The accuracy of Vesical Imaging-Reporting and Data System (VI-RADS): an updated comprehensive multi-institutional, multi-readers systematic review and meta-analysis from diagnostic evidence into future clinical recommendations

[mpMRI of the Urinary Bladder: Significance and Clinical Use]

The diagnosis and staging of bladder cancer is challenging. TUR-B and CT diagnostics bear limitations in detecting muscle invasion and perivesical fat invasion. Thus, second TUR-B is required to ensure more reliable pathological staging. The mpMRI of the urinary bladder is a new diagnostic tool in evaluation of tumor muscle invasion. Numerous retrospective and prospective studies indicate high diagnostic accuracy of the mpMRI in this setting. Current meta-analyses show sensitivities of up to 90% with a high specificity of >85%. The "Vesical Imaging-Reporting and Data System" (VI-RADS) is a standardized and clinically easy-to-use reporting system for mpMRI of the urinary bladder. The EAU guidelines recommend the mpMRI and the VI-RADS system for local staging of urinary bladder cancer. A recently published consensus statement based on a Delphi conference of 92 international experts favors the use of the mpMRI in various clinical situations. This includes imaging before and after TUR-B when muscle invasion is possible or during neoadjuvant chemotherapy.Based on good evidence, the mpMRI of the bladder emerges as a useful imaging tool in the evaluation of urinary bladder cancer in various clinical scenarios. Availability, costs and limited experience currently stand in the way of widespread use.

Node-RADS: a systematic review and meta-analysis of diagnostic performance, category-wise malignancy rates, and inter-observer reliability

OBJECTIVE

To perform a systematic review and meta-analysis to estimate diagnostic performance, category-wise malignancy rates, and inter-observer reliability of Node Reporting and Data System 1.0 (Node-RADS).

METHODS

Five electronic databases were systematically searched for primary studies on the use of Node-RADS to report the possibility of cancer involvement of lymph nodes on CT and MRI from January 1, 2021, until April 15, 2024. The study quality was assessed by modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and Quality Appraisal of Diagnostic Reliability (QAREL) tools. The diagnostic accuracy was estimated with bivariate random-effects model, while the pooled category-wise malignancy rates were obtained with random-effects model.

RESULTS

Six Node-RADS-CT studies and three Node-RADS-MRI studies covering nine types of cancer were included. The study quality was mainly damaged by inappropriate index test and unknown timing according to QUADAS-2, and unclear blindness during the rating process according to QAREL. The area under hierarchical summary receiver operating characteristic curve (95% conventional interval) was 0.92 (0.89-0.94) for Node-RADS ≥ 3 as positive and 0.91 (0.88-0.93) for Node-RADS ≥ 4 as positive, respectively. The pooled malignancy rates (95% CIs) of Node-RADS 1 to 5 were 4% (0-10%), 31% (9-58%), 55% (34-75%), 89% (73-99%), and 100% (97-100%), respectively. The inter-observer reliability of five studies was interpreted as fair to substantial.

CONCLUSION

Node-RADS presented a promising diagnostic performance with an increasing probability of malignancy along higher category. However, the evidence for inter-observer reliability of Node-RADS is insufficient, and may hinder its implementation in clinical practice for lymph node assessment.

KEY POINTS

Question Node-RADS is designed for structured reporting of the possibility of cancer involvement of lymph nodes, but the evidence supporting its application has not been summarized. Findings Node-RADS presented diagnostic performance with AUC of 0.92, and malignancy rates for categories 1-5 ranged from 4% to 100%, while the inter-observer reliability was unclear. Clinical relevance Node-RADS is a useful tool for structured reporting of the possibility of cancer involvement of lymph nodes with high diagnostic performance and appropriate malignancy rate for each category, but unclear inter-observer reliability may hinder its implementation in clinical practice.

Preoperative prediction of muscle invasion in bladder cancer in the Indian population using the Vesical Imaging-Reporting and Data System (VI-RADS) score and individual multiparametric magnetic resonance imaging (MRI) characteristics

AIM

This study aimed to prospectively validate the Vesical Imaging-Reporting and Data System (VI-RADS) score in the preoperative prediction of muscle invasion in bladder cancer in the Indian population.

MATERIALS AND METHODS

The study prospectively reviewed patients with bladder masses who underwent 1.5T multiparametric magnetic resonance imaging between December 2018 and April 2023. Clinical and pathological data were collected, and bladder tumors were evaluated using a 5-point VI-RADS scoring system. Independent measurements of quantitative parameters (maximum tumor diameter [DMax] and tumor contact length [TCL]) were performed. These parameters and VI-RADS scores were compared to postoperative pathology to assess muscle invasion. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated using a cutoff score of 4. Receiver Operating Characteristic (ROC) analysis evaluated the diagnostic performance of quantitative values.

RESULTS

A total of 55 patients were included in the analysis, of whom 36 were non-muscle invasive and 19 were muscle invasive on the final histopathological report. A VI-RADS score of ≥4 as the cutoff for muscle invasion yielded a sensitivity and specificity of 94.7% (95% CI 72.7%-99.9%) and 97.2% (95% CI 85%-99.9%), with PPV and NPV value of 94.7% and 97.2%, respectively. The receiver operating curve showed an area under the curve (AUC) of 0.958 (95% CI 0.89-1.0). The AUC of TCL and TCL/DMax values for muscle invasion were 0.811 and 0.835, respectively.

CONCLUSIONS

The VI-RADS scoring system, qualitative parameters, as well as the TCL and TCL/Dmax exhibits a strong correlation with pathological staging, indicating to be an effective method for the preoperative determination of muscle invasion in bladder cancer.

Randomized Comparison of Magnetic Resonance Imaging Versus Transurethral Resection for Staging New Bladder Cancers: Results From the Prospective BladderPath Trial

PURPOSE

Transurethral resection of bladder tumor (TURBT) is the initial staging procedure for new bladder cancers (BCs). For muscle-invasive bladder cancers (MIBCs), TURBT may delay definitive treatment. We investigated whether definitive treatment can be expedited for MIBC using flexible cystoscopic biopsy and multiparametric magnetic resonance imaging (mpMRI) for initial staging.

PATIENTS AND METHODS

We conducted a prospective open-label, randomized study conducted within 17 UK hospitals (registered as ISRCTN 35296862). Participants with suspected new BC were randomly assigned 1:1 to TURBT-staged or mpMRI-staged care, with minimization factors of sex, age, and clinician visual assessment of stage. Blinding was not possible. Patients unable/unwilling to undergo mpMRI or with previous BC were ineligible. The study had two stages with separate primary outcomes of feasibility and time to correct treatment (TTCT) for MIBC, respectively.

RESULTS

Between May 31, 2018, and December 31, 2021, 638 patients were screened, and 143 participants randomly assigned to TURBT (n = 72; 55 males, 15 MIBCs) or initial mpMRI (n = 71; 53 males, 14 MIBCs). For feasibility, 36 of 39 (92% [95% CI, 79 to 98]) participants with suspected MIBC underwent mpMRI. The median TTCT for participants with MIBC was significantly shorter with initial mpMRI (n = 12, 53 days [95% CI, 20 to 89] v n = 14, 98 days [95% CI, 72 to 125] for TURBT, log-rank P .02). There was no detriment for participants with non-MIBC (median TTCT: n = 30, 17 days [95% CI, 8 to 25] for mpMRI v n = 28, 14 days [95% CI, 10 to 29] for TURBT, log-rank P = .67). No serious adverse events were reported.

CONCLUSION

The mpMRI-directed pathway led to a 45-day reduction in TTCT for MIBC. Incorporating mpMRI ahead of TURBT into the standard pathway was beneficial for all patients with suspected MIBC.

Recent Advances and Emerging Innovations in Transurethral Resection of Bladder Tumor (TURBT) for Non-Muscle Invasive Bladder Cancer: A Comprehensive Review of Current Literature

Bladder cancer management, particularly non-muscle-invasive bladder cancer (NMIBC), has evolved significantly due to advancements in imaging techniques and surgical methodologies. Enhanced tumor visualization methods, including Photodynamic Diagnosis (PDD) and Narrow-Band Imaging (NBI), offer improved detection rates for both papillary tumors and carcinoma in situ (CIS), compared to traditional white-light cystoscopy (WLC). Recent studies suggest that these technologies enhance diagnostic accuracy, reduce recurrence rates, and improve oncological outcomes. Additionally, transurethral resection of bladder tumors (TURBT), performed with advanced imaging, has demonstrated better resection quality, particularly in terms of detrusor muscle presence. Despite these innovations, challenges remain in the long-term impact on recurrence-free and progression-free survival. Artificial intelligence (AI) integration into cystoscopic imaging further promises enhanced diagnostic precision and cost-effective bladder cancer management. As personalized treatment paradigms emerge, predictive biomarkers, including genomic and pathological markers, may help stratify patients for aggressive treatment, sparing those at lower risk from unnecessary interventions. Future research should focus on validating these AI models and combining them with enhanced imaging modalities to refine treatment protocols further. These advancements collectively represent a significant leap toward precision medicine in bladder cancer care.

The role of MRI in muscle-invasive bladder cancer: an update from the last two years

PURPOSE OF REVIEW

Muscle invasive bladder cancer (MIBC) is aggressive and requires radical cystectomy and neoadjuvant therapy, yet over 40% of patients face recurrence. The loss of the bladder also significantly reduces quality of life. Accurate staging, crucial for treatment decisions, is typically done through transurethral resection (TURBT), but inconsistencies in pathology affect diagnosis in 25% of cases. MRI is the most precise imaging method for evaluating local tumor invasiveness. This review discusses recent advances in MRI for staging MIBC and predicting responses to neoadjuvant therapy.

RECENT FINDINGS

Vesical imaging - reporting and data system (VI-RADS) accuracy may improve if combined with ADC maps and tumor contact length, while a bi-parametric MRI approach without contrast could reduce side effects without losing diagnostic precision, though evidence is mixed. VI-RADS shows promise in predicting neoadjuvant therapy responses, and the new nacVI-RADS score is in development. Non-Gaussian diffusion-weighted imaging techniques and machine learning could enhance accuracy but need more integration with mpMRI. VI-RADS may assist in evaluating responses in bladder-sparing regimens. Urodrill, an MRI-guided biopsy, aims to replace diagnostic TURBT but needs more accuracy data.

SUMMARY

MRI in MIBC is evolving, offering potential for accurate local staging and reduced side effects by avoiding TURBT. Predicting neoadjuvant treatment response could guide personalized treatment and bladder preservation. Larger trials are needed to validate these findings.

Is there a role for neoadjuvant therapies followed by radical cystectomy in oligometastatic bladder cancer?

PURPOSE OF REVIEW

This review explores the potential role of neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) for oligometastatic bladder cancer (OMBC) treatment. We focused on extrapolating evidence from studies including lymph node-positive only and metastatic bladder cancer to address the key challenges and therapeutic strategies for OMBC.

RECENT FINDINGS

Current evidence for NAC and RC in OMBC is limited, with most data derived from studies in locally advanced bladder cancer. NAC has shown efficacy in downstaging and improving survival in patients with locally advanced disease, but its benefits in OMBC remain speculative. Additionally, diagnostic uncertainties, particularly regarding the inclusion of pelvic lymph nodes and the role of FDG-PET/CT, pose significant challenges to accurate staging and treatment decisions. Recent studies highlight the potential of metastasis-directed therapy, but uncertainties remain on patient selection and treatment protocols for OMBC.

