Prostate Cancer Localization Using Multiparametric MR Imaging: Comparison of Prostate Imaging Reporting and Data System (PI-RADS) and Likert Scales

Abstract

The goal of this investigation was to retrospectively compare the recently proposed Prostate Imaging Reporting and Data System (PI-RADS) scale with the older Likert scale, using multiparametric MRI in 70 men with prostate cancer who underwent radical prostatectomy. A 3-T MRI system with pelvic phased array was used. The imaging studies were interpreted by 3 radiologists, each with 6 years of relevant experience. Maximal accuracy was determined for the detection of tumors larger than 3 mm in maximal diameter at prostatectomy using score thresholds of 8 and higher on the PI-RADS scale system and 3 and higher on the Likert scale system. Accuracy and diagnostic concordance between the 2 scales was better for peripheral zone tumors than for transitional zone tumors. Viewpoint Multiparametric MRI of the prostate gland has been shown to be useful in decreasing the sampling error rate associated with standard biopsy by providing image-based targets at the time of initial or repeat biopsy sessions.[1,2] However, the lack of standard guidelines for image interpretation and reporting has been a major hindrance to adoption of MRI in routine clinical practice. Recently, the European Society of Urogenital Radiology organized an expert panel that developed the PI-RADS criteria to address this challenge.[3] Table 2 in the article selected for this Viewpoint summarizes the PI-RAD