Tumor Characteristics of Urothelial Carcinoma on Multidetector Computerized Tomography Urography

Feasibility of Early Evaluation for the Recurrence of Bladder Cancer after Trans-Urethral Resection: A Comparison between Magnetic Resonance Imaging and Multidetector Computed Tomography

(1) Background: This study investigates the early evaluation value of magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) in diagnosing the recurrence of bladder cancer (BC) after trans-urethral resection (TUR) alone or combined with intravesical perfusion chemotherapy. (2) Methods: This retrospective study enrolled 92 patients with BC who underwent MRI and MDCT after TUR. The time interval between MRI and MDCT was no more than 1 week. Tumor recurrence was recorded by two experienced radiologists who were double-blind. Recurrent patients were divided into nodular masses, irregular wall thickening and smooth wall thickening groups according to tumor morphology in cystoscopy and resected gross specimens. Inter- and intra-observer agreement was evaluated using the Kappa test. Imaging diagnostic performance was assessed using receiver operating characteristic (ROC) analysis and McNemar’s test based on pathology. (3) Results: There were 56 relapsed and 36 non-relapsed patients. The intra-observer agreement for the imaging diagnosis was excellent (κ = 0.96 for MRI and κ = 0.91 for MDCT, both p < 0.001). The area under the ROC curve of MRI was higher than that for MDCT (0.91 vs. 0.74, p < 0.001) in identifying tumor recurrence and benign treatment-related changes. The sensitivity, specificity and accuracy of MRI (87.5%, 94.4% and 90.2%, respectively) were higher than those of MDCT (67.9%, 80.6% and 72.8%, respectively) in diagnosing tumor recurrence. Two observers missed 10 cases of small lesions (<1 cm) on MDCT. The accuracy of MRI (100%, 90.0% and 25.0%, respectively) was higher than that of MDCT (92.1%, 30.0% and 0%, respectively) in diagnosing nodular masses, irregular wall thickening and smooth wall thickening recurrence patterns. (4) Conclusions: Compared with MDCT, MRI had a higher accuracy in detecting BC recurrence early, especially for nodular masses and irregular wall thickening, and could better differentiate tumor recurrence from benign treatment-related changes.

The accuracy of computed tomography in the diagnosis of upper urinary tract urothelial carcinoma in correlation with the final histopathology: A retrospective study in 275 patients at a Tertiary Urology Institute

Introduction:

Because the reports in the literature of radiologic investigations for upper tract urothelial cancer (UTUC) are limited by the number of patients, and included patients with different pathologies, we aimed to study the overall accuracy of computed tomography (CT) in the diagnosis of UTUC and their accuracy on predicting tumor location.

Methods:

A retrospective review from 1990 to 2017 included patients who were treated for UTUC. Unenhanced CT scan was obtained first using Multi-Detector Computed Tomography (MDCT, Philips Medical Systems), then nonionic contrast medium, containing 350 mg iodine/ml was injected at 4 mL/s. Analysis was performed using SPSS^®.

Results:

Of 275 patients, complete data on CT was available on 270 (98%) patients. CT reported only two false positive and six false negative results and the overall accuracy was 96-97%. In comparison to the final pathological reports, CT/CTU detected 85% of the tumor location of in the renal pelvic and 50% of the calyceal tumors. In ureteric tumors, they detected distal (66/71= 93%) more than proximal ureteric tumors (60%).

Conclusion:

In our cohort, CT/ CTU has a high overall accuracy (97%) in diagnosing UTUC, capability to well visualize tumors of distal ureter and renal pelvis, but could miss calyceal tumors. The matter to rely only on CT without ureteroscopic biopsy in the diagnosis of UTUC especially if radical surgery is planned needs further prospective studies.

Diagnostic ureteroscopy for upper tract urothelial carcinoma: friend or foe?

Introduction

The European Association of Urology guidelines recommend offering kidney-sparing surgery (KSS) as a primary treatment option to patients with low-risk tumours. Cystoscopy, urinary cytology, and computed tomography urography (CTU) do not always allow correct disease staging and grading, and sometimes there is even a lack of certainty regarding the diagnosis of UTUC. Diagnostic ureteroscopy (d-URS) may therefore be of crucial importance within the diagnostic framework and fundamental in establishing the appropriate therapeutic approach.

Evidence acquisition and synthesis

A systematic review of the literature was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Risk of bias was assessed using Risk of Bias in Non-randomized Studies of interventions (ROBINS-I). Overall, from 3791 identified records, 186 full-text articles were assessed for eligibility. Finally, after a quantitative review of the selected literature, with the full agreement of all authors, 62 studies were considered relevant for this review.

