64-Slice CT urography: 30 months of clinical experience

Research progress of near-infrared fluorescence imaging in accurate theranostics in bladder cancer

BACKGROUND

With among the highest 5-year recurrence rate, bladder cancer is a relatively common type of malignancy that typically originates from the urothelial cells lining the bladder. Additionally, bladder cancer is one of the most financially burdensome neoplasms to medical institutions in terms of management. Hence, prompt identification and accurate handling of bladder cancer are pivotal for enhancing patient prognosis. Optical imaging has experienced remarkable advancements in fundamental medical research owing to its cost-effectiveness and capacity for real-time imaging. The utilization of near-infrared imaging techniques has also become a prominent area of research in recent times. By effectively decreasing the adverse effects of light scattering and tissue autofluorescence, this technique offers a deeper penetration depth, a better signal-to-noise ratio of images, and a clear resolution for imaging. Thus, this article introduces the application of near-infrared fluorescence imaging in diagnosing and treating bladder cancer. Furthermore, the paper delves into the field's obstacles, possibilities, and upcoming prospects.

RESULTS

Near-infrared fluorescence has advantages over white or blue light in theory and in most articles. However, the lack of penetration depth of NIR fluorescence imaging is still a challenge.

CONCLUSION

Despite notable improvements in the depth of near-infrared fluorescence imaging, the penetration of deeper tissues remains a barrier. It is our hope and pursuit that NIR fluorescence imaging technology can achieve good depth and precision in surgery.

Performance and Clinical Implications of VI-RADS in detecting muscle invasion in bladder tumors: A prospective observational study

Introduction

Bladder cancer staging is pivotal for guiding therapeutic decisions. In this study, the primary objective was to assess the diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI), The study aimed to classify bladder tumors as either nonmuscle-invasive bladder cancers or muscle-invasive bladder cancers (MIBC) using the Vesical Imaging Reporting and Data System (VI-RADS) scoring. A secondary objective of the study focused on the accuracy of biparametric magnetic resonance imaging (bpMRI) in comparison to mpMRI.

Methods

Thirty-three patients with bladder tumors were enrolled and underwent both mpMRI and bpMRI scoring assessments. VI-RADS scores were assigned and subsequently compared with histopathological findings posttransurethral resection of bladder tumor., Statistical measures included sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for VI-RADS scores at cutoff thresholds of ≥4 and 5.

Results

MpMRI at a VI-RADS cutoff of ≥4 yielded an 83.33% sensitivity and 100% specificity, with a diagnostic accuracy of 90.91%. At a cutoff of 5, sensitivity was 100%, specificity was 77.27%, and diagnostic accuracy was 84.85%. bpMRI at a cutoff of ≥4 showed an 80% sensitivity and 100% specificity, with diagnostic accuracy matching mpMRI at 90.91%.

Conclusions

This prospective analysis demonstrates that VI-RADS scoring with mpMRI provides reliable diagnostic accuracy for bladder cancer staging. mpMRI exhibits high sensitivity and specificity at a cutoff of ≥ 4, making it a robust tool for MIBC detection. bpMRI is an effective alternative in select patients. The study validates the use of VI-RADS scoring in clinical practice for effective treatment planning.

Glycosylated phospholipid-coated upconversion nanoparticles for bioimaging of non-muscle invasive bladder cancers

Detection of non-muscle invasive bladder cancer (NMIBC) is crucial to facilitate complete tumor resection, thus improving the survival rate as well as reducing the recurrence frequency and treatment expense. Fluorescence imaging cystoscopy is an effective method for the detection of NMIBC. However, its application is limited as the commonly applied fluorescent agents such as dyes and photosensitizers usually lack specific tumor accumulation and are vulnerable to photobleaching. Furthermore, the broad emission band of conventional fluorescent agents limits their imaging and detection efficacy. To overcome these limitations, upconversion nanoparticles (UCNPs) have been selected as the fluorescent agent, due to their resistance to photobleaching, less background auto-fluorescence, and narrow emission bands. In order to achieve active tumor targeting, the UCNPs are coated with a glycosylated phospholipid layer. The glycosylated phospholipid-coated UCNPs exhibited high selective accumulation in cancer cells over normal cells and enhanced the upconversion luminescence (UCL) (at 540 nm and 660 nm) from bladder cancer cells under 980 nm laser irradiation. Glycosylated phospholipid coating that promotes uptake of UCNPs by cancer cells, and UCL emitted from UCNPs under NIR (980 nm) laser irradiation for cancer cell imaging.

