Narrow-band imaging assisted cystoscopy in the follow-up of patients with transitional cell carcinoma of the bladder: a randomized study in comparison with white light cystoscopy

In vivo assessment of bladder cancer with diffuse reflectance and fluorescence spectroscopy: A comparative study

OBJECTIVES

The aim of this work is to assess the performance of multimodal spectroscopic approach combined with single core optical fiber for detection of bladder cancer during surgery in vivo.

METHODS

Multimodal approach combines diffuse reflectance spectroscopy (DRS), fluorescence spectroscopy in the visible (405 nm excitation) and near-infrared (NIR) (690 nm excitation) ranges, and high-wavenumber Raman spectroscopy. All four spectroscopic methods were combined in a single setup. For 21 patients with suspected bladder cancer or during control cystoscopy optical spectra of bladder cancer, healthy bladder wall tissue and/or scars were measured. Classification of cancerous and healthy bladder tissue was performed using machine learning methods.

RESULTS

Statistically significant differences in relative total haemoglobin content, oxygenation, scattering, and visible fluorescence intensity were found between tumor and normal tissues. The combination of DRS and visible fluorescence spectroscopy allowed detecting cancerous tissue with sensitivity and specificity of 78% and 91%, respectively. The addition of features extracted from NIR fluorescence and Raman spectra did not improve the quality of classification.

CONCLUSIONS

This study demonstrates that multimodal spectroscopic approach allows increasing sensitivity and specificity of bladder cancer detection in vivo. The developed approach does not require special probes and can be used with single-core optical fibers applied for laser surgery.

Development and validation of a predictive model for the diagnosis of bladder tumors using narrow band imaging

PURPOSE

At present, the prediction of bladder tumor nature during cystoscopy is partially dependent on the clinician's own experience. Subjective factors may lead to excessive biopsy or delayed treatment. The purpose of our study is to establish a reliable model for predicting the nature of bladder tumors using narrow band imaging.

METHODS

From November 2021 to November 2022, the clinical data of 231 patients who required a cystoscopy were prospectively collected at our center. Cystoscopy was performed in 219 eligible patients, in which both tumor and vascular morphology characteristics were recorded. Pathological results were used as the diagnostic standard. A logistic regression analysis was used to screen out factors related to tumor pathology. Bootstrap resampling was used for internal validation. A total of 71 patients from four other centers served as an external validation cohort.

RESULTS

The following diagnostic factors were identified: tumor morphology (cauliflower-like or algae-like lesions), vascular morphology (dotted or circumferential vessels), tumor boundary (clear or unclear), and patients' symptoms (gross hematuria) and were included in the prediction model. The internal validation results showed that the area under the curve was 0.94 (95% CI 0.92-0.97), and the P value from the goodness-of-fit test was 0.97. After external validation, the results showed the area under the curve was 0.89 (95% CI 0.82-0.97) and the P value of the goodness-of-fit test was 0.24.

CONCLUSION

A diagnostic prediction nomogram was established for bladder cancer. The verification results showed that the prediction model has good prediction performance.

Diagnostic and therapeutic effects of fluorescence cystoscopy and narrow-band imaging in bladder cancer: a systematic review and network meta-analysis

BACKGROUND

This review aims to compare the efficacies of fluorescence cystoscopy, narrow-band imaging (NBI), and white light cystoscopy in the treatment and diagnosis of bladder cancer.

METHODS

The authors searched PubMed, EMbase, Web of Science, and the Cochrane Library from January 1990 to April 2022. A total of 26 randomized controlled studies and 22 prospective single-arm studies were selected. Most patients had nonmuscle-invasive bladder cancer. The study protocol has been registered at PROSPERO.

RESULTS

In the pairwise meta-analysis, 5-aminolevulinic acid (5-ALA) reduced the short-term and long-term recurrence rates of bladder cancer compared with white light cystoscopy (WLC); however, no statistical difference was observed in intermediate-term recurrence rates (RR=0.79, 95% CI: 0.57-1.09). Hexaminolevulinic acid and NBI reduced short-term, intermediate-term, and long-term recurrence rates. The sensitivity of 5-ALA, hexaminolevulinic acid, NBI, and WLC for bladder cancer were 0.89 (95% CI: 0.81-0.94), 0.96 (95% CI: 0.92-0.98), 0.96 (95% CI: 0.92-0.98), and 0.75 (95% CI: 0.70-0.79), respectively; however, only NBI had the same specificity as WLC (0.74 vs. 0.74). Compared with WLC, 5-ALA improved the detection rate of carcinoma in situ and Ta stage bladder cancer but had no advantage in T1 stage tumors (OR=2.39, 95% CI:0.79-7.19). Hexaminolevulinic acid and NBI improved the detection rates of all nonmuscular-invasive bladder cancers. In the network meta-analysis, there was no significant difference in either recurrence or detection rates between 5-ALA, hexaminolevulinic acid, and NBI.

