Dynamic contrast-enhanced MRI in patients with muscle-invasive transitional cell carcinoma of the bladder can distinguish between residual tumour and post-chemotherapy effect

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.

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.

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.

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.

Multiparametric MRI in Era of Artificial Intelligence for Bladder Cancer Therapies

This review focuses on the principles, applications, and performance of mpMRI for bladder imaging. Quantitative imaging biomarkers (QIBs) derived from mpMRI are increasingly used in oncological applications, including tumor staging, prognosis, and assessment of treatment response. To standardize mpMRI acquisition and interpretation, an expert panel developed the Vesical Imaging-Reporting and Data System (VI-RADS). Many studies confirm the standardization and high degree of inter-reader agreement to discriminate muscle invasiveness in bladder cancer, supporting VI-RADS implementation in routine clinical practice. The standard MRI sequences for VI-RADS scoring are anatomical imaging, including T2w images, and physiological imaging with diffusion-weighted MRI (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI). Physiological QIBs derived from analysis of DW- and DCE-MRI data and radiomic image features extracted from mpMRI images play an important role in bladder cancer. The current development of AI tools for analyzing mpMRI data and their potential impact on bladder imaging are surveyed. AI architectures are often implemented based on convolutional neural networks (CNNs), focusing on narrow/specific tasks. The application of AI can substantially impact bladder imaging clinical workflows; for example, manual tumor segmentation, which demands high time commitment and has inter-reader variability, can be replaced by an autosegmentation tool. The use of mpMRI and AI is projected to drive the field toward the personalized management of bladder cancer patients.

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.

The assessment of pathological response to neoadjuvant chemotherapy in muscle-invasive bladder cancer patients with DCE-MRI and DWI: a systematic review and meta-analysis

OBJECTIVE

The purpose of this meta-analysis was to determine the value of dynamic contrast-enhanced-MRI (DCE-MRI) and diffusion-weighted imaging (DWI) in evaluating the pathological response of muscle invasive bladder cancer (MIBC) to neoadjuvant chemotherapy (NAC), and further indirectly compare the diagnostic performance of DCE-MRI and DWI.

METHODS

Literatures associated to DCE-MRI and DWI in the evaluation of pathological response of MIBC to NAC were searched from PubMed, Cochrane Library, web of science, and EMBASE databases. The quality assessment of diagnostic accuracy studies 2 tool was used to assess the quality of studies. Pooled sensitivity (SE), specificity (SP), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the receiver operating characteristic curves (AUC) with their 95% confidence intervals (CIs) were calculated to evaluate the diagnostic performance of DCE-MRI and DWI in predicting the pathological response to NAC in patients with MIBC.

RESULTS

There were 11 studies involved, 6 of which only underwent DCE- MRI examination, 4 of which only underwent DWI examination, and 1 of which underwent both DCE- MRI and DWI examination. The pooled SE, SP, PLR, NLR, DOR of DCE-MRI were 0.88 (95% CI: 0.78-0.93), 0.88 (95% CI: 0.67-0.96), 7.4 (95% CI: 2.3-24.2), 0.14 (95% CI: 0.07-0.27), and 53 (95% CI: 10-288), respectively. The pooled SE, SP, PLR, NLR, DOR of DWI were 0.83 (95% CI: 0.75-0.88), 0.88 (95% CI: 0.81-0.93), 7.1 (95% CI: 4.3-11.7), 0.20 (95% CI: 0.14-0.28), and 36 (95% CI:18-73), respectively. The AUCs of SROC curve for DCE-MRI and DWI were 0.93 (95% CI: 0.91-0.95) and 0.92 (95% CI: 0.89-0.94), respectively. There were no significant differences between DWI and DCE-MRI for SE, SP, and AUC.

CONCLUSION

This meta-analysis demonstrated high diagnostic performance of both DCE-MRI and DWI in predicting the pathological response to NAC in MIBC. DWI might be a potential substitute for DCE-MRI, with no significant difference in diagnostic performance between the two. However, caution should be taken when applying our results, as our results were based on indirect comparison.

ADVANCES IN KNOWLEDGE

No previous studies have comprehensively analysed the value of DCE-MRI and DWI in evaluating the pathological response to NAC in MIBC. According to the current study, both DCE-MRI and DWI yielded high diagnostic performance, with the AUCs of 0.93 and 0.92, respectively. Indirect comparison no significant difference in the diagnostic performanceof DCE-MRI and DWI.

Predictive Value of Computed Tomography Following Neoadjuvant Chemotherapy for Muscle Invasive Bladder Cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) prior to radical cystectomy (RC) remains standard treatment for select patients with muscle-invasive bladder cancer (MIBC). Although computed tomography (CT) is often obtained prior to RC, its ability to predict pathologic response is poorly characterized.

OBJECTIVE

The purpose of this study is to evaluate the predictive value of CT in assessing disease burden after NAC.

