Validation of Confocal Laser Endomicroscopy Features of Bladder Cancer: The Next Step Towards Real-time Histologic Grading.

BACKGROUND: Cystoscopy enables the visualisation of suspicious bladder lesions but lacks the ability to provide real-time histopathologic information. Confocal laser endomicroscopy (CLE) is a probe-based optical technique that can provide real-time microscopic images. This high-resolution optical imaging technique may enable real-time tumour grading during cystoscopy. OBJECTIVE: To validate and adapt CLE criteria for bladder cancer diagnosis and grading. DESIGN, SETTING, AND PARTICIPANTS: Prospectively, 73 patients scheduled for transurethral resection of bladder tumour(s) were included. CLE imaging was performed intraoperatively prior to en bloc resection. Histopathology was the reference standard for comparison. INTERVENTION: Cystoscopic CLE imaging. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Three independent observers evaluated the CLE images to classify tumours as low- or high-grade urothelial carcinoma (UC), or benign lesions. Interobserver agreement was calculated with Fleiss kappa analysis and diagnostic accuracy with 2×2 tables. RESULTS AND LIMITATIONS: Histopathology of 66 lesions (53 patients) revealed 25 low-grade UCs, 27 high-grade UCs, and 14 benign lesions. For low-grade UC, most common features were papillary configuration (100%), distinct cell borders (81%), presence of fibrovascular stalks (79%), cohesiveness of cells (77%), organised cell pattern (76%), and monomorphic cells (67%). A concordance between CLE-based classification and histopathology was found in 19 cases (76%). For high-grade UC, pleomorphic cells (77%), indistinct cell borders (77%), papillary configuration (67%), and disorganised cell pattern (60%) were the most common features. A concordance with histopathology was found in 19 cases (70%). In benign lesions, the most prevalent features were disorganised cell pattern (57%) and pleomorphic cells (52%), and a concordance with histopathology was found in four cases (29%). CONCLUSIONS: The CLE criteria enable identification of UC. CLE features correlate to histopathologic features that may enable real-time tumour grading. However, flat lesions remain difficult to classify. PATIENT SUMMARY: Confocal laser endomicroscopy may enable real-time cancer differentiation during cystoscopy, which is important for prognosis and disease management.

The Role of Fluorescence In Situ Hybridization for Predicting Recurrence after Adjuvant bacillus Calmette-Guérin in Patients with Intermediate and High Risk Nonmuscle Invasive Bladder Cancer: A Systematic Review and Meta-Analysis of Individual Patient Data.

PURPOSE: The objective of this study was to assess the value of fluorescence in situ hybridization to predict early recurrence in patients with nonmuscle invasive bladder cancer at intermediate and high risk treated with bacillus Calmette-Guérin. MATERIALS AND METHODS: We performed a systematic review using MEDLINE®, Embase® and the Cochrane Library. Individual patient data from prospective observational studies of fluorescence in situ hybridization in patients treated with bacillus Calmette-Guérin were included. A 2-stage individual patient data meta-analysis was done to assess the value of fluorescence in situ hybridization to predict tumor recurrence after bacillus Calmette-Guérin induction therapy. RESULTS: From a total of 4 studies we obtained individual data on 422 patients, of whom 408 with a median followup of 18.8 months were included in the final analysis. When fluorescence in situ hybridization was positive, the recurrence HR was 1.20 (95% CI 0.81-1.79) before bacillus Calmette-Guérin (time 0), 2.23 (95% CI 1.31-3.62) at 6 weeks (time 1), 3.70 (95% CI 2.34-5.83) at 3 months (time 2) and 23.44 (95% CI 5.26-104.49) at 6 months (time 3). CONCLUSIONS: A positive fluorescence in situ hybridization test after bacillus Calmette-Guérin correlated with higher risk of recurrent tumor. Fluorescence in situ hybridization could aid urologists in risk stratifying and counseling patients. Based on the HR and the narrowest CI the preferred timing of fluorescence in situ hybridization is 3 months after transurethral resection of bladder tumor. This is also in time for patients in whom induction therapy fails to enter clinical trials or change the treatment strategy.

Toward Automated In Vivo Bladder Tumor Stratification Using Confocal Laser Endomicroscopy.