CONCLUSION

Fluorescence cystoscopy and NBI are advantageous for treating and diagnosing patients with nonmuscle-invasive bladder cancer.

Narrow band imaging versus white light cystoscopy alone for transurethral resection of non-muscle invasive bladder cancer

BACKGROUND

Disease recurrence and progression remain major challenges for the treatment of non-muscle invasive bladder cancer. Narrow band imaging (NBI) is an optical enhancement technique that may improve resection of non-muscle invasive bladder cancer and thereby lead to better outcomes for people undergoing the procedure.  OBJECTIVES: To assess the effects of NBI- and white light cystoscopy (WLC)-guided transurethral resection of bladder tumor (TURBT) compared to WLC-guided TURBT in the treatment of non-muscle invasive bladder cancer.

SEARCH METHODS

We performed a comprehensive literature search of 10 databases, including the Cochrane Library, the Cochrane Database of Systematic Reviews, MEDLINE, Embase, several clinical trial registries, and grey literature for published and unpublished studies, irrespective of language. The search was performed per an a priori protocol on 3 December 2021.

SELECTION CRITERIA

We included randomized controlled trials of participants with suspected or confirmed non-muscle invasive bladder cancer. Participants in the control group must have received WLC-guided TURBT alone (hereinafter simply referred to as 'WLC TURBT'). Participants in the intervention group had to have received NBI- and WLC-guided TURBT (hereinafter simply referred to as 'NBI + WLC TURBT').

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion/exclusion, performed data extraction, and assessed risk of bias. We conducted meta-analysis on time-to-event and dichotomous data using a random-effects model in RevMan, according to Cochrane methods. We rated the certainty of evidence for each outcome according to the GRADE approach. Primary outcomes were time to recurrence, time to progression, and the occurrence of a major adverse event, defined as a Clavien-Dindo III, IV, or V complication. Secondary outcomes included time to death from bladder cancer and the occurrence of a minor adverse event, defined as a Clavien-Dindo I or II complication.  MAIN RESULTS: We included eight studies with a total of 2152 participants randomized to the standard WLC TURBT or to NBI + WLC TURBT. A total of 1847 participants were included for analysis.  Based on limited confidence in the time-to-event data, we found that participants who underwent NBI + WLC TURBT had a lower risk of disease recurrence over time compared to participants who underwent WLC TURBT (hazard ratio 0.63, 95% CI 0.45 to 0.89; I2 = 53%; 6 studies, 1244 participants; low certainty of evidence). No studies examined disease progression as a time-to-event outcome or a dichotomous outcome. There was likely no difference in the risk of a major adverse event between participants who underwent NBI + WLC TURBT and those who underwent WLC TURBT (risk ratio 1.77, 95% CI 0.79 to 3.96; 4 studies, 1385 participants; low certainty of evidence). No studies examined death from bladder cancer as a time-to-event outcome or a dichotomous outcome. There was likely no difference in the risk of a minor adverse event between participants who underwent NBI + WLC TURBT and those who underwent WLC TURBT (risk ratio 0.88, 95% CI 0.49 to 1.56; I2 = 61%; 4 studies, 1385 participants; low certainty of evidence).  AUTHORS' CONCLUSIONS: Compared to WLC TURBT alone, NBI + WLC TURBT may lower the risk of disease recurrence over time while having little or no effect on the risks of major or minor adverse events.

The Role of New Technologies in the Diagnosis and Surveillance of Non-Muscle Invasive Bladder Carcinoma: A Prospective, Double-Blinded, Monocentric Study of the XPERT© Bladder Cancer Monitor and Narrow Band Imaging© Cystoscopy

Simple Summary

Patients with bladder cancer (BC) require close follow-up with white-light cystoscopy (WLC) and cytology. In this study, we sought to assess (a) the performance of a novel cystoscopy technology based on Narrow Band Imaging© (NBI), and (b) a new urine test (XPERT© Bladder Cancer Monitor, XBCM) that detects cancer proteins. We compared these to the established standard follow-up diagnostics. Our study showed that NBI cystoscopy does not provide any additional benefit over standard WLC. However, the XBCM urine test performed particularly well in instances of aggressive high-grade tumor recurrence. Therefore, XBCM may have enhanced utility in the early detection of potentially harmful BC recurrence.