Radiologic Diagnosis and Staging of Bladder Cancer: An Update

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

Utility of an automatic adaptive iterative metal artifact reduction AiMAR algorithm in improving CT imaging of patients with hip prostheses evaluated for suspected bladder malignancy

PURPOSE

To compare the utility of a novel metal artifact reduction algorithm to standard imaging in improving visualization of key structures, diagnostic confidence, and patient-level confidence in malignancy in patients with suspected bladder cancer.

METHODS

Patients with hip implants undergoing CT urography for suspected bladder malignancy were enrolled. Images were reconstructed using 3 methods: (1) Filtered Back Projection (FBP), (2) Iterative Metal Artifact Reduction (iMAR), and (3) Adaptive Iterative Metal Artifact Reduction (AiMAR) strength 4. In multiple reading sessions, three radiologists graded visualization of critical anatomic structures and artifact severity (6-point scales, lower scores desirable), and diagnostic confidence in blinded fashion. They also graded patient-level confidence in malignancy based on imaging findings in each patient.

RESULTS

Thirty-two patients (8 females) with a mean age of 74.5 ± 8.5 years were included. The median (range) visualization scores for FBP, iMAR, and AiMAR were 3.6 (1.1-4.9), 1.6 (0.3-2.8), and 1.6 (0.3-2.6), respectively. Both iMAR and AiMAR had anatomic visualization and artifact scores better than FBP (P < 0.001 for both) and similar to each other (P > 0.05). Structures with the most improvement in visualization score with the use of metal artifact reduction algorithms included the obturator internus muscle, internal and external iliac nodal chains, and vagina. iMAR and AiMAR improved diagnostic confidence (P < 0.001) and patient-level confidence in malignancy (P ≤ 0.24).

CONCLUSION

For patients with hip prostheses and suspected bladder malignancy, the use of iMAR or AiMAR was shown to significantly reduce metal artifacts, thus improving diagnostic confidence and patient-level confidence in malignancy.

A Bright, Renal-Clearable NIR-II Brush Macromolecular Probe with Long Blood Circulation Time for Kidney Disease Bioimaging

Early detection of kidney disease is of vital importance due to its current prevalence worldwide. Fluorescence imaging, especially in the second near-infrared window (NIR-II) has been regarded as a promising technique for the early diagnosis of kidney disease due to the superior resolution and sensitivity. However, the reported NIR-II organic renal-clearable probes are hampered by their low brightness (ϵmax Φf>1000 nm <10 M-1  cm-1 ) and limited blood circulation time (t1/2 <2 h), which impede the targeted imaging performance. Herein, we develop the aza-boron-dipyrromethene (aza-BODIPY) brush macromolecular probes (Fudan BDIPY Probes (FBP 912)) with high brightness (ϵmax Φf>1000 nm ≈60 M-1  cm-1 ), which is about 10-fold higher than that of previously reported NIR-II renal-clearable organic probes. FBP 912 exhibits an average diameter of ≈4 nm and high renal clearance efficiency (≈65 % excretion through the kidney within 12 h), showing superior performance for non-invasively diagnosis of renal ischemia-reperfusion injury (RIR) earlier than clinical serum-based protocols. Additionally, the high molecular weight polymer brush enables FBP 912 with prolonged circulation time (t1/2 ≈6.1 h) and higher brightness than traditional PEGylated renal-clearable control fluorophores (t1/2 <2 h), facilitating for 4T1 tumor passive targeted imaging and renal cell carcinoma active targeted imaging with higher signal-to-noise ratio and extended retention time.

French ccAFU guidelines – Update 2018–2020: Bladder cancer

Objective

To propose updated French guidelines for non-muscle invasive (NMIBC) and muscle-invasive (MIBC) bladder cancers.

Methods

A Medline search was achieved between 2015 and 2018, as regards 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 for NMIBC and MIBC.

Evaluation of the value of the VI-RADS scoring system in assessing muscle infiltration by bladder cancer

Background

The Vesical Imaging-Reporting and Data System (VI-RADS) was created in 2018, and a 5-point VI-RADS scoring system was proposed to determine whether the muscularis of the bladder has been infiltrated by tumor tissues.

Purpose

To verify the accuracy of the VI-RADS scoring system in predicting muscle-invasive bladder cancer and to explore its value in clinical application.