Purpose: Urothelial carcinoma of the bladder (UCB) is the most common urinary cancer. White-light cystoscopy (WLC) forms the corner stone for the diagnosis of UCB. However, histopathological assessment is required for adjuvant treatment selection. Probe-based confocal laser endomicroscopy (pCLE) enables visualization of the microarchitecture of bladder lesions during WLC, which allows for real-time tissue differentiation and grading of UCB. To improve the diagnostic process of UCB, computer-aided classification of pCLE videos of in vivo bladder lesions were evaluated in this study. Materials and Methods: We implemented preprocessing methods to optimize contrast and to reduce striping artifacts in each individual pCLE frame. Subsequently, a semiautomatic frame selection was performed. The selected frames were used to train a feature extractor based on pretrained ImageNet networks. A recurrent neural network, in specific long short-term memory (LSTM), was used to predict the grade of bladder lesions. Differentiation of lesions was performed at two levels, namely (i) healthy and benign vs malignant tissue and (ii) low-grade vs high-grade papillary UCB. A total of 53 patients with 72 lesions were included in this study, resulting in ∼140,000 pCLE frames. Results: The semiautomated frame selection reduced the number of frames to ∼66,500 informative frames. The accuracy for differentiation of (i) healthy and benign vs malignant urothelium was 79% and (ii) high-grade and low-grade papillary UCB was 82%. Conclusions: A feature extractor in combination with LSTM results in proper stratification of pCLE videos of in vivo bladder lesions.

Three-dimensional histopathological reconstruction of bladder tumours.

BACKGROUND: Histopathological analysis is the cornerstone in bladder cancer (BCa) diagnosis. These analysis suffer from a moderate observer agreement in the staging of bladder cancer. Three-dimensional reconstructions have the potential to support the pathologists in visualizing spatial arrangements of structures, which may improve the interpretation of specimen. The aim of this study is to present three-dimensional (3D) reconstructions of histology images. METHODS: En-bloc specimens of transurethral bladder tumour resections were formalin fixed and paraffin embedded. Specimens were cut into sections of 4 µm and stained with Hematoxylin and Eosin (H&E). With a Phillips IntelliSite UltraFast scanner, glass slides were digitized at 20x magnification. The digital images were aligned by performing rigid and affine image alignment. The tumour and the muscularis propria (MP) were manually delineated to create 3D segmentations. In conjunction with a 3D display, the results were visualized with the Vesalius3D interactive visualization application for a 3D workstation. RESULTS: En-bloc resection was performed in 21 BCa patients. Per case, 26-30 sections were included for the reconstruction into a 3D volume. Five cases were excluded due to export problems, size of the dataset or condition of the tissue block. Qualitative evaluation suggested an accurate registration for 13 out of 16 cases. The segmentations allowed full 3D visualization and evaluation of the spatial relationship of the BCa tumour and the MP. CONCLUSION: Digital scanning of en-bloc resected specimens allows a full-fledged 3D reconstruction and analysis and has a potential role to support pathologists in the staging of BCa.

Monopolar vs. bipolar transurethral resection for non-muscle invasive bladder carcinoma: A post-hoc analysis from a randomized controlled trial.

PURPOSE: Traditionally, transurethral resection of bladder tumors (TURB) is performed using monopolar technique. Bipolar resection has been postulated to reduce complications. In this study we compare safety and efficacy between monopolar TURB (mTURB) and bipolar TURB (bTURB) for patients with primary non-muscle invasive bladder cancer (NMIBC). MATERIALS AND METHODS: Data were obtained from an international multicenter randomized clinical trial that compared the use of white light cystoscopy with narrow band imaging-assisted TURB using the Olympus system between 2010 and 2014. Main outcomes of interest were operative time, perioperative, and postoperative complications, and 12-month recurrence-free survival. RESULTS: In total, 716 patients were treated for primary NMIBC with mTURB (310 patients) or bTURB (406 patients). The use of white light cystoscopy or narrow band imaging was equally distributed between the 2 resection techniques. Multilevel logistic and linear regression corrected for possible confounders showed no significant difference between mTURB and bTURB for postoperative complications (OR = 1.76, P = 0.180), postoperative bleeding (OR = 1.27, P = 0.722), and the combination of intra + postoperative bleeding (OR = 1.992, P = 0.108). Additionally, no significant difference was found between mTURB and bTURB concerning operative time (1.05min. longer for bTURB, P = 0.536), intraoperative bleeding requiring intervention (OR:1.38, P=0.809), incidence of obturator reflex (OR = 0.93, P = 0.854), and bladder perforation (OR = 3.05, P = 0.195). In total, 185 patients (25.8%) developed a recurrence (mTURB = 88, bTURB = 97). Recurrence-free survival at 12 months in the mTURB and bTURB group was 70% and 74% (P = 0.410), respectively. CONCLUSION: Based on these results, bTURB is as safe and effective as mTURB in treatment of primary NMIBC. bTURB seems to have no evident advantages over mTURB with respect to operation time, perioperative and postoperative complication rates, and recurrence rates at 12 months.

