Dynamic contrast-enhanced imaging has limited added value over T2-weighted imaging and diffusion-weighted imaging when using PI-RADSv2 for diagnosis of clinically significant prostate cancer in patients with elevated PSA

AIM: To determine the added value of dynamic contrast- enhanced imaging (DCE) over T2weighted imaging (T2- WI) and diffusion- weighted imaging (DWI) for detection of clinically significant prostate cancer (csPC) in patients with elevated prostate- specific antigen (PSA). METHODS AND MATERIALS: Two hundred and forty- five patients with elevated PSA underwent multiparametric (mp) magnetic resonance imaging (MRI) of the prostate before biopsy. mpMRI was performed using a 3 T MRI system without an endorectal coil. Patients underwent transrectal ultrasound- guided systematic 12 core biopsy followed by radical prostatectomy (n = 68), radiation therapy (n = 91), or clinical follow- up for at least 2 years (n = 86). csPC was defined as Gleason score >= 3+4 and/ or tumour volume of >= 0.5 ml, and/ or tumour stage >= T3a. The MRI findings were scored according to the Prostate Imaging Reporting and Data System version 2 (PI- RADSv2) and an alternative overall assessment category (PIRADSv2Alt) based on only T2- WI and DWI. RESULTS: In 144 patients (58.8%), csPC was found within 2 years after MRI. With scoring according to the PI- RADSv2 guidelines, DCE was not needed for determination of the overall assessment category in 80.8% (198/ 245) of patients. Receiver operating characteristic (ROC) analysis showed an area under the curve of 0.79 (95% confidence interval [ CI]: 0.74-0.85) for PI- RADSv2 and 0.79 (95% CI: 0.73-0.85) for PI- RADSv2Alt. CONCLUSION: The added value of DCE over T2- WI and DWI is limited when using PI- RADSv2 for diagnosis of csPC in patients with elevated PSA before biopsy. An alternative overall assessment score using only T2- WI and DWI yielded similar performance to PI- RADSv2. (C) 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.