Accuracy of 3 Tesla pelvic phased-array multiparametric MRI in diagnosing prostate cancer at repeat biopsy

Introduction. Multiparametric pelvic magnetic resonance imaging (mpMRI) accuracy in prostate cancer (PCa) diagnosis was evaluated. Materials and Methods. From June 2011 to December 2013, 168 patients (median 65 years) with negative digital rectal examination underwent repeat transperineal saturation biopsy (SPBx; median 28 cores) for persistently high or increasing PSA values, PSA >10 ng/ml or PSA values between 4.1-10 o r 2.6-4 ng/ml with free/total PSA < 25% and < 20%, respectively. All patients underwent mpMRI using a 3.0 Tesla scanner equipped with surface 16 channels phased-array coil and lesions suspicious for PCa were submitted to additional targeted biopsies. Results. A T1c PCa was found in 66 (39%) cases; SPBx and mpMRI-suspicious targeted biopsy diagnosed 60 (91%) and 52 (78.8%) cancers missing 6 (all of the anterior zone) and 14 cancers (12 and 2 of the lateral margins and anterior zone), respectively; in detail, mpMRI missed 12 (18.1%) PCa charaterized by microfocal (1 positive core with greatest percentage of cancer and Gleason score equal to 5% and 6, respectively) disease at risk for insignificant cancer. The diameter of the suspicious mpMRI lesion was directly correlated to the diagnosis of PCa with poor Gleason score (p < 0.05); detection rate of cancer for each suspicious mpMRI core was 35.3%. Diagnostic accuracy, sensitivity, specificity, positive and negative predictive value of mpMRI in diagnosing PCa was 75.7%, 82.5%, 71.8%, 78.9%, 87.9%, respectively. Conclusion. Multiparametric pMRI improved SPBx accuracy in diagnosing significant anterior PCa; the diameter of mpMRI suspicious lesion resulted significantly predictive of aggressive cancers.