Diagnostic performance of image technique based transurethral resection for non-muscle invasive bladder cancer: systematic review and diagnostic meta-analysis

Advanced optical imaging techniques for bladder cancer detection and diagnosis: a systematic review

OBJECTIVES

To systematically assess the current available literature concerning advanced optical imaging methods for the detection and diagnosis of bladder cancer (BCa), focusing particularly on the sensitivity and specificity of these techniques.

METHODS

First a scoping search was performed to identify all available optical techniques for BCa detection and diagnosis. The optical imaging techniques used for detecting BCa are: the Storz professional image enhancement system (IMAGE1 S), narrow-band imaging (NBI), photoacoustic imaging (PAI), autofluorescence imaging (AFI), photodynamic diagnosis (PDD), and scanning fibre endoscopy (SFE). The staging and grading techniques for BCa are: optical coherence tomography (OCT), confocal laser endomicroscopy (CLE), Raman spectroscopy, endocytoscopy, and non-linear optical microscopy (NLO). Then a systematic literature search was conducted using MEDLINE, EMBASE and Web of Science from inception to 21 November 2023. Articles were screened and selected by two independent reviewers. Inclusion criteria were: reporting on both the sensitivity and specificity of a particular technique and comparison to histopathology, and in the case of a detection technique comparison to white light cystoscopy (WLC).

RESULTS

Out of 6707 articles, 189 underwent full-text review, resulting in 52 inclusions. No articles met criteria for IMAGE1 S, PAI, SFE, Raman spectroscopy, and endocytoscopy. All detection techniques showed higher sensitivity than WLC, with NBI leading (87.8-100%). Overall, detection technique specificity was comparable to WLC, with PDD being most specific (23.3-100%). CLE and OCT varied in sensitivity and specificity, with OCT showing higher specificity for BCa diagnosis, notably for carcinoma in situ (97-99%) compared to CLE (62.5-81.3%). NLO demonstrated high sensitivity and specificity (90-97% and 77-100%, respectively) based on limited data from two small ex vivo studies.

CONCLUSIONS

Optical techniques with the most potential are PDD for detecting and OCT for staging and grading BCa. Further research is crucial to validate their integration into routine practice and explore the value of other imaging techniques.

Carcinoma In Situ (CIS): Is There a Difference in Efficacy between Various BCG Strains? A Comprehensive Review of the Literature

Introduction: Intravesical Bacillus Calmette-Guérin (BCG) immunotherapy is the standard of care for high-risk and intermediate-risk non-muscle-invasive bladder cancer (NMIBC) as well as for Carcinoma in situ (CIS). Evidence supports that the different BCG strains, despite genetic variability, are equally effective clinically for preventing the recurrence and progression of papillary NMIBC. The available evidence regarding possible differences in clinical efficacy between various BCG strains in CIS is lacking. Methods: We reviewed the literature on the efficacy of different BCG strains in patients with CIS (whether primary, secondary, concomitant, or unifocal/multifocal), including randomized clinical trials (RCTs), phase II/prospective trials, and retrospective studies with complete response rates (CRR), recurrence-free survival (RFS), or progression-free survival (PFS) as endpoints. Results: In most studies, being RCTs, phase II prospective trials, or retrospective studies, genetic differences between BCG strains did not translate into meaningful differences in clinical efficacy against CIS, regardless of the CIS subset (primary, secondary, or concurrent) or CIS focality (unifocal or multifocal). CRR, RFS, and PFS were not statistically different between various BCG strains. None of these trials were designed as head-to-head comparisons between BCG strains focusing specifically on CIS. Limitations include the small sample size of many studies and most comparisons between strains being indirect rather than head-to-head. Conclusions: This review suggests that the clinical efficacy of the various BCG strains appears similar, irrespective of CIS characteristics. However, based on the weak level of evidence available and underpowered studies, randomized studies in this space should be encouraged as no definitive conclusion can be drawn at this stage.

Comparison of hexaminolevulinate (HAL) -guided versus white light transurethral resection for NMIBC: A systematic review and meta-analysis of randomized controlled trials

PURPOSE

We systematically reviewed the effectiveness of hexaminolevulinic acid (HAL) after traditional light cystoscopy vs. only white light cystoscopy (WLC) on nonmuscle-invasive bladder cancer (NMIBC) clinical outcomes.