SUMMARY

There is need for prospective studies to evaluate neoadjuvant systemic treatments and RC specifically in OMBC. Moreover, resolving current diagnostic challenges is crucial to avoid undertreatment due to inaccurate staging. Until more concrete evidence emerges, changes to standard treatment protocols should be approached with caution and offered only within trials.

Multiparametric MRI for Bladder Cancer: A Practical Approach to the Clinical Application of VI-RADS

Multiparametric MRI of the bladder is highly accurate in the detection and local staging of bladder cancer. The Vesical Imaging Reporting and Data System (VI-RADS) scoring system has improved the diagnostic accuracy, reproducibility, and interpretability of bladder MRI in the assessment of the invasion of the muscularis propria. There are several technical details concerning bladder MRI that need to be strictly applied to obtain the highest possible diagnostic potential from the MRI. In addition, image evaluation, accurate interpretation, and reporting need to be standardized to optimize diagnostic accuracy and interreader agreement. This review describes the patient population for bladder MRI and discusses, with a practical approach, the correct acquisition protocol for optimal image quality using VI-RADS with reporting tips, pitfalls, and challenges for its clinical application. This review also discusses the latest evidence, clinical implications, current controversies, and future challenges, including gaps in knowledge, of the VI-RADS scoring system.

VI-RADS followed by Photodynamic Transurethral Resection of Non-Muscle-Invasive Bladder Cancer vs White-Light Conventional and Second-resection: the 'CUT-less' Randomised Trial Protocol

BACKGROUND

A second transurethral resection of bladder tumour (Re-TURBT) is recommended by European Association of Urology (EAU) Guidelines on non-muscle-invasive bladder cancers (NMIBCs) due to the risk of understaging and/or persistent disease following the primary resection. However, in many cases this may be unnecessary, potentially harmful, and significantly expensive constituting overtreatment. The CUT-less trial aims to combine the preoperative staging accuracy of Vesical Imaging-Reporting and Data System (VI-RADS) and the intraoperative enhanced ability of photodynamic diagnosis (PDD) to overcome the primary TURBT pitfalls thus potentially re-defining criteria for Re-TURBT indications.

STUDY DESIGN

Single-centre, non-inferiority, phase IV, open-label, randomised controlled trial with 1:1 ratio.

ENDPOINTS

The primary endpoint is short-term BC recurrence between the study arms to assess whether patients preoperatively categorised as VI-RADS Score 1 and/or Score 2 (i.e., very-low and low likelihood of MIBC) could safely avoid Re-TURBT by undergoing primary PDD-TURBT. Secondary endpoints include mid- and long-term BC recurrences and progression (i-ii). Also, health-related quality of life (HRQoL) outcomes (iii) and health-economic cost-benefit analysis (iv) will be performed.

PATIENTS AND METHODS

All patients will undergo preoperative Multiparametric Magnetic Resonance Imaging of the bladder with VI-RADS score determination. A total of 327 patients with intermediate-/high-risk NMIBCs, candidate for Re-TURBT according to EAU Guidelines, will be enrolled over a 3-year period. Participants will be randomised (1:1 ratio) to either standard of care (SoC), comprising primary white-light (WL) TURBT followed by second WL Re-TURBT; or the Experimental arm, comprising primary PDD-TURBT and omitting Re-TURBT. Both groups will receive adjuvant intravesical therapy and surveillance according to risk-adjusted schedules. Measure of the primary outcome will be the relative proportion of BC recurrences between the SoC and Experimental arms within 4.5 months (i.e., any 'early' recurrence detected at first follow-up cystoscopy). Secondary outcomes measures will be the relative proportion of late BC recurrences and/or BC progression detected after 4.5 months follow-up. Additionally, we will compute the HRQoL variation from NMIBC questionnaires modelled over a patient lifetime horizon and the health-economic analyses including a short-term cost-benefit assessment of incremental costs per Re-TURBT avoided and a longer-term cost-utility per quality-adjusted life year gained using 2-year clinical outcomes to drive a lifetime model across the two arms of treatment.

TRIAL REGISTRATION

ClinicalTrial.gov identifier (ID): NCT05962541; European Union Drug Regulating Authorities Clinical Trials Database (EudraCT) ID: 2023-507307-64-00.

Nuclear Medicine and Molecular Imaging in Urothelial Cancer: Current Status and Future Directions

Background: The role of molecular imaging in urothelial cancer is less defined than other cancers, and its utility remains controversial due to limitations such as high urinary tracer excretion, complicating primary tumour assessment in the bladder and upper urinary tract. This review explores the current landscape of PET imaging in the clinical management of urothelial cancer, with a special emphasis on potential future advancements including emerging novel non-18F FDG PET agents, PET radiopharmaceuticals, and PET-MRI applications. Methods: We conducted a comprehensive literature search in the PubMed database, using keywords such as "PET", "PET-CT", "PET-MRI", "FDG PET", "Urothelial Cancer", and "Theranostics". Studies were screened for relevance, focusing on imaging modalities and advances in PET tracers for urothelial carcinoma. Non-English language, off-topic papers, and case reports were excluded, resulting in 80 articles being selected for discussion. Results: 18F FDG PET-CT has demonstrated superior sensitivity over conventional imaging, such as contrast-enhanced CT and MRI, for detecting lymph node metastasis and distant disease. Despite these advantages, FDG PET-CT is limited for T-staging of primary urothelial tumours due to high urinary excretion of the tracer. Emerging evidence supports the role of PETC-CT in assessing response to neoadjuvant chemotherapy and in identifying recurrence, with a high diagnostic accuracy reported in several studies. Novel PET tracers, such as 68Ga-labelled FAPI, have shown promising results in targeting cancer-associated fibroblasts, providing higher tumour-to-background ratios and detecting lesions missed by traditional imaging. Antibody-based PET tracers, like those targeting Nectin-4, CAIX, and uPAR, are under investigation for their diagnostic and theranostic potential, and initial studies indicate that these agents may offer advantages over conventional imaging and FDG PET. Conclusions: Molecular imaging is a rapidly evolving field in urothelial cancer, offering improved diagnostic and prognostic capabilities. While 18F FDG PET-CT has shown utility in staging, further prospective research is needed to establish and refine standardised protocols and validate new tracers. Advances in theranostics and precision imaging may revolutionise urothelial cancer management, enhancing the ability to tailor treatments and improve patient outcomes.

New Trends and Future Perspectives in the Diagnosis of Urothelial Carcinoma: A Comprehensive Review of the Literature

Despite the high incidence of bladder cancer (it represents the 7th most common cancer in males), EAU guidelines do not recommend any technique for screening and prevention, whereas the main diagnostic tools remain computed tomography urography (CTU), cytology, and cystoscopy. Unfortunately, these gold-standard modalities are mainly characterized by low sensitivity and accuracy. To minimize the limitations and increase the detection rates of urothelial cancer, several technologies have been developed. In our review, we summarize all the available data concerning the contemporary technological novelties that include imaging, cytology, and endoscopic techniques in pursuit of finding the optimal combination of diagnostic tools that can provide better detection accuracy.

Multiparametric MRI and artificial intelligence in predicting and monitoring treatment response in bladder cancer

Bladder cancer is the 10th most common and 13th most deadly cancer worldwide, with urothelial carcinomas being the most common type. Distinguishing between non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) is essential due to significant differences in management and prognosis. MRI may play an important diagnostic role in this setting. The Vesical Imaging Reporting and Data System (VI-RADS), a multiparametric MRI (mpMRI)-based consensus reporting platform, allows for standardized preoperative muscle invasion assessment in BCa with proven diagnostic accuracy. However, post-treatment assessment using VI-RADS is challenging because of anatomical changes, especially in the interpretation of the muscle layer. MRI techniques that provide tumor tissue physiological information, including diffusion-weighted (DW)- and dynamic contrast-enhanced (DCE)-MRI, combined with derived quantitative imaging biomarkers (QIBs), may potentially overcome the limitations of BCa evaluation when predominantly focusing on anatomic changes at MRI, particularly in the therapy response setting. Delta-radiomics, which encompasses the assessment of changes (Δ) in image features extracted from mpMRI data, has the potential to monitor treatment response. In comparison to the current Response Evaluation Criteria in Solid Tumors (RECIST), QIBs and mpMRI-based radiomics, in combination with artificial intelligence (AI)-based image analysis, may potentially allow for earlier identification of therapy-induced tumor changes. This review provides an update on the potential of QIBs and mpMRI-based radiomics and discusses the future applications of AI in BCa management, particularly in assessing treatment response. CRITICAL RELEVANCE STATEMENT: Incorporating mpMRI-based quantitative imaging biomarkers, radiomics, and artificial intelligence into bladder cancer management has the potential to enhance treatment response assessment and prognosis prediction. KEY POINTS: Quantitative imaging biomarkers (QIBs) from mpMRI and radiomics can outperform RECIST for bladder cancer treatments. AI improves mpMRI segmentation and enhances radiomics feature extraction effectively. Predictive models integrate imaging biomarkers and clinical data using AI tools. Multicenter studies with strict criteria validate radiomics and QIBs clinically. Consistent mpMRI and AI applications need reliable validation in clinical practice.

The impact of preoperative venous thromboembolism on patients undergoing TURBT: Perioperative outcomes and healthcare costs from US insurance claims data

Objectives

To assess the impact of a positive history of venous thromboembolism (VTE) on perioperative outcomes, including length of in-hospital stay, readmission rates, 90-day postoperative complications, and healthcare costs in bladder cancer (BCa) patients undergoing transurethral resection of bladder tumour (TURBT) in the United States.

Patients and Methods

Patients aged ≥18 years with a BCa diagnosis undergoing TURBT were identified in the Merative® Marketscan® Research de-identified databases between 2007 and 2021. Multivariable logistic regression adjusted by relevant perioperative confounders was used to investigate the association between diagnosis of VTE before TURBT and 90-day complication rates, new postoperative VTE events, re-hospitalization, and total hospital expenditures (2021 US dollars). Sensitivity analyses on VTE severity (pulmonary embolism [PE], deep venous thrombosis [DVT] or superficial thrombophlebitis/phlebitis [SVT]), as well as TURBT extent (minor vs. major) were additionally examined.

Results

In total, 139 800 patients were identified, with 5.3% having preoperative VTE, including DVT (n = 3112, 42.20%), PE (n = 2046, 27.74%) and SVT (n = 2217, 30.06%). A history of preoperative VTE predicted higher rates of any complication (adjusted odds ratio [aOR] 1.28, 95% CI 1.14-1.43) and also higher rates of infectious and haemorrhagic complications. Additionally, preoperative VTE increased the risk of novel VTE events following TURBT (aOR 17.30, 95% CI 16.05-18.65), hospital length of stay (aOR 2.23, 95% CI 1.90-2.62), readmissions (aOR 1.47, 95% CI 1.39-1.56), and hospital associated costs (aOR 1.17, 95% CI 1.12-1.23). DVT and non-minor TURBT procedures did not increase the risk of any, infectious, or haemorrhagic complications, but other associations were maintained regardless of the severity of VTE (PE, DVT, SVT) or TURBT extent (minor/major).

