Optical improvements in the diagnosis of bladder cancer: implications for clinical practice

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.

Urinary extracellular vesicles-encapsulated miRNA signatures: A new paradigm for urinary bladder cancer diagnosis and classification

Bladder cancer (BCa) stands as prevalent malignancy of the urinary system globally, especially among men. The clinical classification of BCa into non-muscle invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) is crucial for prognosis and treatment decisions. However, challenges persist in current diagnostic methods like Urine cytopathology that shows poor sensitivity therefore compromising on accurately diagnosing and monitoring BCa. In recent years, research has emphasized the importance of identifying urine and blood-based specific biomarkers for BCa that can enable early and precise diagnosis, effective tumor classification, and monitoring. The convenient proximity of urine with the urinary bladder epithelium makes urine a good source of noninvasive biomarkers, in particular urinary EVs because of the packaged existence of tumor-associated molecules. Therefore, the review assesses the potential of urinary extracellular vesicles (uEVs) as noninvasive biomarkers for BCa. We have elaborately reviewed and discussed the research that delves into the role of urinary EVs in the context of BCa diagnosis and classification. Extensive research has been dedicated to investigating differential microRNA (miRNA) expressions, with the goal of establishing distinct, noninvasive biomarkers for BCa. The identification of such biomarkers has the potential to revolutionize early detection, risk stratification, therapeutic interventions, and ultimately, the long-term prognosis of BCa patients. Despite notable advancements, inconsistencies persist in the biomarkers identified, methodologies employed, and study populations. This review meticulously compiles reported miRNA biomarkers, critically assessing the variability and discrepancies observed in existing research. By synthesizing these findings, the article aims to direct future studies toward a more cohesive and dependable approach in BCa biomarker identification, fostering progress in patient care and management.

Evaluation of a polarization-enhanced laparoscopy prototype for improved intra-operative visualization of peritoneal metastases

Despite careful staging, the accuracy for preoperative detection of small distant metastases remains poor, creating a clinical need for enhanced operative staging to detect occult peritoneal metastases. This study evaluates a polarization-enhanced laparoscopy (PEL) prototype and assesses its potential for label-free contrast enhancement of peritoneal metastases. This is a first-in-human feasibility study, including 10 adult patients who underwent standard staging laparoscopy (SSL) for gastrointestinal malignancy along with PEL. Image frames of all detectable peritoneal lesions underwent analysis. Using Monte Carlo simulations, contrast enhancement based on the color dependence of PEL (mPEL) was assessed. The prototype performed safely, yet with limitations in illumination, fogging of the distal window, and image co-registration. Sixty-five lesions (56 presumed benign and 9 presumed malignant) from 3 patients represented the study sample. While most lesions were visible under human examination of both SSL and PEL videos, more lesions were apparent using SSL. However, this was likely due to reduced illumination under PEL. When controlling for such effects through direct comparisons of integrated (WLL) vs differential (PEL) polarization laparoscopy images, we found that PEL imaging yielded an over twofold Weber contrast enhancement over WLL. Further, enhancements in the discrimination between malignant and benign lesions were achieved by exploiting the PEL color contrast to enhance sensitivity to tissue scattering, influenced primarily by collagen. In conclusion, PEL appears safe and easy to integrate into the operating room. When controlling for the degree of illumination, image analysis suggested a potential for mPEL to provide improved visualization of metastases.

Photodynamic Therapy for Bladder Cancers, A Focused Review†

Bladder cancer is the first cancer for which PDT was clinically approved in 1993. Unfortunately, it was unsuccessful due to side effects like bladder contraction. Here, we summarized the recent progress of PDT for bladder cancers, focusing on photosensitizers and formulations. General strategies to minimize side effects are intravesical administration of photosensitizers, use of targeting strategies for photosensitizers and better control of light. Non-muscle invasive bladder cancers are more suitable for PDT than muscle invasive and metastatic bladder cancers. In 2010, the FDA approved blue light cystoscopy, using PpIX fluorescence, for photodynamic diagnosis of non-muscle invasive bladder cancer. PpIX produced from HAL was also used in PDT but was not successful due to low therapeutic efficacy. To enhance the efficacy of PpIX-PDT, we have been working on combining it with singlet oxygen-activatable prodrugs. The use of these prodrugs increases the therapeutic efficacy of the PpIX-PDT. It also improves tumor selectivity of the prodrugs due to the preferential formation of PpIX in cancer cells resulting in decreased off-target toxicity. Future challenges include improving prodrugs and light delivery across the bladder barrier to deeper tumor tissue and generating an effective therapeutic response in an In vivo setting without causing collateral damage to bladder function.

Surgical experience is predictive for bladder tumour resection quality

OBJECTIVES

To assess the resection quality of transurethral bladder tumour resection (TURBT) and the association to surgeon experience depending on the presence of detrusor muscle.

METHODS

A retrospective study on 640 TURBT procedures performed at Zealand University Hospital, Denmark, from 1 January 2015 - 31 December 2016. Data included patient characteristics, procedure type, surgeon category, supervisor presence, surgical report data, pathological data, complications data and recurrence data. Analysis was performed using simple and multiple logistic regression on the association between surgeon experience and the presence of detrusor muscle in resected tissue from TURBT.

