The Role of Imaging in Bladder Cancer Diagnosis and Staging

Antispasmodic Agents in Magnetic Resonance Imaging of the Urinary Bladder-A Narrative Review

Accurate assessment of muscular layer infiltration of the urinary bladder wall is crucial for diagnostic precision and is significantly influenced, among other factors, by the elimination of motion artifacts. This review explores the potential benefits of using spasmolytic agents to achieve improved imaging results. Specifically, it examines two commonly available pharmaceutical preparations: butylscopolamine (buscolysin) and glucagon. The review highlights the similarities and differences between these agents and discusses the optimal methods of administration to enhance urinary bladder imaging. By addressing these factors, the article aims to provide insights into improving diagnostic accuracy in clinical practice.

The Current Role of Contrast-Enhanced Ultrasound (CEUS) in the Diagnosis and Staging of Bladder Cancer: A Review of the Available Literature

Contrast-enhanced ultrasound (CEUS) is an advanced imaging technique that integrates conventional US with the intravenous injection of specific US contrast agents (UCAs), combining the non-invasiveness of US with the higher accuracy of contrast-enhanced imaging. In contrast with magnetic resonance imaging (MRI), computed tomography (CT) and cystoscopy, CEUS has few contraindications, and UCAs are non-nephrotoxic agents that can be safely used in patients with kidney failure. CEUS is a well-established method for the detection of liver lesions and for echocardiography, and its indications are expanding. The updated 2018 WFUMB-EFSUMB guidelines have added the urinary bladder under non-hepatic applications of CEUS. The technique is able to distinguish between benign tissue, such as clots or hematoma, and malignant lesions by perfusing the mass with contrast agent. Thanks to the different perfusion rates of the various layers of the bladder wall, CEUS is also able to predict tumor invasion depth and stage. Despite that, current urological guidelines do not include CEUS as a plausible imaging technique for bladder urothelial carcinoma. The main reason for this omission might be the presence of scarce randomized evidence and the absence of large validated series. In this review, we describe the rationale behind the use of CEUS in bladder cancer and the added value of this imaging technique in the detection and staging of bladder lesions. In addition, we researched the available literature on the topic and then described the results of randomized clinical trials and a meta-analysis investigating the accuracy of CEUS in bladder cancer diagnosis and staging. The reported studies show that CEUS is a highly accurate diagnostic and staging tool for BC, reaching levels of specificity and sensitivity in differentiating between Ta-T1, or low-grade BC, and T2, or high-grade BC, that are comparable to those shown by the reference standard methods. Nonetheless, several limitations were found and are highlighted in this review. The aim of this study is to further validate and promote the use of CEUS as a quick, economic and effective diagnostic tool for this high-impact disease.

Performance of 18F-FDG PET/MRI and its parameters in staging and neoadjuvant therapy response evaluation in bladder cancer

18F-FDG PET/MRI shows potential efficacy in the diagnosis of bladder cancer (BLCA). However, the performance of 18F-FDG PET/MRI in staging and neoadjuvant therapy (NAT) response evaluation for BLCA patients remains elusive. Here, we conduct this study to evaluate the performance of 18F-FDG PET/MRI and its derived parameters for tumor staging and NAT response prediction in BLCA. Forty BLCA patients were retrospectively enrolled to evaluate the performance of 18F-FDG PET/MRI in staging and NAT response prediction in BLCA. The feasibility of using 18F-FDG PET/MRI-related parameters for tumor staging and NAT response evaluation was also analyzed. In conclusion, 18F-FDG PET/MRI is found to show good performance in the BLCA staging and NAT response prediction. Moreover, ΔSUVmean is an efficacious candidate parameter for NAT response prediction. This study highlights that 18F-FDG PET/MRI is a promising imaging approach in the clinical diagnosis and treatment for BLCA.

A Clinicopathologic Study of Urinary Bladder Lesions Amongst North Indian Population: An Experience From a Tertiary Care Centre

BACKGROUND

Urinary bladder cancer (UBC) is amongst the most common urological malignancies.

AIM

To study different types of urinary bladder lesions in the north Indian population and to correlate various clinical and pathological findings.