Conclusions

A history of VTE before undergoing transurethral procedures for BCa is associated with significantly worse perioperative outcomes and higher healthcare costs. These findings may help us to counsel on the risks of the intervention and hopefully improve our ability to mitigate such risks.

Current Status of Magnetic Resonance Imaging Use in Bladder Cancer

ABSTRACT

Bladder cancer (BC) is a significant global health concern, with over 500,000 new cases and 200,000 deaths annually, emphasizing the need for accurate staging and effective management. Traditional diagnostic techniques, such as cystoscopy and transurethral resection, are fundamental but have limitations in accurately assessing the depth of invasion. These limitations include the possibility of understaging and procedural variability, which can significantly impact treatment decisions. This review focuses on the role of multiparametric magnetic resonance imaging (mpMRI) in the diagnosis and staging of BC, particularly emphasizing the Vesical Imaging-Reporting and Data System (VI-RADS) framework. By enhancing interpretive consistency and diagnostic accuracy, mpMRI and VI-RADS offer detailed visualization of tumor characteristics and depth of invasion, while reducing the need for more invasive traditional methods. These advancements not only improve staging accuracy but also enhance treatment planning, underscoring the importance of advanced imaging in evolving BC management and positively influencing patient outcomes.

Prospective Assessment of VI-RADS with Muscle Invasion in Urinary Bladder Cancer and Its Implication on Re-Resection/Restaging TURBT Patients

BACKGROUND

Bladder cancer (BCa) diagnosis relies on distinguishing muscle-invasive bladder cancer (MIBC) from non-muscle-invasive bladder cancer (NMIBC) forms. Transurethral resection of the bladder tumor (TURBT) is a standard procedure for initial staging and treatment. The Vesical Imaging-Reporting and Data System (VI-RADS) enhances diagnostic accuracy for muscle invasiveness through advanced imaging techniques, potentially reducing reliance on repeat TURBT and improving patient management.

OBJECTIVE

We aimed to evaluate the role of VI-RADS in predicting muscle invasiveness in BCa and its potential to predict adverse pathology in high-risk NMIBC to avoid unnecessary repeat TURBT procedures.

METHODS

In this prospective study, we included 62 patients over the age of 18 years who underwent TURBT. In a secondary phase, patients selected for restaging TURBT (re-TURBT) were included, but those with T2 tumors or low-risk NMIBC were excluded. Multiparametric magnetic resonance imaging (MRI) examinations were scored by a radiologist using the VI-RADS 5 method, while a pathologist analyzed TURBT and re-TURBT samples for accurate staging. Statistical analysis evaluated the role of VI-RADS in BCa staging.

RESULTS

The VI-RADS score was the only predictive factor for muscle invasion in multivariate analysis. Setting the VI-RADS score at >3 resulted in the highest sensitivity, specificity, and diagnostic accuracy, with values of 67.0%, 89.0%, and 78%, respectively. The receiver operating characteristic area under the curve score for VI-RADS for muscle invasion was 85% for stage Ta, 61% for stage T1, and 88% for stage T2, which shows the utility of VI-RADS in the predictiveness of MIBC/NMIBC.

CONCLUSION

VI-RADS is effective in stratifying BCa patients by predicting muscle invasiveness and identifying NMIBC cases that may not need repeat TURBT.

Diagnostic accuracy and inter-reader agreement of the nacVI-RADS for bladder cancer treated with neoadjuvant chemotherapy: a prospective validation study

OBJECTIVE

The primary aim was to determine the performance of neoadjuvant chemotherapy VI-RADS (nacVI-RADS) in predicting response to systemic therapy in patients with MIBC and to evaluate its inter-reader agreement.

MATERIALS AND METHODS

Prospective study, including patients with non-metastatic muscle-invasive bladder cancer (MIBC) who underwent neoadjuvant chemotherapy before radical cystectomy (RC). Patients underwent pre- and post-treatment MRI. Radiological response was evaluated by two experienced radiologists using nacVI-RADS scoring system. Reference standard was defined using histopathological findings. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy were calculated to assess nacVI-RADS performance for each reader. Inter-reader agreement was determined with Cohen's k statistics.

RESULTS

Fifty-five patients with non-metastatic MIBC, 46 males (84%) and 9 females (16%) with a median age of 69 (interquartile range (IQR) 66-72 years) were enrolled. Diagnostic performance of nacVI-RADS in detecting complete response to neoadjuvant chemotherapy showed a sensitivity of 76.5-85.3% and specificity of 76.2-81%. The area under the curve was 0.93 (95% CI: 0.86-0.99) for detecting any residual tissue, for the more experienced reader. Inter-reader agreement was optimal with a K of 0.85. In the multivariable logistic regression model, the variables showing independent correlation with response prediction to neoadjuvant therapy were nacVI-RADS score (p = 0.01 for the more experienced reader) and tumor regression grade (TRG; p < 0.001).

CONCLUSION

NacVI-RADS scoring system offers a reliable and reproducible approach, employing a well-structured and easily interpretable method, to assess the response to systemic therapy in patients with MIBC.

KEY POINTS

Question There is a lack of a standardized approach to distinguish between responders and non-responders to neoadjuvant chemotherapy for muscle-invasive bladder cancer. Findings The neoadjuvant chemotherapy VI-RADS (nacVI-RADS) score diagnostic performance for detecting complete response to neoadjuvant chemotherapy showed 85.3% sensitivity, 81% specificity, and an AUC of 0.93. Clinical relevance NacVI-RADS score represents a valid predictor of response to neoadjuvant systemic therapy, impacting therapeutic decision-making and improving overall patients' management.

Implementing VIRADS score for image-guided assessment of muscle invasiveness in bladder cancer pre-TURBT: An updated meta-analysis

Background

Bladder urothelial carcinoma is the most prevalent malignancy of the urinary system worldwide. Accurate staging of bladder cancer, particularly distinguishing between non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC), is essential for determining appropriate treatment. This systematic review and meta-analysis aimed to evaluate the diagnostic accuracy, sensitivity, and specificity of the vesical imaging-reporting and data system (VI-RADS) scoring system using multiparametric MRI in differentiating NMIBC from MIBC.

Methods

A systematic review and meta-analysis were conducted following PRISMA guidelines. Comprehensive searches were performed in PubMed, Web of Science, Embase, and Cochrane databases up to December 2023. Studies that evaluated the diagnostic accuracy of the VI-RADS scoring system using multiparametric magnetic resonance imaging (MRI) to distinguish between NMIBC and MIBC were included. Data from eligible studies were extracted to calculate pooled sensitivity and specificity, and heterogeneity was assessed using meta-regression and subgroup analyses by using STATA V17.0.

Results

A total of 31 studies, comprising 3,798 bladder cancer patients, were included in the meta-analysis. The pooled sensitivity and specificity for predicting MIBC using a VI-RADS cutoff score of ≥ 3 was 89%, with moderate heterogeneity observed across studies. Subgroup analysis revealed variations in diagnostic performance based on geographic location (North America, Europe, and Asia), MRI technical parameters, and study design. Studies utilizing 3.0 Tesla MRI scanners and those involving multiple radiologists demonstrated higher diagnostic accuracy.

Conclusion

The VI-RADS system demonstrates high diagnostic accuracy in distinguishing between NMIBC and MIBC, with a cutoff score of ≥ 3 yielding optimal sensitivity and specificity. Its integration into clinical practice has the potential to reduce the need for invasive procedures, improve staging accuracy, and expedite treatment decisions. Future research should focus on standardizing MRI protocols and further validating these findings across diverse clinical settings to enhance the utility of VI-RADS in bladder cancer management.

Neoadjuvant Chemotherapy VI-RADS Scores for Assessing Muscle-invasive Bladder Cancer Response to Neoadjuvant Immunotherapy with Multiparametric MRI

Background An accurate method of assessing the response of muscle-invasive bladder cancer (MIBC) to neoadjuvant treatment is needed for selecting candidates for bladder-sparing strategies. Purpose To evaluate the diagnostic accuracy and reproducibility of neoadjuvant chemotherapy Vesical Imaging Reporting and Data System (nacVI-RADS) scores and posttreatment Vesical Imaging Reporting and Data System (VI-RADS) scores when assessing MIBC response to neoadjuvant immunotherapy with multiparametric MRI (mpMRI). Materials and Methods A retrospective analysis of MRI scans was conducted in patients enrolled in the PURE-01 study (NCT02736266) from February 2017 to December 2019 who underwent pre- and postimmunotherapy mpMRI before radical cystectomy. Five readers independently reviewed the scans using VI-RADS and nacVI-RADS criteria. Diagnostic accuracy was evaluated for each reader, and the final histopathologic diagnosis served as the reference standard. Interreader agreement was assessed with the percentage of agreement, Conger κ, and Gwet agreement coefficient AC1. Results A total of 110 patients (median age, 67 years [IQR: 61-74]; 96 male) with 220 MRI scans were included; 80 (73%) patients had pure urothelial carcinoma. A total of 46 of 110 (42%) patients achieved a complete pathologic response. The sensitivity, specificity, and negative predictive value of nacVI-RADS 3 or higher for detecting residual disease (higher than stage ypT0) at radical cystectomy were 67%-84%, 63%-96%, and 63%-75%, respectively; for residual muscle-invasive disease (higher than stage ypT1), these values were 91%-98%, 55%-94%, and 93%-98%, respectively. The accuracy of nacVI-RADS was 72%-81% for stage ypT0 or higher disease and 71%-95% for stage ypT1 or higher disease. The accuracy of VI-RADS 3 or higher was 80%-95% for stage ypT1 or higher disease. The percentage of agreement for nacVI-RADS scores was 82% (κ = 0.62-0.65; AC1 = 0.65). Conclusion The nacVI-RADS scores showed good accuracy and reproducibility when assessing MIBC response to neoadjuvant immunotherapy. © RSNA, 2024 Supplemental material is available for this article.

Prospective Comparison of 2D and 3D T2-Weighted Imaging in Multiparametric MRI for Assessing Muscle Invasion Accuracy Using VI-RADS in Bladder Cancer

RATIONALE AND OBJECTIVES

T2-weighted imaging (T2WI) is an essential sequence for assessing the staging of bladder cancer. This study aimed to compare the image quality and diagnostic performance of three-dimensional (3D) and two-dimensional (2D) T2WI in diagnosing muscle invasion of bladder cancer using Vesical Imaging Reporting and Data System (VI-RADS).

MATERIALS AND METHODS

Between August 2022 and May 2023, 101 participants with bladder cancer underwent multiparametric MRI including 3D and 2D T2WI. Two radiologists independently reviewed 2D and 3D T2WI, evaluating image quality and muscle invasion based on VI-RADS scoring. The paired Wilcoxon signed-rank test assessed the differences between 2D and 3D T2WI. The areas under the receiver operating characteristic curve (AUCs) were utilized to compare the diagnostic performance.

