Computed tomography urography with corticomedullary phase can exclude urinary bladder cancer with high accuracy

Diagnostic Performance of GeneXpert BC as a Triage Test for Patients Presenting with Macroscopic Hematuria Suspicious for Urinary Bladder Cancer: A Multicenter Prospective Case-Control Study

Background and objective

Our objective was to assess whether GeneXpert BC can be used as a triage test to exclude urinary bladder cancer (UBC) for patients with macroscopic hematuria.

Methods

We conducted a prospective study that include consecutive patients being evaluated for macroscopic hematuria between September 2020 and December 2022. Before cystoscopy, study participants provided a voided urine sample for GeneXpert BC analysis according to a case-control design with an emphasis on UBC detection. Descriptive statistics are reported for patient and tumor characteristics. To assess the diagnostic accuracy of the GeneXpert BC test, the sensitivity, specificity, and negative predictive value (NPV) were calculated, using the histopathologically proven UBC as the ground truth.

Key findings and limitations

In total, 1505 subjects presenting with macroscopic hematuria were enrolled in the study. After randomization and exclusions, GeneXpert BC testing was carried out for 312 participants. Of these, 151 patients from the case arm had UBC, 122 patients from the control arm (random 10%) were negative for UBC, and 39 patients from the case arm did not have malignancy. Using a predefined linear discriminant analysis (LDA) threshold of ≥0.22, the test had sensitivity of 0.94 (95% confidence interval [CI] 0.90-0.97), specificity of 0.52 (95% CI 0.42-0.59), and NPV of 0.99 (95% CI 0.98-0.99). All false-negative tumors were of low grade (Ta grade 1-2). Cystoscopy and computed tomography urography could have been omitted in 44% of the patients with macroscopic hematuria. At a secondary LDA threshold of ≥0.45, the test had sensitivity of 0.79 (95% CI 0.73-0.86), specificity of 0.83 (95% CI 0.76-0.89), and NPV of 0.97 (95% CI 0.96-0.98).

Conclusions and clinical implications

GeneXpert BC is a reliable triage test for deciding on whether further investigations are necessary in patients with macroscopic hematuria.

Patient summary

We assessed a test called GeneXpert BC for the detection of bladder cancer in patients with blood in their urine. GeneXpert BC performed well in ruling out bladder cancer for patients who did not have cancer according to further tests. Use of GeneXpert BC could help in avoiding scans and invasive tests for patients with a negative result.

A novel model of artificial intelligence based automated image analysis of CT urography to identify bladder cancer in patients investigated for macroscopic hematuria

OBJECTIVE

To evaluate whether artificial intelligence (AI) based automatic image analysis utilising convolutional neural networks (CNNs) can be used to evaluate computed tomography urography (CTU) for the presence of urinary bladder cancer (UBC) in patients with macroscopic hematuria.

METHODS

Our study included patients who had undergone evaluation for macroscopic hematuria. A CNN-based AI model was trained and validated on the CTUs included in the study on a dedicated research platform (Recomia.org). Sensitivity and specificity were calculated to assess the performance of the AI model. Cystoscopy findings were used as the reference method.

RESULTS

The training cohort comprised a total of 530 patients. Following the optimisation process, we developed the last version of our AI model. Subsequently, we utilised the model in the validation cohort which included an additional 400 patients (including 239 patients with UBC). The AI model had a sensitivity of 0.83 (95% confidence intervals [CI], 0.76-0.89), specificity of 0.76 (95% CI 0.67-0.84), and a negative predictive value (NPV) of 0.97 (95% CI 0.95-0.98). The majority of tumours in the false negative group (n = 24) were solitary (67%) and smaller than 1 cm (50%), with the majority of patients having cTaG1-2 (71%).

CONCLUSIONS

We developed and tested an AI model for automatic image analysis of CTUs to detect UBC in patients with macroscopic hematuria. This model showed promising results with a high detection rate and excessive NPV. Further developments could lead to a decreased need for invasive investigations and prioritising patients with serious tumours.

Diagnostic value of repeated comprehensive investigation with CT urography and cystoscopy for recurrent macroscopic haematuria

Objectives

To perform a descriptive analysis of a series of patients with recurrent macroscopic haematuria after a primary standard evaluation including computed tomography urography (CTU) and cystoscopy negative for urinary bladder cancer (UBC) and upper tract urothelial cancer (UTUC) and to identify potential factors associated with occurrence of recurrent macroscopic haematuria.

Methods

All patients older than 50 years who underwent urological investigation for macroscopic haematuria with both cystoscopy and CTU 2015-2017 were retrospectively reviewed. A descriptive analysis of the primary and later investigations for recurrent macroscopic haematuria was performed. To investigate the association between explanatory variables and the occurrence of recurrent macroscopic haematuria, a Poisson regression analysis was performed.

Results

A total of 1395 eligible individuals with primary standard investigation negative for UBC and UTUC were included. During a median follow-up of 6.2 (IQR 5.3-7) years, 248 (18%) patients had recurrent macroscopic haematuria, of whom six patients were diagnosed with UBC, two with prostate cancer, one with renal cell carcinoma and one had a suspected UTUC at the repeated investigation. Within 3 years, 148 patients (11%) experienced recurrent macroscopic haematuria, of whom two patients were diagnosed with low-grade UBC (TaG1-2), one with T2G3 UBC and one with low-risk prostate cancer. The presence of an indwelling catheter, use of antithrombotic medication, pathological findings at CTU or cystoscopy or history of pelvic radiotherapy were all statistically significant independent predictors for increased risk for recurrent macroscopic haematuria.

Conclusion

In the case of recurrent macroscopic haematuria within 3 years of primary standard evaluation for urinary tract cancer, there was a low risk of later urological malignancies in patients initially negative for UBC and UTUC. Therefore, waiting 3 years before conducting another complete investigation in cases of recurrent macroscopic haematuria might be appropriate.

Cornerstones of CT urography: a shared document by the Italian board of urogenital radiology

CT urography is a single term used to refer to different scanning protocols that can be applied for a number of clinical indications. If, on the one hand, this highlights the role of the radiologist in deciding the most suitable technique to perform according to the patient's needs, on the other hand, a certain confusion may arise due to the different technical and clinical variables that have to be taken into account. This has been well demonstrated by a previous work based on an online questionnaire administered to a population of Italian radiologists that brought out similarities as well as differences across the national country. Defining precise guidelines for each clinical scenario, although desirable, is a difficult task to accomplish, if not even unfeasible. According to the prementioned survey, five relevant topics concerning CT urography have been identified: definition and clinical indications, opacification of the excretory system, techniques, post-processing reconstructions, and radiation dose and utility of dual-energy CT. The aim of this work is to deepen and share knowledge about these main points in order to assist the radiology in the daily practice. Moreover, a synopsis of recommendations agreed by the Italian board of genitourinary imaging is provided.