METHODS

Patients with MIBC having received NAC prior to RC were identified. Pre- and post-NAC CT scans were reviewed by an abdominal radiologist. The correlation between pathologic complete response (PCR) and radiologic complete response (RCR) was determined as the primary aim. As a secondary aim, the correlation between pathologic partial response (PPR) and radiologic partial response (RPR) was determined. Logistic regression analysis was utilized to determine the predictive value of CT in determining disease burden at RC.

RESULTS

A total of 141 patients were identified for analysis. PCR and PPR was achieved in 34% and 16% of patients, respectively. The positive predictive value of post-NAC CT was 53.5% for PCR and 28.8% for PPR. The negative predictive value of post-NAC CT was 73.5% for PCR and 46.2% for PPR. There was no significant association between RCR and PCR (OR 1.13, p = 0.67). Similarly, there was no meaningful association between RPR and PPR, lymph node involvement, or presence of extravesical disease.

CONCLUSIONS

CT findings correlate poorly with final pathology at RC and should not be used to evaluate local disease burden.

VI-RADS score system - A primer for urologists

Bladder cancer (BCa) is one of the most common cancers worldwide and is also considered to be one of the most relapsing and aggressive neoplasms. About 30% of patients will present with muscle invasive disease, which is associated with a higher risk for metastatic disease. The aim of this article is to review the state of art imaging in Radiology, while providing a complete guide to urologists, with case examples, for the rationale of the development of the Vesical Imaging Reporting and Data System (VI-RADS), a scoring system emphasizing a standardized approach to multiparametric Magnetic Resonance Imaging (mpMRI) acquisition, interpretation, and reporting for BCa. Also, we examine relevant external validation studies and the consolidated literature of mpMRI for bladder cancer. In addition, this article discusses some of the potential clinical implications of this scoring system for disease management and follow-up.

Biparametric magnetic resonance imaging assessment for detection of muscle-invasive bladder cancer: a systematic review and meta-analysis

OBJECTIVES

To investigate if removing DCE from the Vesical Imaging Reporting and Data System (VI-RADS) influences the diagnostic accuracy of muscle-invasive bladder cancer (MIBC). We also explored using different reference standards on the MRI diagnostic performance.

METHODS

We searched the Cochrane Library, Embase, and PubMed databases to June 26, 2021. Pooled biparametric MRI (bpMRI, T2WI+DWI) and multiparametric MRI (mpMRI, T2WI+DWI+DCE) sensitivities and specificities and the diagnostic performances of these methods for MIBC were compared using different reference standards.

RESULTS

Seventeen studies with 2344 patients were finally included, of which 7 studies, including 1041 patients, reported the diagnostic performance of bpMRI. VI-RADS showed sensitivities and specificities of 0.91 (95% CI 0.87-0.94) and 0.86 (95% CI 0.77-0.91) at cutoff scores of 3, and 0.85 (95% CI 0.77-0.90) and 0.93 (95% CI 0.89-0.96) at cutoff scores of 4. BpMRI showed sensitivities and specificities of 0.90 (95% CI 0.69-0.97) and 0.90 (95% CI 0.81-0.95), and 0.84 (95% CI 0.78-0.88) and 0.97 (95% CI 0.87-0.99), respectively, for cutoff scores of 3 and 4. The sensitivities of bpMRI vs mpMRI for MIBC were not significantly different, but bpMRI was more specific than mpMRI at cutoff scores of 3 (p = 0.02) and 4 (p = 0.02). The VI-RADS studies using primary transurethral resection of bladder tumors (TURBT) as the reference standard had significantly higher sensitivities (p < 0.001) than those using secondary TURBT or radical cystectomy as the reference.

DATA CONCLUSION

BpMRI and conventional VI-RADS had similar diagnostic efficacies for MIBC. Since MRI overestimated MIBC diagnoses using primary TURBT as the reference standard, we recommend using secondary TURBT as the reference standard.

KEY POINTS

• Biparametric MRI without DCE had similar diagnostic efficacies for MIBC compared with conventional VI-RADS. • The sensitivity of VI-RADS was overestimated when referring to the primary TURBT results. • Biparametric MRI comprised of T2WI and DWI could be used for detecting MIBC in clinical practice.

Diagnostic accuracy of vesical imaging-reporting and data system (VI-RADS) for the detection of muscle-invasive bladder cancer: a meta-analysis

PURPOSE

Vesical Imaging-Reporting and Data System (VI-RADS) was proposed and considered as a standardized reporting criterion for bladder magnetic resonance imaging (MRI). VI-RADS could suggest the likelihood of muscle invasion based on the multiparametric MRI (mp-MRI) findings which contain five-point scores. The current study is designed to comprehensively and systematically evaluate the diagnostic performance of VI-RADS (score 3 and 4) for predicting muscle invasion.

METHODS

The Cochrane Library, Embase, and PubMed were searched comprehensively from inception to October 2021.