RESULTS

3D T2WI demonstrated significantly superior overall image quality scores with less artifacts than 2D T2WI. Compared to 2D T2WI, 3D T2WI categories had significantly higher AUC for both readers (reader 1: 0.937 vs. 0.909, p = .02; reader 2: 0.923 vs.0.884, p = .04). The VI-RADS score of 3D MR protocol had higher accuracy than 2D MR protocol (reader 1: 0.931 vs. 0.921, p = .02; reader 2: 0.931 vs. 0.911, p = .02). However, there were no significant differences in AUC values of VI-RADS categories between 2D and 3D MR protocol (all p > 0.05).

CONCLUSION

In assessing muscle invasion of bladder cancer, 3D T2WI exhibited superior overall image quality and diagnostic performance than 2D T2WI. However, 3D T2WI did not significantly improve the diagnostic performance of VI-RADS.

Comparison of golden-angle radial sparse parallel (GRASP) and conventional cartesian sampling in 3D dynamic contrast-enhanced mri for bladder cancer: a preliminary study

PURPOSE

To compare the image quality, inter-reader agreement, and diagnostic capability for muscle-invasive bladder cancer (MIBC) of the reconstructed images in sections orthogonal to the bladder tumor obtained by 3D Dynamic contrast-enhanced (DCE)-MRI using the Golden-angle Radial Sparse Parallel (GRASP) technique with the images directly captured using the Cartesian sampling.

MATERIALS AND METHODS

This study involved 68 initial cases of bladder cancer examined with DCE-MRI (GRASP: n = 34, Cartesian: n = 34) at 3 Tesla. Four radiologists conducted qualitative evaluations (overall image quality, absence of motion artifact, absence of streak artifact, and tumor conspicuity) using a five-point Likert scale (5 = Excellent/None) and quantitative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements. The areas under the receiver-operating characteristic curves (AUCs) for the Vesical Imaging-Reporting and Data System (VI-RADS) DCE score for MIBC assessment were calculated. Inter-reader agreement was also assessed.

RESULTS

GRASP notably enhanced overall image quality (pooled score: GRASP 4 vs. Cartesian 3, P < 0.0001), tumor conspicuity (5 vs. 3, P < 0.05), SNR (Median 38.2 vs. 19.0, P < 0.0001), and CNR (7.9 vs. 6.0, P = 0.005), with fewer motion artifacts (5 vs. 3, P < 0.0001) and minor streak artifacts (5 vs. 5, P > 0.05). Although no significant differences were observed, the GRASP group tended to have higher AUCs for MIBC (pooled AUCs: 0.92 vs. 0.88) and showed a trend toward higher inter-reader agreement (pooled kappa-value: 0.70 vs. 0.63) compared to the Cartesian group.

CONCLUSIONS

Using the GRASP for 3D DCE-MRI, the reconstructed images in sections orthogonal to the bladder tumor achieved higher image quality and improve the clinical work flow, compared to the images directly captured using the Cartesian. GRASP tended to have higher diagnostic ability for MIBC and showed a trend toward higher inter-reader agreement compared to the Cartesian.

Use of Multiparametric and Biparametric Magnetic Resonance Imaging in Bladder Cancer Staging: Prospective Observational Study and Analysis of Radiologist Learning Curve

Background: Nowadays, thanks to the introduction of the VI-RADS scoring system, mpMRI has shown promising results in pre-TURBT assessment of muscular invasiveness of BCa, even if its application in everyday practice is still limited. This might be due to a lack in the literature about the learning curve of radiologists and about the characteristics of the exam. With the aim to reduce scan time and patient discomfort while maintaining diagnostic accuracy, bpMRI has been introduced as a possible alternative to mpMRI in this group of patients. This study reports a single-center experience using mpMRI and the VI-RADS scoring system to differentiate NMIBC from MIBC. The primary aim of the study is to assess diagnostic accuracy of mpMRI using the VI-RADS scoring system. The secondary aim is to evaluate the learning curve of an experienced mpMRI radiologist. Additionally, we perform a retrospective assessment of the same group of patients evaluating only DWIs and T2-weighted images, as they underwent bpMRI, to compare the performance of mpMRI and bpMRI. Materials and Methods: From 11/2021 to 11/2023, patients with suspected newly diagnosed BCa were enrolled in this prospective study. All patients underwent mpMRI prior to TURBT in a highly specialized radiology center for MRI. According to VI-RADS, a cutoff of ≥3 was assumed to define MIBC. Histological TURBT reports were compared with preoperative VI-RADS scores to assess the accuracy of mpMRI in discriminating between NMIBC and MIBC. Furthermore, to assess the learning curve of the reading radiologist we analyzed the rate of patients correctly classified as MIBC at MRI. Finally, we evaluated the performance of a hypothetic biparametric MRI in classifying our cohort according to VI-RADS score and compared it with mpMRI performance by using DeLong's test. Data analysis was performed using Jamovi software v.2.3 and R software v.4.2.1. Results: A total of 133 patients were enrolled. mpMRI showed sensitivity and specificity of 86% (95% confidence interval [CI]: 64-97) and 95% (95% CI: 89-98), respectively. The learning curve analysis of the reading radiologist showed that the rate of patients correctly classified as MIBC rapidly increases reaching its plateau after 40 cases. The hypothetic bpMRI showed a sensitivity of 76% (95% CI: 53-92) and a specificity of 93% (95% CI: 86-97), with no significant difference with mpMRI performance (p = 0.10). Conclusions: Our study confirms the effectiveness of MRI, particularly with the VI-RADS scoring system, in differentiating NMIBC from MIBC. The learning curve analysis underscores the importance of radiologist training in optimizing diagnostic accuracy. Future research should focus on enhancing the sensitivity of bpMRI and further validating these findings in larger and multicentric studies.

Retrospective analysis of multiparametric MRI in predicting complete pathologic response of neo-adjuvant chemotherapy in bladder cancer

BACKGROUND

Muscle invasive bladder cancer (MIBC) treatment combines systemic therapy and radical cystectomy (RC) or local (chemo-)radiotherapy. Response to systemic therapy is an important outcome predictor but is difficult to assess pre-operatively.

METHODS

We analyzed multiparametric MRI (mpMRI) in consecutive MIBC patients receiving cisplatin-based neo-adjuvant chemotherapy at our institution. Two readers, blinded for pathological outcome, independently scored mpMRI before and after 2 and 4 cycles using both a qualitative 3-step method and nacVI-RADS. We analyzed accuracy of mpMRI scores to predict pathologic complete response (pCR) and inter-observer agreement.

RESULTS

We analyzed 46 patients receiving NAC, 6 patients did not undergo RC after NAC and were excluded. Eleven out of 40 (28%) patients showed a pCR. mpMRI could be assessed in over 90% of patients. Radiologic complete response (rCR) using both methods was significantly associated with pCR, with an overall specificity of 96% and sensitivity of 36% and a high inter-observer agreement. rCR as assessed by the 3-step score was significantly associated with disease free survival (DFS) benefit.

CONCLUSION

The use of nacVI-RADS can predict pCR after NAC with high specificity but low sensitivity and a high inter-observer agreement. A 3-step score adds value in determining local residual disease, rCR assessed by this method could correlate with DFS benefit. mpMRI scores should be prospectively assessed in future trials of multimodal management of MIBC and can be a predictive asset in routine clinical management.

Effect of accumulating experience on diagnostic performance of VI-RADS in bladder cancer

PURPOSE

MRI-based VI-RADS score aids in differentiating MIBC and NMIBC, but the experience's impact remains unexplored. We aimed to determine the effect of accumulating experience in the diagnostic performance of VI-RADS.

METHODS

In our previously published series 71 primary bladder cancer patients who underwent multiparametric MRI before the transurethral resection were analyzed. The radiologist who assessed the VI-RADS scores at the time the study was performed, re-evaluated all cases after 3 years, in a blinded fashion. During these three years, more than 300 additional bladder MRIs were performed for VI-RADS assessment. The diagnostic performances of the initial and subsequent VI-RADS analyses were compared. Moreover, VIRADS results obtained by a newly trained abdominal radiologist was also compared with experienced radiologist's results. For this study, VI-RADS ≥3 was accepted for predicting MIBC.

RESULTS

Overall 71 patients [62 (87.3 %) males, 67.4 ± 10.2 years] who underwent bladder MRI before TURBT were included. Histopathology revealed MIBC in 16 (26.2 %) cases. The initial MRI analysis revealed VI-RADS score ≥ 3 in 36 (50.7 %) cases. The sensitivity and specificity for depicting MIBC were 75 % and 56.4 % respectively. The subsequent MRI analysis revealed VI-RADS score ≥ 3 in 23 (32.4 %) cases. The sensitivity and specificity were 93.8 % and 85.5 % respectively. The MRI analysis performed by the recently trained abdominal radiologist revealed VI-RADS score ≥ 3 in 24 (33.8 %) cases. The sensitivity and specificity were 87.5 % and 56.4 % respectively.

CONCLUSION

The diagnostic performance of VI-RADS for the interpretation of bladder MRI can improve over time by increasing the experience of the urogenital radiologist.

The Role of Maximal TURBT in Muscle-Invasive Bladder Cancer: Balancing Benefits in Bladder Preservation and Beyond

Radical cystectomy with lymph node dissection and urinary diversion is the gold-standard treatment for non-metastatic muscle-invasive bladder cancer (MIBC). However, in patients who refuse cystectomy, or in whom cystectomy carries a high risk, bladder-preserving therapies remain potential options. Bladder preservation therapies can include maximal debulking transurethral resection of bladder tumor (TURBT), concurrent chemoradiation therapy, followed by cystoscopy to assess response. At this time, maximal TURBT is recommended for patients prior to the initiation of chemoradiation therapy or in patients with residual bladder tumors after the completion of chemoradiation therapy. That being said, TURBT carries significant risks such as bladder perforation, bleeding, and infection, ultimately risking delayed systemic treatment. Hence, understanding its role within trimodal therapy is crucial to avoid undue suffering in patients. Herein, we review the current literature on the impact of debulking TURBT in non-metastatic MIBC.

[Application of Magnetic Resonance Imaging Report Combined With VI-RADS Bi-Parametric and Multi-Parametric Scoring Systems in Bladder Cancer Diagnosis]

Objective

To verify by retrospective analysis the performance of applying dual-parametric (T2 weighted image [T2WI] and diffusion weighted image [DWI]) and multi-parametric (T2WI, DWI, and dynamic contrast enhance [DCE]) evaluation systems of Vesical Imaging-Reporting and Data System (VI-RADS) in the magnetic resonance imaging (MRI) diagnosis of bladder cancer.

Methods

The imaging and clinical data of bladder cancer patients who underwent bladder MRI examination in the Department of Urology of our hospital between January 2020 and December 2021 were collected. A total of 215 bladder cancer patients, among whom there were 183 males and 32 females with an average age of (67.60±11.42) years, were included. The bladder cancer diagnosis of all the cases was verified by pathology analysis of tissue samples. Two radiologists, who were double-blinded, scored multiple sequences separately. Then, a comparative analysis was made on the diagnostic performance of dual-parametric and multi-parametric VI-RADS diagnostic scores. The diagnostic test with receiver operator characteristic (ROC) curves and Cohen's Kappa were used to evaluate the diagnostic efficacy and consistency.

