Local Staging Of Bladder Cancer Research Articles

Progress of Multiparameter Magnetic Resonance Imaging in Bladder Cancer: A Comprehensive Literature Review.

Magnetic resonance imaging (MRI) has been proven to be an indispensable imaging method in bladder cancer, and it can accurately identify muscular invasion of bladder cancer. Multiparameter MRI is a promising tool widely used for preoperative staging evaluation of bladder cancer. Vesical Imaging-Reporting and Data System (VI-RADS) scoring has proven to be a reliable tool for local staging of bladder cancer with high accuracy in preoperative staging, but VI-RADS still faces challenges and needs further improvement. Artificial intelligence (AI) holds great promise in improving the accuracy of diagnosis and predicting the prognosis of bladder cancer. Automated machine learning techniques based on radiomics features derived from MRI have been utilized in bladder cancer diagnosis and have demonstrated promising potential for practical implementation. Future work should focus on conducting more prospective, multicenter studies to validate the additional value of quantitative studies and optimize prediction models by combining other biomarkers, such as urine and serum biomarkers. This review assesses the value of multiparameter MRI in the accurate evaluation of muscular invasion of bladder cancer, as well as the current status and progress of its application in the evaluation of efficacy and prognosis.

MRI-Based Radiomics in Bladder Cancer: A Systematic Review and Radiomics Quality Score Assessment.

(1): Background: With the recent introduction of vesical imaging reporting and data system (VI-RADS), magnetic resonance imaging (MRI) has become the main imaging method used for the preoperative local staging of bladder cancer (BCa). However, the VI-RADS score is subject to interobserver variability and cannot provide information about tumor cellularity. These limitations may be overcome by using a quantitative approach, such as the new emerging domain of radiomics. (2) Aim: To systematically review published studies on the use of MRI-based radiomics in bladder cancer. (3) Materials and Methods: We performed literature research using the PubMed MEDLINE, Scopus, and Web of Science databases using PRISMA principles. A total of 1092 papers that addressed the use of radiomics for BC staging, grading, and treatment response were retrieved using the keywords "bladder cancer", "magnetic resonance imaging", "radiomics", and "textural analysis". (4) Results: 26 papers met the eligibility criteria and were included in the final review. The principal applications of radiomics were preoperative tumor staging (n = 13), preoperative prediction of tumor grade or molecular correlates (n = 9), and prediction of prognosis/response to neoadjuvant therapy (n = 4). Most of the developed radiomics models included second-order features mainly derived from filtered images. These models were validated in 16 studies. The average radiomics quality score was 11.7, ranging between 8.33% and 52.77%. (5) Conclusions: MRI-based radiomics holds promise as a quantitative imaging biomarker of BCa characterization and prognosis. However, there is still need for improving the standardization of image preprocessing, feature extraction, and external validation before applying radiomics models in the clinical setting.

Radiologic Diagnosis and Staging of Bladder Cancer: An Update.

Although cystoscopic biopsy is the standard of care for initial diagnosis and local staging of bladder cancer, radiologic imaging plays a major role in identifying local invasion, nodal status, distant metastasis, and posttreatment surveillance. Recent development of the Vesical Imaging-Reporting and Data System for interpretation of multiparametric magnetic resonance imaging of the bladder has expanded the role diagnostic imaging in the management of bladder cancer. This article reviews multimodality imaging appearances, staging, and differential diagnosis of bladder cancer.

Head-to-Head Comparison between High-Resolution Microultrasound Imaging and Multiparametric MRI in Detecting and Local Staging of Bladder Cancer: The BUS-MISS Protocol.

MRI has been proposed as a new staging tool for bladder cancer (BC), but use is limited by its high costs and low availability. 29-MHz high-resolution micro-ultrasound (mUS) technology has been suggested as an alternative to detect BC and distinguish between muscle-invasive and non-muscle invasive BC. The aim was to compare the diagnostic accuracy of mUS vs. magnetic resonance imaging (MRI) in differentiating NMIBC and MIBC at definitive pathological examination. This is a prospective study of patients with a primary diagnosis of BC with either positive urine cytology (UC) or negative UC and a tumor size > 25 mm from a tertiary care high volume center. mUS, with the ExactVu system with an EV29L 29 MHz side-fire transducer, and a 3-Tesla MRI were performed before transurethral resection of bladder tumor (TURBT) in every patient before undergoing TURBT. We compared the imaging results with pathological reports. The analyzed population consisted of 58 individuals. The reported mUS and MRI sensitivity, specificity, positive, and negative predictive values were 85.0%, 76.3%, 65.4%, and 90.6%, versus 85.0%, 50.0%, 47.2%, and 86.4%, respectively. In accuracy analysis, the AUC for mUS and MRI were respectively 0.807 and 0.675. In our population mUS seems to have a better performance in distinguishing NMIBC from MIBC. The main limitation of mUS is the probe shape that makes its use problematic in cases with a large prostate and inadequate rectal preparation. Further studies with a larger population are ongoing to compare and validate these techniques in this setting.

