Early Detection of Carcinoma In Situ of the Bladder: A Comparative Study of White Light Cystoscopy, Narrow Band Imaging, 5-ALA Fluorescence Cystoscopy and 3-Dimensional Optical Coherence Tomography

Diagnostic accuracy of optical coherence tomography for bladder cancer: A systematic review and meta-analysis

BACKGROUND

Bladder cancer is the fourth most common malignancy in men and a considerable disease burden globally. Multiple studies have focused on the accuracy of optical coherence tomography for bladder cancer diagnosis; however, the findings are inconsistent. Here, we assessed the accuracy of optical coherence tomography for bladder cancer diagnosis.

METHODS

Embase, PubMed, Medline, Web of Science, and the Cochrane Library database were searched for relevant studies from the earliest date available through March 11, 2019. Studies evaluating the accuracy of optical coherence tomography bladder cancer diagnosis were included. Pooled sensitivity, specificity, and area under the curve values of weighted symmetric summary receiver operating curves, were calculated at the per-lesion level.

RESULTS

Eleven studies, with a total of 1933 lesions, were included in the final analysis. The pooled results indicated that optical coherence tomography can differentiate bladder cancer from benign lesions: sensitivity, 94.9% (95% confidence interval: 92.7%-96.6%); specificity, 84.6% (95% confidence interval: 82.6%-86.4%); area under the curve, 0.97. Moreover, compared with optical coherence tomography alone, combined optical coherence tomography and fluorescence cystoscopy increased the diagnostic accuracy (sensitivity, 94.3% vs. 87.3%; specificity, 89.2% vs. 73.9%). Cross-polarization optical coherence tomography could also distinguish bladder cancer from normal tissue: sensitivity, 92.0% (95% confidence interval: 87.0%-95.6%); specificity, 84.4% (95% confidence interval: 81.7%-86.9%); area under the curve, 0.95.

CONCLUSIONS

Optical coherence tomography can accurately differentiate malignant from benign bladder lesions, particularly when combined with fluorescence cystoscopy.

Enhanced Endoscopy in Bladder Cancer

PURPOSE OF REVIEW

Endoscopy coupled with targeted resections represents a cornerstone in the diagnosis, staging, and treatment of patients with bladder cancer. Direct visualization can be challenging and imprecise due to patient-, tumor-, and surgeon-specific factors. We will review contemporary endoscopic technologies and techniques used to improve our ability to safely identify and resect malignant lesions in patients with bladder cancer.

RECENT FINDINGS

Enhanced endoscopic imaging technology may improve detection rates for bladder cancer throughout the upper and lower urinary tract, which may lead to improvements in recurrence and progression rates for non-muscle invasive bladder cancer (NMIBC). New techniques including narrow-band imaging (NBI), photodynamic diagnosis (PDD), Storz Professional Image Enhancement System (SPIES), optical coherence tomography (OCT), and others have shown benefit and may further improve our ability to detect and stage bladder tumors. Enhanced endoscopy technologies have already demonstrated value in improving the sensitivity of bladder cancer detection and early results suggest they may improve short- and long-term oncologic outcomes.

Optical redox ratio and endogenous porphyrins in the detection of urinary bladder cancer: A patient biopsy analysis

Bladder cancer is among the most common cancers in the UK and conventional detection techniques suffer from low sensitivity, low specificity, or both. Recent attempts to address the disparity have led to progress in the field of autofluorescence as a means to diagnose the disease with high efficiency, however there is still a lot not known about autofluorescence profiles in the disease. The multi-functional diagnostic system "LAKK-M" was used to assess autofluorescence profiles of healthy and cancerous bladder tissue to identify novel biomarkers of the disease. Statistically significant differences were observed in the optical redox ratio (a measure of tissue metabolic activity), the amplitude of endogenous porphyrins and the NADH/porphyrin ratio between tissue types. These findings could advance understanding of bladder cancer and aid in the development of new techniques for detection and surveillance.

