The Efficacy of Multiparametric Magnetic Resonance Imaging and Magnetic Resonance Imaging Targeted Biopsy in Risk Classification for Patients with Prostate Cancer on Active Surveillance

Abstract

Purpose To determine if multiparametric-MRI (mpMRI)-targeted biopsies may replace systematic biopsies to detect higher grade prostate cancer (Gleason score ≥ 7), and whether biopsy may be avoided based on mpMRI among men with Gleason 3+3 prostate cancer on active surveillance (AS). Materials and Methods We identified men with previously diagnosed Gleason score 3+3 prostate cancer on AS who underwent a mpMRI and a follow-up prostate biopsy. Suspicion for higher grade cancer was scored on a standardized 5-point scale. All patients received a systematic biopsy. Patients with mpMRI regions-of-interest also underwent an MRI-targeted biopsy. The detection rate of higher grade cancer was estimated for different mpMRI scores using 3 biopsy strategies: systematic, MRI-targeted, and combined. Results Of 206 consecutive men on AS, 135 (66%) had a mpMRI region-of-interest. Overall, higher grade cancer was detected in 72 (35%) men. Higher mpMRI score was associated with an increased probability of detecting higher grade cancer (Wilcoxon-type trend test p < 0.0001). MRI-targeted biopsy detected higher grade cancer in 23% of men. MRI-targeted biopsy alone missed higher grade cancers in 17%, 12%, and 10% of patients with mpMRI scores of 3, 4, and 5, respectively. Conclusions MRI-targeted biopsies increased detection of higher grade cancer for men on AS compared to systematic biopsy alone; however a clinically relevant proportion of higher grade cancer was detected only using systematic biopsy. Despite the improved detection of disease progression using MRI-targeted biopsy, systematic biopsy cannot be excluded as part of surveillance for men with low risk prostate cancer.

Four‐year outcomes from a multiparametric magnetic resonance imaging (MRI)‐based active surveillance programme: PSA dynamics and serial MRI scans allow omission of protocol biopsies

“…We also did not have data on those who progressed to radical therapy prior to the first MRI scan. This is in fact true of most similar studies in the field , but must be borne in mind when interpreting these studies and ours. It does not detract from results related to follow‐up of patients who remained on active surveillance.…”

“…This is no longer the case when MRI risk stratification is taken into account. Other studies have shown that ~10% of men on active surveillance with no visible MRI lesion will be found to have upgrading if routine confirmatory biopsies are performed . In the present study, only 1.8% of patients with negative MRI were found to have upgrading on confirmatory biopsy.…”

Factors predicting prostate cancer upgrading on magnetic resonance imaging–targeted biopsy in an active surveillance population

“…For instance, the upgrading of low‐grade tumors on MRI/US confirmation biopsy less than 6 months after random TRUS biopsy has been shown to occur in up to 35% of patients being considered for AS . In our study, 20 of 76 patients (26.3%) were found to have Gleason score upgrading on MRI/US fusion–guided biopsy.…”

Multiparametric MRI: an important tool to improve risk stratification for active surveillance in prostate cancer

“…Recabal et al. . confirmed these conclusions in their retrospective assessment of an institutionally maintained prospective dataset.…”