METHODS

Systematic literature searches of PubMed, Embase, Web of Science, and the Cochrane database and reference lists were performed. A total of 12 randomized controlled trials (RCTs) of HAL fluorescent cystoscopy (FC) and WLC vs. white light cystoscopy alone for the diagnosis of initial or recurrent bladder cancer that reported bladder cancer recurrence, progression, recurrence-free survival (RFS), and other effects were selected for review.

RESULTS

Our results included 2,775 patients identified for analysis and showed that the HAL group had a lower recurrence rate than the white light cystoscopy group with a statistically significant difference (RR=0.77, 95% CI 0.69-0.85. P < 0.05), and this advantage still existed for patients receiving intravesical chemotherapy. There was also a statistically significant difference in favour of fluorescent cystoscopy in recurrence-free survival and progression rate (HR=0.79, 95% CI 0.67-0.92. P < 0.05, RR = 0.63, 95% CI 0.43-0.94. P < 0.05, respectively). The time to first recurrence was not significantly different from that in the WLC group (SMD=0.73, 95% CI, -0.39-1.85. P = 0.2). And the HAL group did not have a significantly reduced residual tumor rate (RR=0.59, 95% CI 0.23-1.51. P = 0.27).

CONCLUSIONS

Fluorescent cystoscopy was associated with a reduced risk of bladder cancer recurrence and reduced progression rate; it also has advantages for RFS. However, there was no significant difference in the rate of residual tumor and the time of first recurrence. More studies are needed to better understand the effects of the photosensitizer used on NMIBC patients.

Photodynamic versus white-light-guided resection of first-diagnosis non-muscle-invasive bladder cancer: PHOTO RCT

BACKGROUND

Around 7500 people are diagnosed with non-muscle-invasive bladder cancer in the UK annually. Recurrence following transurethral resection of bladder tumour is common, and the intensive monitoring schedule required after initial treatment has associated costs for patients and the NHS. In photodynamic diagnosis, before transurethral resection of bladder tumour, a photosensitiser that is preferentially absorbed by tumour cells is instilled intravesically. Transurethral resection of bladder tumour is then conducted under blue light, causing the photosensitiser to fluoresce. Photodynamic diagnosis-guided transurethral resection of bladder tumour offers better diagnostic accuracy than standard white-light-guided transurethral resection of bladder tumour, potentially reducing the chance of subsequent recurrence.

OBJECTIVE

The objective was to assess the clinical effectiveness and cost-effectiveness of photodynamic diagnosis-guided transurethral resection of bladder tumour.

DESIGN

This was a multicentre, pragmatic, open-label, parallel-group, non-masked, superiority randomised controlled trial. Allocation was by remote web-based service, using a 1 : 1 ratio and a minimisation algorithm balanced by centre and sex.

SETTING

The setting was 22 NHS hospitals.

PARTICIPANTS

Patients aged ≥ 16 years with a suspected first diagnosis of high-risk non-muscle-invasive bladder cancer, no contraindications to photodynamic diagnosis and written informed consent were eligible.

INTERVENTIONS

Photodynamic diagnosis-guided transurethral resection of bladder tumour and standard white-light cystoscopy transurethral resection of bladder tumour.

MAIN OUTCOME MEASURES

The primary clinical outcome measure was the time to recurrence from the date of randomisation to the date of pathologically proven first recurrence (or intercurrent bladder cancer death). The primary health economic outcome was the incremental cost per quality-adjusted life-year gained at 3 years.