MATERIALS AND METHODS

The present prospective study was conducted on 100 cases undergoing transurethral resection of bladder tumor (TURBT) and/or radical cystectomy over a period of 2.5 years followed by histopathological examination. Liquid-based cytology for malignant cells in urine was also performed. Immunohistochemistry was employed for tumor typing wherever needed.

RESULTS

A total of 100 cases were studied. Male to female ratio was 15.7:1 and most of the patients were in the sixth decade (40%). Painless hematuria was the commonest clinical presentation (60%) and smoking was the commonest risk factor (80%). The most common lesion was infiltrating urothelial carcinoma seen in 72 cases followed by papillary urothelial neoplasm of low malignant potential (PUNLMP) seen in eight cases. Grade and depth of invasion were assessed and correlated. Several variants of infiltrating urothelial carcinoma such as squamous differentiation, glandular differentiation, microcystic, clear cell, nested, and micropapillary were also identified. Clinical, cystoscopic and histopathological findings were correlated in all the cases.

CONCLUSION

Infiltrating urothelial carcinoma high grade was the most common bladder lesion identified and muscle invasion was more common with higher-grade lesions. A decade-younger age group was found to be more affected in the present series. Urine cytology for malignant cells is useful for early diagnosis of cancer. Immunohistochemistry is an important ancillary adjunct.

Occult urothelial carcinoma with mediastinal metastasis: A case report

Occult urothelial carcinoma (UC), particularly with mediastinal metastases, is an uncommon clinical occurrence. The present study describes the unusual case of a 70-year-old male patient who developed mediastinal metastases from an occult UC. Histological evaluations and immunohistochemical features of the mediastinal tumor were indicative of UC; however, extensive imaging failed to identify the primary urological lesion. The findings suggest that mediastinal metastases from UCs, despite their rarity, should be considered in cases where patients with mediastinal tumors exhibit chest-related symptoms. Prompt pathological examinations are crucial for ascertaining the nature and origin of the tumor. Moreover, individualized treatment should be performed in strict accordance with the established oncology guidelines.

New Perspectives on the Role of Liquid Biopsy in Bladder Cancer: Applicability to Precision Medicine

Bladder cancer (BC) is one of the most common tumors in the world. Cystoscopy and tissue biopsy are the standard methods in screening and early diagnosis of suspicious bladder lesions. However, they are invasive procedures that may cause pain and infectious complications. Considering the limitations of both procedures, and the recurrence and resistance to BC treatment, it is necessary to develop a new non-invasive methodology for early diagnosis and multiple evaluations in patients under follow-up for bladder cancer. In recent years, liquid biopsy has proven to be a very useful diagnostic tool for the detection of tumor biomarkers. This non-invasive technique makes it possible to analyze single tumor components released into the peripheral circulation and to monitor tumor progression. Numerous biomarkers are being studied and interesting clinical applications for these in BC are being presented, with promising results in early diagnosis, detection of microscopic disease, and prediction of recurrence and response to treatment.

Initial Experience with 68Ga-FAP-2286 PET Imaging in Patients with Urothelial Cancer

