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.