SC253 - Head-to-head comparison between high-resolution microultrasound imaging and multiparametric MRI in detecting and local staging of bladder cancer: the BUS-MISS protocol

SC253 - Head-to-head comparison between high-resolution microultrasound imaging and multiparametric MRI in detecting and local staging of bladder cancer: the BUS-MISS protocol

P0727 - Head-to-head comparison between high-resolution microultrasound imaging and multiparametric MRI in detecting and local staging of bladder cancer: The bus-miss protocol

P0727 - Head-to-head comparison between high-resolution microultrasound imaging and multiparametric MRI in detecting and local staging of bladder cancer: The bus-miss protocol

Utilization of imaging for staging in bladder cancer: is there a role for MRI or PET-computed tomography?

Accurate staging of bladder cancer is essential to guide appropriate management. In this review, we discuss the principles, applications and performance of multiparametric MRI (mpMRI) and PET-computer tomography (PET-CT) for local and distant staging of bladder cancer. Bladder mpMRI has a high diagnostic performance in local staging of bladder cancer, superior to other imaging modalities. It can accurately differentiate muscle invasive bladder cancer (MIBC) from non-MIBC (NMIBC), as well as ≤T2 from ≥T3 stages. mpMRI can be used to assess pelvic lymph nodes, although its sensitivity is relatively low. For the assessment of the upper urinary tract, CT urography is the imaging modality of choice. magnetic resonance urography is a viable alternative to CT in selected cases. Although PET-CT is accurate for nodal and distant staging of bladder cancer, there is no clear evidence on its superior diagnostic performance compared with contrast-enhanced CT. mpMRI is the most accurate imaging modality for local staging of bladder cancer, capable to accurately distinguish MIBC from NMIBC. Nodal and distant staging relies primarily on contrast-enhanced CT.

Overview of VI-RADS in Bladder Cancer.

OBJECTIVE. The purpose of this article is to review the natural history and management of bladder cancer, with insight into MRI applications for the assessment of muscle invasiveness of bladder cancer using the newly developed Vesical Imaging Reporting and Data System (VI-RADS) score. CONCLUSION. Multiparametric MRI and the VI-RADS score have been consistently validated across several different institutions as appropriate tools for local staging of bladder cancer and have been proven to contribute to the diagnostic workup and management of urinary bladder cancer.

Diagnostic Accuracy of Multi-Parametric Magnetic Resonance Imaging for Tumor Staging of Bladder Cancer: Meta-Analysis

Purpose: Evaluate the diagnostic accuracy of multi-parametric magnetic resonance imaging (mp-MRI) for local staging of bladder cancer (BCa).Materials and Methods: The databases of PubMed, Web of Science, Wanfang, and CNKI were searched for related literatures about BCa diagnosed by mp-MRI from January 1, 2000 to April 12, 2019. The strict inclusion and exclusion criteria were set up to extract records. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 was used to evaluate quality of the candidate studies. The pooled sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (−LR), and diagnostic odds ratio (DOR) were calculated to assess the diagnostic authenticity of mp-MRI. The summarized receiver operating characteristic (SROC) curve corresponding with the area under the curve (AUC) were analyzed to comprehensively evacuate the diagnostic value of mp-MRI.Results: A total of 140 studies were retrieved by computer-based searching. After quality control, 4 studies with 259 patients were enrolled for meta-analysis. The pooled results showed 0.84 of sensitivity [95% confidence interval (CI) = 0.79-0.89], 0.91 of specificity (95% CI = 0.87–0.93), 8.24 of +LR (95% CI = 4.87–13.92), 0.18 of –LR (95% CI = 0.10–0.31), 49.42 of DOR (95% CI = 19.07–128.09), and 0.946 of AUC. The Spearman correlation analysis found no threshold effect (p = 0.684). A significant heterogeneity existed among 4 included studies with sensitivity (I2 = 65.7%), specificity (I2 = 60.0%) and diagnostic OR (I2 = 67.5%). The Begg's test (p = 0.497) and the egger's test (p = 0.337) found no publication bias.Conclusion: mp-MRI acts a good diagnostic performance for bladder cancer. It is plausible that mpMRIs can be used as an important method for bladder cancer staging.