Materials and methods

A total of 220 patients with bladder cancer who underwent multiparameter magnetic resonance imaging from January 2017 to June 2019 were selected. Then, two radiologists with equivalent qualifications gave their diagnoses of bladder tumors on T2-weighted imaging, diffusion-weighted imaging and dynamic contrast enhanced imaging. Meanwhile, the bladder tumor was also scored on the basis of the VI-RADS system; for multifocal tumors, the highest tumor load was selected for scoring. Furthermore, the final pathological results of the patients were unknown during the imaging diagnosis and scoring. Next, the VI-RADS score was compared with the pathological results after surgery, and the ability of the VI-RADS score to assess the degree of muscularis infiltration was finally analyzed.

Results

A total of 220 patients were included in our study, including 194 males and 26 females. Among them, the pathological results were 113 cases of muscle-invasive bladder cancer and 107 cases of non-muscle-invasive bladder cancer. The results showed that there was a positive correlation between the pathological results and VI-RADS score (r = 0.821, P < 0.05). The area under the receiver operating characteristic curve of the VI-RADS score was 0.960 (95% CI: 0.937, 0.983). When the VI-RADS score was above 3, the sensitivity, specificity and accuracy of predicting muscle-invasive bladder cancer were 82.3, 95.3 and 88.64%, respectively.

Conclusion

The VI-RADS scoring system has good diagnostic value in predicting the degree of tumor invasion and can be used to guide clinical decision-making and management.

A Renal-Clearable Macromolecular Reporter for Near-Infrared Fluorescence Imaging of Bladder Cancer

Bladder cancer (BC) is a prevalent disease with high morbidity and mortality; however, in vivo optical imaging of BC remains challenging because of the lack of cancer-specific optical agents with high renal clearance. Herein, a macromolecular reporter (CyP1) was synthesized for real-time near-infrared fluorescence (NIRF) imaging and urinalysis of BC in living mice. Because of the high renal clearance (ca. 94 % of the injection dosage at 24 h post-injection) and its cancer biomarker (APN=aminopeptidase N) specificity, CyP1 can be efficiently transported to the bladder and specially turn on its NIRF signal to report the detection of BC in living mice. Moreover, CyP1 can be used for optical urinalysis, permitting the ex vivo tracking of tumor progression for therapeutic evaluation and easy translation of CyP2 as an in vitro diagnostic assay. This study not only provides new opportunities for non-invasive diagnosis of BC, but also reveals useful guidelines for the development of molecular reporters for the detection of bladder diseases.

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.

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.

RETRACTED: Recommandations françaises du Comité de Cancérologie de l’AFU — Actualisation 2018—2020 : tumeurs de la vessie French ccAFU guidelines — Update 2018—2020: Bladder cancer

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). Cet article est retiré de la publication à la demande des auteurs car ils ont apporté des modifications significatives sur des points scientifiques après la publication de la première version des recommandations. Le nouvel article est disponible à cette adresse: doi:10.1016/j.purol.2019.01.006. C’est cette nouvelle version qui doit être utilisée pour citer l’article. This article has been retracted at the request of the authors, as it is not based on the definitive version of the text because some scientific data has been corrected since the first issue was published. The replacement has been published at the doi:10.1016/j.purol.2019.01.006. That newer version of the text should be used when citing the article.

Advancements in optical techniques and imaging in the diagnosis and management of bladder cancer

Accurate detection and staging is critical to the appropriate management of urothelial cancer (UC). The use of advanced optical techniques during cystoscopy is becoming more widespread to prevent recurrent nonmuscle invasive bladder cancer. Standard of care for muscle-invasive UC includes the use of computed tomography and/or magnetic resonance imaging, but staging accuracy of these tests remains imperfect. Novel imaging modalities are being developed to improve current test performance. Positron emission tomography/computed tomography has a role in the initial evaluation of select patients with muscle-invasive bladder cancer and in disease recurrence in some cases. Several novel immuno-positron emission tomography tracers are currently in development to address the inadequacy of current imaging modalities for monitoring of tumor response to newer immune-based treatments. This review summaries the current standards and recent advances in optical techniques and imaging modalities in localized and metastatic UC.

Bladder cancer diagnosis: the role of CT urography

AIMS AND BACKGROUND

To evaluate the diagnostic performance of computed tomography urography (CTU), we first compared it with cystoscopy and subsequently analyzed which CTU phase of acquisition has the highest diagnostic accuracy in identifying bladder cancer.