RESULTS

We enrolled 538 participants from 22 UK hospitals between 11 November 2014 and 6 February 2018. Of these, 269 were allocated to photodynamic diagnosis and 269 were allocated to white light. A total of 112 participants were excluded from the analysis because of ineligibility (n = 5), lack of non-muscle-invasive bladder cancer diagnosis following transurethral resection of bladder tumour (n = 89) or early cystectomy (n = 18). In total, 209 photodynamic diagnosis and 217 white-light participants were included in the clinical end-point analysis population. All randomised participants were included in the cost-effectiveness analysis. Over a median follow-up period of 21 months for the photodynamic diagnosis group and 22 months for the white-light group, there were 86 recurrences (3-year recurrence-free survival rate 57.8%, 95% confidence interval 50.7% to 64.2%) in the photodynamic diagnosis group and 84 recurrences (3-year recurrence-free survival rate 61.6%, 95% confidence interval 54.7% to 67.8%) in the white-light group (hazard ratio 0.94, 95% confidence interval 0.69 to 1.28; p = 0.70). Adverse event frequency was low and similar in both groups [12 (5.7%) in the photodynamic diagnosis group vs. 12 (5.5%) in the white-light group]. At 3 years, the total cost was £12,881 for photodynamic diagnosis-guided transurethral resection of bladder tumour and £12,005 for white light. There was no evidence of differences in the use of health services or total cost at 3 years. At 3 years, the quality-adjusted life-years gain was 2.094 in the photodynamic diagnosis transurethral resection of bladder tumour group and 2.087 in the white light group. The probability that photodynamic diagnosis-guided transurethral resection of bladder tumour was cost-effective was never > 30% over the range of society's cost-effectiveness thresholds.

LIMITATIONS

Fewer patients than anticipated were correctly diagnosed with intermediate- to high-risk non-muscle-invasive bladder cancer before transurethral resection of bladder tumour and the ratio of intermediate- to high-risk non-muscle-invasive bladder cancer was higher than expected, reducing the number of observed recurrences and the statistical power.

CONCLUSIONS

Photodynamic diagnosis-guided transurethral resection of bladder tumour did not reduce recurrences, nor was it likely to be cost-effective compared with white light at 3 years. Photodynamic diagnosis-guided transurethral resection of bladder tumour is not supported in the management of primary intermediate- to high-risk non-muscle-invasive bladder cancer.

FUTURE WORK

Further work should include the modelling of appropriate surveillance schedules and exploring predictive and prognostic biomarkers.

TRIAL REGISTRATION

This trial is registered as ISRCTN84013636.

FUNDING

This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 40. See the NIHR Journals Library website for further project information.

PDD-guided tumor excision combined with photodynamic therapy in patients with extramammary Paget's disease

BACKGROUND

In recent years, photodynamic diagnosis (PDD) has been a technique that plays a pivotal role in visualizing tumor size during the assessment of surgery. Photodynamic therapy (PDT) is a developing treatment method apart from surgery, chemotherapy, radiotherapy, and immunotherapy and is approved for several types of tumors and nonmalignant diseases. The purpose of this study was to illustrate the efficiency and safety of PDD-guided tumor excision combined with ALA-PDT in patients with extramammary Paget's disease (EMPD).

METHODS

In our study, 7 cases of EMPD were treated with PDD-guided tumor excision combined with ALA-PDT. After removal of the tumor detected by PDD, each tumor region was irradiated with 177 J/cm² using a 635-nm laser for 15 min. Two to four ALA-PDT cycles were applied during and after surgery. EMPD was confirmed by biopsy.

RESULTS

PDD may forecast tumor margins in EMPD to guide surgery, and PDT has an inhibitory effect on tumor growth. There was no local recurrence in the follow-up of 2.9 years (range, 0.8-5 years). Only one patient experienced distant recurrence under the armpit. The patients with EMPD were able to complete the treatment protocol, with good results and no significant side effects.

CONCLUSIONS

The present study demonstrated an effective protocol using PDD for diagnosis and PDT for multiple therapies, showing potential as an alternative clinical treatment for EMPD.

Role of Macroscopic Image Enhancement in Diagnosis of Non-Muscle-Invasive Bladder Cancer: An Analytical Review