Improved imaging modalities are needed to accurately stage patients with muscle-invasive bladder cancer (MIBC) and metastatic urothelial carcinoma. Imaging with small-molecule ligands or inhibitors of fibroblast activation protein (FAP) is a promising modality that has demonstrated initial efficacy across a broad range of tumors. We present our experience with the novel FAP-peptide binder 68Ga-FAP-2286 in patients with MIBC. Methods: Patients with histopathologically confirmed bladder cancer who had either localized disease at diagnosis (localized cohort, n = 13) or known metastatic disease (metastatic cohort, n = 8) were imaged with 68Ga-FAP-2286 PET as part of a clinical trial (NCT04621435). The SUVmax of 68Ga-FAP-2286 PET-positive lesions and lesion size were documented. In patients who had available 18F-FDG PET performed within 45 d of 68Ga-FAP-2286 PET (n = 5), uptake on the 2 scans was compared. When there was a discrepancy between imaging modalities on retrospective review, biopsy of suggestive lesions was performed as the standard of care. Results: In the metastatic and localized cohorts, 36 and 18 68Ga-FAP-2286-avid lesions, respectively, were identified across multiple anatomic locations, including lymph nodes, visceral metastases, and bones. Fourteen of 36 lesions in the metastatic cohort and 14 of 18 lesions in the localized cohort were lymph nodes measuring less than 1 cm. Among lesions measuring less than 0.5 cm, 0.5-1 cm, and more than 1 cm, average SUVmax was 5.2 ± 2.6, 9.6 ± 3.7, and 13.0 ± 4.3, respectively, in the metastatic cohort and 10.5 ± 5.1, 10.8 ± 5.7, and 9.9 ± 5.4, respectively, in the localized cohort. Five patients had 18F-FDG PET available for comparison. The average SUVmax for lesions avid on 68Ga-FAP-2286 PET and 18F-FDG PET was 9.9 ± 3.4 versus 4.2 ± 1.9, respectively (n = 16 lesions). For 3 patients in the localized cohort, 68Ga-FAP-2286 PET informed clinical management, including identification of both false-positive findings on 18F-FDG PET and false-negative findings on conventional CT. Conclusion: 68Ga-FAP-2286 imaging is highly sensitive in patients with urothelial cancer and is effective in identifying metastatic lesions across a variety of anatomic sites, including subcentimeter lymph nodes that would not have raised suspicion on conventional scans. This novel imaging modality may inform clinical decision-making in patients with MIBC both by refining local nodal staging and by defining metastatic disease that would otherwise be undetectable on conventional imaging.

Metabolomic Signatures of Treatment Response in Bladder Cancer

Bladder cancer (BC) stands as one of the most prevalent urological malignancies, with over 500 thousand newly diagnosed cases annually. Treatment decisions in BC depend on factors like the risk of recurrence, the type of tumor, and the stage of the disease. While standard therapeutic approaches encompass transurethral resection of the bladder tumor, radical cystectomy, and chemo- or immunotherapy, these methods exhibit limited efficacy in mitigating the aggressive and recurrent nature of bladder tumors. To overcome this challenge, it is crucial to develop innovative methods for monitoring and predicting treatment responses among patients with BC. Metabolomics is gaining recognition as a promising approach for discovering biomarkers. It has the potential to reveal metabolic disruptions that precisely reflect how BC patients respond to particular treatments, providing a revolutionary method to improve accuracy in monitoring and predicting outcomes. In this article, we present a comprehensive review of studies employing metabolomics approaches to investigate the metabolic responses associated with different treatment modalities for BC. The review encompasses an exploration of various models, samples, and analytical techniques applied in this context. Special emphasis is placed on the reported changes in metabolite levels derived from these studies, highlighting their potential as biomarkers for personalized medicine in BC.

Recent advances in three-dimensional ultrasound virtual cystoscopy in modeling and local staging for urothelial carcinoma with histopathological correlation: a cohort prospective study

Background

Bladder urothelial carcinoma is an alarming urologic malignancy. Complex factors like modelling and local staging can affect treatment strategy. However, local staging, particularly the muscle invasion status, significantly influences decisions regarding treatment strategies. Therefore, this study aims to evaluate the novel advances of three-dimensional (3D) ultrasound (US) imaging to assess local staging in comparison with conventional cystoscopy.

Methods

Forty-three patients with painless haematuria and conventional cystoscopy findings of bladder mass underwent 3D US virtual cystoscopy. All specimens from conventional cystoscopy were processed histologically.

Results

Out of 43 participants, 18 (41.9%) patients proved to have invasive urothelial carcinoma by histopathology. The 3D US had a sensitivity of 97.5% and a specificity of 100%; however conventional cystoscopy was accurate in only 53.5% of the studied cases. Furthermore, in the case of malignant ulcers, mural extension into both the submucosal and the muscle layers was more readily appreciated in multiplanar images.

Conclusion

3D US updates are promising for use in bladder tumour modelling and local staging; however, they can be of value in evaluating mural and extramural tumour extent and have proven accuracy.

