Usefulness of a Combined Approach of T1-Weighted, T2-Weighted, Dynamic Contrast-Enhanced, and Diffusion-Weighted Imaging in Prostate Cancer

PURPOSE We evaluated the value of a combined approach of T1-weighted (T1W) imaging, T2-weighted (T2W) imaging, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and diffusion-weighted imaging (DWI) for the detection of prostate cancer and extracapsular extension (ECE) in patients with prostate cancer by using pathologic data after radical prostatectomy. MATERIALS AND METHODS From April 2009 to December 2011, 126 patients who underwent radical prostatectomy and prostate MRI for prostate cancer were analyzed retrospectively. The MRI findings were compared with the pathologic findings of the radical prostatectomy specimens in each patient. The sensitivity, specificity, and accuracy of the detection of prostate cancer and extracapsular extension were analyzed. RESULTS The prostate cancer detection rate by use of T1W and T2W imaging, DCE-MRI, and their combination was 65.1%, 69.0%, and 80.2%, respectively (p=0.023). The detection rate using T1W and T2W imaging, DCE-MRI, DWI, and their combination was 57.7%, 65.4%, 67.3%, and 80.8%, respectively (p=0.086). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of combination MRI (T1W, T2W, and DCE-MRI) for ECE were 46.4%, 91.4%, 83.9%, and 68.1%, respectively. The sensitivity of combination MRI (T1W, T2W, and DCE-MRI) for ECE tended to increase as the prostate-specific antigen level rose (p=0.010). The sensitivity, specificity, PPV, and NPV of combination MRI (T1W, T2W, DCE-MRI, and DWI) for ECE were 65.0%, 87.5%, 76.5%, and 80.0%, respectively. CONCLUSIONS A combined approach of T1W, T2W, and DCE-MRI with DWI demonstrated an accurate detection rate of prostate cancer. Also, combination approaches showed a high specificity for predicting ECE, although sensitivity was relatively lower. Therefore, these methods are reliable for predicting prostate cancer. However, a new protocol is necessary to enhance the sensitivity for predicting ECE.