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

Multiparameter interferometric polarization-enhanced imaging differentiates carcinoma in situ from inflammation of the bladder: an ex vivo study

Significance

Successful differentiation of carcinoma in situ (CIS) from inflammation in the bladder is key to preventing unnecessary biopsies and enabling accurate therapeutic decisions. Current standard-of-care diagnostic imaging techniques lack the specificity needed to differentiate these states, leading to false positives.

Aim

We introduce multiparameter interferometric polarization-enhanced (MultiPIPE) imaging as a promising technology to improve the specificity of detection for better biopsy guidance and clinical outcomes.

Approach

In this ex vivo study, we extract tissue attenuation-coefficient-based and birefringence-based parameters from MultiPIPE imaging data, collected with a bench-top system, to develop a classifier for the differentiation of benign and CIS tissues. We also analyze morphological features from second harmonic generation imaging and histology slides and perform imaging-to-morphology correlation analysis.

Results

MultiPIPE enhances specificity to differentiate CIS from benign tissues by nearly 20% and reduces the false-positive rate by more than four-fold over clinical standards. We also show that the MultiPIPE measurements correlate well with changes in morphological features in histological assessments.

Conclusions

The results of our study show the promise of MultiPIPE imaging to be used for better differentiation of bladder inflammation from flat tumors, leading to a fewer number of unnecessary procedures and shorter operating room (OR) time.

Prognostic Significance of PD-L2 Expression in Association with Neutrophil-to-Lymphocyte Ratio in Urothelial Carcinoma of the Bladder

BACKGROUND

The prognostic significance of tumoral programmed death-ligand 2 (PD-L2) expression in urothelial bladder cancer (UBCs) is under-investigated , although it can potentially  to become a regulatory agent of cancer immunity. In the search for supporting biomarkers, the neutrophil-to-lymphocyte ratio (NLR) as a readily available surrogate marker of immune status has been associated with clinical outcomes and other prognostic factors in various types  of cancer. Here we evaluate the prognostic ability of baseline NLR in addition to PD-L2 expression in bladder cancer.

METHODS

We used a retrospective cohort of UBCs patients from the authors' institutions. We classified patients according to their PD-L2 and NLR levels. We associated the prognostic outcome of each group with disease-free survival (DFS) and overall survival (OS).

RESULTS

Thirty patients had a tumor with positive PD-L2 expression. We found no significant correlation between PD-L2 expression and NLR. PD-L2 status failed to provide a significant prognostic impact (disease-free survival [DFS] and overall survival [OS] rate at 5 years, 42.85% in PD-L2-high versus 65.75% in PD-L2-low patients; p = 0.057, 42.85% in PD-L2-high patients versus 62.5% in PD-L2-low patients; p = 0.112, respectively). NLR status also failed to exhibit a significant prognostic impact (DFS and OS rate at 5 years, 44.44% in PD-L2-high versus 66.66% in PD-L2-low patients; p = 0.232, 55.55% in PD-L2-high versus 71.43% in PD-L2-low patients; P = 0.894, respectively). When PD-L2 status and NLR status were combined, the NLR-low and PD-L2-low were significant factors to predict a favorable disease-free survival (hazard ratio, 4.525 [95% confidence interval, 1.020 to 20.080]; P = 0.047. However, the multivariate analysis failed to show it as an independent factor.

CONCLUSION

These findings suggest that the prognostic impact of PD-L2 expression could be affected by the NLR status.

[Transurethral resection of the urinary bladder : Status quo and outlook on new developments]

BACKGROUND

Transurethral resection of the urinary bladder (TURB) is the standard intervention in the diagnostic workup and treatment of non-muscle invasive bladder cancer. In order to minimize cancer recurrence and potential complications, continuous technical development of TURB is of high clinical interest.

OBJECTIVES

Presentation of the current standards and discussion of technological changes.

MATERIALS AND METHODS

Analysis of the current guideline recommendations and literature research.

RESULTS

The limitations of classic monopolar TURB is supplemented by new resection methods (en bloc) and technologies (bipolar and laser resection). Along with improved visualization through partially established technologies of photodynamic and digital image enhancement, there is potential for optimization regarding the likelihood of recurrences and complications as well as the histological quality of the resected material.

CONCLUSION

A positive impact on the oncological value and safety of TURB seems possible through the use of modern technologies. Further establishment up to evidence-based guideline recommendations are necessary.

Statistical evaluation of reader variability in assessing the diagnostic performance of optical coherence tomography

SIGNIFICANCE

Optical coherence tomography (OCT) is widely used as a potential diagnostic tool for a variety of diseases including various types of cancer. However, sensitivity and specificity analyses of OCT in different cancers yield results varying from 11% to 100%. Hence, there is a need for more detailed statistical analysis of blinded reader studies.

AIM

Extensive statistical analysis is performed on results from a blinded study involving OCT of breast tumor margins to assess the impact of reader variability on sensitivity and specificity.

APPROACH

Five readers with varying levels of experience reading OCT images assessed 50 OCT images of breast tumor margins collected using an intraoperative OCT system. Statistical modeling and analysis was performed using the R language to analyze reader experience and variability.

RESULTS

Statistical analysis showed that the readers' prior experience with OCT images was directly related to the probability of the readers' assessment agreeing with histology. Additionally, results from readers with prior experience specific to OCT in breast cancer had a higher probability of agreement with histology compared to readers with experience with OCT in other (noncancer) diseases.

CONCLUSIONS

The results from this study demonstrate the potential impact of reader training and experience in the assessment of sensitivity and specificity. They also demonstrate even greater potential improvement in diagnostic performance by combining results from multiple readers. These preliminary findings suggest valuable directions for further study.

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.

Transurethral resection of bladder tumours: established and new methods of tumour visualisation

Transurethral resection (TUR) of bladder tumours does not only serve diagnostic purposes by securing histological proof of the disease but might also resemble the final therapy. During recent years, technical innovations improved the intraoperative detection and visibility of tumourous lesions during TUR. The most important techniques, which have individually found their way into international guidelines, are photodynamic imaging (PDI) and narrowband imaging (NBI). Furthermore, there are more or less experimental approaches such as optical coherence tomography (OCT), confocal laser endomicroscopy (CLE), red/green/blue analysis (RGB) of WLC. Moreover, the combination of two or more techniques in a multiparametric setting is another development in improving intraoperative imaging. The aim of this review is to describe today’s knowledge of the more established methods and to depict the most recent developments in intraoperative imaging.

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.