Potential Utility of Diffusion-Weighted Magnetic Resonance Imaging in Diagnosis of Residual Bladder Cancer before Second Transurethral Resection

Abstract

Introduction: The study aimed to investigate the diagnostic utility of diffusion-weighted MRI (DW-MRI) in differentiating residual bladder cancer from benign postoperative changes before a second transurethral resection of the bladder (TURB). Materials and Methods: Of the 75 bladder cancer patients who underwent a second TURB from 2013 to 2015, 23 patients who underwent multi-sequence bladder MRI after their initial TURB were retrospectively evaluated. Thirty lesions were histologically examined at the second TURB and the results of them were compared with the findings obtained through T2-weighted MRI, dynamic contrast-enhanced MRI (DCE-MRI), and DW-MRI. Results: Positive findings of 27, 28, and 15 lesions showed up on T2W-, DCE-, and DW-MRI, respectively. Thirteen lesions were confirmed histologically to constitute residual cancer. The sensitivity/specificity/accuracy of T2W-, DCE-, and DW-MRI were 100/18/53, 100/12/50, and 92/82/87%, respectively. DW-MRI was significantly superior in specificity and accuracy to T2W- (p < 0.01 for both) and DCE-MRI (p < 0.01 for both). Conclusions: This study first showed the superiority of DW-MRI to T2W- and DCE-MRI in differentiating residual cancer before a second TURB.

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

“…Inflammatory edema, fibrosis and scar tissue secondary to TURBT and intravesical instillation can morphologically manifest as mural nodules or irregular wall thickening, thus simulating tumor recurrence [ 10 , 11 , 16 , 17 ]. It is difficult to distinguish from flat or diffuse tumors that infiltrate the bladder wall, which is the difficulty of imaging diagnosis.…”

“…However, the accuracy decreased as lesion size decreased. Postoperative inflammation and fibrosis can be enhanced due to peri-tumoral neovascularization, which may persist for many years as an inflammatory change [ 11 , 17 ]. Among patients with irregular wall thickening, six cases were misdiagnosed as inflammation by MDCT due to focal wall thickening with homogeneous enhancement.…”

Observational Studies Requested by European Health Authorities: Governmental Interference or an Enhancement of Everyday Urological Practice? The Hexvix® Observational Patients Evaluation Study as an Example of What to Expect

“…Likewise, the impact of instrument capacity or availability on non-use of hexaminolevulinate cannot be estimated from these data. Many patients had previous TURB and this may also have driven the frequency of hexaminolevulinate use; whether more recent data on the use of diffusion-weighted magnetic resonance imaging in the diagnosis of residual cancer before re-TURB [23] will influence the use of blue-light cystoscopy is difficult to predict. However, these findings from the HOPE study do illustrate how important such post-authorisation studies may be to Health Authorities for making accurate cost-effectiveness analyses (but it should be stressed that no costeffectiveness analysis was included in the HOPE study).…”

A glance at imaging bladder cancer

“…For differentiating residual BCa from postoperative changes before a second TURB, in 75 patients, T2W-MRI had 100% sensitivity, only 18% specificity, and 53% accuracy. DCE-MRI had 100% sensitivity, 12% specificity, 50% accuracy and DW-MRI had 92% sensitivity, 82% specificity, 87% accuracy [51].…”