METHODS

In 2013, 177 patients underwent both cystoscopy and CTU. For all acquisition phases, we calculated sensitivity, specificity, diagnostic accuracy, and positive and negative predictive value (PPV and NPV, respectively). We also evaluated the Cohen κ coefficient.

RESULTS

Computed tomography urography sensitivity, specificity, diagnostic accuracy, PPV, and NPV were as follows: 96.3%, 86.4%, 92.8%, 92.9%, and 92.7%; concordance calculated with Cohen κ was good: 0.8413. The arterial acquisition phase showed the highest diagnostic accuracy, identifying 93.4% of all lesions.

CONCLUSIONS

Computed tomography urography is an accurate examination for the diagnosis of bladder cancer, and the arterial acquisition phase provides the best diagnostic information.

Comparison of computed tomographic urography, magnetic resonance urography and the combination of diffusion weighted imaging in diagnosis of upper urinary tract cancer

PURPOSE

To evaluate the performance of computed tomographic urography (CTU), static-fluid magnetic resonance urography (static-fluid MRU) and combinations of CTU, static-fluid MRU and diffusion weighted imaging (DWI) in the diagnosis of upper urinary tract cancer.

MATERIAL AND METHODS

Between January 2010 and June 2011, patients with suspected UUT cancer underwent CTU, static-fluid MRU and DWI (b=1000s/mm(2)) within a 1-week period. The diagnostic performances of CTU, static-fluid MRU and combinations of CTU, static-fluid MRU and DWI for upper urinary tract cancer were prospectively evaluated. The ureteroscopic and histopathologic findings were compared with the imaging findings.

RESULTS

Compared to static-fluid MRU alone (sensitivity: 76/75%, reader 1/reader 2), combining DWI with MRI can increase the sensitivity (sensitivity: 84/84%, p=0.031/p=0.016) of upper urinary tract cancer diagnosis. CTU had greater sensitivity (95/94%) and accuracy (92/91%) than both static-fluid MRU (sensitivity: p<0.001/p<0.001 and accuracy: 83/81%, p=0.001/p<0.001) and static-fluid MRU with DWI (sensitivity: p=0.023/p=0.039 and accuracy: 87/85%, p=0.042/p=0.049) for the diagnosis of upper urinary tract cancers. Compared with CTU alone, CTU with DWI did not significantly increase sensitivity, specificity or accuracy. However, the diagnostic confidence was improved when the combined technique was used (p=0.031/p=0.024). Moreover, there was no significant change in sensitivity, specificity, accuracy or diagnostic confidence when static-fluid MRU was used in combination with CTU and DWI.

CONCLUSION

Although there is a potential role for static-fluid MRU and static-fluid MRU with DWI in urinary tract imaging, CTU is still the better choice for the diagnosis of upper urinary tract cancer. Combining DWI with CTU can help improve confidence in upper urinary tract cancer diagnoses.

Magnetic resonance urography vs computed tomography urography in the evaluation of patients with haematuria

PURPOSE

This study was done to evaluate by direct comparison the image quality of magnetic resonance urography (MRU) and computed tomography urography (CTU) and to assess the diagnostic confidence of the two techniques in detecting urothelial malignancy in patients with haematuria

MATERIALS AND METHODS

Thirty-five patients with haematuria underwent both CTU and MRU. Two different investigators evaluated calyceal, renal pelvis, ureteral and bladder visibility. Their diagnostic confidence in detecting urothelial malignancy with the two procedures was assessed. A Wilcoxon matched-pairs test was performed to compare results. Inter-reader agreement was calculated by weighted kappa (WK) statistic. Patient history (further examinations, cystoscopy and histological specimens) was considered as reference standard to calculate receiver operating characteristic (ROC) curves of diagnostic confidence.

RESULTS

CTU provided better visibility of urothelial structures (p<0.01) and allowed for greater diagnostic confidence (ROC area 0.994 vs. 0.938) than MRU, with a good inter-reader agreement (WK=0.62). Nevertheless, in obstructive patients with impaired excretory function, MRU, thanks to the static-fluid technique, offered better visualisation than CTU.

CONCLUSIONS

There is a potential role for MRU in urinary tract imaging, but as diagnostic confidence in detecting urothelial malignancy is poorer than in CTU, it might be stareserved for patients at low risk for malignancy and for evaluating obstructed patients.

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.