Results

The area under the curve (AUC) and 95% confidence interval (CI) of the multi-parametric VI-RADS evaluation system by the two radiologists in the overall population were 0.878 (0.830-0.925) and 0.856 (0.805-0.907), while those for the bi-parametric VI-RADS evaluation system were 0.889 (0.844-0.934) and 0.856 (0.805-0.907), showing no statistically significant difference. No significant difference was observed in the subgroup analysis of patients who underwent transurethral resection of bladder tumor (TURBT). Furthermore, the Kappa values for inter-rater agreement between of the two radiologists were 0.694 and 0.546 (with the VI-RADS score≥3 defined as being positive) and 0.693 and 0.712 (with the VI-RADS score≥4 defined as being positive) in multi-parametric and bi-parametric evaluation, respectively (all P<0.001).

Conclusion

The bi-parametric VI-RADS scoring system can achieve a diagnostic efficacy comparable to that of the multi-parametric scoring system, offering an alternative to patients who are unable to undergo contrast-enhanced MRI due to allergic reaction to contrasts.

Preoperative Prediction of Muscle Invasiveness in Bladder Cancer: The Role of 3D Volumetric Radiomics Using Diffusion-Weighted MRI, the VI-RADS Score, or a Combination of Both

BACKGROUND

Bladder cancer treatment decisions hinge on detecting muscle invasion. The 2018 "Vesical Imaging Reporting and Data System" (VI-RADS) standardizes multiparametric MRI (mp-MRI) use. Radiomics, an analysis framework, provides more insightful information than conventional methods.

PURPOSE

To determine how well MIBC (Muscle Invasive Bladder Cancer) and NMIBC (Non-Muscle Invasive Bladder Cancer) can be distinguished using mp-MRI radiomics features.

METHODS

We conducted a study with 73 bladder cancer patients diagnosed pathologically, who underwent preoperative mp-MRI from January 2020 to July 2022. Utilizing 3D Slicer (version 4.8.1) and Pyradiomics, we manually extracted radiomic features from apparent diffusion coefficient (ADC) maps created from diffusion-weighted imaging. The LASSO approach identified optimal features, and we addressed sample imbalance using SMOTE. We developed a classification model using textural features alone or combined with VI-RADS, employing a random forest classifier with 10-fold cross-validation. Diagnostic performance was assessed using the area under the ROC curve analysis.

RESULTS

Among 73 patients (63 men, 10 women; median age: 63 years), 41 had muscle-invasive and 32 had superficial bladder cancer. Muscle invasion was observed in 25 of 41 patients with VI-RADS 4 and 5 scores and 12 of 32 patients with VI-RADS 1, 2, and 3 scores (accuracy: 77.5%, sensitivity: 67.7%, specificity: 88.8%). The combined VI-RADS score and radiomics model (AUC = 0.92 ± 0.12) outperformed the single radiomics model using ADC MRI (AUC = 0.83 ± 0.22 with 10-fold cross-validation) in this dataset.

CONCLUSION

Before undergoing surgery, bladder cancer invasion in muscle might potentially be predicted using a radiomics signature based on mp-MRI.

Pictorial review of multiparametric MRI in bladder urothelial carcinoma with variant histology: pearls and pitfalls

Bladder cancer (BC), predominantly comprising urothelial carcinomas (UCs), ranks as the tenth most common cancer worldwide. UCs with variant histology (variant UC), including squamous differentiation, glandular differentiation, plasmacytoid variant, micropapillary variant, sarcomatoid variant, and nested variant, accounting for 5-10% of cases, exhibit more aggressive and advanced tumor characteristics compared to pure UC. The Vesical Imaging-Reporting and Data System (VI-RADS), established in 2018, provides guidelines for the preoperative evaluation of muscle-invasive bladder cancer (MIBC) using multiparametric magnetic resonance imaging (mpMRI). This technique integrates T2-weighted imaging (T2WI), dynamic contrast-enhanced (DCE)-MRI, and diffusion-weighted imaging (DWI) to distinguish MIBC from non-muscle-invasive bladder cancer (NMIBC). VI-RADS has demonstrated high diagnostic performance in differentiating these two categories for pure UC. However, its accuracy in detecting muscle invasion in variant UCs is currently under investigation. These variant UCs are associated with a higher likelihood of disease recurrence and require precise preoperative assessment and immediate surgical intervention. This review highlights the potential value of mpMRI for different variant UCs and explores the clinical implications and prospects of VI-RADS in managing these patients, emphasizing the need for careful interpretation of mpMRI examinations including DCE-MRI, particularly given the heterogeneity and aggressive nature of variant UCs. Additionally, the review addresses the fundamental MRI reading procedures, discusses potential causes of diagnostic errors, and considers future directions in the use of artificial intelligence and radiomics to further optimize the bladder MRI protocol.

Image directed redesign of bladder cancer treatment pathways: the BladderPath RCT

Background

Transurethral resection of bladder tumour has been the mainstay of bladder cancer staging for > 60 years. Staging inaccuracies are commonplace, leading to delayed treatment of muscle-invasive bladder cancer. Multiparametric magnetic resonance imaging offers rapid, accurate and non-invasive staging of muscle-invasive bladder cancer, potentially reducing delays to radical treatment.

Objectives

To assess the feasibility and efficacy of the introducing multiparametric magnetic resonance imaging ahead of transurethral resection of bladder tumour in the staging of suspected muscle-invasive bladder cancer.

Design

Open-label, multistage randomised controlled study in three parts: feasibility, intermediate and final clinical stages. The COVID pandemic prevented completion of the final stage.

Setting

Fifteen UK hospitals.

Participants

Newly diagnosed bladder cancer patients of age ≥ 18 years.

Interventions

Participants were randomised to Pathway 1 or 2 following visual assessment of the suspicion of non-muscle-invasive bladder cancer or muscle-invasive bladder cancer at the time of outpatient cystoscopy, based upon a 5-point Likert scale: Likert 1-2 tumours considered probable non-muscle-invasive bladder cancer; Likert 3-5 possible muscle-invasive bladder cancer. In Pathway 1, all participants underwent transurethral resection of bladder tumour. In Pathway 2, probable non-muscle-invasive bladder cancer participants underwent transurethral resection of bladder tumour, and possible muscle-invasive bladder cancer participants underwent initial multiparametric magnetic resonance imaging. Subsequent therapy was determined by the treating team and could include transurethral resection of bladder tumour.

Main outcome measures

Feasibility stage: proportion with possible muscle-invasive bladder cancer randomised to Pathway 2 which correctly followed the protocol. Intermediate stage: time to correct treatment for muscle-invasive bladder cancer.

Results

Between 31 May 2018 and 31 December 2021, of 638 patients approached, 143 participants were randomised; 52.1% were deemed as possible muscle-invasive bladder cancer and 47.9% probable non-muscle-invasive bladder cancer. Feasibility stage: 36/39 [92% (95% confidence interval 79 to 98%)] muscle-invasive bladder cancer participants followed the correct treatment by pathway. Intermediate stage: median time to correct treatment was 98 (95% confidence interval 72 to 125) days for Pathway 1 versus 53 (95% confidence interval 20 to 89) days for Pathway 2 [hazard ratio 2.9 (95% confidence interval 1.0 to 8.1)], p = 0.040. Median time to correct treatment for all participants was 37 days for Pathway 1 and 25 days for Pathway 2 [hazard ratio 1.4 (95% confidence interval 0.9 to 2.0)].

Limitations

For participants who underwent chemotherapy, radiotherapy or palliation for multiparametric magnetic resonance imaging-diagnosed stage T2 or higher disease, it was impossible to conclusively know whether these were correct treatments due to the absence of histopathologically confirmed muscle invasion, this being confirmed radiologically in these cases. All patients had histological confirmation of their cancers. Due to the COVID-19 pandemic, we were unable to realise the final stage.

Conclusion

The multiparametric magnetic resonance imaging-directed pathway led to a substantial 45-day reduction in time to correct treatment for muscle-invasive bladder cancer, without detriment to non-muscle-invasive bladder cancer participants. Consideration should be given to the incorporation of multiparametric magnetic resonance imaging ahead of transurethral resection of bladder tumour into the standard pathway for all patients with suspected muscle-invasive bladder cancer. The improved decision-making accelerated time to treatment, even though many patients subsequently needed transurethral resection of bladder tumour. A proportion of patients can avoid transurethral resection of bladder tumour completely, reducing costs and morbidity, given the much lower cost of magnetic resonance imaging and biopsy compared to transurethral resection of bladder tumour.

Future work

Further work to cross-correlate with the recently developed Vesical Imaging-Reporting and Data System will improve accuracy and aid dissemination. Longer follow-up to examine the effect of the pathway on outcomes is also required. Incorporation of liquid deoxyribonucleic acid-based biomarkers may further improve the quality of decision-making and should also be investigated further.

Study registration

This study is registered as ISRCTN 35296862.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR135775) and is published in full in Health Technology Assessment; Vol. 28, No. 42. See the NIHR Funding and Awards website for further award information.

The role of VI-RADS scoring criteria for predicting oncological outcomes in bladder cancer

PURPOSE

Our purpose was to evaluate the prognostic value of Vesical Imaging Reporting and Data System (VI-RADS) in bladder cancer (BCa) staging and predicting recurrence or progression.

METHODS

We retrospectively analyzed the prospectively collected data from 96 patients with bladder tumors who underwent VI-RADS-based multiparametric magnetic resonance imaging (mpMRI) before endourological treatment from April 2021 to December 2022. Diagnostic performance was evaluated by comparing mpMRI reports with final pathology, using logistic regression for muscle-invasive bladder cancer (MIBC) predictors. Follow-up until May 2023 included Kaplan-Meier and Cox regression analysis to assess VI-RADS predictive roles for recurrence-free survival (RFS) and progression-free survival (PFS).

RESULTS

A total of 96 patients (19.8% women, 80.2% men; median age 68.0 years) were included, with 71% having primary tumors and 29% recurrent BCa. Multiparametric MRI exhibited high sensitivity (92%) and specificity (79%) in predicting MIBC, showing no significant differences between primary and recurrent cancers (AUC: 0.96 vs. 0.92, P = .565). VI-RADS emerged as a key predictor for MIBC in both univariate (OR: 40.3, P < .001) and multivariate (OR: 54.6, P < .001) analyses. Primary tumors with VI-RADS ≥ 3 demonstrated significantly shorter RFS (P = .02) and PFS (P = .04).

CONCLUSIONS

In conclusion, mpMRI with VI-RADS has a high diagnostic value in predicting MIBC in both primary and recurrent BCa. A VI-RADS threshold ≥ 3 is a strong predictor for MIBC, and in primary tumors predicts early recurrence and progression.

Comparison of staging MRI to re-resection for localised bladder cancer: Narrative review

Introduction

Bladder cancer (BCa) is characterised by high prevalence, multifocality, and frequent recurrence, imposing significant clinical and economic burdens. Accurate staging, particularly distinguishing non-muscle-invasive bladder cancer (NMIBC) from muscle-invasive bladder cancer (MIBC) disease, is crucial for guiding treatment decisions. This narrative review explores the potential implications of incorporating multiparametric magnetic resonance imaging (mpMRI) and the Vesical Imaging Reporting Data System (VI-RADS) into BCa staging, focusing on repeat transurethral resection of bladder tumour (re-TURBT).

Methods

A comprehensive search of PubMed, EMBASE, and MEDLINE databases identified studies published from 2018 to 2023 discussing mpMRI or VI-RADS in the context of re-TURBT for BCa staging. Studies meeting inclusion criteria underwent qualitative analysis.

