Nonsuspicious prebiopsy multiparametric MRI: is prostate biopsy still necessary?

Purpose: To evaluate the negative predictive value (NPV) of multiparametric magnetic resonance imaging (mpMRI), alone or combined with Prostate-Specific Antigen density (PSAd) to exclude clinically significant prostate cancer (csPCa).

Patients and methods: We performed a retrospective chart review of all the patients who had transrectal ultrasound-guided biopsy (TRUSGB) in our center between January 2014 and March 2019. We included patients who had nonsuspicious prebiopsy mpMRI defined as Prostate Imaging-Reporting and Data System (PI-RADS) ≤ 2. MRI was performed using a 1.5 or 3-Tesla Magnetic Resonance scanners with external phased-array coil. The primary outcome was the detection of csPCa, defined as a Gleason score 3 + 4 (ISUP 2) or higher on at least one biopsy core.

Results: One hundred and ninety-one consecutive men (median age: 65 years, median PSA level: 9.3 ng/mL) underwent TRUSGB following negative prebiopsy mpMRI corresponding to 126 (66%) biopsy-naïve patients, 36 (18.8%) patients with prior negative biopsy, and 29 (15.2%) patients under active surveillance with confirmatory biopsies. The overall PCa and csPCA detection rates were 26.7% and 5.2%, conferring a NPV of 73.3% and 94.8%, respectively. The NPV of negative mpMRI improved to 95.8% in patients with PSAd < 0.15 ng/mL/cm³ and to 100% in patients with PSAd < 0.10 ng/mL/cm³.

Conclusions: A negative prebiopsy mpMRI had an overall NPV of 94.8% for csPCa when mpMRI was used alone to 95.8% when combined with PSAd < 0.15 ng/mL/cm³. Future studies are needed to balance the low benefit of a biopsy in this indication with the morbidity of the procedure.