212% (+15.1 ml/s) after three months, 201% (+14.3 ml/s) after six months and 252% (+17.9 ml/s) after 12 months. Correspondingly, Vres, IPSS and Bother Score improved to an extent that was statistically highly significant (p<0.001) immediately after surgery. The observed complication rate within one year was low. CONCLUSIONS: 80 W KTP laser vaporization is a virtually bloodless, safe and effective procedure for surgical treatment of LUTS secondary to BPH. A significant improvement of objective and subjective voiding parameters was observed just after surgery. KTP laser vaporization is associated with a low rate of complications.