RESULTS

Finally, 19 studies incorporating 2900 patients were enrolled. The pooled sensitivity and specificity of VI-RADS 3 for predicting muscle invasion were 0.92 (95%CI 0.89-0.94) and 0.82 (95%CI 0.76-0.87), respectively. The pooled sensitivity and specificity of VI-RADS 4 were 0.78 (95%CI 0.72-0.83) and 0.96 (95%CI 0.93-0.97), respectively. And the area under the curve (AUCs) of VI-RADS 3 and 4 were all 0.94 (95%CI 0.92-0.96). No significant publication biases were not observed for VI-RADS 3 (P = 0.74) and 4 (P = 0.57).

CONCLUSION

The VI-RADS reveals a good diagnostic performance for predicting muscle invasive in bladder cancer, which also has good clinical utilities and applicability. And VI-RADS 3 and 4 as cutoff values provide similar overall diagnostic and could be selectively applied individually. Prospective studies with a large scale are further required to validate the accuracy of the VI-RADS score.

Role of Vesical Imaging-Reporting and Data System in predicting muscle-invasive bladder cancer: A diagnostic meta-analysis

The objective of this study is to systematically evaluate the diagnostic performance of the Vesical Imaging-Reporting and Data System for predicting muscle-invasive bladder cancer. Embase, PubMed and Web of Science were systematically searched from 1 September 2018 to 30 July 2021 to include proper studies. We included studies that included data on Vesical Imaging-Reporting and Data System and their associated pathological findings, and we assessed their quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The pooled sensitivity and specificity were calculated and plotted using hierarchical summary receiver operating characterisijutic modeling. Meta-regression analysis was carried out to detect heterogeneity. A total of 20 studies with 2725 patients were included. When the cut-off point was 3, the pooled sensitivity and specificity were 0.92 (0.89-0.94) and 0.85 (0.78-0.90), respectively, and 0.82 (0.75-0.88) and 0.95 (0.91-0.97), respectively, when the cut-off point was 4. The area under the curve was 0.95 and 0.95, respectively. Heterogeneity was substantially considerable in sensitivity and specificity. All subgroup variables, including patient number, study design, magnetic resonance imaging field strength, number of radiologists, surgery pattern, diffusion-weighted imaging, and dynamic contrast-enhanced magnetic resonance imaging, contributed to sensitivity heterogeneity when the cut-off point was 3 and specificity heterogeneity when the cut-off point was 4. Multiple image acquisition plane of diffusion-weighted imaging achieved a higher sensitivity than single image acquisition plane of diffusion-weighted imaging in both the Vesical Imaging-Reporting and Data System 3 and 4 groups, and higher specificity in the Vesical Imaging-Reporting and Data System 4 group. Another significant source of heterogeneity was the cut-off point. The diagnostic performance of the Vesical Imaging-Reporting and Data System for predicting muscle-invasive bladder cancer was excellent in both cut-off points of the Vesical Imaging-Reporting and Data System 3 and 4. Multiple image acquisition planes of diffusion-weighted imaging should be given more attention in the Vesical Imaging-Reporting and Data System.

[French ccAFU guidelines - update 2020-2022: bladder cancer]

OBJECTIVE

- To update French guidelines for the management of bladder cancer specifically non-muscle invasive (NMIBC) and muscle-invasive bladder cancers (MIBC).

METHODS

- A Medline search was achieved between 2018 and 2020, notably regarding diagnosis, options of treatment and follow-up of bladder cancer, to evaluate different references with levels of evidence.

RESULTS

- Diagnosis of NMIBC (Ta, T1, CIS) is based on a complete deep resection of the tumor. The use of fluorescence and a second-look indication are essential to improve initial diagnosis. Risks of both recurrence and progression can be estimated using the EORTC score. A stratification of patients into low, intermediate and high risk groups is pivotal for recommending adjuvant treatment: instillation of chemotherapy (immediate post-operative, standard schedule) or intravesical BCG (standard schedule and maintenance). Cystectomy is recommended in BCG-refractory patients. Extension evaluation of MIBC is based on contrast-enhanced pelvic-abdominal and thoracic CT-scan. Multiparametric MRI can be an alternative. Cystectomy associated with extended lymph nodes dissection is considered the gold standard for non-metastatic MIBC. It should be preceded by cisplatin-based neoadjuvant chemotherapy in eligible patients. An orthotopic bladder substitution should be proposed to both male and female patients with no contraindication and in cases of negative frozen urethral samples; otherwise transileal ureterostomy is recommended as urinary diversion. All patients should be included in an Early Recovery After Surgery (ERAS) protocol. For metastatic MIBC, first-line chemotherapy using platin is recommended (GC or MVAC), when performans status (PS <1) and renal function (creatinine clearance >60 mL/min) allow it (only in 50% of cases). In second line treatment, immunotherapy with pembrolizumab demonstrated a significant improvement in overall survival.

CONCLUSION

- These updated French guidelines will contribute to increase the level of urological care for the diagnosis and treatment of patients diagnosed with NMIBC and MIBC.

