The PICTURE study: diagnostic accuracy of multiparametric MRI in men requiring a repeat prostate biopsy

Abstract

Background:Transrectal prostate biopsy has limited diagnostic accuracy. Prostate Imaging Compared to Transperineal Ultrasound-guided biopsy for significant prostate cancer Risk Evaluation (PICTURE) was a paired-cohort confirmatory study designed to assess diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI) in men requiring a repeat biopsy.Methods:All underwent 3 T mpMRI and transperineal template prostate mapping biopsies (TTPM biopsies). Multiparametric MRI was reported using Likert scores and radiologists were blinded to initial biopsies. Men were blinded to mpMRI results. Clinically significant prostate cancer was defined as Gleason ⩾4+3 and/or cancer core length ⩾6 mm.Results:Two hundred and forty-nine had both tests with mean (s.d.) age was 62 (7) years, median (IQR) PSA 6.8 ng ml (4.98–9.50), median (IQR) number of previous biopsies 1 (1–2) and mean (s.d.) gland size 37 ml (15.5). On TTPM biopsies, 103 (41%) had clinically significant prostate cancer. Two hundred and fourteen (86%) had a positive prostate mpMRI using Likert score ⩾3; sensitivity was 97.1% (95% confidence interval (CI): 92–99), specificity 21.9% (15.5–29.5), negative predictive value (NPV) 91.4% (76.9–98.1) and positive predictive value (PPV) 46.7% (35.2–47.8). One hundred and twenty-nine (51.8%) had a positive mpMRI using Likert score ⩾4; sensitivity was 80.6% (71.6–87.7), specificity 68.5% (60.3–75.9), NPV 83.3% (75.4–89.5) and PPV 64.3% (55.4–72.6).Conclusions:In men advised to have a repeat prostate biopsy, prostate mpMRI could be used to safely avoid a repeat biopsy with high sensitivity for clinically significant cancers. However, such a strategy can miss some significant cancers and overdiagnose insignificant cancers depending on the mpMRI score threshold used to define which men should be biopsied.

Use of Prostate Specific Antigen Density Combined with Multiparametric Magnetic Resonance Imaging Improves Triage for Prostate Biopsy

“…The goals are not only to stage the disease and to locate and target suspect lesions but also to guide decisions about whether to proceed with a biopsy [4,10]. Unfortunately, the results of some mpMRI studies have been inconclusive, as discussed below.…”

Immunohistochemical biomarker validation in highly selective needle biopsy microarrays derived from mpMRI‐characterized prostates

“…All prostate tissue was acquired during the PICTURE trial, a paired‐cohort confirmatory study designed to assess the accuracy of mpMRI in detecting clinically significant cancer . For this purpose, 249 men with a previous TRUS biopsy requiring a repeat evaluation underwent a 3T mpMRI followed by TPM biopsies of the entire prostate at 5 mm intervals.…”

Editorial Comment

“…Nevertheless, its accuracy and clinical implications have been questioned by many. [2][3][4] As an attempt to address this concern, the present study assessed the relationship between MRI-based preoperative grading and staging compared to pathologic outcome following radical prostatectomy (RP). The authors found significant discordance in grade group and stage leading to a change in the NCCN risk stratification in 45% of patients, of which 33% would have been in a higher risk group and 12% would have been in a lower risk group based on RP pathology.…”

“…First, the accuracy of the fusion biopsy is not sufficient to forego the conventional systematic biopsy at the present time. 2,7 Second, appropriate radiological expertise is critical to the success of the fusion biopsy platform. In this regard, there is concern for a market-driven, rapid implementation of a new technology without the appropriate expertise to optimize the benefit of a new technology.…”