Results

Six recent studies met inclusion criteria. VI-RADS scoring, accurately predicted muscle invasion, aiding in NMIBC/MIBC differentiation. VI-RADS scores of ≥3 indicated MIBC with high sensitivity and specificity. VI-RADS potentially identified patients benefiting from re-TURBT and those for whom it could be safely omitted.

Discussion

mpMRI and VI-RADS offer promising prospects for BCa staging, potentially correlating more closely with re-TURBT and radical cystectomy histopathology than initial TURBT. However, validation and careful evaluation of clinical integration are needed. Future research should refine patient selection and optimise mpMRI's role in BCa management.

Conclusion

VI-RADS scoring could revolutionise BCa staging, especially regarding re-TURBT. There is potential that VI-RADS correlates more with the histopathology of re-TURBT and radical cystectomy than initial TURBT. While promising, ongoing research is essential to validate utility, refine selection criteria, and address economic considerations. Integration of VI-RADS into BCa staging holds potential benefits for patients and health care systems.

The impact of venous thromboembolism before open or minimally-invasive radical cystectomy in the USA: insurance claims data on perioperative outcomes and healthcare costs

BACKGROUND

The relationship between venous thromboembolism (VTE) and solid malignancy has been established over the decades. With rising projected rates of bladder cancer (BCa) worldwide as well as increasing number of patients experiencing BCa and VTE, our aim is to assess the impact of a preoperative VTE diagnosis on perioperative outcomes and health-care costs in BCa cases undergoing radical cystectomy (RC).

METHODS

Patients ≥18 years of age with BCa diagnosis and undergoing open or minimally invasive (MIS) RC were identified in the Merative™ Marketscan® Research Databases between 2007 and 2021. The association of previous VTE history with 90-day complication rates, postoperative VTE events, rehospitalization, and total hospital costs (2021 USA dollars) was determined by multivariable logistic regression modeling adjusted for patient and perioperative confounders. Sensitivity analysis on VTE degree of severity (i.e., pulmonary embolism [PE] and/or peripheral deep venous thrombosis [DVT]) was also examined.

RESULTS

Out of 8759 RC procedures, 743 (8.48%) had a previous positive history for any VTE including 245 (32.97%) PE, 339 (45.63%) DVT and 159 (21.40%) superficial VTE. Overall, history of VTE before RC was strongly associated with almost any worse postoperative outcomes including higher risk for any and apparatus-specific 90-days postoperative complications (odds ratio [OR]: 1.21, 95% CI, 1.02-1.44). Subsequent incidence of new VTE events (OR: 7.02, 95% CI: 5.93-8.31), rehospitalization (OR: 1.25, 95% CI: 1.06-1.48), other than home/self-care discharge status (OR: 1.53, 95% CI: 1.28-1.82), and higher health-care costs related to the RC procedure (OR: 1.43, 95% CI: 1.22-1.68) were significantly associated with a history of VTE.

CONCLUSIONS

Preoperative VTE in patients undergoing RC significantly increases morbidity, post-procedure VTE events, hospital length of stay, rehospitalizations, and increased hospital costs. These findings may help during the BCa counseling on risks of surgery and hopefully improve our ability to mitigate such risks.

Clinical application of bladder MRI and the Vesical Imaging-Reporting and Data System

Diagnostic work-up and risk stratification in patients with bladder cancer before and after treatment must be refined to optimize management and improve outcomes. MRI has been suggested as a non-invasive technique for bladder cancer staging and assessment of response to systemic therapy. The Vesical Imaging-Reporting And Data System (VI-RADS) was developed to standardize bladder MRI image acquisition, interpretation and reporting and enables accurate prediction of muscle-wall invasion of bladder cancer. MRI is available in many centres but is not yet recommended as a first-line test for bladder cancer owing to a lack of high-quality evidence. Consensus-based evidence on the use of MRI-VI-RADS for bladder cancer care is needed to serve as a benchmark for formulating guidelines and research agendas until further evidence from randomized trials becomes available.

Determining the clinicopathological significance of the VI-RADS ≧4 group: a retrospective study

BACKGROUND

The Vesical Imaging Reporting and Data System (VI-RADS) is widely used for predicting muscle-invasive bladder cancer (MIBC). This study aimed to determine the clinicopathological significance of the VI-RADS ≧4 (VI≧4) group.

METHODS

Patients who underwent transurethral resections of bladder tumors during the study period and preoperative magnetic resonance imaging were considered. The patients were pathologically diagnosed with urothelial carcinoma (UC). We first compared the results of patients with VI-RADS scores of 3 and 4 to determine the cut-off score for MIBC; thereafter, the patients were divided into the VI≧4 and VI-RADS ≦3 (VI≦3) groups using VI-RADS. The clinicopathological significance of the VI≧4 group was examined retrospectively by comparing the characteristics of each group.

RESULTS

In total, 121 cases were examined, of which 28 were pathologically diagnosed with MIBC. Of the 28 MIBC cases, three (10.7%) had a VI-RADS score of ≦3, and 25 (89.3%) had a VI-RADS score of ≧4. Of the 93 NMIBC cases, 86 (92.5%) had a VI-RADS score of ≦3, and seven (7.5%) had a VI-RADS score of ≧4. The diagnostic performance of the VI-RADS with a cut-off score of 4 was 89.3% for sensitivity, 92.5% for specificity, and an area under the curve (AUC) of 0.91. Contrastingly, for a cut-off score of 3, the sensitivity was 89.3%, specificity was 62.0%, and AUC was 0.72. A VI-RADS score of ≥ 4 could predict MIBC. In the VI≧4 group, 30 of 32 (93.8%) patients had high-grade tumors. The VI≧4 group had significantly more high-grade bladder cancers than the VI≦3 group (p < 0.001 OR = 31.77 95%CI:8.47-1119.07). In addition, the VI≧4 group had more tumor necrosis (VI≧4 vs VI≦3, p < 0.001 OR = 7.46 95%CI:2.61-21.34) and more UC variant cases (VI≧4 vs VI≦3, p = 0.034 OR = 3.28 95%CI:1.05-10.25) than the VI≦3 group.

CONCLUSIONS

This study suggests that VI-RADS has a high diagnostic performance in predicting MIBC and that VI-RADS could diagnose high-grade tumors, necrosis, and UC variants.

Practical Guide to VI-RADS: MRI Protocols, Lesion Characterization, and Pitfalls

Urothelial carcinoma is the most common type of bladder cancer (BC), accounting for approximately 90% of all cases. Evaluating the depth of tumor invasion in the bladder wall (tumor staging) is essential for determining the treatment and prognosis in patients with BC. Neoadjuvant therapy followed by radical cystectomy is the most common treatment of localized muscle-invasive BC (MIBC). Therefore, it is vital to differentiate non-MIBC from MIBC. Transurethral resection of bladder tumor (TURBT) is the reference standard to determine the extent of tumor invasion into the bladder wall through tissue sampling. However, this diagnostic and therapeutic method may not adequately sample the muscularis propria, leading to a higher risk of residual disease, early recurrence, and tumor understaging in approximately 50% of patients during the initial TURBT. Multiparametric MRI can overcome some of the limitations of TURBT when evaluating BC, particularly regarding tumor staging. In this context, the Vesical Imaging Reporting and Data System (VI-RADS) classification was developed to establish standards for bladder multiparametric MRI and interpretation. It uses a 5-point scale to assess the likelihood of detrusor muscle invasion. T2-weighted MR images are particularly useful as an initial guide, especially for categories 1-3, while the presence of muscular invasion is determined with diffusion-weighted and dynamic contrast-enhanced sequences. Diffusion-weighted imaging takes precedence as the dominant method when optimal image quality is achieved. The presence of a stalk or a thickened inner layer and no evidence of interruption of the signal intensity of the muscular layer are central for predicting a low likelihood of muscle invasion. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Hoegger in this issue.

Amide Proton Transfer-Weighted MRI and Diffusion-Weighted Imaging in Bladder Cancer: A Complementary Tool to the VI-RADS

RATIONALE AND OBJECTIVES

To investigate the feasibility of amide proton transfer-weighted (APTw) and diffusion-weighted Magnetic Resonance Imaging (MRI) as a means by which to add value to the Vesical Imaging Reporting and Data System (VI-RADS) for discriminating muscle invasive bladder cancer (MIBC) from nonmuscle invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

This prospective study enrolled participants with pathologically confirmed bladder cancer (BCa) who underwent preoperative multiparametric MRI, including APTw and diffusion-weighted MRI, from July 2020 to January 2023. The exclusion criteria were lesions smaller than 10 mm, missing smooth muscle layer in the operation specimen, neoadjuvant therapy before MRI, inadequate image quality, and malignancy other than urothelial neoplasm. Two radiologists independently assigned the VI-RADS score for each participant. Quantitative parameters derived from APTw and diffusion-weighted MRI were obtained by another two radiologists. Receiver operating characteristic (ROC) curve analysis with the area under the ROC curve (AUC) was performed to evaluate the diagnostic performances of quantitative parameters for discriminating BCa detrusor muscle invasion status.

RESULTS

A total of 106 participants were enrolled (mean age, 64 ± 12 years [SD]; 90 men): 32 with MIBC and 74 with NMIBC. Lower apparent diffusion coefficient (ADC) values (0.88 × 10-3 mm2/s ± 0.12 vs. 1.08 × 10-3 mm2/s ± 0.25; P < 0.001) and higher APTw values (6.89% [interquartile range {IQR}, 5.05%-12.17%] vs. 3.61% [IQR, 2.23%-6.83%]; P < 0.001) were observed in the MIBC group. Compared to VI-RADS alone, both APTw (P = 0.003) and ADC (P = 0.020) values could improve the diagnostic performance of VI-RADS in differentiating MIBC from NMIBC. The combination of the three yielded the highest diagnostic performance (AUC, 0.93; 95% CI:0.87,0.97) for evaluating muscle invasion status. The addition of the APTw values to the combination of VI-RADS and ADC values notably improved the diagnostic performance for differentiating NMIBC from MIBC (VI-RADS+ADC vs. VI-RADS+APTw+ADC, P = 0.046).

CONCLUSION

MRI parameters derived from APTw and diffusion-weighted MRI can be used to accurately assess muscle invasion status in BCa and provide additional value to VI-RADS.

The role of gadolinium-based contrast agents in magnetic resonance imaging structured reporting and data systems (RADS)

Among the 28 reporting and data systems (RADS) available in the literature, we identified 15 RADS that can be used in Magnetic Resonance Imaging (MRI). Performing examinations without using gadolinium-based contrast agents (GBCA) has benefits, but GBCA administration is often required to achieve an early and accurate diagnosis. The aim of the present review is to summarize the current role of GBCA in MRI RADS. This overview suggests that GBCA are today required in most of the current RADS and are expected to be used in most MRIs performed in patients with cancer. Dynamic contrast enhancement is required for correct scores calculation in PI-RADS and VI-RADS, although scientific evidence may lead in the future to avoid the GBCA administration in these two RADS. In Bone-RADS, contrast enhancement can be required to classify an aggressive lesion. In RADS scoring on whole body-MRI datasets (MET-RADS-P, MY-RADS and ONCO-RADS), in NS-RADS and in Node-RADS, GBCA administration is optional thanks to the intrinsic high contrast resolution of MRI. Future studies are needed to evaluate the impact of the high T1 relaxivity GBCA on the assignment of RADS scores.

