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Prospective assessment of vesical imaging reporting and data system (VI-RADS) and its clinical impact on the management of high-risk non–muscle-invasive bladder cancer patients candidate for repeated transurethral resection

  • Francesco Del Giudice 1,
  • Giovanni Barchetti 2,
  • Ettore De Berardinis 1,
  • Martina Pecoraro 2,
  • Vincenzo Salvo 2,
  • Giuseppe Simone 3,
  • Alessandro Sciarra 1,
  • Costantino Leonardo 1,
  • Michele Gallucci 1,
  • Carlo Catalano 2,
  • James W.F. Catto 4,
  • Valeria Panebianco 2
1 Department of Maternal-Child and Urological Sciences, “Sapienza” Rome University, Policlinico Umberto I Hospital, Rome, Italy 2 Department of Radiological, Oncological and Anatomopathological Sciences, “Sapienza” Rome University, Policlinico Umberto I Hospital, Rome, Italy 3 Department of Urology, ''Regina Elena'' National Cancer Institute, IRCCS, Rome, Italy 4 Academic Urology Unit, University of Sheffield, Sheffield, UK

Publication: European Urology, Volume 77, Issue 1, January 2020, Pages 101-109

Background

Vesical Imaging Reporting and Data System (VI-RADS) score is adopted to provide preoperative bladder cancer (BCa) staging. Repeated transurethral resection of bladder tumor (Re-TURBT) is recommended in most of high-risk non–muscle-invasive bladder cancers (HR-NMIBCs) due to possibility of persistent/understaged disease after initial TURBT. No diagnostic tools able to improve patient’s stratification for such recommendation exist.

Objective

To (1) prospectively validate VI-RADS for discriminating between NMIBC and muscle-invasive bladder cancer (MIBC) at TURBT, and (2) evaluate the accuracy of VI-RADS for identifying HR-NMIBC patients who could avoid Re-TURBT and detecting those at higher risk for understaging after TURBT.

Design, setting, and participants

Patients with BCa suspicion were offered multiparametric magnetic resonance imaging (mpMRI) before TURBT. According to VI-RADS, a cutoff of ≥3 to define MIBC was assumed. TURBT reports were compared with preoperative VI-RADS scores to assess accuracy of mpMRI for discriminating between NMIBC and MIBC. HR-NMIBC Re-TURBT reports were compared with preoperatively recorded VI-RADS scores to assess mpMRI accuracy in predicting Re-TURBT outcomes.

Intervention

Multiparametric MRI of the bladder before TURBT.

Outcome measurements and statistical analysis

Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values were calculated for mpMRI performance in patients undergoing TURBT and for HR-NMIBC patients candidate for Re-TURBT. Performance of mpMRI was assessed by receiver operating characteristic curve analysis. Ƙ statistics was used to estimate inter- and intrareader variability.

Results and limitations

A total of 231 patients were enrolled. Multiparametric MRI showed sensitivity, specificity, PPV, and NPV for discriminating NMIBC from MIBC at initial TURBT of 91.9% (95% confidence interval [CI]: 82.2–97.3), 91.1% (95% CI: 85.8–94.9), 77.5% (95% CI: 65.8–86.7), and 97.1% (95% CI: 93.3–99.1), respectively. The area under the curve (AUC) was 0.94 (95% CI: 0.91–0.97). Among HR-NMIBC patients (n = 114), mpMRI before TURBT showed sensitivity, specificity, PPV, and NPV of 85% (95% CI: 62.1–96.8), 93.6% (95% CI: 86.6–97.6), 74.5% (95% CI: 52.4–90.1), and 96.6% (95% CI: 90.5–99.3) respectively, to identify patients with MIBC at Re-TURBT. The AUC was 0.93 (95% CI: 0.87–0.97).

Conclusions

VI-RADS is accurate for discriminating between NMIBC and MIBC. Within HR-NMIBC cases, VI-RADS could, in future, improve the selection of patients who are candidate for Re-TURBT.

Expert's summary

By Dr. Moschini

Transurethral resection of the bladder (TURB) represents an important diagnostic and therapeutic step in the management of bladder cancer patients. The majority of patients are diagnosed with non-muscle invasive bladder cancer (NMIBC). In this manuscript, authors prospectively evaluated the vesical imaging reporting and data system (VI-.RADS) for discriminating between NMIBC and muscle invasive bladder cancer (MIBC) at TURB. The aim was to report the accuracy of VI-RADS in identifying high-risk NMIBC patients in order to avoid re-TURB by detecting those at higher risk of under staging at initial TURB. All the MRI were performed before TURB. In total 231 patients were enrolled. Multiparametric MRI showed high sensitivity, specificity, positive predictive value and negative predictive value for discriminating NMIBC from MIBC at initial TURB of 91.9%, 91.1%, 77.5% and 97.1%, respectively. The area under the curve was 0.94. Among HR-NMIBC patients, mpMRI before TURB showed sensitivity, specificity, positive predictive value and negative predictive value of 85%, 93.6%, 74.5% and 96.6%, respectively to identify patients with MIBC at re-TURBT. The area under curve was 0.93. Authors conclude that VI-RADS is accurate for discriminating between NMIBC and MIBC and in future might improve the selection of patients who are candidates for re-TURB. 

Expert's comment

By Dr. Moschini

Authors have to be complimented for this prospective evaluation, showing that mp-MRI can be used to differentiate NMIBC and MIBC. However, it has to be reminded that pathological evaluation remains fundamental in order to capture several other features that cannot be diagnosed with mp-MRI such as the presence of histological variants, lymphovascular invasion or presence of carcinoma in situ. Apart to this consideration, combining pathological and radiological findings will be in the future of foremost importance to evaluate patients’ prognosis and help the decision-making for optimal management of bladder cancer patients.