Diagnostic accuracy of magnetic resonance imaging for tumour staging of bladder cancer: systematic review and meta-analysis.

The purpose of this study is to evaluate accuracy of magnetic resonance imaging (MRI) for local staging of bladder cancer for four clinical scenarios (T-stage thresholds) considered against current standards for clinical staging and secondarily to identify sources for variability in accuracy. Systematic review of patients with bladder cancer undergoing T-staging MRI to evaluate the diagnostic accuracy using bivariate random-effects meta-analysis. Sub-group analysis was done to explore variability; risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. The search identified 30 studies (5156 patients). Pooled accuracy at multiple T-stage thresholds: ≤T1 vs ≥T2 = sensitivity 87% (95% confidence interval [CI] 82-91), specificity 79% (95% CI 72-85); T-any vs T0 = sensitivity 65% (95% CI 23-92), specificity 90% (95% CI 83-94); ≤T2 vs ≥T3 = sensitivity 83% (95% CI 75-88), specificity 87% (95% CI 78-93); and <T4b vs pT4b = sensitivity 85% (95% CI 63-95), specificity 98% (95% CI 95-99). For ≤T1 vs ≥T2, accuracy was higher in studies at low risk of bias. No variability in accuracy was identified for: field strength, transurethral resection of bladder tumour status, publication date, index test parameters. For ≤T1 vs ≥T2, accuracy was higher than reported for clinical staging. For T-any vs T0 accuracy was lower than clinical staging. For ≤T2 vs ≥T3, sensitivity was slightly lower than clinical staging but specificity was considerably higher. For <T4b vs pT4b sensitivity exceeded the estimated accuracy for clinical staging. Limitations: two scenarios had few studies (T-any vs T0; <T4b vs pT4b) and several studies were at high risk of bias. MRI staging for ≤T1 vs ≥T2, ≤T2 vs ≥T3, and <T4b vs pT4b should be considered as potentially superior to the current standard for clinical staging. MRI accuracy for T-any vs T0 may not be superior to clinical staging. However, cautious interpretation is warranted related to risk of bias and sample size; validation in trials comparing clinical staging strategies vs MRI is warranted.

Bladder cancer local staging: multiparametric MRI performance following transurethral resection.

To evaluate the performance of multiparametric MRI (mpMRI) for the local staging of bladder cancer following transurethral resection of bladder tumor. This Institutional Review Board-approved, retrospective study identified 45 patients with pathology-proven bladder cancer who underwent transurethral resection followed by mpMRI between August 2011 and October 2016. Two radiologists reviewed each MRI independently and assigned T and N stage. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the presence of muscle invasion (T2 or higher), peri-vesical invasion (T3 or higher), and regional nodal disease compared to findings at cystectomy as the reference standard. Inter-observer agreement was measured using Cohen's κ coefficient. Of 45 patients, 13% were stage T2, 27% T3, 16% T4; of 40 patients, 28% had regional nodal disease. Sensitivity, specificity, PPV, NPV, and accuracy of mpMRI for readers 1 and 2, respectively, were muscle invasion, 92% and 88%, 74% and 84%, 81% and 88%, 88% and 84%, 84% and 86%; peri-vesical invasion, 72% and 67%, 92% and 92%, 87% and 86%, 81% and 79%, 83% and 81%; regional nodal disease, 45% and 45%, 93% and 90%, 71% and 63%, 82% and 81%, 80% and 78%. Inter-observer agreement was good using all sequences. mpMRI was both sensitive and specific in the detection of muscle invasive bladder cancer, and was specific but not sensitive for both peri-vesical invasion and nodal involvement. mpMRI may have a role at locally staging bladder cancer following transurethral resection.

Diagnostic performance of MRI for prediction of muscle-invasiveness of bladder cancer: A systematic review and meta-analysis