Diagnostic performance of contrast-enhanced dynamic and diffusion-weighted MR imaging in the assessment of tumor response to neoadjuvant therapy in muscle-invasive bladder cancer

OBJECTIVES

To evaluate the diagnostic performance of DCE MRI and DWI in the assessment of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in patients with muscle-invasive bladder cancer (MIBC).

METHODS

This prospective study included 90 patients with MIBC who finished NAC. Two radiologists independently assessed MRI for the determination of semi-quantitative parameters (wash-in rate and wash-out rate) and apparent diffusion coefficient (ADC) value. The correlation between pCR and wash-in rate, wash-out rate, ADC value were analyzed. The area under the ROC curve (AUC) was used to evaluate the diagnostic performance for detecting pCR. Inter-reader agreement was assessed using the ICC statistics.

RESULTS

On cystectomy specimens, pCR was confirmed in (43.3%, 39/90). pCR is negatively correlated with wash-out rate (r = - 0.701, p = 0.01) and ADC value (r = - 0.621, p = 0.01). ADC value is positively correlated with wash-out rate (r = 0.631, p = 0.001). The diagnostic accuracy of ADC value (cut-off value: 0.911 × 10^-3mm²/s) and wash-out rate (cut-off value: 0.677 min^-1) in the identification of pCR was (92% for reader 1, 91% for reader 2), and (90% for reader 1, 88% for reader 2), respectively. The sensitivity, specificity for predicting pCR using ADC value + washout rate cut off values were 95.4%, 97.7% for reader 1, and 96%, 97% for reader 2, respectively. AUC was 0.981 for reader 1, 0.971 for reader 2. The overall reproducibility of the mean ADC value and wash out rate was excellent (ICC = 0.83-0.90). The ICC values for the mean ADC value, washout rate was 0.89 (95% CI 0.84-0.89) and 0.87 (95% CI 0.86-0.91), respectively.

CONCLUSION

Semi-quantitative parameter (wash-out) derived from DCE-MRI and ADC has the potential to assess the tumor's complete pathologic response. The two parameters using together can offer the best possibility to identify complete response to NAC in MIBC.

Neoadjuvant Chemotherapy-Guided Bladder-Sparing Treatment for Muscle-Invasive Bladder Cancer: Results of a Pilot Phase II Study

Purpose

Reduced quality of life after cystectomy has made bladder preservation a popular research topic for muscle-invasive bladder cancer (MIBC). Previous research has indicated significant tumor downstaging after neoadjuvant chemotherapy (NAC). However, maximal transurethral resection of bladder tumor (TURBT) was performed before NAC to define the pathology, impacting the real evaluation of NAC. This research aimed to assess real NAC efficacy without interference from TURBT and apply combined modality therapies guided by NAC efficacy.

Materials and Methods

Patients with cT2-4aN0M0 MIBC were confirmed by cystoscopic biopsy and imaging. NAC efficacy was assessed by imaging, urine cytology, and cystoscopy with multidisciplinary team discussion. Definite responders (≤ T1) underwent TURBT plus concurrent chemoradiotherapy. Incomplete responders underwent radical cystectomy or partial cystectomy if feasible. The primary endpoint was the bladder preservation rate.

Results

Fifty-nine patients were enrolled, and the median age was 63 years. Patients with cT3-4 accounted for 75%. The median number of NAC cycles was three. Definite responders were 52.5%. The complete response (CR) was 10.2%, and 59.3% of patients received bladder-sparing treatments. With a median follow-up of 44.6 months, the 3-year overall survival (OS) was 72.8%. Three-year OS and relapse-free survival were 88.4% and 60.0% in the bladder-sparing group but only 74.3% and 37.5% in the cystectomy group. The evaluations of preserved bladder function were satisfactory.

Conclusion

After stratifying MIBC patients by NAC efficacy, definite responders achieved a satisfactory bladder-sparing rate, prognosis, and bladder function. The CR rate reflected the real NAC efficacy for MIBC. This therapy is worth verifying through multicenter research.

Role of magnetic resonance imaging in tumor staging and follow-up for bladder cancer

Urothelial carcinoma of the bladder is a common urologic malignancy. Complex factors, such as local stage, tumor grade, biologic potential, and various conditions, can affect the treatment strategy for bladder cancer. However, the local stage-in particular, the presence or absence of muscle invasion-significantly influences decisions regarding treatment strategy. The role of cystoscopy for screening, diagnosis, and transurethral resection cannot be overlooked. The importance of local staging with magnetic resonance imaging is increasing; magnetic resonance imaging of the bladder is considered a useful staging modality. Moreover, a radiologic reporting system for evaluating and scoring muscle invasion of bladder cancer was recently released. This system is based on multiparametric magnetic resonance imaging and is also expected to be feasible for post-treatment follow-up of bladder cancer. In this review, we discuss the role of magnetic resonance imaging in the local staging of urothelial carcinoma of the urinary bladder and post-treatment imaging. In addition, several technical aspects for obtaining appropriate quality magnetic resonance images of the bladder will be discussed.