Early diagnosis of non-muscle-invasive bladder cancer (NMIBC) is of paramount importance to prevent morbidity and mortality due to bladder cancer. Although white light imaging (WLI) cystoscopy has long been considered the gold standard in the diagnosis of bladder cancer, it can miss lesions in a substantial percentage of patients and is very likely to miss carcinoma in situ and dysplasia. Tumor margin detection by WLI can be inaccurate. Moreover, WLI could, sometimes, be inadequate in distinguishing inflammation and malignancy. To improve the diagnostic efficacy of cystoscopy, various optical image enhancement modalities have been studied. These image enhancement modalities have been classified as macroscopic, microscopic, or molecular. Photodynamic diagnosis (PDD), narrow band imaging (NBI), and Storz image 1 S enhancement (formerly known as SPIES) are macroscopic image enhancement modalities. A relevant search was performed for literature describing macroscopic image enhancement modalities like PDD, NBI, and image 1 S enhancement. The advantages, limitations, and usefulness of each of these in the diagnosis of bladder cancer were studied. Photodynamic diagnosis requires intravesical instillation of a photosensitizing agent and a special blue light cystoscope system. PDD has been shown to be more sensitive than WLI in the detection of bladder cancer. It is superior to WLI in the detection of flat lesions. Bladder tumor resection (TURBT) by PDD results in more complete resection and reduced recurrence rates. PDD-guided TURBT may have some role in reducing the risk of progression. Narrow band imaging provides increased contrast between normal and abnormal tissues based on neovascularization, thereby augmenting WLI. NBI requires a special light source. There is no need for intravesical contrast instillation. NBI is superior to WLI in the detection of bladder cancer. The addition of NBI to WLI improves the detection of flat lesions like carcinoma in situ. NBI is not useful in predicting invasive tumors or grades of tumors. NBI-directed TURBT reduces recurrence rates and recurrence free survival. But its efficacy in retarding progression is unproven. Image 1 S-enhancement utilizes software-based image enhancement modes without the need for a special light source or intravesical contrast instillation. This system provides high-quality images and identifies additional abnormal-looking areas. Another advantage of this system is simultaneous side-by-side visualization of WLI and enhanced image, providing WLI images as the control for comparison. As with PDD, S-enhancement produces a lower rate of a missed bladder cancer diagnosis. The system significantly improves the diagnosis of NMIBC. The sensitivity and negative predictive value of image 1 S enhancement increase with the increase in cancer grade. A negative test by S-enhancement effectively rules out NMIBC. All the image enhancement modalities have proven their utility in improving detection and short-term cancer control. But none of these modalities have proven their utility in delaying progression, or in long-term cancer control. Cancer progression and long-term control are governed by the biological nature of cancer cells. Early detection by optical enhancement may not be of utility in this regard. Well-designed studies are needed to establish the efficacy of these modalities in the evaluation of patients with bladder cancer. The last word, in this regard, is yet to be written.

Current Status of Photodynamic Technology for Urothelial Cancer

5‐Aminolevulinic acid is a new‐generation photosensitizer with high tumor specificity. It has been used successfully in the diagnosis, treatment, and screening of urological cancers including bladder cancer; specifically, it has been used in photodynamic diagnosis to detect tumors by illuminating the lesion with a specific wavelength of light to produce fluorescence in the lesion after administration of 5‐aminolevulinic acid, in photodynamic therapy, which induces tumor cell death via production of cytotoxic reactive oxygen species, and in photodynamic screening, in which porphyrin excretion in the blood and urine is used as a tumor biomarker after administration of 5‐aminolevulinic acid. In addition to these applications in urological cancers, 5‐aminolevulinic acid–based photodynamic technology is expected to be used as a novel strategy for a large number of cancer types because it is based on a property of cancer cells known as the Warburg effect, which is a basic biological property that is common across all cancers.

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.

Significance of 5-Aminolevulinic Acid-mediated Photodynamic Diagnosis Following Standard Transurethral Resection in Non-muscle Invasive Bladder Cancer

BACKGROUND/AIM

Transurethral resection of bladder tumors (TURBT) guided by photodynamic diagnosis (PDD) with 5-aminolevulinic acid (5-ALA) has been shown to be superior to conventional white light (WL) cystoscopy with regard to diagnostic accuracy, for non-muscle invasive bladder cancer (NMIBC); however, PDD is usually performed prior to WL TURBT. The objective of this study was to investigate the diagnostic significance of 5-ALA-mediated PDD following TUR of NMIBC.

PATIENTS AND METHODS

In 83 NMIBC patients, all visible tumors were completely resected under the conventional WL guidance followed by additional resection if fluorescent lesions were observed under the blue light (BL) guidance, and random biopsy was further conducted.