Abstract

Follow-up is essential for the early detection of recurrent non-muscle invasive bladder cancers (NMIBC). This study investigates the clinical relevance of new diagnostic tools such as an mRNA-based urine test (XPERT© Bladder Cancer Monitor, XBCM) and Narrow Band Imaging© (NBI) and compares them with the established follow-up diagnostics (white-light cystoscopy (WLC) and urine cytology). This was a prospective, double-blind, single-center study that involved patients undergoing NMIBC screening at a tertiary care center. Enrollment occurred between January 2018 and March 2020. In addition to standard care (WLC, cytology, and ultrasound), patients underwent XBCM urine testing and NBI cystoscopy. In total, 301 WLCs were performed; through this, 49 patients demonstrated NMIBC recurrence. NBI cystoscopy was congruent with WLC in all patients. Cytology showed a sensitivity (SE) and specificity (SP) of 27% and 97% (PPV: 65%; NPV 87%), respectively, whereas XBCM showed SE and SP of 58% and 89%, respectively (PPV: 51%; NPV: 92%; AUC: 0.79 (0.716–0.871)). Subgroup analysis showed improved SE and similar SP (PPV, NPV) for high grade (HG) recurrence, with a SE of 74% and SP of 89% (39%, 97%). NBI cystoscopy does not necessarily provide additional benefit over standard WLC. However, the XBCM may provide better SE and a diagnostic advantage in instances of HG disease recurrence.

Performance of Narrow Band Imaging (NBI) and Photodynamic Diagnosis (PDD) Fluorescence Imaging Compared to White Light Cystoscopy (WLC) in Detecting Non-Muscle Invasive Bladder Cancer: A Systematic Review and Lesion-Level Diagnostic Meta-Analysis

Despite early detection and regular surveillance of non-muscle invasive bladder cancer (NMIBC), recurrence and progression rates remain exceedingly high for this highly prevalent malignancy. Limited visualization of malignant lesions with standard cystoscopy and associated false-negative biopsy rates have been the driving force for investigating alternative and adjunctive technologies for improved cystoscopy. The aim of our systematic review and meta-analysis was to compare the sensitivity, specificity, and oncologic outcomes of photodynamic diagnosis (PDD) fluorescence, narrow band imaging (NBI), and conventional white light cystoscopy (WLC) in detecting NMIBC. Out of 1,087 studies reviewed, 17 prospective non-randomized and randomized controlled trials met inclusion criteria for the study. We demonstrated that tumor resection with either PDD and NBI exhibited lower recurrence rates and greater diagnostic sensitivity compared to WLC alone. NBI demonstrated superior disease sensitivity and specificity as compared to WLC and an overall greater hierarchical summary receiver operative characteristic. Our findings are consistent with emerging guidelines and underscore the value of integrating these enhanced technologies as a part of the standard care for patients with suspected or confirmed NMIBC.

Systematic review and meta-analysis of narrow band imaging for non-muscle-invasive bladder cancer

To assess the effect of narrow band imaging-guided transurethral resection of bladder tumor compared with white light on recurrence rates in non-muscle-invasive bladder cancer. A systematic review of the literature from inception to November 2020 using Medline, EMBASE and CENTRAL was undertaken. Randomized controlled trials comparing transurethral resection of bladder tumor undertaken with narrow band imaging with those undertaken with white light that reported recurrence rates of at least 12 months were included in the analysis. Primary outcomes were recurrence rates at 12 and 24 months. Secondary outcomes were reported adverse effects. A total of 387 abstracts were screened, of which 14 full text identified and three studies included in the meta-analysis (921 patients). Meta-analysis did not show a statistically significant benefit to narrow band imaging at 12 months; risk ratio 0.75 (95% confidence interval 0.50-1.14, P = 0.18, I²  = 61%). No included studies provided recurrence data beyond 12 months. Adverse effects were reported in one study and no significant difference of complication rate was observed between the two groups. Risk of bias was assessed to be generally low, and grading of recommendations assessment development and evaluations were of high certainty. This meta-analysis of randomized controlled trials shows no difference in recurrence rates using narrow band imaging, although a trend in its favor was identified. Limitations include the varied reporting and administration of adjuvant therapies. Further well-designed trials are required to examine the benefit of this technology.

Novel Visualization Methods Assisted Transurethral Resection for Bladder Cancer: An Updated Survival-Based Systematic Review and Meta-Analysis

Background

Photodynamic diagnosis and narrow-band imaging could help improve the detection rate in transurethral resection (TUR) of bladder cancer. It remained controversial that the novel visualization method assisted transurethral resection (VA-TUR) could elongate patients' survival compared to traditional TUR.

Methods

We performed electronic and manual searching until December 2020 to identify randomized controlled trials comparing VA-TUR with traditional TUR, which reported patients' survival data. Two reviewers independently selected eligible studies, extracted data, assessed the risk of bias. Meta-analysis was conducted according to subgroups of types of visualization methods (A) and clinical stage of participants. Publication bias was detected.