VI-RADS for Bladder Cancer: Current Applications and Future Developments

Bladder cancer (BCa) is among the ten most frequent cancers globally. It is the tumor with the highest lifetime treatment-associated costs, and among the tumors with the heaviest impacts on postoperative quality of life. The purpose of this article is to review the current applications and future perspectives of the Vesical Imaging Reporting and Data System (VI-RADS). VI-RADS is a newly developed scoring system aimed at standardization of MRI acquisition, interpretation, and reporting for BCa. An insight will be given on the BCa natural history, current MRI applications for local BCa staging with assessment of muscle invasiveness, and clinical implications of the score for disease management. Future applications include risk stratification of nonmuscle invasive BCa, surveillance, and prediction and monitoring of therapy response. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Staging of bladder cancer with multiparametric MRI

The distinction of non-muscle-invasive bladder cancer and muscle-invasive bladder cancer is important for the selection of the optimal treatment. Multiparametric MRI (mp-MRI) has been an useful modality for the T staging of bladder cancer, and a systematic evaluation of mp-MRI is needed. The Vesical Imaging Reporting and Data System was designed to standardize the scanning and reporting criteria based on mp-MRI for clinical and research applications. This review briefly describes the method, interpretation, and timing of mp-MRI examinations in the clinical settings. Validation studies of Vesical Imaging Reporting and Data System and future perspectives are also considered.

Overview of VI-RADS in Bladder Cancer

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

MRI of Bladder Cancer: Local and Nodal Staging

Accurate staging of bladder cancer (BC) is critical, with local tumor staging directly influencing management decisions and affecting prognosis. However, clinical staging based on clinical examination, including cystoscopy and transurethral resection of bladder tumor (TURBT), often understages patients compared to final pathology at radical cystectomy and lymph node (LN) dissection, mainly due to underestimation of the depth of local invasion and the presence of LN metastasis. MRI has now become established as the modality of choice for the local staging of BC and can be additionally utilized for the assessment of regional LN involvement and tumor spread to the pelvic bones and upper urinary tract (UUT). The recent development of the Vesical Imaging-Reporting and Data System (VI-RADS) recommendations has led to further improvements in bladder MRI, enabling standardization of image acquisition and reporting. Multiparametric magnetic resonance imaging (mpMRI) incorporating morphological and functional imaging has been proven to further improve the accuracy of primary and recurrent tumor detection and local staging, and has shown promise in predicting tumor aggressiveness and monitoring response to therapy. These sequences can also be utilized to perform radiomics, which has shown encouraging initial results in predicting BC grade and local stage. In this article, the current state of evidence supporting MRI in local, regional, and distant staging in patients with BC is reviewed. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:649-667.

Imaging in Localized Bladder Cancer: Can Current Diagnostic Modalities Provide Accurate Local Tumor Staging?

PURPOSE OF REVIEW

Local tumor staging is paramount in the evaluation and management of bladder cancer. While neoadjuvant chemotherapy (NAC) followed by radical cystectomy and urinary diversion remains the gold standard for management of muscle-invasive bladder cancer, bladder-sparing regimens involving systemic chemotherapy and pelvic radiotherapy remain a viable option for select patients. Moreover, pre-cystectomy identification of patients with a complete response to NAC may obviate the need for radical cystectomy, but accurate post-therapy staging can be difficult to achieve. Contemporary imaging techniques may provide additional benefit in local tumor staging beyond standard imaging and cystoscopic biopsy. Our purpose is to summarize the ability of different imaging modalities to accurately stage bladder cancer patients in the treatment-naïve and post-chemotherapy settings.

RECENT FINDINGS

Contemporary investigations have been studying multiparametric magnetic resonance imaging (mp-MRI) in the evaluation of bladder cancer. Its recent incorporation into bladder cancer staging is mainly being assessed in treatment-naïve patients; however, different sequences are being studied to assess their accuracy after the introduction of chemotherapy and possibly radiation. Multiple recent studies incorporating cystoscopy and biopsy are proving to be less accurate than originally predicted. Imaging has generally had a very limited role in guiding therapy in localized bladder cancer, but with the incorporation of newer sequences and techniques, imaging is poised to become vital in decision-making strategies of this cancer. Reliable local tumor staging through improved imaging may help better select patients for bladder-sparing treatments while maintaining optimized oncologic outcomes and allow this paradigm to become more acceptable in the urologic oncology community.

Role of perfusion parameters on DCE-MRI and ADC values on DWMRI for invasive ductal carcinoma at 3.0 Tesla

BACKGROUND

The value of apparent diffusion coefficient (ADC) values and quantitative parameters (Ktrans, Kep, Ve) in detecting prognostic factor at 3.0 Tesla remains unclear, especially in predicting prognosis of breast cancer.