Urothelial Tumors and Dual-Band Imaging: A New Concept in Confocal Laser Endomicroscopy

OBJECTIVES

Confocal laser endomicroscopy (CLE) uses a low-energy laser light source to obtain microscopic histology images of bladder tissue exposed to a fluorescent dye. To evaluate the feasibility of using CLE with two fluorophores: fluorescein (FLUO) and hexylaminolevulinate (HAL) to determine histologic and cytologic bladder cancer criteria.

METHODS

Patients eligible for HAL-photodynamic diagnosis-assisted transurethral resection of bladder tumor were included. The procedures were performed with the patient under regional or general anesthesia (60-90 minutes) after bladder instillation of HAL (50 mL, 8 mmol/L; Hexvix^®; Ipsen, France). Resected tissue was examined ex vivo using CLE either with Cellvizio^® system (CVI) single laser (488 nm) or with Cellvizio Dual system (CVII) double laser (488, 660 nm).

RESULTS

Twenty-one patients were included, 12 examined by CVI and 9 by CVII. Sample examination on CVI after HAL-CLE-only histologic analysis was not possible because HAL is mostly cytoplasmic and gives poor details on cellular architecture. On the contrary, FLUO-CLE gives good extracellular architecture and not clear information of nucleocytoplasmic abnormality. Samples on CVII for seven out of nine patients clearly showed cytoplasm of suspect cells and nuclei. In real time, fluorescence observed on bandwidth (673-800 nm) with HAL and FLUO was associated with the presence of cancer, with a sensibility and specificity of 80% and 100%, respectively.

CONCLUSIONS

Real-time cytodetection was feasible using two fluorophores (FLUO and HAL) and the new system of CVII. This technology was useful to observe cytoplasm, nuclei, and nucleocytoplasmic abnormality, but an improved system is necessary (to overcome the overlapping of fluorescence) to increase the specificity.

A Comparison of the Progression and Recurrence Risk Index in Non-Muscle-Invasive Bladder Tumors Detected by Narrow-Band Imaging Versus White Light Cystoscopy, Based on the EORTC Scoring System

Background:

Transitional cell carcinoma of the bladder, the second most common urologic malignancy, is amenable to early diagnosis. This study presents the potential prognostic benefit for a less invasive modification to the standard endoscopic approach.

Objectives:

To evaluate the risk index for the progression and recurrence of additional tumors detected with narrow-band imaging (NBI) cystoscopy compared to standard white light imaging (WLI) cystoscopy in non-muscle-invasive bladder cancer (NMIBC), based on the European organization for research and treatment of cancer (EORTC) scoring system.

Patients and Methods:

Patients with NMIBC, who were scheduled for resection between May 2012 and May 2013, were studied and mapped under NBI and WLI cystoscopy by independent surgeons prior to resection. Detection rates and tumor characteristics, including EORTC progression and the recurrence risk index, were compared.

Results:

Fifty patients, aged 63.86 ± 10.05 years, were enrolled. The overall detection rate was 98.9% for NBI vs. 89.4% for WLI (P = 0.001), and the false-positive rates were 9.6% and 5.8%, respectively (P = 0.051). Ten tumors were detected by NBI alone, including four grade I tumors, four grade III tumors, and two carcinomas in situ. The tumor progression index was not significantly reduced with NBI compared to WLI (P > 0.05); however, the recurrence index was significantly lower in the NBI group (P < 0.05).

Conclusions:

NBI cystoscopy improved the detection rate. Although false positives were more common with NBI, this was not statistically significant. NBI found additional aggressive tumors, which underscores the impact of detection in EORTC recurrence risk scoring.