Results

CTU has a sensitivity and specificity for UTUC of 92% and 95% respectively, but is not able to detect small or flat lesions with adequate accuracy. The sensitivity of voided urinary cytology for UTUC is around 67–76% and ranges from 43% to 78% for selective ureteric urine collection. As no technique offers a diagnosis of certainty, d-URS can allow an increase in diagnostic accuracy. In the present review the pros and cons of d-URS were analysed. This technique may provide additional information in the selection of patients suitable for neoadjuvant chemotherapy or KSS, distinguishing between normal tissue and low- and high-grade UTUC thanks to the emerging technologies.

Conclusions

Information obtainable from d-URS and ureteroscopic-guided biopsy can prove extremely valuable when the diagnosis of UTUC is doubtful or KSS is being considered. Notwithstanding concerns remain regarding the potential risk of bladder recurrence, cancer dissemination, and/or delay in radical treatment.

Abbreviations: CLE: confocal laser endomicroscopy; CSS: cancer-specific survival; CTU: CT urography; d-URS: diagnostic ureteroscopy; EAU: European Association of Urology; HR: hazard ratio; IMAGE1S: Storz professional imaging enhancement system; IVR: intravesical recurrence; KSS: kidney-sparing surgery; MFS: Metastasis-free survival; NAC: neoadjuvant chemotherapy; NBI: narrow-band imaging; OCT: optical coherence tomography; RFS: Recurrence-free survival; RNU: radical nephroureterectomy; ROBINS-I: Risk of Bias in Non-randomized Studies of interventions; URS(-GB): Ureteroscopy(-guided biopsy); UTUC: upper tract urothelial carcinoma; UUT: upper urinary tract

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.

Optical and Cross-Sectional Imaging Technologies for Bladder Cancer

Optical and cross-sectional imaging plays critical roles in bladder cancer diagnostics. White light cystoscopy remains the cornerstone for the management of non-muscle-invasive bladder cancer. In the last decade, significant technological improvements have been introduced for optical imaging to address the known shortcomings of white light cystoscopy. Enhanced cystoscopy modalities such as blue light cystoscopy and narrowband imaging survey a large area of the urothelium and provide contrast enhancement to detect additional lesions and decrease cancer recurrence. However, higher false-positive rates accompany the gain of sensitivity. Optical biopsy technologies, including confocal laser endomicroscopy and optical coherence tomography, provide cellular resolutions combined with subsurface imaging, thereby enabling optical-based cancer characterization, and may lead to real-time cancer grading and staging. Coupling of fluorescently labeled binding agents with optical imaging devices may translate into high molecular specificity, thus enabling visualization and characterization of biological processes at the molecular level. For cross-sectional imaging, upper urinary tract evaluation and assessment potential extravesical tumor extension and metastases are currently the primary roles, particularly for management of muscle-invasive bladder cancer. Multi-parametric MRI, including dynamic gadolinium-enhanced and diffusion-weighted sequences, has been investigated for primary bladder tumor detection. Ultrasmall superparamagnetic particles of iron oxide (USPIO) are a new class of contrast agents that increased the accuracy of lymph node imaging. Combination of multi-parametric MRI with positron emission tomography is on the horizon to improve accuracy rates for primary tumor diagnostics as well as lymph node evaluation. As these high-resolution optical and cross-sectional technologies emerge and develop, judicious assessment and validation await for their clinical integration toward improving the overall management of bladder cancer.

A comparison between computerised tomography and magnetic resonance imaging in the primary staging of bladder cancer as compared to final histology

Introduction:

Accurate and effective imaging to determine the stage of the primary tumour is crucial in deciding whether patients should be treated conservatively, or with surgical or radiochemotherapeutic treatment. There are still concerns about the staging accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) scanners.

Methods:

We conducted a retrospective analysis of 254 single-surgeon radical cystectomies on a population destined for potentially curative surgery (without evidence of metastatic disease) over 14 years. We compared the staging accuracy of 245 CT scans against 62 conventional T2-weighted MRI scans and compared them to the absolute gold standard, histological analysis using the TNM staging system.

Results:

Overall, when comparing all the scanner results from 1999 to 2016, the following was observed: • MRI initially appears to be better than CT in staging the primary tumour as either localised or locally advanced disease; and • CT is significantly better than MRI for nodal staging. However, when comparing the more recent results using 53 patients who had both CT and MRI prior to operation, from 2005 to 2016, we find CT improves to match MRI in both primary tumour staging and nodal staging with ‘fair’ kappa scores ( p = 0.84).