METHODS

A total of 151 patients with IDC underwent breast DCE-MRI and DWI-MRI at 3.0 Tesla following surgery. The ADC values were acquired with b values of 0 and 1000 s/mm². The relationship between ADC values or DCE-MRI quantitative parameters and size, histologic grade (HG), lymph node metastasis (LNM), ER, PR, and Ki67 was evaluated. The predictive values of ADC, Ktrans, Kep, and Ve to prognosis of IDC were assessed.

RESULTS

ADC value was positively related to size (P = 0.04) and HER2 (P = 0.046) expression and negatively related to ER (P = 0.012) and PR (P < 0.001) expression. Ktrans value has positive correlation with size (P < 0.001), HG (P < 0.001), LNM (P < 0.001), HER2 (P = 0.007), and Ki67 (P < 0.001) expression and negative correlation with ER (P < 0.001) and PR (P < 0.001) expression. Kep value was positively related to size (P < 0.001) and negatively related to ER (P < 0.001) and PR (P < 0.001) expression. Ve value was negatively related to HER2 expression (P = 0.004). The Cox hazard ratio (HR) of ADC, Ktrans, Kep, and Ve values on survival was 5.26 (P = 0.093), 1.081 (P = 0.002), 1.006 (P = 0.941), and 0.883 (P = 0.926), respectively.

CONCLUSIONS

Ktrans value was a best predictive indicator of HG, LNM, ER, PR, and Ki67 expression, and ADC value was the best predictive indicator of HER2. Preoperative use of the 3.0 Tesla could provide important information to determine the optimal treatment plan.

Multiparametric Magnetic Resonance Imaging for Bladder Cancer: Development of VI-RADS (Vesical Imaging-Reporting And Data System)

CONTEXT

Management of bladder cancer (BC) is primarily driven by stage, grade, and biological potential. Knowledge of each is derived using clinical, histopathological, and radiological investigations. This multimodal approach reduces the risk of error from one particular test, but may present a staging dilemma when results conflict. Multiparametric magnetic resonance imaging (mpMRI) may improve patient care through imaging of the bladder with better resolution of the tissue planes than computed tomography and without radiation exposure.

OBJECTIVE

To define a standardized approach to imaging and reporting mpMRI for BC, by developing a VI-RADS score.

EVIDENCE ACQUISITION

We created VI-RADS (Vesical Imaging-Reporting And Data System) through consensus using existing literature.

EVIDENCE SYNTHESIS

We describe standard imaging protocols and reporting criteria (including size, location, multiplicity, and morphology) for bladder mpMRI. We propose a five-point VI-RADS score, derived using T2-weighted MRI, diffusion-weighted imaging, and dynamic contrast enhancement, which suggests the risks of muscle invasion. We include sample images used to understand VI-RADS.

CONCLUSIONS

We hope that VI-RADS will standardize reporting, facilitate comparisons between patients, and in future years, will be tested and refined if necessary. While we do not advocate mpMRI for all patients with BC, this imaging may compliment pathology or reduce radiation-based imaging. Bladder mpMRI may be most useful in patients with non-muscle-invasive cancers, in expediting radical treatment or for determining response to bladder-sparing approaches.

PATIENT SUMMARY

Magnetic resonance imaging (MRI) scans for bladder cancer are becoming more common and may provide accurate information that helps improve patient care. Here, we describe a standardized reporting criterion for bladder MRI. This should improve communication between doctors and allow better comparisons between patients.

Pre-treatment tumour perfusion parameters and initial RECIST response do not predict long-term survival outcomes for patients with head and neck squamous cell carcinoma treated with induction chemotherapy

Objectives

Previously, we showed that pre-treatment tumour plasma perfusion (F_p) predicts RECIST response to induction chemotherapy (ICT) in locoregionally advanced head and neck squamous cell carcinoma (HNSCC). The aim here was to determine whether the pre-treatment tumour F_p estimate, changes in tumour F_p or RECIST response post 2 cycles of ICT were prognostic for long-term survival outcomes.

Methods

A prospective study enrolled patients with high stage HNSCC treated with docetaxel (T), cisplatin (P) and 5-fluorouracil (F) (ICT) followed by synchronous cisplatin and intensity modulated radiotherapy. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before and after two cycles of ICT was used to measure F_p and RECIST response.

Results

Forty-two patients were recruited and 37 underwent two scans. The median follow-up was 36 (range 23–49) months. Pre-treatment tumour F_p (stratified by median) was not prognostic for overall survival (p = 0.42), disease specific survival (p = 0.20) and locoregional control (p = 0.64). Neither change in tumour F_p nor RECIST response post two cycles of ICT was prognostic for any outcome (p>0.21).

Conclusion

DCE-MRI parameters do not predict long-term survival outcomes following ICT and RECIST response to ICT may not be an appropriate endpoint to determine early efficacy of a treatment in HNSCC patients.