RESULTS

Supervised junior residents had significant lower detrusor muscle presence (73%) compared with consultants (83%) (OR = 0.4, 95% CI = 0.21-0.83). Limitations were the retrospective design and the diversity of included TURBT.

CONCLUSIONS

It was found that surgical experience predicts detrusor muscle presence and supervised junior residents performing TURBT on patients resulted in less detrusor muscle than consultants.

Urine exosomes as biomarkers in bladder cancer diagnosis and prognosis: From functional roles to clinical significance

Bladder cancer is one of the top ten most common cancers and top ten causes of cancer death globally. 5-year survival rates have decreased in Australia from 66% to 55% in the past three decades. The current gold standard for diagnosis is cystoscopy. However, cystoscopies are an invasive and health-resource intensive procedure which has sub-optimal sensitivity for flat lesions such as CIS (carcinoma in situ) and low specificity for differentiating inflammation from cancer - hence requiring biopsies under anesthesia. Frequent and life-long surveillance cystoscopy is required for most patients since there are high rates of progression and local recurrence in high-risk non-muscle invasive cancer (NMIBC) as well as poor outcomes associated with delayed detection of muscle-invasive bladder cancer (MIBC). There is an unmet need for a non-invasive test to provide better discrimination and risk-stratification of bladder cancer which could aid clinicians by improving patient selection for cystoscopy; enhanced risk stratification methods may guide the frequency of surveillance cystoscopies and inform treatment choices. Exosomes, which are nano-sized extracellular vesicles containing genetic material and proteins, have been shown to have functional roles in the development and progression of bladder cancer. Exosomes have also been demonstrated to be a robust source of potential biomarkers for bladder cancer diagnosis and prognosis and may also have roles as therapeutic agents. In this review, we summarize the latest evidence of biological roles of exosomes in bladder cancer and highlight their clinical significance in bladder cancer diagnosis, surveillance and treatment.

Evaluation of an image enhancement system for the assessment of nasal and paranasal sinus diseases

PURPOSE

Dysplasia and cancer of the upper aerodigestive tract are characterized by significant neoangiogenesis. This can be recognized by optical methods like the Storz Professional Image Enhancement System (SPIES). Up to now, there are no reports of using this novel technique for examining nasal diseases. The objective of this study was to evaluate the use of SPIES during sinus surgery to help differentiate various nasal pathologies and determine their extension.

METHODS

Patients (n = 27) with different pathologies in the region of the paranasal sinuses were operated via functional endoscopic surgery using a 2D-HD-camera with white light and SPIES. In addition, 10 healthy individuals were examined. The system was evaluated using two different questionnaires.

RESULTS

The handling and operation of SPIES was intuitive and easy. Use of SPIES did not prolong the procedure. There was no disturbing image distortion. SPIES seemed to improve the visualization, differentiation and evaluation of vascularization of paranasal pathologies and allowed for precise and accurate surgery. Compared to examination with the 2D-HD-camera and white light alone, SPIES appeared to facilitate the identification of mucosal pathologies.

CONCLUSION

SPIES could be a promising adjunct tool to evaluate nasal pathologies intraoperatively. Especially in the case of vascularized tumors the enhanced image endoscopy seemed to be clearly superior to standard white light alone. In our study, the system facilitated the assessment of tumor extension and vascularization as well as the differentiation of healthy mucosa. Future randomized studies will be necessary to prove the potential of integrating this novel technique into the clinical routine for the differentiation of nasal pathologies and the improvement of resection margins during nasal tumor surgery.

DNA Hydroxymethylation in Smoking-Associated Cancers

5-hydroxymethylcytosine (5-hmC) was first detected in mammalian DNA five decades ago. However, it did not take center stage in the field of epigenetics until 2009, when ten-eleven translocation 1 (TET1) was found to oxidize 5-methylcytosine to 5-hmC, thus offering a long-awaited mechanism for active DNA demethylation. Since then, a remarkable body of research has implicated DNA hydroxymethylation in pluripotency, differentiation, neural system development, aging, and pathogenesis of numerous diseases, especially cancer. Here, we focus on DNA hydroxymethylation in smoking-associated carcinogenesis to highlight the diagnostic, therapeutic, and prognostic potentials of this epigenetic mark. We describe the significance of 5-hmC in DNA demethylation, the importance of substrates and cofactors in TET-mediated DNA hydroxymethylation, the regulation of TETs and related genes (isocitrate dehydrogenases, fumarate hydratase, and succinate dehydrogenase), the cell-type dependency and genomic distribution of 5-hmC, and the functional role of 5-hmC in the epigenetic regulation of transcription. We showcase examples of studies on three major smoking-associated cancers, including lung, bladder, and colorectal cancers, to summarize the current state of knowledge, outstanding questions, and future direction in the field.

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.

