Who Benefits from Multiparametric Magnetic Resonance Imaging After Suspicion of Prostate Cancer?

Background: Prostate cancer (PC) suspicion is based on prostate-specific antigen (PSA) and digital rectal examination (DRE). Multiparametric magnetic resonance imaging (mpMRI) increases prostate biopsy (PBx) specificity and sensitivity for detection of aggressive PC.

Objective: To identify who benefits from mpMRI according to biopsy scenario (initial biopsy [IBx] vs repeated biopsy [RBx]) and the risk of aggressive PC according to PSA-DRE groups (G1, PSA <10ng/ml and -DRE; G2, PSA <10ng/ml and +DRE; G3, PSA ≥10ng/ml and -DRE; G4, PSA ≥10ng/ml and +DRE).

Design, setting, and participants: We carried out a retrospective analysis for 768 consecutive men with PC suspicion and scheduled for PBx in a referral institution in 2016 and 2017.

Intervention: Pelvic 3-T mpMRI scanning, targeted biopsy (TBx) for suspicious lesions (Prostate Imaging-Reporting and Data System [PI-RADS] score >1), and 12-core systematic biopsy (SBx).

Outcome measurements and statistical analysis: We measured the rate of PBx procedures that could be avoided and the rate of high-grade PC (HGPC) that would be missed among men with negative mpMRI, and the increase in HGPC detection due to TBx. Univariate and multivariate analyses were performed.

Results and limitations: The rate of avoidable biopsies (PI-RADS <3) was 24.2% overall, with 25.7% for IBx and 20.5% for RBx (p=0.057). The IBx and RBx rates were 31.2% and 19.8% in G1, 13.5% and 30.4% in G2, 23.7% and 21.9% in G3, and 2.5% and 0% in G4, respectively. The overall rate of missed HGPC was 1.0% for IBx and 6.5% for RBx (p=0.170), while the IBx and RBx rates were 1.1% and 5.2% for G1, 2.0% and 11.1% for G2, 0% and 7.7% for G3, and 0% and 0% for G4, respectively (p<0.001). The rate of HGPC (PI-RADS 3-5) diagnosed following TBx increased to 23.9% for IBx and to 32.6% for RBx overall (p<0.001), while the IBx and RBx rates were 29.0% and 45.5% for G1, 20.0% and 33.3% for G2, 40.0% and 38.9% for G3, and 0% and 0% for G4, respectively (p<0.001). Limitations are the single-institution design, the lack of randomisation, and small samples for subgroup analyses.

Conclusions: mpMRI was of no benefit for men with PSA ≥10ng/ml and +DRE. Among the other men, mpMRI was of benefit in IBx and RBx as would reduce the biopsy rate by up to 25.7% and increase the net HGPC detection rate by up to 28.4%.

Patient summary: All men with suspected prostate cancer could benefit from multiparametric prostate cancer and targeted biopsy except for those with prostate-specific antigen ≥10ng/ml and positive digital rectal examination. The benefits include avoiding unnecessary prostate biopsy procedures and increasing the detection of aggressive cancer.