Differential diagnosis of human bladder mucosa pathologies in vivo with cross-polarization optical coherence tomography

Quantitative image analysis and parameter extraction using a specific implementation of polarization-sensitive optical coherence tomography (OCT) provides differential diagnosis of mucosal pathologies in in-vivo human bladders. We introduce a cross-polarization (CP) OCT image metric called Integral Depolarization Factor (IDF) to enable automatic diagnosis of bladder conditions (assessment the functional state of collagen fibers). IDF-based diagnostic accuracy of identification of the severe fibrosis of normal bladder mucosa is 79%; recurrence of carcinoma on the post-operative scar is 97%; and differentiation between neoplasia and acute inflammation is 75%. The promising potential of CP OCT combined with image analysis in human urology is thus demonstrated in vivo.

Novel endoscopic diagnosis for bladder cancer

Advances in endoscopic imaging technology may improve sensitivity for the detection of bladder cancer and provide a more complete understanding of the urothelial landscape, and it also may lead to improved short-term and long-term cancer control. Fluorescence cystoscopy requires intravesical administration of a photosensitizing agent (5-aminolevulinic acid or hexaminolevulinate), and imaging with a blue-light endoscopy system demonstrably improves the detection of papillary and flat bladder lesions compared with conventional white-light cystoscopy. Prospective phase 3 clinical trials have demonstrated improved diagnostic ability, enhanced tumor resection, and a small but significant reduction in recurrence-free survival. Optical coherence tomography delineates subsurface microarchitecture information about bladder lesions in real time and has the ability to discriminate between noninvasive and invasive cancers. Narrow-band imaging may augment white-light cystoscopy by providing increased contrast between normal and abnormal tissue on the basis of neovascularity. Confocal laser endoscopy has been applied to the urinary tract using thinner probes adapted from use in gastrointestinal malignancies and provides exquisite images at microscopic resolution. More technology is on the horizon that may further enhance our ability to detect and accurately stage bladder tumors and distinguish benign from malignant or dysplastic lesions.

The role of narrow-band imaging in the management of non-muscle-invasive bladder cancer

Narrow-band imaging is a young optical enhancement technology for endoscopy. It is a filter to the standard white light which increases the contrast between underlying vasculature and epithelial strata of the mucosa, improving the detection of bladder cancer with particular regard to high grade, flat lesions. Narrow band imaging is absolutely safe, may be used any time during a procedure, either during office cystosopy or transurethral resection, and implies a minimal burden for the healthcare provider given the absence of a learning curve and the limited cost of the camera and light source. The ameliorated detection translates into an improved management of the disease and a lower recurrence risk in prospective randomized studies, suggesting the inclusion of the technology in daily clinical practice.

Detection of bladder urothelial carcinoma using in vivo noncontact, ultraviolet excited autofluorescence measurements converted into simple color coded images: a feasibility study

PURPOSE

A difficulty in nonmuscle invasive bladder cancers is the diagnosis of flat and small lesions during white light cystoscopy. We assessed a prototype that measures ultraviolet laser induced autofluorescence for endoscopic detection of nonmuscle invasive bladder cancer.

MATERIALS AND METHODS

We compared spectroscopic results with histological findings in 3 groups, including normal urothelium, papillary tumors and flat lesions. The developed method is based on exciting the fluorescence of molecules naturally present in tissue using ultraviolet laser pulses. The diagnostic signal was converted into the intensity ratio of the emitted light at approximately 360 and 450 nm. This ratio depends on the histopathological state of the tissue. The signal was converted into a simple color coded image, in which green indicates normal tissue and red indicates neoplasm.

RESULTS

A total of 14 patients were included in analysis. At 360 and 450 nm excitation wavelengths the overall fluorescence intensity of bladder tumors was clearly decreased compared to that of normal urothelium regardless of tumor stage or grade. At the 308 nm excitation wavelength the shape of the tumor spectra, including carcinoma in situ, was markedly different from that of normal or nonspecific inflammatory mucosa. The correlation between red images and tumor in the specimen was 100%. No absolute intensity determinations were required since a definite diagnosis was established based on the fluorescence intensity ratio at 360 and 450 nm.

CONCLUSIONS

This feasibility study confirms the functionality of our clinical prototype for the noncontact imaging detection of nonmuscle invasive bladder cancer via an endoscope using ultraviolet excited autofluorescence measurements.