Label-free optical redox ratio from urinary extracellular vesicles as a screening biomarker for bladder cancer

Extracellular vesicles (EVs) have been studied for their potential applications in cancer screening, diagnosis, and treatment monitoring. Most studies have focused on the bulk content of EVs; however, it is also informative to investigate their metabolic status, and changes under different physiological and environmental conditions. In this study, noninvasive, multimodal, label-free nonlinear optical microscopy was used to evaluate the optical redox ratio of large EVs (microvesicles) isolated from the urine of 11 dogs in three cohorts (4 healthy, 4 transitional cell carcinoma (TCC) of the bladder, and 3 prostate cancer). The optical redox ratio is a common metric comparing the autofluorescence intensities of metabolic cofactors FAD and NAD(P)H to characterize the metabolic profile of cells and tissues, and has recently been applied to EVs. The optical redox ratio revealed that dogs with TCC of the bladder had a more than 2-fold increase in NAD(P)H-rich urinary EVs (uEVs) when compared to healthy dogs, whereas dogs with prostate cancer had no significant difference. The optical redox ratio values of uEVs kept at -20°C for 48 hours were significantly different from those of freshly isolated uEVs, indicating that this parameter is more reliable when assessing freshly isolated uEVs. These results suggest that the label-free optical redox ratio of uEVs, indicating relative rates of glycolysis and oxidative phosphorylation of parent cells and tissues, may act as a potential screening biomarker for bladder cancer.

Enhanced Visualization Methods for First Transurethral Resection of Bladder Tumour in Suspected Non-muscle-invasive Bladder Cancer: A Health Technology Assessment

BACKGROUND

Bladder cancer begins in the innermost lining of the bladder wall and, on histological examination, is classified as one of two types: non-muscle-invasive bladder cancer (NMIBC) or muscle-invasive bladder cancer. Transurethral resection of bladder tumour (TURBT) is the standard treatment for people with NMIBC, but the high rate of cancer recurrence after first TURBT is a challenge that physicians and patients face. Tumours seen during follow-up may have been missed or incompletely resected during first TURBT. TURBT is conventionally performed using white light to see the tumours. However, small papillary or flat tumours may be missed with the use of white light alone. With the emergence of new technologies to improve visualization during TURBT, better diagnostic and patient outcomes may be expected. We conducted a health technology assessment of two enhanced visualization methods, both as an adjunct to white light to guide first TURBT for people with suspected NMIBC-hexaminolevulinate hydrochloride (HAL), a solution that is instilled into the bladder to make tumours fluoresce under blue-violet light, and narrow band imaging (NBI), a technology that filters light into wavelengths that can be absorbed by hemoglobin in the tumours, making them appear darker. Our assessment included an evaluation of effectiveness, safety, cost-effectiveness, and the budget impact of publicly funding these new technologies to improve patient outcomes following first TURBT. The use of NBI in diagnostic cystoscopy was out of scope for this health technology assessment.

METHODS

We performed a systematic literature search of the clinical evidence from inception to April 15, 2020. We searched for randomized controlled trials (RCTs) that compared the outcomes of first TURBT with the use of HAL or NBI, both as an adjunct to white light, with the outcomes of first TURBT using white light alone, or studies that made such comparison between HAL and NBI. We conducted pairwise meta-analyses using a fixed effects model where head-to-head comparisons were available. In the absence of any published RCT for comparison between HAL and NBI, we indirectly compared the two technologies through indirect treatment comparison (ITC) analysis. We assessed the risk of bias of each included study using the Cochrane risk-of-bias tool. We assessed the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 15-year time horizon from a public payer perspective. We also analyzed the budget impact of publicly funding HAL and NBI as an adjunct to white light in people undergoing their first TURBT for suspected non-muscle-invasive bladder cancer in Ontario.

RESULTS

In the clinical evidence review, we identified 8 RCTs that used HAL or NBI as an adjunct to white light during first TURBT. Pairwise meta-analysis of HAL studies showed that HAL-guided TURBT as an adjunct to white light significantly reduces recurrence rate at 12 months compared with TURBT using white light alone (risk ratio 0.70, 95% confidence interval [CI] 0.51-0.95) (GRADE: Moderate). Five-year recurrence-free survival was significantly higher when HAL was used as an adjunct to white light than when white light was used alone (GRADE: Moderate). There was little to no difference in the tumour progression rate (GRADE: Moderate).Meta-analysis of NBI studies did not show a significant difference between NBI-guided TURBT as an adjunct to white light and TURBT using white light alone in reducing the rate of recurrence at 12 months (risk ratio 0.94, 95% CI 0.75-1.19) (GRADE: Moderate). No evidence on the effect on recurrence-free survival or tumour progression rate was identified for NBI-guided TURBT. The indirect estimate from the network analysis showed a trend toward a lower rate of recurrence after HAL-guided TURBT than after NBI-guided TURBT but the difference was not statistically significant (risk ratio 0.76, 95% CI 0.51-1.11) (GRADE: Low). Studies showed that use of HAL or NBI during TURBT was generally safe.The incremental cost-effectiveness ratio of HAL-guided TURBT compared with NBI-guided TURBT, both as an adjunct to white light, is $12,618 per quality-adjusted life-year (QALY) gained. Compared with TURBT using white light alone and using adjunct NBI, the probability of HAL-guided TURBT being cost-effective is 69.1% at a willingness-to-pay value of $50,000 per QALY gained and 74.6% at a willingness-to-pay of $100,000 per QALY gained. The annual budget impact of publicly funding HAL-guided TURBT in Ontario over the next 5 years ranges from an additional $0.6 million in year 1 to $2.5 million in year 5.