What do we see when we do not see the bladder? Review of the main urinary diversion techniques and their complications

OBJECTIVE

To review the different types of urinary diversion surgeries (UDS) in order to recognize the expected findings in a postoperative study, using different imaging techniques. To recognize the main postoperative complications, both early and late.

CONCLUSION

UDS are surgical procedures whose purpose is to redirect urine flow after cystectomy, generally in an oncologic context. The imaging evaluation of urological surgeries is often a radiological challenge, with CT being the most commonly used image modality. Therefore, it is essential to know the main surgical techniques, the expected postoperative findings and the optimization of imaging techniques for early diagnosis and correct evaluation of postoperative complications.

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

Background

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

Methods

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

Results

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

Conclusions

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

Bladder Cancer during Pregnancy: A Review of the Literature

Bladder malignancy represents the fourth most common cancer in men and the eighth in women in the western world. Women under 75 years of age have a risk of 0.5-1% of developing bladder cancer. The diagnosis usually occurs between 65 and 70 years of age, whereas the mortality rate for women varies from 0.5 to 4 per 100,000 every year. Nulliparous women present a greater risk than women who have given birth. The risk is further decreased when parity increases. Theoretically, hormonal changes occurring during pregnancy play a protective role. Smoking and occupational exposure to specific chemicals are the most common risk factors of bladder cancer. Other risk factors such as chronic urinary tract inflammation, cyclophosphamide, radiotherapy, and familial correlation have been reported. The aim of this review is to highlight a rare combination, which is the co-existence of bladder malignancy and pregnancy. We present thirteen different cases of women who were diagnosed with malignant bladder tumors during their pregnancy. A review of the literature was conducted, focusing on the unspecific symptoms, possible diagnostic tools, and suitable treatment modalities. The management of bladder cancer in pregnancy is a challenging process. The fragile balance between the possible complications of pregnancy and maternal health is yet to be discussed.

Head-to-Head Comparison of FDG and Radiolabeled FAPI PET: A Systematic Review of the Literature

FAPI-based radiopharmaceuticals are a novel class of tracers, mainly used for PET imaging, which have demonstrated several advantages over [18F]FDG, especially in the case of low-grade or well-differentiated tumors. We conducted this systematic review to evaluate all the studies where a head-to-head comparison had been performed to explore the potential utility of FAPI tracers in clinical practice. FAPI-based radiopharmaceuticals have shown promising results globally, in particular in detecting peritoneal carcinomatosis, but studies with wider populations are needed to better understand all the advantages of these new radiopharmaceuticals.

Classification of formalin-fixed bladder cancer cells with laser tweezer Raman spectroscopy

Bladder cancer is a common cancer that is relatively hard to detect at an early stage because of its non-obvious symptoms. It is known that bladder cells can be found in urine samples which potentially could be used for early detection of bladder cancer. Raman spectroscopy is a powerful non-invasive tool for accessing biochemical information of cells. Combined with laser tweezers, to allow isolation of single cells, Raman spectroscopy has been used to characterise a number of bladder cells that might be found in a urine sample. Using principal component-canonical variates analysis (PC-CVA) and k-fold validation, the results shows that the invasive bladder cancer cells can be identified with accuracy greater than 87%. This demonstrates the potential of developing an early detection method that identifies the invasive bladder cancer cells in urine samples.

Fluorodeoxyglucose positron emission tomography (18F-FDG PET)-computed tomography (CT) in the initial staging of bladder cancer: a single institution experience

BACKGROUND

The purpose of this study was to assess the usefulness of fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)-computed tomography (CT) scan for staging urinary bladder cancer. The study also sought to determine the effect of ¹⁸F-FDG PET/CT on management decisions and its implications for patient care.

METHODS

A total of 133 patients with bladder cancer who had both conventional imaging and ¹⁸F-FDG PET/CT for initial staging were identified. All ¹⁸F-FDG-PET/CT findings were classified as true positive, true negative, false positive, or false negative based on their potential to impact the intent of treatment. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated using the standard definition. Furthermore, the rate of change in therapy intent was determined for the entire sample and for subgroups with non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) patients.