Conclusions:

We confirm that MRI is better at staging extravesical disease and CT better at staging localised disease. Regarding primary tumour accuracy, the volume of the tumour has an influence on its correct staging. Regarding nodal accuracy, the presence of extracapsular extension had no influence. Knowing these limitations of the two modalities should enable better counselling of patients, regardless of their subsequent treatment regimen.

High-Performance Identification of Human Bladder Cancer Using a Signal Self-Amplifiable Photoacoustic Nanoprobe

Cancer diagnostics has been an important research field, and identification of small lesions that are less noticeable plays a vital role in thoroughly removing the tumor, thereby reducing the recurrence rate of cancer. Herein, we synthesized a signal self-amplifiable photoacoustic (PA) liposomal nanoprobe composed by ammonium hydrogen carbonate (AHC) payload and aggregated purpurin-18 (P18) within the bilayer. Under PA laser irradiation, P18 aggregates efficiently generated local heat, leading to the launch of wide-band ultrasonic emission. In parallel, the heat also triggered the decomposition of AHC and production of CO₂ bubbles, which consequently dramatically amplified the acoustic signal. For clinical translation, by decorating bladder cancer (BC) specific CD44v6 antibody onto nanoprobe, we were capable of utilizing this high sensitive and specific PA probe for human BC tissue imaging. The results indicated that small tumor lesion (<5 mm) was identified and the tumor-to-normal tissue ratio was ∼18 folds enhancement by using this PA probe, which rendered the tumor boundary distinct. All together, we developed a new strategy for exploring high-performance imaging probes, which might potentially benefit for the imaging-guided surgery in clinics.

Could Nonenhanced Computer Tomography Suffice as the Imaging Study of Choice for the Screening of Asymptomatic Microscopic Hematuria?

OBJECTIVE

To compare the diagnostic accuracy of the noncontrast and contrast-enhanced phases of computed tomographic urography for detection of upper urinary tract findings in adults undergoing initial evaluation of newly diagnosed asymptomatic microscopic hematuria to determine if less-intensive noncontrast imaging has the potential to become a suitable imaging alternative in the work-up of this common condition.

MATERIALS AND METHODS

Retrospective review from 2010-2015 for adults who underwent computed tomographic urography for initial evaluation of asymptomatic microscopic hematuria. Three nonblinded physicians independently categorized the upper urinary tract findings described in the computed tomography reports into one of three groups: normal, benign, or suspicious for malignancy. The noncontrast images of a randomized portion of the studies categorized as normal and all studies categorized as suspicious and benign were submitted to two blinded radiologists who independently classified each study into one of the aforementioned categories.

RESULTS

The noncontrast images for 475 subjects were blindly reviewed. When compared to the computed tomographic urography reports, the negative predictive values of noncontrast images were 97.25% and 94.92% for radiologist 1 and radiologist 2, respectively, with an associated specificity of 88.6% and 97.95%. Of the 5 true upper tract malignancies, both blinded radiologists correctly identified 4 of the 5.

CONCLUSION

Contrast imaging added little diagnostic value when compared with noncontrast imaging for most subjects undergoing initial evaluation for asymptomatic microscopic hematuria. Less-intensive imaging with nonenhanced computed tomography could reduce the nontrivial risks associated with multiphasic contrast imaging but further work is necessary to identify risk-stratifying criteria.

Advances in medical imaging for the diagnosis and management of common genitourinary cancers

Medical imaging of the 3 most common genitourinary (GU) cancers-prostate adenocarcinoma, renal cell carcinoma, and urothelial carcinoma of the bladder-has evolved significantly during the last decades. The most commonly used imaging modalities for the diagnosis, staging, and follow-up of GU cancers are computed tomography, magnetic resonance imaging (MRI), and positron emission tomography (PET). Multiplanar multidetector computed tomography and multiparametric MRI with diffusion-weighted imaging are the main imaging modalities for renal cell carcinoma and urothelial carcinoma, and although multiparametric MRI is rapidly becoming the main imaging tool in the evaluation of prostate adenocarcinoma, biopsy is still required for diagnosis. Functional and molecular imaging using 18-fluorodeoxyglucose-PET and sodium fluoride-PET are essential for the diagnosis, and especially follow-up, of metastatic GU tumors. This review provides an overview of the latest advances in the imaging of these 3 major GU cancers.

Plasmacytoid urothelial carcinoma (PUC): Imaging features with histopathological correlation

INTRODUCTION

Plasmacytoid urothelial carcinoma (PUC) is a high-grade variant of conventional urothelial cell carcinoma. This study is the first to describe the imaging findings of PUC, which are previously unreported, using clinical and histopathological correlation.