MRI for risk stratification of muscle invasion by upper tract urothelial carcinoma: a feasibility study

BACKGROUND

Magnetic resonance imaging (MRI) is recommended in patients with upper tract urothelial carcinoma (UTUC) only when computed tomography (CT) is contraindicated. However, CT does not allow distinguishing ureter wall layers, making impossible to assess muscle invasion, a factor contributing to differentiate high- from low-risk UTUCs, which require different therapeutic approaches. We investigated the feasibility of MRI assessment of UTUC muscle invasion.

METHODS

From June 2022 to March 2023, we prospectively enrolled patients suspected of UTUC, i.e., with positive urinary tract ultrasound and/or ureteroscopy, or positive urinary cytology and/or hematuria but negative cystoscopy and bladder ultrasound at two Italian centers. They underwent CT followed by MRI (≤ 24 h apart), independently reported by two experienced radiologists, blinded from histopathology results. After imaging confirmation, they all underwent nephroureterectomy and histopathology analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the receiver operating characteristic curve (AUC) were calculated.

RESULTS

Thirty-nine lesions were detected in 30 patients on both CT and MRI. Muscle-invasive UTUC prevalence was 81% (21/26) among patients with MRI suspicion and 8% (1/13) among those without MRI suspicion (p < 0.001). Considering the assessment of muscle-layer invasion, the more experienced reader achieved 95% sensitivity (95% confidence interval 82-100), 71% specificity (47-88), 81% PPV (63-93), 92% NPV (70-100), 85% accuracy (67-96), and 0.84 AUC (0.70-0.98). Inter-reader agreement was substantial (κ = 0.73).

CONCLUSIONS

MRI showed a promising diagnostic performance for the assessment of UTUC risk of muscle invasion.

RELEVANCE STATEMENT

Resulting feasible both in technical and clinical terms, MRI could be helpful for upper tract urothelial carcinomas pre-operative risk stratification, to allow a personalized patients' management. These results play in favor of promoting preoperative MRI for UTUC, as already proven for bladder cancer.

KEY POINTS

• Muscle invasion is a crucial information for tailored treatments of upper tract urothelial carcinomas. • CT does not distinguish ureter wall layers, making muscle invasion risk assessment not feasible. • MRI was shown to reliably diagnose muscle-layer invasion by upper tract urothelial carcinomas (sensitivity 95%, specificity 71%).

Biparametric versus Multiparametric Magnetic Resonance Imaging for Assessing Muscle Invasion in Bladder Urothelial Carcinoma with Variant Histology Using the Vesical Imaging-Reporting and Data System

BACKGROUND

The diagnostic performance of contrast medium-free biparametric magnetic resonance imaging (bpMRI; combining T2-weighted imaging [T2WI] and diffusion-weighted imaging [DWI]) for evaluating variant-histology urothelial carcinoma (VUC) remains unknown.

OBJECTIVE

To compare the diagnostic performance of bpMRI and multiparametric MRI (mpMRI; combining T2WI, DWI, and dynamic contrast-enhanced MRI]) for assessing muscle invasion of VUC.

DESIGN, SETTING, AND PARTICIPANTS

This multi-institution retrospective analysis included 118 patients with pathologically verified VUC who underwent bladder mpMRI before transurethral bladder tumor resection between 2010 and 2019.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Three board-certified radiologists separately evaluated two sets of images, set 1 (bpMRI) and set 2 (mpMRI), in accordance with the Vesical Imaging Reporting and Data System (VI-RADS). The histopathology results were utilized as a reference standard. Receiver operating characteristic curve analysis, Z test, and Wald test were used to assess diagnostic abilities.

RESULTS AND LIMITATIONS

Sixty-six (55.9%) and 52 (44.1%) of the 118 patients with VUC included in the analysis (mean age, 71 ± 10 yr; 88 men) had muscle-invasive bladder cancer (MIBC) and non-MIBC, respectively. For the diagnosis of MIBC, the areas under the curve for bpMRI were significantly smaller than those for mpMRI (0.870-0.884 vs 0.902-0.923, p < 0.05). The sensitivity of bpMRI was significantly lower than that of mpMRI for all readers with a VI-RADS cutoff score of 4 (65.2-66.7% vs 77.3-80.3%, p < 0.05). The specificity of bpMRI and mpMRI did not differ significantly for all readers (88.5-90.4 vs 88.5-92.3, p > 0.05). A limitation of the study is the limited sample size because of the rarity of VUC.

CONCLUSIONS

In patients with VUC, on applying VI-RADS, the diagnostic results of bpMRI were inferior to those of mpMRI for evaluating muscle invasion. Therefore, mpMRI-based methods are recommended for evaluating muscle invasiveness of VUC.

PATIENT SUMMARY

Contrast medium-free biparametric magnetic resonance imaging (bpMRI)-based Vesical Imaging Reporting and Data System (VI-RADS) can accurately diagnose pure urothelial carcinomas, similar to conventional multiparametric magnetic resonance imaging-based VI-RADS. However, bpMRI-based VI-RADS may misdiagnose muscle invasiveness of urothelial carcinoma with variant histology, particularly when its cutoff score is 4.

Diagnostic validity of the vesical imaging-reporting and data system (VI-RADS): a real-world study

OBJECTIVES

Preoperative Vesical Imaging-Reporting and Data System (VI-RADS) becomes widespread. We aimed to validate the diagnostic performance of VI-RADS in differentiating muscle-invasive (MIBC) from non-muscle-invasive bladder cancer (NMIBC) in a real-world setting.

METHODS

Between December 2019 and February 2022 suspected primary bladder cancer patients were reviewed. Those with proper multiparametric MRI (mpMRI) protocol for VI-RADS before any invasive treatment were included. Patients were locally staged according to transurethral resection, second resection, or radical cystectomy as the reference standard. Two experienced genitourinary radiologists who were blinded to clinical and histopathological data evaluated the mpMRI images independently and retrospectively. The diagnostic performance of both radiologists and the interreader agreement were analyzed.

RESULTS

Among 96 patients, 20 (20.8%) had MIBC, and 76 (79.2%) had NMIBC. Both radiologists had great diagnostic performance in diagnosing MIBC. The first radiologist had an area under curve (AUC) of 0.83 and 0.84, the sensitivity of 85% and 80%, and the specificity of 80.3% and 88.2% for VI-RADS ≥3 and ≥4, respectively. The second radiologist had an area under curve (AUC) of 0.79 and 0.77, the sensitivity of 85% and 65%, and the specificity of 73.7% and 89.5% for VI-RADS ≥3 and ≥4, respectively. The overall VI-RADS score agreement between the two radiologists was moderate (κ = 0.45).

CONCLUSION

VI-RADS is diagnostically powerful in differentiating MIBC from NMBIC prior to transurethral resection. The agreement between radiologists is moderate.

Tumor contact length with bladder wall provides effective risk stratification for lesions with a VIRADS score of 2-3

OBJECTIVES

To evaluate the diagnostic performance of the tumor contact length (TCL) in the prediction of MIBC (muscle-invasive bladder cancer) in lesions corresponding to the vesical imaging-reporting and data system (VIRADS) score 2-3.

METHODS

This is a single institution, retrospective study targeting 191 consecutive patients assigned of VIRADS score 2-3, who had pre-transurethral resection MRI from July 2019 to September 2021. Logistic regression analyses were performed to determine meaningful predictors of MIBC for this score group, and a nomogram was plotted with those variables. The diagnostic performance of each predictor was compared at predefined thresholds (VIRADS score 3 and TCL 3 cm) using the generalized linear model and ROC analysis.

RESULTS

Both VIRADS score and TCL remained independent predictors of MIBC for this score group (odds ratio 7.3 for VIRADS score, and 1.3 for TCL, p < 0.01 for both). The contribution of TCL to the probability of MIBC in the nomogram was greater than that of the VIRADS score. VIRADS score had a sensitivity of 0.54 (14/26), specificity of 0.92 (203/221), and diagnostic accuracy of 0.88 (217/247), and TCL showed a sensitivity of 0.89 (23/26), specificity of 0.95 (209/221), and diagnostic accuracy of 0.94 (232/247). The difference in sensitivity (p = 0.03) and accuracy (p = 0.04) was statistically significant. The AUC was also significantly wider for TCL than for VIRADS (0.97 vs. 0.73, p < 0.01).

CONCLUSION

A simple index, TCL, may be helpful in further risk stratification for MIBC in patients with a score of VIRADS 2-3.

CLINICAL RELEVANCE STATEMENT

For bladder cancer patients with insufficient qualitative evidence of muscle layer invasion using VIRADS categorization, TCL, a simple quantitative indicator defined as the curvilinear contact length between the bladder wall and the tumor, may be helpful in risk stratification.

KEY POINTS

• Even when only lesions with score 2-3 were targeted, VIRADS was still a meaningful indicator of MIBC. • With a predefined threshold of 3 cm applied, TCL outperformed VIRADS in the score 2-3 group, in predicting MIBC. • A longer TCL for a lesion with a VIRADS score 2 may warrant an additional warning for MIBC, whereas a shorter TCL for a lesion with a score 3 may indicate a lower risk of MIBC.

Evaluating residual tumor after neoadjuvant chemotherapy for muscle-invasive urothelial bladder cancer: diagnostic performance and outcomes using biparametric vs. multiparametric MRI

BACKGROUND

Neoadjuvant chemotherapy (NAC) before radical cystectomy is standard of care in patients with muscle-invasive bladder cancer (MIBC). Response assessment after NAC is important but suboptimal using CT. We assessed MRI without vs. with intravenous contrast (biparametric [BP] vs. multiparametric [MP]) for identifying residual disease on cystectomy and explored its prognostic role.

METHODS

Consecutive MIBC patients that underwent NAC, MRI, and cystectomy between January 2000-November 2022 were identified. Two radiologists reviewed BP-MRI (T2 + DWI) and MP-MRI (T2 + DWI + DCE) for residual tumor. Diagnostic performances were compared using receiver operating characteristic curve analysis. Kaplan-Meier curves and Cox proportional-hazards models were used to evaluate association with disease-free survival (DFS).

RESULTS

61 patients (36 men and 25 women; median age 65 years, interquartile range 59-72) were included. After NAC, no residual disease was detected on pathology in 19 (31.1%) patients. BP-MRI was more accurate than MP-MRI for detecting residual disease after NAC: area under the curve = 0.75 (95% confidence interval (CI), 0.62-0.85) vs. 0.58 (95% CI, 0.45-0.70; p = 0.043). Sensitivity were identical (65.1%; 95% CI, 49.1-79.0) but specificity was higher in BP-MRI compared with MP-MRI for determining residual disease: 77.8% (95% CI, 52.4-93.6) vs. 38.9% (95% CI, 17.3-64.3), respectively. Positive BP-MRI and residual disease on pathology were both associated with worse DFS: hazard ratio (HR) = 4.01 (95% CI, 1.70-9.46; p = 0.002) and HR = 5.13 (95% CI, 2.66-17.13; p = 0.008), respectively. Concordance between MRI and pathology results was significantly associated with DFS. Concordant positive (MRI+/pathology+) patients showed worse DFS than concordant negative (MRI-/pathology-) patients (HR = 8.75, 95% CI, 2.02-37.82; p = 0.004) and compared to the discordant group (MRI+/pathology- or MRI-/pathology+) with HR = 3.48 (95% CI, 1.39-8.71; p = 0.014).