RESULTS

The overall concordance rate between PET/CT and conventional imaging was around 54%. On conventional images, 18% of patients had localized disease, which was upstaged in 6.8% of cases using ¹⁸F-FDG PET/CT. Pelvic lymph node involvement was detected in 18.8% of cases using conventional imaging, which was downstaged to localized disease in 4.5% of cases using ¹⁸F-FDG PET/CT. While 63.2% of patients had systemic disease on a CT scan, 24.7% of cases were downstaged using PET/CT. Overall, the rate of change in therapy intent was 26.3% for the entire sample, 24.5% for NMIBC subgroup, and 27.3% for MIBC patients.

CONCLUSIONS

The study found that ¹⁸F-FDG PET/CT is an effective and accurate tool for staging bladder cancer in newly diagnosed patients. Approximately one quarter of patients had a change in management intent based on ¹⁸F-FDG PET/CT results. The study suggests that PET/CT should be used as a standard for newly diagnosed patients, but more research is needed to confirm this.

Role of Multiparametric-MRI in Bladder Cancer

Purpose of Review

This narrative review article aims to show the actual role of imaging, in particular MRI, and the role of VI-RADS Score, in recognition and follow-up of the tumor.

Recent Findings

A team of professionals created VI-RADS with the goal of standardizing the acquisition and interpretation of multiparametric-MRI in bladder cancer.

Summary

Bladder cancer is the most common cancer involving the urinary system. It is the fourth most common urological cancer in men and the second most frequent cancer affecting the urinary tract. Main risks factors are advanced age, male sex, and cigarette smoking. Bladder cancer ranges from unaggressive and usually non-invasive tumors that recur and commit patients to long-term invasive surveillance, to aggressive and invasive tumors with high disease-specific mortality. At the time of diagnosis, 70% of patients are experiencing non-muscle-invasive bladder cancer. Vesical imaging-reporting and data system score (VI-RADS) is a scoring system useful to standardize the approach to multiparametric-MRI interpretation, and reporting for bladder cancer.

Multi-task deep learning based on T2-Weighted Images for predicting Muscular-Invasive Bladder Cancer

BACKGROUND

An accurate preoperative assessment of Non-Muscle-Invasive Bladder Cancer (NMIBC) and Muscle-Invasive Bladder Cancer (MIBC) in Bladder Cancer (BCa) can help the urologist make diagnostic decisions. Considering the absence of multiparametric MRI for contrast medium allergy and economic reasons, this study aims to develop a deep learning method based on T2-Weighted (T2WI) images alone for predicting NMIBC and MIBC.

METHOD

We propose a Multi-task BCa Muscular Invasion Prediction (MBMIP) model to discriminate MIBC from NMIBC. The three-channel-input including the original T2WI image, segmented bladder, and the region of interest can help the MBMIP model locate the bladder and pay more attention to the surrounding information of the tumor. Inception V3 is used as the feature extraction module, which uses multiple branches to extract high-level features with different degrees of abstraction. In addition, based on the idea of multi-task learning, a reconstruction block for T2WI images is also introduced to assist the backbone classification network to improve the classification performance.

RESULTS

The entire data consist of retrospective data (390 cases), prospective data (39 cases), and multi-center data (39 cases). In the retrospective test, the accuracy, sensitivity, and specificity of the MBMIP model are 0.911, 0.889, and 0.920 respectively, while those of the prospective test are 0.923, 1.000, and 0.885. And in the muti-center test, the MBMIP model yields accuracy, sensitivity, and specificity of 0.846, 0.667, and 0.879.

CONCLUSION

The MBMIP model could achieve a satisfactory prediction result in discriminating between NMIBC and MIBC, which may aid urologists in preoperative decision-making for BCa patients.