CONCLUSIONS

First TURBT guided by HAL as an adjunct to white light likely reduces the rate of recurrence at 12 months and increases 5-year recurrence-free survival when compared with first TURBT using white light alone. There is likely little to no difference in the tumour progression rate. First TURBT guided by NBI as an adjunct to white light likely results in little to no difference in the rate of recurrence at 12 months when compared with first TURBT using white light alone. Based on an indirect comparison, there may be little to no difference in cancer recurrence rate between HAL-guided and NBI-guided first TURBT. Use of HAL or NBI during first TURBT is generally safe. For people undergoing their first TURBT for suspected non-muscle-invasive bladder cancer, using HAL as an adjunct to white light is likely to be cost-effective compared with using white light alone or with using NBI as an adjunct to white light. We estimate that publicly funding HAL as an adjunct to white light to guide first TURBT for people in Ontario with suspected NMIBC would result in additional costs of between $0.6 million and $2.5 million per year over the next 5 years.

Limited utility of 5-ALA optical fluorescence in endoscopic endonasal skull base surgery: a multicenter retrospective study

OBJECTIVE

Incomplete resection of skull base pathology may result in local tumor recurrence. This study investigates the utility of 5-aminolevulinic acid (5-ALA) fluorescence during endoscopic endonasal approaches (EEAs) to increase visibility of pathologic tissue.

METHODS

This retrospective multicenter series comprises patients with planned resection of an anterior skull base lesion who received preoperative 5-ALA at two tertiary care centers. Diagnostic use of a blue light endoscope was performed during EEA for all cases. Demographic and tumor characteristics as well as fluorescence status, quality, and homogeneity were assessed for each skull base pathology.

RESULTS

Twenty-eight skull base pathologies underwent blue-light EEA with preoperative 5-ALA, including 15 pituitary adenomas (54%), 4 meningiomas (14%), 3 craniopharyngiomas (11%), 2 Rathke's cleft cysts (7%), as well as plasmacytoma, esthesioneuroblastoma, and sinonasal squamous cell carcinoma. Of these, 6 (21%) of 28 showed invasive growth into surrounding structures such as dura, bone, or compartments of the cavernous sinus. Tumor fluorescence was detected in 2 cases (7%), with strong fluorescence in 1 tuberculum sellae meningioma and vague fluorescence in 1 pituicytoma. In all other cases fluorescence was absent. Faint fluorescence of the normal pituitary gland was seen in 1 (7%) of 15 cases. A comparison between the particular tumor entities as well as a correlation between invasiveness, WHO grade, Ki-67, and positive fluorescence did not show any significant association.

CONCLUSIONS

With the possible exception of meningiomas, 5-ALA fluorescence has limited utility in the majority of endonasal skull base surgeries, although other pathology may be worth investigating.

A Flexible Cystoscope Based on Hydrodynamic Cavitation for Tumor Tissue Ablation

OBJECTIVE

Hydrodynamic cavitation is characterized by the formation of bubbles inside a flow due to local reduction of pressure below the saturation vapor pressure. The resulting growth and violent collapse of bubbles lead to a huge amount of released energy. This energy can be implemented in different fields such as heat transfer enhancement, wastewater treatment and chemical reactions. In this study, a cystoscope based on small scale hydrodynamic cavitation was designed and fabricated to exploit the destructive energy of cavitation bubbles for treatment of tumor tissues. The developed device is equipped with a control system, which regulates the movement of the cystoscope in different directions. According to our experiments, the fabricated cystoscope was able to locate the target and expose cavitating flow to the target continuously and accurately. The designed cavitation probe embedded into the cystoscope caused a significant damage to prostate cancer and bladder cancer tissues within less than 15 minutes. The results of our experiments showed that the cavitation probe could be easily coupled with endoscopic devices because of its small diameter. We successfully integrated a biomedical camera, a suction tube, tendon cables, and the cavitation probe into a 6.7 mm diameter cystoscope, which could be controlled smoothly and accurately via a control system. The developed device is considered as a mechanical ablation therapy, can be a solid alternative for minimally invasive tissue ablation methods such as radiofrequency (RF) and laser ablation, and could have lower side effects compared to ultrasound therapy and cryoablation.

Novel transurethral resection technologies and training modalities in the management of nonmuscle invasive bladder cancer: a comprehensive review

PURPOSE OF REVIEW

Conventional transurethral resection (TURBT) with tumor fragmentation is the primary step in the surgical treatment of nonmuscle invasive bladder cancer. Recently, new surgical techniques and training modalities have emerged with the aim to overcome short-comings of TURBT and improve oncologic outcomes. In this review, we provide a comprehensive update of recent techniques/techniques that aim to improve upon conventional TURBT and beyond.

RECENT FINDINGS

A systemic approach during conventional TURBT that features the use of a surgical checklist has been shown to improve recurrence-free survival. Several simulators have been developed and validated to provide additional training opportunities. However, transfer of improved simulator performance into real world surgery still requires validation. While there is no convincing data that demonstrate superior outcomes with bipolar TURBT, en-bloc resection already promises to offer lower rates of complications as well as potentially lower recurrence probabilities in select patients.

SUMMARY

TURBT remains the quintessential procedure for the diagnosis and treatment of bladder cancer. Urologists need to be aware of the importance and challenges of this procedure. Aside of embracing new resection techniques and a conceptual-systematic approach, training opportunities should be expanded upon to improve patient outcomes.