CONCLUSION

BP-MRI was more accurate than MP-MRI for identifying residual disease after NAC. A negative BP-MRI was associated with better outcomes, providing complementary information to pathological assessment of cystectomy specimens.

Accuracy of Vesical Imaging-Reporting and Data System for muscle-invasive bladder cancer detection from multiparametric magnetic resonance imaging

PURPOSE

The Vesical Imaging-Reporting and Data System (VI-RADS) was used to distinguish the invasive nature of bladder masses before surgery. These imaging criteria can be used to carefully select patients who are candidates for repeat transurethral resection of bladder tumor (Re-TUR-BT). One-third of patients are understage at the time of Re-TUR-BT. This study aimed to evaluate the discrimination accuracy of VI-RADS between non-muscle-invasive bladder cancer and muscle-invasive bladder cancer.

MATERIALS AND METHODS

Patients with a bladder mass identified by cystoscopy who were assigned for TUR-BT were offered multiparametric magnetic resonance imaging (mpMRI) for VI-RADS. TUR-BT reports were compared with preoperative VI-RADS scores to evaluate the accuracy of discrimination of the muscle-invasive nature of the bladder mass.

RESULTS

A total of 58 bladder tumor lesions were included, 13 with muscle-invasive bladder cancer and 45 with non-muscle-invasive bladder cancer. Sensitivity and specificity were 92.3% and 86.7%, respectively, when a VI-RADS cutoff of 4 or more was used to define muscle-invasive bladder cancer. Positive predictive value and negative predictive value were 66.7% and 97.5%, with an accuracy of 87.9%. The area under the receiver operating characteristic curve was 0.932 (95% confidence interval, 0.874-0.989), and the empirical optimal cutpoint from the Youden method was 3.

CONCLUSIONS

VI-RADS is an accurate tool for correctly differentiating muscle-invasive bladder cancer from non-muscle-invasive bladder cancer. We found a cutpoint of VI-RADS 1-3 vs. 4-5 to have the highest specificity and accuracy for the discrimination of non-muscle-invasive from muscle-invasive bladder cancer.

Magnetic resonance radiographic features which might lead to misdiagnosis of muscle-invasive bladder cancer based on vesical imaging reporting and data system: the application experience of a single center

Background

The Vesical Imaging Reporting and Data System (VI-RADS) has been widely used for diagnosing muscle-invasive bladder cancer (MIBC), yet instances of misdiagnosis persist. However, limited research discusses the factors affecting its accuracy. This study aimed to evaluate the diagnostic efficacy of the VI-RADS in our center and to preliminarily identify possible magnetic resonance imaging (MRI) characteristics of misdiagnosis.

Methods

From January 2018 to February 2023, a consecutive series of 211 participants pathologically diagnosed with bladder cancer (BC) who underwent an MRI exam were retrospectively enrolled. MRI was interpreted by 2 radiologists with different levels of experience, the diagnostic performance was validated using the receiver operating characteristic (ROC) curve, and VI-RADS ≥4 was considered to indicate MIBC-positive status. The clinical and radiographic characteristics of the true-positive (TP), true-negative (TN), false-positive (FP), and false-negative (FN) groups were analyzed using Kruskal-Wallis test or Fisher exact test.

Results

With VI-RADS ≥4 as the cutoff value, the area under the ROC curves (AUCs) were 0.951 (0.912-0.976) and 0.847 (0.791-0.893) for the more-experienced reader and less-experienced reader, respectively, with good interobserver agreement (κ=0.74105). The median tumor size in the TP (more experienced: 57 cases; less experienced: 44 cases) and FP (more experienced: 8 cases; less experienced: 9 cases) groups was larger than that in the TN (more experienced: 141 cases; less experienced: 139 cases) group for the more-experienced reader (TP: 28 mm; FP: 31 mm; TN: 19 mm; P<0.001 and P=0.031, respectively) and the less-experienced reader (TP: 31 mm; FP: 28 mm; TN: 19 mm; P<0.001 and P=0.042, respectively). The tumor base in the TP and FP groups was larger than that in the TN group for the more-experienced reader (TP: 37 mm; FP: 48 mm; TN: 15 mm; both P<0.001) and for the less-experienced reader (FP: 42 mm; FP: 36 mm; TN: 15 mm; P<0.001 and P=0.022, respectively). The median tumor base in the TP group was larger than that in the FN group for the less-experienced reader (TP: 42 mm; FN: 17 mm; P=0.004).

Conclusions

We observed good to excellent AUCs with good interobserver agreement among radiologists with different levels of expertise using VI-RADS. Large tumor size and wide tumor base affected the accuracy of VI-RADS in MIBC diagnosis.

Diagnostic performance of multiparametric MRI based Vesical Imaging-Reporting and Data System (VI-RADS) scoring in discriminating between non-muscle invasive and muscle invasive bladder cancer

Purpose

The purpose of the present study was to assess the diagnostic accuracy of the Vesical Imaging-Reporting and Data System (VI-RADS) scoring system in predicting muscle infiltration of bladder cancer (BC) on a pre-operative multiparametric magnetic resonance imaging (mpMRI).

Methods

The prospective study enrolled patients with bladder lesions detected on a preliminary ultrasonography or cystoscopy. The patients underwent mpMRI on a 3T MRI scanner followed by surgery within 2 weeks. The tumours were assigned a VI-RADS score by 2 experienced abdominal radiologists. The VI-RADS score was compared with postoperative histopathological findings to confirm detrusor muscle infiltration. The diagnostic performance of VI-RADS for predicting muscle invasion was assessed by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy.

Results

A total of 60 patients were included in the study with a male: female ratio of 4.4 : 1. Transurethral resection of bladder tumour (TURBT) was performed in 47 (78.4%) and radical cystectomy in 13 (21.6%) patients. 19 (31.7%) had non-muscle invasive invasive BC (NMIBCa) and 41 (68.3%) had muscle invasive BC (MIBCa) on histopathology. There was a significant association between VI-RADS score and its components with muscle invasion (p < 0.05). A VI-RADS score of ≥ 3 had a sensitivity of 97.56% (95% CI: 0.87-0.99%), specificity of 73.68% (95% CI: 0.49-0.91), positive predictive value of 88.9% (95% CI: 0.79-0.94), negative predictive value of 93.33% (95% CI: 0.66-0.99), and diagnostic accuracy of 90% (95% CI: 0.80-0.96) for prediction of muscle invasion.

Conclusion

VI-RADS scoring system pre-operatively predicts the likelihood of muscle invasion in BC with a satisfactory diagnostic performance, and it should be incorporated in the diagnostic work-up of BC patients.

Accuracy of actual stage prediction using Vesical Imaging Reporting and Data System (VI-RADS) before radical cystectomy for urothelial carcinoma in SUPER-UC-Cx

BACKGROUND

Previous studies using the Vesical Imaging Reporting and Data System (VI-RADS) to predict muscle-invasive bladder cancer (MIBC) had some limitations. Most studies were performed with transurethral resection of bladder tumor (TUR-BT) specimens with few samples. This study was conducted to address these shortcomings and confirm the accuracy of VI-RADS for bladder cancer.

METHODS

This study used data from the Seoul National University Prospectively Enrolled Registry for Urothelial Cancer-Radical Cystectomy (SUPER-UC-Cx). Patients who underwent multiparametric magnetic resonance imaging (mp-MRI) before radical cystectomy (RC) were included in this study between March 2020 and March 2022. All images were reported by radiologists and reviewed by two urologists. The patient characteristics and clinical information were blinded during the review. The performance of qualitative and quantitative variables in predicting muscle layer invasion or perivesical fat infiltration was verified by receiver operating characteristic (ROC) curve analysis.

RESULTS

Of 208 patients, 182 (87.5%) underwent mp-MRI before RC. Twenty-three patients with non-urothelial carcinoma, inappropriate MRI scans, and bladder filling were excluded. Cut-off for muscle invasion, VI-RADS score of 4 had the highest area under the curve (AUC) (sensitivity 0.84; specificity 0.93; accuracy 0.90; positive predictive value (PPV) 0.84; negative predictive value (NPV) 0.93, and AUC 0.88). Cut-off for perivesical fat invasion and VI-RADS score of 5 had the highest AUC (sensitivity, 0.78; specificity, 0.99; accuracy, 0.95; PPV, 0.96; NPV, 0.95; and AUC, 0.89).

CONCLUSIONS

VI-RADS is a good predictor of bladder cancer staging before RC and is especially helpful in predicting muscle invasion and perivesical fat infiltration.

To determine correlation between VIRADS scoring and pathological staging in bladder cancer: A prospective study and review of literature

The development of standardized reporting systems is of paramount importance in medical-imaging. Based on the "RADS" methodology, PIRADS and BI-RADS have been successfully used. The management of bladder cancer (BC) depends on the stage at the time of identification. Accurate assessment of the muscle-invasive stage can alter therapies that are radically different. MRI can accurately diagnose this in a standardized manner (Vesical Imaging-Reporting and Data System: VIRADS) and spare additional procedures. The aim of the study is to determine diagnostic accuracy of VIRADS scoring in evaluation of muscle invasiveness in patients with BC. This study was conducted in a single center over a period of 2 years from April 2020. A total of 76 patients with bladder SOL/diagnosed BC were included. Final VIRADS scoring was calculated and compared with histopathological report.76 patients were evaluated which included 64 males and 12 females. Most of the cases came under the VIRADS-II category (23, 30.26%) followed by VIRADS-V (17, 22.36%). VIRADS-I was reported in 14 cases (18.42%). A total of 8 cases (10.52 %) were reported as VIRADS III and 14 cases (18.42%) as VIRADS IV. VIRADS-III was taken as cut off and found to have a sensitivity of 94.44%, a specificity of 87.50%, a positive predictive value of 87.17% and a negative predictive value of 94.59%. Though number of cases are still less to accurately predict test characteristics of VIRADS, our results are consistent with previously done retrospective studies and VIRADS has got good correlation with pathological staging.

Approaches to Clinical Complete Response after Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer: Possibilities and Limitations

In the surgical oncology field, the change from a past radical surgery to an organ preserving surgery is a big trend. In muscle-invasive bladder cancer treatment, neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is the standard of care for muscle-invasive bladder cancer (MIBC) patients eligible for cisplatin. There is a growing interest in bladder preserving strategies after NAC because good oncologic outcome has been reported for pathologic complete response (pCR) patients after NAC, and many studies have continued to discuss whether bladder preservation treatment is possible for these patients. However, in actual clinical practice, decision-making should be determined according to clinical staging and there is a gap that cannot be ignored between clinical complete response (cCR) and pCR. Currently, there is a lack in a uniform approach to post-NAC restaging of MIBC and a standardized cCR definition. In this review, we clarify the gap between cCR and pCR at the current situation and focus on emerging strategies in bladder preservation in selected patients with MIBC who achieve cCR following NAC.