Prediction of histological stage based on cystoscopic appearances of newly diagnosed bladder tumours

INTRODUCTION In the 75-80% of urothelial bladder cancers (UBC) presenting as non-muscle invasive bladder cancer (NMIBC), transurethral resection of bladder tumour (TURBT) is the key treatment and staging procedure. In the 20-25% of patients with muscle invasive bladder cancer (MIBC), further cross-sectional imaging is required to complete the staging process before considering radical treatment. Given the adverse effects of ionising radiation, clinicians identify patients believed to have MIBC, and so requiring further imaging pre-TURBT, at the tumour histology/stage based on the tumour's visual characteristics. There is minimal evidence describing the accuracy of such predictions in newly-diagnosed patients. METHODS Over a 6-year period, a database of patients undergoing resection of newly-diagnosed bladder lesions in a single UK centre was prospectively established. Predictions based on histology were simultaneously recorded, and the accuracy of these predictions of histology/stage subsequently assessed. RESULTS One hundred and twenty two (73.1%) patients with histologically confirmed NMIBC had predictions recorded versus 45 (26.9%) patients with MIBC. Visual assessment predictions of MIBC had a sensitivity of 88.9% (95% confidence interval [CI] 76.5%-95.2%) and a specificity of 91.0% (95% CI 84.6%-94.9%), giving a positive predictive value of 78.4% (95% CI 65.4%-87.5%) and a negative predictive value of 95.7% (95% CI 90.3%-98.1%). CONCLUSIONS We find that visual assessment is accurate in predicting the presence of MIBC. This supports the practice of stratifying patients at the time of initial cystoscopy for those requiring further radiological staging pre-TURBT.

Improving Staging in Bladder Cancer: The Increasing Role of Multiparametric Magnetic Resonance Imaging

CONTEXT

In bladder cancer (BCa) patients, accurate local and regional tumor staging is required when planning treatment. Clinical understaging frequently occurs and leads to undertreatment of the disease, with a negative impact on survival. An improvement in staging accuracy could be attained by advances in imaging. Magnetic resonance imaging (MRI) is currently the best imaging technique for locoregional staging for several malignancies because of its superior soft tissue contrast resolution with the advantage of avoiding exposure to ionizing radiation. Important improvements in MRI technology have led to the introduction of multiparametric MRI (mpMRI), which combines anatomic and functional evaluation.

OBJECTIVE

To review the fundamentals of mpMRI in BCa and to provide a contemporary overview of the available data on the role of this emerging imaging technology.

EVIDENCE ACQUISITION

A nonsystematic literature search using the Medline and Cochrane Library databases was performed up to March 2016. Additional articles were retrieved by cross-matching references of selected articles. Only articles reporting complete data with regard to image acquisition protocols, locoregional staging, monitoring response to therapy, and detection of locoregional recurrence after primary treatment in BCa patients were selected.

EVIDENCE SYNTHESIS

Standardization of acquisition and reporting protocols for bladder mpMRI is paramount. Combining anatomic and functional sequences improves the accuracy of local tumor staging compared with conventional imaging alone. Diffusion-weighted imaging may distinguish BCa type and grade. Functional sequences are capable of monitoring response to chemotherapy and radiation therapy. Diffusion-weighted imaging enhanced by lymphotropic nanoparticles showed high accuracy in pelvic lymph node staging compared with conventional cross-sectional imaging.

CONCLUSIONS

In BCa patients, mpMRI appears a promising tool for accurate locoregional staging, predicting tumor aggressiveness and monitoring response to therapy. Further large-scale studies are needed to confirm these findings.

PATIENT SUMMARY

Better imaging through improved technology will improve outcomes in bladder cancer patients. We reviewed the emerging use of multiparametric magnetic resonance imaging for staging and monitoring bladder cancer. Multiparametric magnetic resonance imaging appears more accurate than current methods for local and nodal staging and monitoring tumor response to treatment, but requires further investigation.

Are complex DCE-MRI models supported by clinical data?

PURPOSE

To ascertain whether complex dynamic contrast enhanced (DCE) MRI tracer kinetic models are supported by data acquired in the clinic and to determine the consequences of limited contrast-to-noise.

METHODS

Generically representative in silico and clinical (cervical cancer) DCE-MRI data were examined. Bayesian model selection evaluated support for four compartmental DCE-MRI models: the Tofts model (TM), Extended Tofts model, Compartmental Tissue Uptake model (CTUM), and Two-Compartment Exchange model.

RESULTS

Complex DCE-MRI models were more sensitive to noise than simpler models with respect to both model selection and parameter estimation. Indeed, as contrast-to-noise decreased, complex DCE models became less probable and simpler models more probable. The less complex TM and CTUM were the optimal models for the DCE-MRI data acquired in the clinic. [In cervical tumors, Ktrans, Fp, and PS increased after radiotherapy (P = 0.004, 0.002, and 0.014, respectively)].