Fluorescence in situ hybridization as prognostic predictor of tumor recurrence during treatment with Bacillus Calmette-Guérin therapy for intermediate- and high-risk non-muscle-invasive bladder cancer.

A significant number of patients with intermediate- or high-risk bladder cancer treated with intravesical Bacillus Calmette-Guérin (BCG) immunotherapy are non-responders to this treatment. Since we cannot predict in which patients BCG therapy will fail, markers for responders are needed. UroVysion® is a multitarget fluorescence in situ hybridization (FISH) test for bladder cancer detection. The aim of this study was to evaluate whether FISH can be used to early identify recurrence during treatment with BCG. In a multicenter, prospective study, three bladder washouts at different time points during treatment (t 0 = week 0, pre-BCG, t 1 = 6 weeks following TURB, t 2 = 3 months following TURB) were collected for FISH from patients with bladder cancer treated with BCG between 2008 and 2013. Data on bladder cancer recurrence and duration of BCG maintenance therapy were recorded. Thirty-six (31.6%) out of 114 patients developed a recurrence after a median of 6 months (range 2-32). No significant association was found between a positive FISH test at t 0 or t 1 and risk of recurrence (p = 0.79 and p = 0.29). A positive t 2 FISH test was associated with a higher risk of recurrence (p = 0.001). Patients with a positive FISH test 3 months following TURB had a 4.0-4.6 times greater risk of developing a recurrence compared to patients with a negative FISH. Patients with a positive FISH test 3 months following TURB and induction BCG therapy have a higher risk of developing tumor recurrence. FISH can therefore be a useful additional tool for physicians when determining a treatment strategy.

Chemohyperthermia in non-muscle-invasive bladder cancer: An overview of the literature and recommendations.

Non-muscle-invasive bladder cancer (NMIBC) is characterised by a high risk of recurrence for the present standard treatment of transurethral resection of the bladder (TURB) followed by intravesical instillation of Mitomycin-C (MMC) or bacillus Calmette-Guérin (BCG). To decrease this high recurrence rate, alternative treatments are studied. Intravesical MMC combined with hyperthermia could be an interesting alternative active treatment for intermediate- and high-risk NMIBC, and has been investigated in the past years. Hyperthermia, raising tumour temperatures to 40-44 °C, can be achieved with several hyperthermia systems, based on three different techniques: 1) intravesical microwave induced heating, 2) conductive heating, and 3) loco-regional, using external radiofrequency antennas. In this review an overview is given of the available hyperthermia systems and the reported outcomes. Future directions are discussed. Optimal implementation of a combined regimen of MMC and hyperthermia requires further clinical trials to identify patients who will benefit most from this treatment, to optimise treatment schedules and to compare the efficacy of different hyperthermia devices.

Cerebellar activation related to saccadic inaccuracies.

Using functional MRI, we assessed activity in the human cerebellum related to the properties of post-saccadic visual errors that drive the plasticity of saccadic eye movements. In the scanner subjects executed blocks of saccadic eye movements toward a target that could be randomly displaced during the saccade. Such an intra-saccadic shift was randomly forward or backward, and could be either small or large. Post-saccadic visual errors induced activation in several cerebellar areas. These areas included, but were not limited to, the oculomotor vermis which is known for its role in saccadic control. Large errors yielded more activation in the cerebellar hemispheres, whereas small errors induced more activation in the vermis. Forward shifts induced more activation than backward shifts. Our results suggest that the differences in cerebellar activation patterns for different sizes and directions of post-saccadic errors could underlie the behavioral differences observed between various saccadic adaptation paradigms. In addition, the outcome argues for an extended range of cerebellar target areas in electrophysiological studies on saccadic eye movement control.