title: Preoperative staging of invasive bladder cancer with dynamic gadolinium-enhanced magnetic resonance imaging: results from a prospective study.
abstract: 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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Urology, USC/Norris Comprehensive Cancer Center, Los Angeles, California 90089-2211, USA. daneshma@med.usc.edu
authors.forename: Siamak
authors.initials: S
authors.lastname: Daneshmand
authors.forename: Hamed
authors.initials: H
authors.lastname: Ahmadi
authors.forename: Ly N
authors.initials: LN
authors.lastname: Huynh
authors.forename: Nora
authors.initials: N
authors.lastname: Dobos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005682:Gadolinium; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009367:Neoplasm Staging; D057234:Preoperative Period; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D001749:Urinary Bladder Neoplasms / Q000473:pathology* / Q000601:surgery
chemical_list: D005682:Gadolinium