Magnetic resonance imaging of bladder pheochromocytomas: a review

Bladder pheochromocytomas (PCCs) are rare tumors that account for 0.06% of all bladder tumors and makeup 1% of all PCCs. Most PCCs are functional, and they secrete catecholamines that lead to clinical symptoms such as paroxysmal hypertension, headaches, palpitations, and sweating. However, some are nonfunctional and asymptomatic and are hence difficult to diagnose. Cystoscopy and biopsy should not be performed when bladder PCCs are suspected. They may provoke a hypertensive crisis if preventative antiadrenergic blockers are not administered prior to the procedure. The diagnostic workup begins with obtaining blood or urine catecholamine and catecholamine metabolite values to make a presumptive diagnosis of bladder PCC. Computed tomography (C.T.) and magnetic resonance imaging (MRI) are then used to localize and stage the tumor for surgical resection. MRI, due to its superior soft tissue resolution and the ability to use multiparametric MRI (mpMRI) to differentiate between layers of the bladder wall and from other bladder masses, is the optimal imaging modality to detect extra-adrenal bladder PCCs and determine locoregional staging. Once antiadrenergic medications are given, the tumor is resected, and the diagnosis is confirmed histologically. However, the differential diagnosis of bladder PCC often gets overlooked, leading to surgical resection in the absence of antiadrenergic medications, increasing the chances of a fatal hypertensive crisis. This makes MRI an essential diagnostic tool for staging bladder PCCs before surgery. This review discusses the indications for MRI in bladder PCCs and describes findings from these tumors on various MRI sequences and when to use them. We also discuss how MRI can differentiate bladder PCCs from other bladder neoplasms.

A novel and sensitive DNA methylation marker for the urine-based liquid biopsies to detect bladder cancer

Background

Better prognostic outcome is closely correlated with early detection of bladder cancer. Current non-invasive urianalysis relies on simultaneously testing multiple methylation markers to achieve relatively high accuracy. Therefore, we have developed an easy-to-use, convenient, and accurate single-target urine-based DNA methylation test for the malignancy.

Methods

By analyzing TCGA data, 344 candidate markers with 424 primer pairs and probe sets synthesized were systematically screened in cancer cell lines, paired tissue specimens, and urine sediments from bladder cancer patients and normal controls. The identified marker was further validated in large case-control cohorts. Wilcoxon rank sum tests and c2 tests were performed to compare methylation levels between case-control groups and correlate methylation levels with demographic and clinical characteristics. In addition, MSP, qMSP, RT-PCR, western blot analysis, and immunohistochemistry were performed to measure levels of DNA methylation, mRNA transcription, and protein expression in cancer cell lines and tissues.

Results

A top-performing DMRTA2 marker identified was tested in both discovery and validation sets, showing similar sensitivity and specificity for bladder cancer detection. Overall sensitivity in the aggregate set was 82.9%(179/216). The specificity, from a control group consisting of patients with lithangiuria, prostatoplasia, and prostatitis, is 92.5%(468/506). Notably, the methylation assay had the highest sensitivities for tumors at stages of T1(90.4%) and T2(95.0%) compared with Ta (63.0%), T3(81.8%), and T4(81.8%). Furthermore, the test showed admirable detection rate of 80.0%(24/30) for recurring cancers. While methylation was observed in 39/54(72.2%) urine samples from patients with carcinomas of renal pelvis and ureter, it was detected at extremely low rate of 6.0%(8/133) in kidney and prostate cancers. Compared with SV-HUC-1, the normal bladder epithelial cell line, DMRTA2 was hypermethylated in 8/9 bladder cancer cell lines, consistent with the results of MSP and qMSP, but not correlated with mRNA and protein expression levels in these cell lines. Similarly, DMRTA2 immunostaining was moderate in some tissues but weak in others. Further studies are needed to address functional implications of DMRTA2 hypermethylation.

Conclusions

Our data demonstrated that a single-target DNA methylation signature, mDMRTA2, could be highly effective to detect both primary and recurring bladder cancer via urine samples.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09616-y.

Explainable artificial intelligence (XAI): closing the gap between image analysis and navigation in complex invasive diagnostic procedures

LITERATURE REVIEW

Cystoscopy is the gold standard for initial macroscopic assessments of the human urinary bladder to rule out (or diagnose) bladder cancer (BCa). Despite having guidelines, cystoscopic findings are diverse and often challenging to classify. The extent of the false negatives and false positives in cystoscopic diagnosis is currently unknown. We suspect that there is a certain degree of under-diagnosis (like the failure to detect malignant tumours) and over-diagnosis (e.g. sending the patient for unnecessary transurethral resection of bladder tumors with anesthesia) that put the patient at risk.