Evaluation of Spectra A and B Modes in Diagnosis of Suspicious Bladder Lesions

Background: White light imaging (WLI) cystoscopy, a "gold standard" for diagnosis of nonmuscle invasive bladder cancer (NMIBC), can miss ∼25% of bladder cancers. Spectra A (SA) and Spectra B (SB) are virtual optical chromoendoscopy modes introduced by Storz. Objective: To evaluate whether SA and SB improve over WLI in diagnosis of NMIBC. Design, Setting, and Participants: Storz Professional Image Enhancement System (SPIES) modes allow side-by-side viewing of WLI and spectra images. Cystoscopy images of some patients with suspected NMIBC and some normal cystoscopy findings were cut in two parts: one WLI and the other SA or SB. Each individual image was sent to the 3721 members of Urological Society of India separately through online survey. Histologic diagnosis was considered final diagnosis. Intervention: The observers were asked whether they considered the image to be cancer; yes, no, or cannot say were the three response options. Outcome Measures and Statistical Analysis: Primary outcome measure was improved diagnosis of NMIBC. Diagnostic efficacy was analyzed through 2 × 2 tables, McNemar test, and Fleiss Kappa. Results and Limitations: A total of 273 observers participated in the study. The sensitivities of WLI, SA, and SB were 89.81, 91.15, and 88.81, respectively. The specificities were 73.18, 66.17, and 68.68, respectively. In patients with cancer, both SA and SB improved the diagnostic efficacy of WLI. SA added significantly to the diagnostic accuracy over WLI (χ² = 12.23, p = 0.00046). SB also added significantly over WLI (χ² = 11.76, p = 0.0006). With increasing cancer grade, the sensitivity and negative predictive value of all modes increased. The major limitation of this study is the online diagnosis based on still images. Conclusions: In patients with cancer, SA and SB significantly add to the diagnostic accuracy of WLI. As compared with the negative WLI, if SA and SB are negative, NMIBC would be less likely.

lncRNA-UCA1 in the diagnosis of bladder cancer: A meta-analysis

BACKGROUND

The main purpose of this study is to systematically evaluate the diagnostic value of long-chain non-coding RNA urothelial carcinoembryonic antigen 1 (lncRNA-UCA1) for bladder cancer, and to provide a scientific basis for the diagnosis of bladder cancer.

METHODS

By searching PubMed, Web of Science, EMBASE, CNKI, Wanfang, Weipu and other databases, in order to collect relevant literature of lncRNA-UCA1 for diagnosis of bladder cancer. The starting and ending time of the search is from the establishment of the database to December 31, 2019. Screen documents and extract data according to inclusion and exclusion criteria. QUADAS entry tool was used to evaluate the quality of literature. Meta-Disc 1.4 and Stata 12.0 software were used for statistical analysis, and UCA1 was combined for the statistics of bladder cancer diagnosis.

RESULTS

A total of 7 articles were included in this study, including 954 cases of bladder cancer patients and 482 cases of non-bladder cancer patients. The receiver operating characteristic curve (ROC) curve AUC of lncRNA-UCA1 used to diagnose bladder cancer was 0.86. The sensitivity was 0.83 (95% CI: 0.80-0.85), and the specificity was 0.86 (95% CI: 0.82-0.89). The positive likelihood ratio is 6.38 (95% CI: 3.01-13.55), and the negative likelihood ratio is 0.20 (95% CI: 0.13-0.31). The diagnostic odds ratio is 33.13 (95% CI: 11.16-98.33).

CONCLUSION

lncRNA-UCA1 has a high value of clinical auxiliary diagnosis for bladder cancer, and it can be further promoted and applied clinically.

[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.

Photodynamic Diagnosis-Assisted En Bloc Transurethral Resection of Bladder Tumor for Nonmuscle Invasive Bladder Cancer: Short-Term Oncologic and Functional Outcomes

Background: We describe the oncologic and functional outcomes and the surgical technique of the photodynamic diagnosis (PDD)-assisted en bloc transurethral resection of bladder tumor (EBTUR) using a rectangular cutting loop. Methods: We reviewed 40 patients with carcinoma in situ-free nonmuscle invasive bladder cancer undergoing PDD-TURBT. Of 40 patients, 12 underwent photodynamic diagnosis-assisted en bloc transurethral resection of bladder tumor (PDD-EBTUR) and 28 underwent PDD-assisted conventional TURBT (cTURBT). Two groups were matched in terms of clinicopathologic background and did not include patients treated with intravesical Bacillus Calmette-Guerin. The assessment of postoperative quality of life (QoL) was based on patient-reported outcome measure, including the International Prostate Symptom Score, Functional Assessment of Cancer Therapy-Bladder (FACT-BL), and 8-item Short Form (SF-8^™) questionnaires before and 1 month after TUR. This study was approved by the Ethics commitee and all participants provided informed consent. Results: PDD guidance provided substantial help for circumferent demarcation around the bladder tumor, which precedes tumor dissection. One female patient (12%) treated by PDD-EBTUR had grade II bladder perforation requiring prolonged catheterization. Pathologic assessment of horizontal and vertical margins in resected specimens by PDD-EBTUR revealed that all specimens had muscularis propria, and the rate of en bloc resection was 100%. No patient had intravesical recurrence in the PDD-EBTUR group (median follow-up, 11 months), while two patients in the PDD-cTURBT group had T_a low-grade recurrent tumors (8 months). Postoperatively, scores of daytime frequency and nocturia were increased in both groups. QoL assessment using the FACT-BL and SF-8 revealed that postoperative deterioration of bladder-specific subscale and emotional/mental scores was found in the EBTUR group but not in the cTURBT group. Conclusions: Based on the initial experience on 12 patients, we considered that PDD-EBTUR is an acceptable surgical method. Further experience and research are mandatory to determine whether this technique yields better outcomes and has true clinical advantage.

