Role of blue-light cystoscopy in detecting invasive bladder tumours: data from a multi-institutional registry

Pressure-enhanced sensing of tissue oxygenation via endogenous porphyrin: Implications for dynamic visualization of cancer in surgery

Fluorescence guidance is routinely used in surgery to enhance perfusion contrast in multiple types of diseases. Pressure-enhanced sensing of tissue oxygenation (PRESTO) via fluorescence is a technique extensively analyzed here, that uses an FDA-approved human precursor molecule, 5-aminolevulinic acid (ALA), to stimulate a unique delayed fluorescence signal that is representative of tissue hypoxia. The ALA precontrast agent is metabolized in most tissues into a red fluorescent molecule, protoporphyrin IX (PpIX), which has both prompt fluorescence, indicative of the concentration, and a delayed fluorescence, that is amplified in low tissue oxygen situations. Applied pressure from palpation induces transient capillary stasis and a resulting transient PRESTO contrast, dominant when there is near hypoxia. This study examined the kinetics and behavior of this effect in both normal and tumor tissues, with a prolonged high PRESTO contrast (contrast to background of 7.3) across 5 tumor models, due to sluggish capillaries and inhibited vasodynamics. This tissue function imaging approach is a fundamentally unique tool for real-time palpation-induced tissue response in vivo, relevant for chronic hypoxia, such as vascular diseases or oncologic surgery.

Assessment of open-field fluorescence guided surgery systems: implementing a standardized method for characterization and comparison

Significance

Fluorescence guided surgery (FGS) has demonstrated improvements in decision making and patient outcomes for a wide range of surgical procedures. Not only can FGS systems provide a higher level of structural perfusion accuracy in tissue reconstruction cases but they can also serve for real-time functional characterization. Multiple FGS devices have been Food and Drug administration (FDA) cleared for use in open and laparoscopic surgery. Despite the rapid growth of the field, there has been a lack standardization methods.

Aim

This work overviews commonalities inherent to optical imaging methods that can be exploited to produce such a standardization procedure. Furthermore, a system evaluation pipeline is proposed and executed through the use of photo-stable indocyanine green fluorescence phantoms. Five different FDA-approved open-field FGS systems are used and evaluated with the proposed method.

Approach

The proposed pipeline encompasses the following characterization: (1) imaging spatial resolution and sharpness, (2) sensitivity and linearity, (3) imaging depth into tissue, (4) imaging system DOF, (5) uniformity of illumination, (6) spatial distortion, (7) signal to background ratio, (8) excitation bands, and (9) illumination wavelength and power.

Results

The results highlight how such a standardization approach can be successfully implemented for inter-system comparisons as well as how to better understand essential features within each FGS setup.

Conclusions

Despite clinical use being the end goal, a robust yet simple standardization pipeline before clinical trials, such as the one presented herein, should benefit regulatory agencies, manufacturers, and end-users to better assess basic performance and improvements to be made in next generation FGS systems.

High-quality Transurethral Resection of Bladder Tumour Needs Additional Forms of Tumour Delineation

Good-quality transurethral resection of non-muscle-invasive bladder cancer may change the course of the disease. Multiple prospective trials have confirmed the efficacy of photodynamic diagnosis in detecting tumours and thus facilitating adequate resection.

Is a restaging TURBT necessary in high-risk NMIBC if the initial TURBT was performed with blue light?

OBJECTIVES

To evaluate whether a restaging transurethral resection of bladder tumor (TURBT) is necessary in high-risk nonmuscle invasive bladder cancer (NMIBC) if the initial TURBT was performed using blue light (BL) technology.

METHODS AND MATERIALS

Using the multi-institutional Cysview registry between 2014 and 2021, all consecutive adult patients with known NMIBC (Ta and T1 disease) who underwent TURBT followed by a restaging TURBT within 8 weeks were reviewed. Patients were stratified according to their initial TURBT, BL vs. white light (WL), and compared to determine rates of residual disease and upstaging. Univariate analysis was performed using Mann-Whitney U and chi-square tests, with P < 0.05 considered significant.

RESULTS

Overall, 115 patients had TURBT for NMIBC followed by a restaging TURBT within 8 weeks and were included in the analysis. Patients who underwent BL compared to WL for their initial TURBT had higher rates of benign pathology on restaging TURBT, although this was not statistically significant (47% vs. 30%; P = 0.08). Of patients with residual tumors on restaging TURBT, there were no differences in rates of Ta (22% vs. 26.5%; P = 0.62), T1 (22% vs. 26.5%; P = 0.62), or CIS (5.5% vs. 13%; P = 0.49) when the initial TURBT was done using BL compared to WL. Rates of upstaging to muscle invasive disease were also not different when initial TURBT was performed using BL compared to WL (3% vs. 4%; P = 0.78).

CONCLUSIONS

TURBT using BL does not reduce rates of residual disease or risk of upstaging on restaging TURBT in Ta or T1 disease. Thus, a restaging TURBT is still necessary even if initial TURBT was performed using BL.

Clinical and economic impact of blue light cystoscopy in the management of NMIBC at US ambulatory surgical centers: what is the site-of-service disparity?

INTRODUCTION AND OBJECTIVE

Management of non-muscle-invasive bladder cancer (NMIBC) significantly impacts healthcare resource utilization due to requirements for ongoing surveillance. White light cystoscopy (WLC) represents the traditional approach to NMIBC disease surveillance, though physicians utilizing WLC alone may fail to detect all cancerous lesions. The approval of blue light cystoscopy (BLC) as an adjunct to WLC enhances the urologist's ability to more readily detect cancerous tissue. A more complete resection will reduce recurrences and could result in reduced costs for the US healthcare system. This analysis quantifies the clinical and economic impact of the incorporation of BLC in the management of NMIBC in ambulatory surgical centers (ASCs) considering current Center for Medicare Services (CMS) patient-physician coverage and reimbursement.

METHODS AND MATERIALS

A budget impact model was developed to assess projected ASC costs for a cohort of 50 newly diagnosed bladder cancer patients over a 2-year follow-up comparing WLC alone vs. WLC + BLC. Treatment and surveillance intervals were based on AUA/SUO clinical guidelines. Clinical and cost metrics for staging and biopsy rates were assessed, with cost inputs based on Medicare reimbursement rates.

RESULTS

Use of WLC + BLC for NMIBC surveillance resulted in the identification of 5 additional NMIBC recurrences compared to WLC alone. There was an associated increased cost of performing BLC in an ASC setting, with a net increase in the total cost of care for NMIBC of $110 per cystoscopy over a 2-year period. If recurrences missed using WLC alone were to progress prior to detection, the model projects an increase in treatment costs borne by Medicare of $9,097 to $34,538 due to more intensive treatments required for the increased risk of recurrence.

CONCLUSIONS

Modeled results suggests that the Medicare program will incur increased costs, due to the gap between added costs per cystoscopy due to BLC. The current discrepancy in reimbursement disincentivizes community-based ASCs from adopting BLC, resulting in suboptimal patient care while increasing downstream treatment costs to Medicare, necessitated when missed disease progresses to higher stage/grade disease. The findings have important clinical implications for the optimal management of NMIBC and should inform healthcare policies that promote cost-effectiveness and enhanced patient outcomes.