MRI of the prostate: Interobserver agreement compared with histopathologic outcome after radical prostatectomy

作者：Ruprecht Oliver^*; Weisser Philipp; Bodelle Boris; Ackermann Hanns; Vogl Thomas J

来源：European Journal of Radiology, 2012, 81(3): 456-460.

DOI：10.1016/j.ejrad.2010.12.076

• Prostate cancer
• MR imaging
• Radical prostatectomy
• Histopathology
• Multireader analysis

Background: The purpose of this study was to evaluate interobserver agreement of prostatic MRI in assessing the performance of staging prostate carcinoma in comparison with histopathologic step section prostate specimens. %26lt;br%26gt;Methods: We retrospectively evaluated 46 patients who underwent prostatic MRI examination at 1.5 T MRI and %26quot;subsequently%26quot; radical prostatectomy. All MR-images were reevaluated by two different experienced radiologists (15 and 1.5 years of experience) with special focus on T2/T3 differentiation. Both radiologists were not aware of the patient%26apos;s clinical data, except that the patient had prostate cancer. These findings were compared with histopathologic whole mount step section prostate specimens, which served as the %26quot;gold standard%26quot;. Fourfold tables were created to calculate sensitivity, specificity, positive and negative predictive values and efficiency for T2/T3 differentiation. Cohen%26apos;s kappa was calculated to measure inter-rater agreement. %26lt;br%26gt;Results: Twenty-eight patients were diagnosed with organ defined cancer (T2), 18 patients were staged with extracapsular extension (T3), and thereof 7 patients were staged with seminal vesicle invasion (T3b) by the pathologists. The experienced reader reached a sensitivity of 77.78% (95%-CI 52.36%; 93.59%) and specificity of 92.86% (95%-CI 76.50%; 99.12%) for T2/T3 differentiation, the less experienced reader however achieved a sensitivity of 33.33% (95%-CI 13.34%; 59.01%) and specificity of 71.43% (95%-CI 51.33%; 86.78%). The Cohen%26apos;s kappa for inter-rater reliability for differentiation between T2 and T3 stage was kappa = 0.0129. %26lt;br%26gt;Conclusions: Evaluation of prostatic MR imaging requires lengthy experience for accurate interpretation and staging. While a highly experienced reader can achieve good correlation with histopathology even without utilization of functional MR imaging, a less experienced reader with theoretical knowledge falls short of expectation.

• 出版日期2012-3