Use of IMAGE1 S technology for detection of cholesteatoma in endoscopic ear surgery: a retrospective case series on 45 patients

PURPOSE

To evaluate the role of selected modalities of Storz Professional Image Enhancement System (IMAGE1 S) in differentiating cholesteatoma during endoscopic ear surgery (EES); to assess the potential usefulness of IMAGE1 S in recognition of cholesteatoma residuals at the end of EES.

METHODS

A retrospective study on 45 consecutive patients who underwent EES for cholesteatoma between March 2019 and November 2019 at a tertiary referral center was performed. For each case, Spectra A and Spectra B filters were applied intra-operatively. When examining the surgical field, a switch from white light (WL) to IMAGE1 S was performed to detect cholesteatoma and differentiate it from non-cholesteatomatous tissue. When the IMAGE1 S pattern was suspicious for the presence of cholesteatoma, images of the field under both enhancement modalities were taken and the targeted lesions were sent for histologic analysis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of IMAGE1 S were calculated. A final recognition of the surgical field using the selected filters was performed to detect any possible cholesteatomatous residuals.

RESULTS

Detection of cholesteatoma by IMAGE1 S selected filters revealed the following data: sensitivity 97%, specificity 95%, PPV 95%, NPV 97%. On three occasions, there was no correspondence between enhanced endoscopy and histology. In 5 out of 45 cases (11%), cholesteatoma residuals, which had not been identified at WL inspection at the end of the procedure, were detected by IMAGE1 S.

CONCLUSION

Our results suggest a potential role for IMAGE1 S Spectra A and B filters in EES for cholesteatoma surgery. We propose the integration of IMAGE1 S as a final overview of the surgical cavity for recognition of cholesteatomatous residuals.

Experience of a tertiary referral center in managing bladder cancer in conjunction with neurogenic bladder

STUDY DESIGN

Case series.

OBJECTIVES

The aim of this study was to present our experience with the management of bladder cancer (BCa) in individuals followed for neurogenic bladder (NB).

SETTING

An Italian tertiary referral center for NB.

METHODS

We retrospectively collected all pre-operative, intra-operative, and post-operative data of our NB cases with BCa, diagnosed from 2004 to 2019.

RESULTS

We included ten cases: eight with acquired spinal cord injury (SCI) and two with myelomeningocele (MMC). Considering individuals with acquired SCI, the median age at BCa diagnosis and time since SCI were 53 and 34 years, respectively. One out of seven cases had positive urine cytology. All cases underwent a radical cystectomy, diagnosing squamous cell carcinoma (SCC) and transitional cell carcinoma in 60 and 40% cases, respectively. Surgical-related complications occurred after 90% procedures. Three out of eight individuals with acquired SCI died 2, 12, and 80 months after the diagnosis. Both individuals with MMC presented no evidence of disease after 24 and 27 months.

CONCLUSIONS

BCa in individuals with NB proved to be associated with a diagnosis at an advanced stage and a high rate of surgical complications. In this population we advocate annual genitourinary ultrasound exam and urine cytology, and cystoscopy in all cases of macrohematuria. Considering the low accuracy of urine cytology and the difficult-to-interpret inflamed bladder walls at cystoscopy in NB, a patient-tailored follow-up schedule based on specific risk factors (e.g., smoking status, indwelling urinary catheter) is mandatory to diagnose and treat BCa at an early stage.

Two diagnostic criteria of optical spectroscopy for bladder tumor detection: Clinical study using 5-ALA induced fluorescence and mathematical modeling

BACKGROUND

The study proposes to improve bladder cancer diagnosis by photodynamic diagnosis (PDD) using red-light excitation (632.8 nm) of 5-ALA induced-protoporphyrin IX. Employing 9 patients' bladders, two types of signals were used to improve diagnostic accuracy for malignancy and we also present numerical modeling of the scattering coefficient to provide biological explanation of the results obtained.

METHODS

Two modalities of bladder cancer spectral diagnosis are presented: conventional PDD and intensity assessment of the diffusely reflected laser light by fiber-optic spectroscopy. Experiments are done in clinical conditions and as a series of numerical simulations.

RESULTS

High-grade cancerous bladder tissues display twice a higher relative fluorescence intensity (mean value 1, n = 9) than healthy (0.39, n = 9), dysplastic (0.44, n = 5) tissues and CIS (0.39, n = 2). The laser back-scattering signal allows to discriminate most effectively high-grade cancerous and dysplastic tissues from normal. Numerical modeling of diffuse reflectance spectra reveals that spectral behavior of the back-scattered light depends on both, nuclear size and nuclear density of tumoral cells.