CONCLUSIONS

XAI robot-assisted cystoscopes would help to overcome the risks/flaws of conventional cystoscopy. Cystoscopy is considered a less life-threatening starting point for automation than open surgical procedures. Semi-autonomous cystoscopy requires standards and cystoscopy is a good procedure to establish a model that can then be exported/copied to other procedures of endoscopy and surgery. Standards also define the automation levels-an issue for medical product law. These cystoscopy skills do not give full autonomy to the machine, and represent a surgical parallel to 'Autonomous Driving' (where a standard requires a human supervisor to remain in the 'vehicle'). Here in robotic cystoscopy, a human supervisor remains bedside in the 'operating room' as a 'human-in-the-loop' in order to safeguard patients. The urologists will be able to delegate personal- and time-consuming cystoscopy to a specialised nurse. The result of automated diagnostic cystoscopy is a short video (with pre-processed photos from the video), which are then reviewed by the urologists at a more convenient time.

Head-to-head Intra-individual Comparison of [68Ga]-FAPI and [18F]-FDG PET/CT in Patients with Bladder Cancer

AIM/PURPOSE

Fibroblast activation protein-(FAP)-ligands, a novel class of tracers for PET/CT imaging, demonstrated promising results in previous studies in various malignancies compared to standard [¹⁸F]FDG PET/CT. ⁶⁸Ga-labeled fibroblast activation protein inhibitor-([⁶⁸Ga]Ga-DOTA-FAPI)-PET/CT impresses with sharp contrasts in terms of high tumor uptake and low background noise leading to clear delineation. [¹⁸F]FDG PET/CT has limited accuracy in bladder cancer due to high background signal. Therefore, we sought to evaluate the diagnostic potential of [⁶⁸Ga]FAPI in patients with bladder cancer.

MATERIAL AND METHODS

This retrospective analysis consisted of 8 patients (median age 66), 7 of whom underwent both [⁶⁸Ga]FAPI and [¹⁸F]FDG PET/CT scans with a median time interval of 5 days (range 1-20 days). Quantification of tracer uptake was determined with SUV_max and SUV_mean. Furthermore, the tumor-to-background ratio (TBR) was derived by dividing the SUV_max of tumor lesions by the SUV_max of adipose tissue, skeletal muscle, and blood pool.

RESULTS

Overall, 31 metastases were detected in five patients including lymph node metastases (n = 23), bone metastases (n = 4), lung metastases (n = 3), and a peritoneal metastasis (n = 1). In one patient, [⁶⁸Ga]FAPI demonstrated significant uptake in the primary tumor located in the bladder wall. [⁶⁸Ga]FAPI-PET/CT demonstrated significantly higher uptake compared to [¹⁸F]FDG PET/CT with higher mean SUV_max (8.2 vs. 4.6; p = 0.01). Furthermore, [⁶⁸Ga]FAPI detected additional 30% (n = 9) lesions, missed by [¹⁸F]FDG. TBR demonstrated favorable uptake for [⁶⁸Ga]FAPI in comparison to [¹⁸F]FDG. Significant differences were determined with regard to metastasis/blood pool ([⁶⁸Ga]FAPI 5.3 vs [¹⁸F]FDG 1.9; p = 0.001).

CONCLUSION

[⁶⁸Ga]FAPI-PET/CT is a promising diagnostic radioligand for patients with bladder cancer. This first described analysis of FAP-ligand in bladder cancer revealed superiority over [¹⁸F]FDG in a small patient cohort. Thus, this so far assumed potential has to be confirmed and extended by larger and prospective studies.