RESULTS

With the BL source, 39 (47.0%) patients were judged to have fluorescent lesions. Twenty (51.3%) of the 39 patients with positive findings by PDD were diagnosed with residual cancer by additional resection, while random biopsy detected cancers in 2 (4.5%) of the 44 patients with negative findings by PDD. Accordingly, the sensitivity, specificity, positive predictive value and negative predictive value in diagnosing residual cancer by our PDD system were 90.9, 68.9, 51.3 and 95.5%, respectively. Univariate analysis showed that the presence of residual cancers shown by WL TURBT was significantly associated with the preoperative findings of urinary cytology, tumor multiplicity, pathological T stage and tumor grade, of which only the preoperative finding on urinary cytology was shown to have an independent impact on the diagnosis of residual cancer.

CONCLUSION

5-ALA-mediated PDD following standard WL TURBT could improve the diagnostic accuracy in NMIBC patients, particularly those who are positive for preoperative urinary cytology.

Monopolar versus bipolar transurethral resection of bladder tumors: An updated systematic review and meta-analysis of existing studies

BACKGROUND

To compare the efficacy and safety of bipolar and monopolar transurethral resection of bladder tumors (TURBT) in non-muscle invasive bladder cancer (NMIBC) treatment.

METHODS

This protocol established in this study has been reported following the preferred reporting items for systematic review and meta-analysis protocols. Web of Science, PubMed, EMBASE, and the Cochrane Library were searched for all randomized controlled trials comparing bipolar TURBT and monopolar TURBT in NMIBC treatment until 31st of June 2020. We will use a combination of Medical Subject Heading and free-text terms with various synonyms to search based on the eligibility criteria. Two investigators independently reviewed the included studies and extracted relevant data. The odds ratio and 95% confidence intervals of were used as effect estimate. I-square (I) test, substantial heterogeneity, sensitivity analysis, and publication bias assessment will be performed accordingly. Stata 15.0 and Review Manger 5.3 are used for meta-analysis and systematic review.

RESULTS

The results will be published in a peer-reviewed journal.

CONCLUSION

The results of this review will be widely disseminated through peer-reviewed publications and conference presentations. This evidence may also provide helpful evidence of the efficacy and safety of bipolar and monopolar transurethral resection of TURBT in NMIBC treatment.

PROSPERO REGISTRATION NUMBER

CRD42020151997.

Endoscopic Molecular Imaging plus Photoimmunotherapy: A New Strategy for Monitoring and Treatment of Bladder Cancer

Due to the high recurrence and progression rate of non-muscle invasive bladder cancer after transurethral resection of bladder tumor, some new optical imaging technologies have arisen as auxiliary imaging modes for white light cystoscopy to improve the detection rate of small or occult tumor lesions, such as photodynamic diagnosis, narrow-band imaging, and molecular imaging. White light cystoscopy is inadequate and imperfect for bladder cancer detection, and thus residual tumors or coexisting flat malignant lesions, especially carcinoma in situ, would be ignored during conventional resection. The bladder, a hollow organ with high compliance, provides an ideal closed operation darkroom for endoscopic molecular imaging free from interference of external light sources. Also, intravesical instillation of a molecular fluorescent tracer is simple and convenient before surgery through the urethra. Molecular fluorescent tracer has high sensitivity and specificity to tumor cells, and its mediated molecular imaging allows small or occult tumor lesion detection while minimizing false-positive results. Meanwhile, endoscopic molecular imaging provides a real-time and dynamic image during surgery, which helps urologists to perform high-quality and complete tumor resection through accurate judgment of tumor boundaries and depth of invasion. Photoimmunotherapy is a novel molecular targeted therapeutic pattern of photodynamic therapy that kills malignant cells selectively and minimizes the cytotoxicity to normal tissues. The combination of endoscopic molecular imaging and photoimmunotherapy used in initial treatment may avoid the need of repeat transurethral resection in strictly selected patients and improve oncological outcomes such as recurrence-free survival and overall survival after operation.

Transurethral Resection of Bladder Tumour: The Neglected Procedure in the Technology Race in Bladder Cancer

Transurethral resection of bladder tumour is the initial, most critical step in the management of bladder cancer; as such, this is a call to arms for the urological community to it the due diligence it deserves regarding technology and training.