CONCLUSIONS

Unlike the fluorescence signal, where its value is higher in the case of pathological tissues, the tendency of the laser signal to, both, decrease or increase in comparison with the signal from normal urothelium, should be perceived as a sign towards neoplasm. Numerical simulation reveals that such a double-analysis at a multiwavelength mode potentially may be used to provide diagnostic accuracy.

A new risk stratification model for intravesical recurrence, disease progression, and cancer-specific death in patients with non-muscle invasive bladder cancer: the J-NICE risk tables

BACKGROUND

The aim of this study is to establish new risk tables for the current clinical setting, enabling short- and long-term risk stratification for recurrence, progression, and cancer-specific death after transurethral resection in non-muscle invasive bladder cancer (NMIBC). Currently available risk tables lack input from the 2004 World Health Organization grading system and risk prediction for cancer-specific death.

METHODS

This was a multi-institutional database study of 1490 patients diagnosed with NMIBC (the development cohort). A multivariate Fine and Gray subdistribution hazard model was used to assess the prognostic impact of various factors. Patients were classified into low-, intermediate-, and high-risk groups according to a sum of the weight of selected factors, and predicted cumulative rates were calculated. Internal validation was conducted using 200 bootstrap resamples to assess the optimism for the c-index and estimate a bias-corrected c-index. External validation of the developed risk table was performed on an independent dataset of 91 patients.

RESULTS

The Japanese NIshinihon uro-onCology Extensive collaboration group (J-NICE) risk stratification table was derived from six, five, and two factors for recurrence, progression, and cancer-specific death, respectively. The internal validation bias-corrected c-index values were 0.619, 0.621, and 0.705, respectively. The application of the J-NICE table to an external dataset resulted in c-indices for recurrence, progression, and cancer-specific death of 0.527, 0.691, and 0.603, respectively.

CONCLUSIONS

We propose a novel risk stratification model that predicts outcomes of treated NMIBC and may overcome the shortcomings of existing risk models. Further external validation is required to strengthen its clinical impact.

Evaluation of autofluorescence and photodynamic diagnosis in assessment of bladder lesions

The ability to detect and diagnose bladder cancer early and precisely is crucial for effective treatment. The aim of this study is to assess the utility of optical biopsy performed with autofluorescence cystoscopy (AFC) using the Onco-LIFE system with numerical color values (NCVs) and by ALA/PDD. Histopathological examination of material obtained during TURBT and/or biopsy of the bladder was carried out in 251 patients. In the case of 35 patients, the selection of the specimen collected for histopathological examination was based using ALA/PDD. In the remaining 216 patients, tissue was collected based on the findings of AFC with NCV. Using AFC, the observed NCV ranged from 0 to 3.86; the highest mean NCV was observed in neoplastic muscle invasive lesions and was equal to 3.18. Furthermore, non-muscle invasive tumors were characterized by a mean NCV equal to 1.54. Tissue with inflammation, metaplasia, and healthy tissue demonstrated significantly lower mean NCV values. The presence of a muscle-invasive tumor increased the NCV by approximately 2.86 compared to healthy tissue. The rates of postoperative complications depend on the examining operator and are observed more often, as much as 65.7 % during ALA/PDD. AFC with NCV using the Onco-LIFE system, as well as ALA/PDD are helpful tools for early diagnosis of bladder precancerous and cancer lesions and for performing targeted biopsies. A significant correlation was found between lesion NCV index and the grade of dysplasia or tumor malignancy. Tissue with inflammation, metaplasia, and healthy tissue demonstrated significantly lower mean NCV values. AFE with NCV have a significantly higher sensitivity than specificity. Low rates of postoperative complications are correlated to the experience of the endoscopist and with AFE/NCV in comparison of ALA/PDD.

Current concept of transurethral resection of bladder cancer: from re-transurethral resection of bladder cancer to en-bloc resection

PURPOSE OF REVIEW

Transurethral resection of bladder cancer (TURB) is the critical step in the management of nonmuscle invasive bladder cancer (NMIBC). This review presents new improvements in the strategy and technique of TURB as well as in technological developments used for tumour visualization and removal.

RECENT FINDINGS

The goal of TURB is to perform complete resection of NMIBC. Tumor visualization during procedure can be improved by enhanced optical technologies. Fluorescence-guided photodynamic diagnosis (PDD) and narrow-band imaging (NBI) used during TURB can improve tumour detection and potentially reduce recurrence rate, their influence on progression, however, remains controversial. TURB can be performed using monopolar or bipolar electrocautery without significant differences in results or safety. To overcome limitations of traditional TURB, the technique of en-bloc resection was introduced to improve the quality of tumour removal. In selected cases, an early re-resection (re-TURB) within 2-6 weeks after initial procedure is recommended.

SUMMARY

TURB is a fundamental step in diagnosis and treatment of NMIBC. Urologists should be aware of promising innovations including new imaging and surgical techniques and their potential benefits. Hopefully, new technologies and performance of TURB bring improved outcomes, which can alter the indication criteria for re-TURB.