PurposeTo review the diagnostic performance of ≥1.5-T MRI for local staging of bladder cancer. MethodsMEDLINE and EMBASE were searched up to February 21, 2017. We included diagnostic accuracy studies published since 2000 that used ≥1.5-T MRI for local staging (≥T2 [muscle-invasive]) in patients with bladder cancer, using pathology as the reference standard. The methodological quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2. Sensitivity and specificity were pooled and plotted in a hierarchical summary receiver operating characteristics plot. Sensitivity analyses using several clinically relevant covariates were performed. Results24 studies (1774 patients) were included. Pooled sensitivity was 0.92 (95% CI 0.88–0.95) with specificity of 0.87 (95% CI 0.78–0.93). Sensitivity analyses showed that sensitivity estimates were comparable and consistently high across all subgroups, but specificity estimates were variable. Studies using 3-T scanners had higher specificity (0.93 [95% CI 0.86–0.98]) than those using 1.5-T scanners (0.83 [95% CI 0.74–0.98]). Studies using multiparametric MRI (conventional+≥2 functional sequences) showed the highest accuracy with sensitivity and specificity of 0.94 (95% CI 0.89–1.00) and 0.95 (95% CI 0.89–0.98), respectively. ConclusionsMRI shows good diagnostic performance for predicting muscle-invasiveness of bladder cancer. Multiparametric 3-T MRI seems to improve both sensitivity and specificity.

Role of magnetic resonance in evaluation of urinary bladder cancer

Objective The aim of this study was to prospectively evaluate the use of MRI as a noninvasive diagnostic tool for staging of bladder tumors using different magnetic resonance (MR) sequences: T2-weighted image (T2WI), diffusion-weighted image (DWI), and precontrast and postcontrast T1-weighted image. Background MRI with its superior resolution and supplemented with new emerging sequences is the optimal imaging modality for accurate local staging of bladder cancer, particularly for differentiation between the muscle-invasive and non-muscle-invasive urinary bladder tumors; it is a cornerstone in treatment decision making. Patients and methods The study protocol received institutional ethical committee approval, and informed consent was obtained. Between November 2014 and November 2015, 50 consecutive patients (44 men and 6 women; mean age: 64.3 years; range: 44–85 years) who presented with gross hematuria or suspected urinary bladder tumors were enrolled prospectively. All patients underwent MR examination followed by conventional cystoscopy. The patients were evaluated using T2-weighted high-spatial-resolution MRI of the urinary bladder, followed by diffusion-weighted-MRI. Precontrast T1 (with or without fat suppression) and immediate postgadolinium injection were performed if there were no contraindications. Results Of all 50 patients, four (8%) were at T1, 12 (24%) were at T2, 23 (46%) were at T3, and 11 (22%) were at T4. The most common symptom was gross hematuria (33 patients; 66%). The overall accuracy of T2WI, DWI, and postcontrast imaging sequences in differentiating stage Tis to T2 tumors from T3 to T4 tumors was 88, 98, and 94%, respectively. DWI has a higher overall accuracy compared with both T2WI and postcontrast T1-weighted image in T staging of bladder cancer. Conclusion MRI with new emerging sequences (diffusion-weighted and contrast-enhanced) is highly reliable for accurate local staging of urinary bladder cancer, which is similar to that of conventional cystoscopy. This noninvasive method could be efficiently used for evaluating patients with hematuria of lower urinary tract origin.

Emerging Endoscopic Imaging Technologies for Bladder Cancer Detection

Modern urologic endoscopy is the result of continuous innovations since the early nineteenth century. White-light cystoscopy is the primary strategy for identification, resection, and local staging of bladder cancer. While highly effective, white light cystoscopy has several well-recognized shortcomings. Recent advances in optical imaging technologies and device miniaturization hold the potential to improve bladder cancer diagnosis and resection. Photodynamic diagnosis and narrow band imaging are the first to enter the clinical arena. Confocal laser endomicroscopy, optical coherence tomography, Raman spectroscopy, UV autofluorescence, and others have shown promising clinical and pre-clinical feasibility. We review their mechanisms of action, highlight their respective advantages, and propose future directions.

Urinary Bladder Cancer: Role of MR Imaging

Urinary bladder cancer is a heterogeneous disease with a variety of pathologic features, cytogenetic characteristics, and natural histories. It is the fourth most common cancer in males and the tenth most common cancer in females. Urinary bladder cancer has a high recurrence rate, necessitating long-term surveillance after initial therapy. Early detection is important, since up to 47% of bladder cancer-related deaths may have been avoided. Conventional computed tomography (CT) and magnetic resonance (MR) imaging are only moderately accurate in the diagnosis and local staging of bladder cancer, with cystoscopy and pathologic staging remaining the standards of reference. However, the role of newer MR imaging sequences (eg, diffusion-weighted imaging) in the diagnosis and local staging of bladder cancer is still evolving. Substantial advances in MR imaging technology have made multiparametric MR imaging a feasible and reasonably accurate technique for the local staging of bladder cancer to optimize treatment. In addition, whole-body CT is the primary imaging technique for the detection of metastases in bladder cancer patients, especially those with disease that invades muscle.