METHODS

With internal review board approval, we identified 22 consecutive patients with PUC from 2007-2014. Clinical parameters, including age, gender, therapy, surgical margins, and long-term outcome, were recorded. Baseline imaging was reviewed by an abdominal radiologist who evaluated for tumour detectability/location/morphology, local staging, and presence/location of metastases. Pelvic peritoneal spread of tumour (defined as >5mm thick soft tissue spreading along fascial planes) was also evaluated. Followup imaging was reviewed for presence of local recurrence or metastases.

RESULTS

Median age at presentation was 74 years (range 51-86), with only three female patients. Imaging features of the primary tumour in this study were not unique for PUC. Muscle-invasive disease was present on pathology in 19/22 (86%) of tumours, with distant metastases in 2/22 (9%) at baseline imaging. Pelvic peritoneal spread of tumour was radiologically present in 4/20 (20%) at baseline. During followup, recurrent/residual tumour was documented in 16/22 (73%) patients and 7/16 (44%) patients eventually developed distant metastases. Median time to disease recurrence in patients who underwent curative surgery was three months (range 0-19).

CONCLUSIONS

PUC is an aggressive variant of urothelial carcinoma with poor prognosis. Pelvic peritoneal spread of tumour as thick sheets extending along fascial planes may represent a characteristic imaging finding of locally advanced PUC.

Imaging muscle-invasive and metastatic urothelial carcinoma

PURPOSE OF REVIEW

Muscle-invasive bladder cancer (MIBC) comprises approximately one-third of bladder cancers and is associated with significant morbidity and mortality. Accurate staging of bladder cancer is essential because of significantly different treatment options and the consequences of inaccurate staging. The current recommended method for staging is transurethral resection of the bladder tumor followed by contrast-enhanced computed tomography (CT). In this review, we discuss cross-sectional imaging approaches used to assess local, nodal, and distant metastases in MIBC.

RECENT FINDINGS

Determining the most accurate imaging method for staging MIBC is a contentious issue. CT with contrast is a practical approach; however, there is potential for understaging of small lymph nodes or foci of metastasis. Multiparametric MRI is emerging as the imaging modality of choice in tumor staging, with a reported accuracy of more than 90%. Locoregional lymph node metastasis can also be accurately evaluated using functional MRI and specific contrast agents with paramagnetic characteristics. PET/CT with conventional radiotracers is a common imaging modality for staging distant metastases.

SUMMARY

Conventional imaging methods for evaluating MIBC are of limited use. However, recent advances in molecular imaging, targeted contrast agents, and functional MRI have shown promising results for the staging of bladder cancer.

Are we closer to seeing carcinoma in situ in the upper urinary tract?

INTRODUCTION

There is observed increase in detection rate of upper urinary tract urothelial cancer worldwide. This is a result of improved imaging as well as implementation of novel technologies of direct visualization of upper urinary tract. Standard techniques still remain insufficient to diagnose flat urothelial lesions. Carcinoma in situ is characterized by flat disordered proliferation of urothelial cells with marked cytologic abnormality, which occur within one cell layer as well as full thickness urothelium and therefore requires a better technology to pick up early and subtle mucosal changes.

MATERIAL AND METHODS

The review presents available diagnostic tools in detection of upper urinary tract urothelial cancer and their ability to depict carcinoma in situ.

RESULTS

Ureterorenoscopy is an investigation of choice as various promising techniques are under pilot investigations to enhance visualization of upper urinary tract carcinoma in situ. So far only photodynamic diagnosis has been reported to be as effective in detection of carcinoma in situ in the upper as within the lower urinary tract.

CONCLUSIONS

Although we are close to see upper urinary tract carcinoma in situ all new promising diagnostic techniques still require further validation in multicenter clinical trials to indicate any change to current recommendations.

Advances in bladder cancer imaging

The purpose of this article is to review the imaging techniques that have changed and are anticipated to change bladder cancer evaluation. The use of multidetector 64-slice computed tomography (CT) and magnetic resonance imaging (MRI) remain standard staging modalities. The development of functional imaging such as dynamic contrast-enhanced MRI, diffusion-weighted MRI and positron emission tomography (PET)-CT allows characterization of tumor physiology and potential genotypic activity, to help stratify and inform future patient management. They open up the possibility of tumor mapping and individualized treatment solutions, permitting early identification of response and allowing timely change in treatment. Further validation of these methods is required however, and at present they are used in conjunction with, rather than as an alternative to, conventional imaging techniques.