Methods for bladder cancer diagnosis - The role of autofluorescence and photodynamic diagnosis

Bladder cancer is one of the most common Genito-urinary malignant tumors in humans. Improved diagnostic and therapeutic methods that aim to reduce rates of recurrence and progression of bladder cancer are needed. In current publications, one can find information on such methods as Raman spectroscopy, ultraviolet autofluorescence microscopy, confocal laser endoscopy, photoacoustic imaging, molecular imaging, multi-photon microscopy and many other new diagnostic techniques. These methods do not show significant adverse effects and are procedures well tolerated by patients as they use mostly physical phenomena that are neutral towards the human body. This review highlights the techniques of autofluorescence (AF) or laser induced fluorescence (LIF) and photodynamic diagnostics (PDD) which have been widely clinically studied for many years as a complement to cystoscopy. These methods can be performed during standard cystoscopy and they can be used in routine practice. This review shows that Autofluorescent and Photodynamic diagnostics are effective and have great potential in enhancing the diagnosis of bladder cancer. However, more research should be performed to help realize their full potential.

A retrospective analysis of patients treated with intravesical BCG for high-risk nonmuscle invasive bladder cancer

Background

Adjuvant intravesical immunotherapy with Bacillus Calmette-Guerin (BCG) is considered as the first-line agent in patients with high-risk nonmuscle invasive bladder cancer (NMIBC) after surgery. There are no data in India where there is a high prevalence of tubercle bacillus and inherent immunity against Bacillus sp. The present study aims to evaluate the outcomes of intravesical BCG in the Indian population.

Methods

A retrospective study of 101 patients who underwent intravesical BCG for high-risk NMIBC between January 2006 and December 2015 was carried out in a single centre. We compared the recurrence-free rate and progression rate of patients who received induction alone and induction with maintenance BCG therapy. The safety profile of intravesical BCG therapy was also assessed in the study.

Results

After a median follow up of 2 years, the disease-free survival (DFS) rates of the induction group and maintenance group were 82% and 88% respectively (p = 0.233). There was no difference in progression-free survival (PFS) rates at 2 years in those who receive maintenance BCG (95%) and those with induction BCG (94.7%; p = 0.721). A total of 69.36% of our patients had local adverse events.

Conclusion

Our results suggest that maintenance therapy does not enhance the therapeutic effects of BCG in patients who respond favourably to 6 weeks of induction. Additional prospective studies are warranted in those countries where tuberculosis exposure is prevalent.

Targeting Fluorescent Nanodiamonds to Vascular Endothelial Growth Factor Receptors in Tumor

The increased expression of vascular endothelial growth factor (VEGF) and its receptors is associated with angiogenesis in a growing tumor, presenting potential targets for tumor-selective imaging by way of targeted tracers. Though fluorescent tracers are used for targeted in vivo imaging, the lack of photostability and biocompatibility of many current fluorophores hinder their use in several applications involving long-term, continuous imaging. To address these problems, fluorescent nanodiamonds (FNDs), which exhibit infinite photostability and excellent biocompatibility, were explored as fluorophores in tracers for targeting VEGF receptors in growing tumors. To explore FND utility for imaging tumor VEGF receptors, we used click-chemistry to conjugate multiple copies of an engineered single-chain version of VEGF site-specifically derivatized with trans-cyclooctene (scVEGF-TCO) to 140 nm FND. The resulting targeting conjugates, FND-scVEGF, were then tested for functional activity of the scVEGF moieties through biochemical and tissue culture experiments and for selective tumor uptake in Balb/c mice with induced 4T1 carcinoma. We found that FND-scVEGF conjugates retain high affinity to VEGF receptors in cell culture experiments and observed preferential accumulation of FND-scVEGF in tumors relative to untargeted FND. Microspectroscopy provided unambiguous determination of FND within tissue by way of the unique spectral shape of nitrogen-vacancy induced fluorescence. These results validate and invite the use of targeted FND for diagnostic imaging and encourage further optimization of FND for fluorescence brightness.

Emerging biomarkers for the diagnosis and monitoring of urothelial carcinoma

Urothelial carcinoma (UC) arises extensively from the renal pelvis, ureter, urinary bladder, and urethra. UC represents a clinical and social challenge because of its incidence, post-treatment recurrence rate, and prognosis. Combinations of urine cytology, cystoscopy, and conventional imaging such as computed tomography are currently used for diagnosis and monitoring modalities of UC. Both the poor diagnostic accuracy of urine cytology and poor cost performance of cystoscopy and conventional imaging modalities emphasize the urgent need for advancement in clinical guidance for UC. Urine- and blood-based biomarkers for detection of UC of the bladder and upper urinary tract represent a considerable research area. Biomarkers can help to improve UC diagnosis with the aim of replacing cystoscopy and other imaging examinations in future and may enable individualizing risk stratification regarding therapy and follow-up. Over the decades, numerous studies have focused on the potential application of biomarkers for UC, including urine, circulating tumor DNA, RNAs, proteins, and extracellular vesicles. Although some biomarkers such as ImmunoCyt/uCyt+, UroVysion, NMP-22, bladder tumor antigen, CxBladder, and Xpert Bladder Cancer are currently available in clinical practice, few biomarkers achieve high sensitivity and specificity. Emerging biomarkers are continuously developed and reported in medical journals. However, there is a significant lack on following external validation using different cohorts. The positive results are needed to be confirmed by more studies with large-scale cohorts and long follow-up periods to prove the true value of novel biomarkers, followed by their adoption in clinical practice. The present paper provides an overview of the evidence based on high-impact studies regarding urine- and blood-based biomarkers and their clinical applications in bladder cancer and upper tract UC.