Results

We included 20 studies (reported in 28 articles) in this review. A total of 6,062 participants were randomized, and 5,217 participants were included in the analysis. Only two studies were assessed at low risk of bias. VA-TURB could significantly improve the recurrence-free survival (RFS) (HR = 0.72, 95% CI: 0.66 to 0.79, P <0.00001, I² = 42%) and progression-free survival (PFS) (HR = 0.62, 95% CI: 0.46 to 0.82, P <0.0008, I² = 0%) compared with TUR under white light. The results remain stable whatever the type of visualization method. The difference could be observed in the non-muscle-invasive bladder cancer (NMIBC) population (P <0.05) but not in the mixed population with muscle-invasive bladder cancer (MIBC) participants (P >0.05).

Conclusion

VA-TUR could improve RFS and PFS in NMIBC patients. No significant difference is found among different types of VA-TUR. VA-TUR may be not indicated to MIBC patients.

Trends in urine biomarker discovery for urothelial bladder cancer: DNA, RNA, or protein?

Urothelial bladder cancer is a complex disease displaying a landscape of heterogenous molecular subtypes, mutation profiles and clinical presentations. Diagnosis and surveillance rely on flexible cystoscopy which has high accuracy, albeit accompanied by a high-cost burden for healthcare providers and discomfort for patients. Advances in "omic" technologies and computational biology have provided insights into the molecular pathogenesis of bladder cancer and provided powerful tools to identify markers for disease detection, risk stratification, and predicting responses to therapy. To date, numerous attempts have been made to discover and validate diagnostic biomarkers that could be deployed as an adjunct to the cystoscopic diagnosis and long-term surveillance of bladder cancer. We report a comprehensive literature analysis using PubMed to assess the changing trends in investigating DNA, RNA, or proteins as diagnostic urinary biomarkers over a period of 5 decades: 1970-2020. A gradual shift has been observed in research away from protein biomarkers to nucleic acids including different classes of RNA, and DNA methylation and mutation markers. Until 2000, publications involving protein biomarker discovery constituted 87% of the total number of research articles with DNA comprising 6% and RNA 7%. Since 2000 the proportion of protein biomarker articles has fallen to 40%, and DNA and RNA studies increased to 32% and 28%, respectively. Clearly research focus, perhaps driven by technological innovation, has shifted from proteins to nucleic acids. We optimistically hypothesise that, following thorough validation, a clinically useful detection test for bladder cancer based on a panel of DNA or RNA markers could become reality within 5-10 years.

The diagnostic challenge of suspicious or positive malignant urine cytology findings when cystoscopy findings are normal: an outpatient blue-light flexible cystoscopy may solve the problem

PURPOSE

To investigate whether outpatient blue-light flexible cystoscopy could solve the diagnostic challenge of positive or suspicious urine cytology findings despite normal white-light flexible cystoscopy results and normal findings on computerized tomography urography, in patients investigated for urothelial cancer.

MATERIAL AND METHODS

In a multicentre study, a total of 70 examinations were performed with the use of blue-light flexible cystoscopy (photodynamic diagnosis) after intravesical instillation of the fluorescence agent hexaminolevulinate. The examination started with a conventional white-light flexible cystoscopy and then the settings were switched to use blue light. Suspicious lesions were biopsied. Afterwards, the patients were interviewed regarding their experience of the examinations.

RESULTS

Bladder cancer was diagnosed in 29 out of 70 (41%) cases, among them 14/29 (48%) had malignant lesions seen only in blue light. The majority had carcinoma in situ (21/29). Normal findings were seen in 41 cases that underwent BLFC. During the further course, malignancy of the bladder was detected in six cases (9%) and malignancy of the upper urinary tract was detected in one case (1%). The majority of patients (93%) preferred the blue-light flexible cystoscopy performed at the outpatient clinic instead of the transurethral resection under general anaesthesia.

CONCLUSION

Blue-light flexible cystoscopy at the outpatient clinic may be a useful tool to solve unclear cases of a malignant or suspicious urinary cytology suggestive of bladder cancer. The procedure was well tolerated by the patients.

[Enhanced imaging in urological endoscopy]

White light cystoscopy and the concise documentation of pathological findings are standard diagnostic procedures in urology. Additional imaging modalities and technical innovations may support clinicians in the detection of bladder tumors. Modern endoscopy systems provide ultra-high-resolution imaging and the option of digital contrast enhancement. Photodynamic diagnostics and narrow band imaging are well-established in clinical routine and have shown significant benefits in the detection of bladder cancer. By means of multispectral imaging, different modalities can now be combined in real-time. Probe-based procedures such as optical coherence tomography (OCT) or Raman spectroscopy can further contribute to advanced imaging through an "optical biopsy" which may primarily improve diagnostics in the upper urinary tract. The aim of all techniques is to optimize the detection rate in order to achieve a more accurate diagnosis, resection and lower recurrence rates. Current research projects aim to digitalize the documentation of endoscopy and also make it more patient- and user-friendly. In the future, the use of image processing and artificial intelligence may automatically support the surgeon during endoscopy.