Preoperative staging of invasive bladder cancer with dynamic gadolinium-enhanced magnetic resonance imaging: Results from a prospective study

Objective: To evaluate the accuracy of dynamic gadolinium-enhanced magnetic resonance imaging (DGE-MRI) to detect extravesical bladder cancer (BC) and lymph node-positive disease in patients with invasive BC. Material and Methods: In a prospective single-center study from 2004 to 2009, patients with clinically invasive BC, who were candidates for curative surgery, underwent preoperative DGE-MRI. Radiologic T and N staging was determined by 2 MRI expert radiologists, and the interobserver agreement was calculated. The sensitivity, specificity, positive and negative predictive values, and accuracy of radiologic staging in differentiating lymph node-negative organ-confined vs nonorgan-confined BC and negative vs positive nodal disease was determined and compared with the postoperative pathologic staging as the reference standard method. Results: A total of 122 patients (72 men) with a mean age of 67.8 years were included. Pathologic examination revealed invasive BC in 80/122 (65.5%), including stage pT4 in 15/122 (12.3%), pT3 in 27/122 (22.1%), and pT2 in 38/122 (31.1%), and 27 patients (22.1%) had node-positive disease. The interobserver agreement for T and N staging according to the κ score was 0.44 and 0.49, respectively. The sensitivity, specificity, and accuracy of DGE-MRI in differentiating lymph node-negative organ-confined from nonorgan-confined BC was 87.5%, 47.6%, and 74% and for the detection of positive nodal disease was 40.7%, 91.5%, and 80.3%, respectively. Conclusion: We have presented the results of the largest cohort of patients with invasive BC underwent preoperative DGE-MRI. Although DGE-MRI improved T and N staging of invasive BC, it is still not the ideal modality and needs a standardized protocol for interpretation of the imaging findings.