Urothelial carcinoma with mandibular metastasis and synchronous prostate cancer

Only 4% of newly diagnosed bladder cancer (BC) patients present with metastatic disease. The most common reported sites of metastases are lymph nodes, bones, lung, liver and peritoneum. Mandibular metastasis is very rare. We report a case of muscle-invasive urothelial cancer metastasised to the mandible and with an incidental finding of high-risk prostate cancer (PC). Incidental finding of PC in BC patients may be suggestive of a common aetiology. Treatment for BC and PC can be delivered in parallel, including platinum-based chemotherapy, cystectomy and androgen depletion therapy. Prognosis of metastatic BC is poor, and high-risk PC may affect progression-free survival of BC. Our case highlights importance of considering BC metastasis to the jaw as well as synchronous PC in the management of patients presenting with BC.

Diagnosis and Staging of Bladder Cancer

Cystoscopic examination remains the gold standard technique for initial diagnosis of bladder cancer (BCa). Despite significant progress in enhanced cystoscopic techniques, blue light cystoscopy and narrow band imaging are the only ones well supported by high-level evidence and, if available, should be used during initial staging of BCa. Multiparametric MRI could be an important imaging tool in local staging of BCa. With ever-expanding targeted therapy and immunotherapy options in both muscle-invasive and non-muscle-invasive BCa, molecular subtyping could become an essential part of initial histologic staging in the near future.

Discovery of Volatile Biomarkers for Bladder Cancer Detection and Staging through Urine Metabolomics

Timely diagnosis is crucial to improve the long-term survival of bladder cancer (BC) patients. The discovery of new BC biomarkers based in urine analysis is very attractive because this biofluid is in direct contact with the inner bladder layer, in which most of the neoplasms develop, and is non-invasively collected. Hence, this work aimed to unveil alterations in the urinary volatile profile of patients diagnosed with BC compared with cancer-free individuals, as well as differences among patients diagnosed at different tumor stages, to identify candidate biomarkers for non-invasive BC diagnosis and staging. Urine analysis was performed by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results unveiled that BC patients have a distinct urinary volatile profile characterized by higher levels of several alkanes and aromatic compounds, and lower levels of aldehydes, ketones and monoterpenes. Seventeen significantly altered volatiles were used to evaluate the performance for overall BC detection, disclosing 70% sensitivity, 89% specificity and 80% accuracy. Moreover, distinct urinary volatile profiles were found among patients diagnosed at different tumor stages (Ta/Tis, T1 and ≥T2). This work identified distinct urinary volatile signatures of BC patients with potential for non-invasive detection and staging of bladder cancer.

Multiparametric magnetic resonance imaging for bladder cancer: a comprehensive systematic review of the Vesical Imaging-Reporting and Data System (VI-RADS) performance and potential clinical applications

BACKGROUND

The Vesical Imaging-Reporting and Data System (VI-RADS) score is a novel standardized approach to image and report bladder cancer (BC) with multiparametric MRI (mpMRI).

OBJECTIVES

To describe and evaluate the performance of the VI-RADS score using mpMRI and assess its potential clinical applications and limitations.

METHODS

A systematic review was conducted using the MEDLINE and EMBASE electronic bibliographic databases between June 2020 and December 2020. All reports deemed relevant to describe the VI-RADS score and assess its performance and applications were retrieved. Results presentation stands as narrative, purely descriptive synthesis based on aggregate studies data.

RESULTS

A total of 20 relevant studies were retrieved: three meta-analyses, five prospective studies, and twelve retrospective studies. The retrospective studies covered 1676 patients, while the prospective studies included a total number of 468 patients. Pooled sensitivity, specificity to differentiate muscle-invasive from non-muscle-invasive bladder cancer, ranged from 74.1% to 97.3%, and 77% to 100%, respectively. The chosen VI-RADS score thresholds for this discrimination varied across studies. The interreader agreement ranged from 0.73 to 0.95. Currently, the potential clinical applications of VI-RADS consist of initial BC risk stratification, assessment of neoadjuvant therapies response, and bladder sparing approaches, although further validation is required.

CONCLUSIONS

The VI-RADS score helps to discriminate muscle invasive from non-muscle invasive BC with good performance and reproducibility. A simple algorithm based on four basic questions may enhance its popularization. Further studies are required to validate the clinical applications.