CONCLUSION

Caution is advised when considering application of complex DCE-MRI kinetic models to data acquired in the clinic. It follows that data-driven model selection is an important prerequisite to DCE-MRI analysis. Model selection is particularly important when high-order, multiparametric models are under consideration. (Parameters obtained from kinetic modeling of cervical cancer clinical DCE-MRI data showed significant changes at an early stage of radiotherapy.) Magn Reson Med 77:1329-1339, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Improved accuracy and precision of tracer kinetic parameters by joint fitting to variable flip angle and dynamic contrast enhanced MRI data

PURPOSE

To improve the accuracy and precision of tracer kinetic model parameter estimates for use in dynamic contrast enhanced (DCE) MRI studies of solid tumors.

THEORY

Quantitative DCE-MRI requires an estimate of precontrast T1 , which is obtained prior to fitting a tracer kinetic model. As T1 mapping and tracer kinetic signal models are both a function of precontrast T1 it was hypothesized that its joint estimation would improve the accuracy and precision of both precontrast T1 and tracer kinetic model parameters.

METHODS

Accuracy and/or precision of two-compartment exchange model (2CXM) parameters were evaluated for standard and joint fitting methods in well-controlled synthetic data and for 36 bladder cancer patients. Methods were compared under a number of experimental conditions.

RESULTS

In synthetic data, joint estimation led to statistically significant improvements in the accuracy of estimated parameters in 30 of 42 conditions (improvements between 1.8% and 49%). Reduced accuracy was observed in 7 of the remaining 12 conditions. Significant improvements in precision were observed in 35 of 42 conditions (between 4.7% and 50%). In clinical data, significant improvements in precision were observed in 18 of 21 conditions (between 4.6% and 38%).

CONCLUSION

Accuracy and precision of DCE-MRI parameter estimates are improved when signal models are fit jointly rather than sequentially. Magn Reson Med 76:1270-1281, 2016. © 2015 Wiley Periodicals, Inc.

Tumor plasma flow determined by dynamic contrast-enhanced MRI predicts response to induction chemotherapy in head and neck cancer

OBJECTIVES

Non-response to induction chemotherapy (IC) occurs in 30% of head and neck squamous cell carcinoma (HNSCC) and has been predicted by tumor plasma flow (Fp) derived by perfusion computed tomography. The present study was designed to test whether baseline tumor Fp determined by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) would predict IC response.

MATERIALS AND METHODS

A prospective open study powered to test the relationship between tumor Fp and response to IC (docetaxel, cisplatin, 5-fluorouracil) enrolled 50 patients with stage IV HNSCC. Response after two IC cycles was measured by MRI using Response Evaluation Criteria in Solid Tumors in 37 patients. Tumor Fp (primary end point) and multiple parameters in tumors and lymph nodes (secondary end points) were generated at baseline. Differences in baseline DCE-MRI parameters according to IC response were assessed by the Mann-Whitney U test, and predictive value by receiver operating characteristic (ROC) analysis.

RESULTS

Median baseline tumor Fp was 53.2ml/100ml/min in 25 responders and 23.9 in 12 non-responders (U 82; P=0.027; area under ROC curve (AUC) 0.73). Median baseline Fp in lymph nodes was 25.8ml/100ml/min for 37 nodes in 25 responders and 17.1 for 15 nodes in 12 non-responders (U 186, P=0.066; AUC 0.67). Frequency of IC response in 37 patients was 68% overall, 83% for tumor Fp above the median (40.6ml/100ml/min) and 45% below the median. Other DCE-MRI parameters were not associated with IC response.

CONCLUSION

Pre-treatment tumor Fp determined by DCE-MRI predicts IC response in HNSCC.

Diagnosis and staging of bladder cancer

Bladder cancer (BCa) is a heterogeneous disease with a variable natural history. Most patients (70%) present with superficial tumors (stages Ta, T1, or carcinoma in situ). However, 3 out of 10 patients present with muscle-invasive disease (T2-4) with a high risk of death from distant metastases. Moreover, roughly between 50% and 70% of superficial tumors do recur, and approximately 10% to 20% of them progress to muscle-invasive disease. However, BCa has a relatively low ratio of mortality versus incidence of new cases. In consequence, there is the danger of overdiagnosis and overtreatment.

Selective organ preservation for the treatment of muscle-invasive transitional cell carcinoma of the bladder: a review of current and future perspectives

Radical treatment remains underutilized for those with muscle-invasive bladder cancer. Radical radiotherapy, in particular, continues to be perceived by many as reserved only for patients unfit for cystectomy. However, with concurrent use of radiosensitizers, radiotherapy can achieve excellent local control and survival comparable to modern surgical series, thus presenting a real alternative to surgery. The possibility of further enhancing patient outcome is likely to come from both advances in radiotherapy treatment delivery and appropriate candidate selection. Growing evidence from selective bladder preservation trials demonstrate long term survival with functional organ preservation. In the era of personalized medicine, we review the evidence supporting an individualized treatment approach, in particular case selection for radical radiotherapy.