Combining Multiparametric Magnetic Resonance Imaging and Prostate-Specific Antigen Density in Selecting Patients for...

Multiparametric magnetic resonance imaging (mpMRI) combined with prostate-specific antigen density (PSAd) has emerged as an effective risk-stratification tool for guiding prostate biopsy decisions. This study aimed to determine the optimal, clinically feasible biopsy strategy by combining the mpMRI Prostate Imaging-Reporting and Data System (PI-RADS) score and PSAd to minimize unnecessary biopsies while maximizing the detection of clinically significant prostate cancer (csPCa; Gleason score {GS} ≥7), using transperineal targeted and systematic biopsy as the reference standard.

We retrospectively analyzed data from 511 men with clinical suspicion of prostate cancer (PCa) (PSA: >4 ng/mL; PI-RADS ≥3), who underwent pre-biopsy mpMRI and a subsequent combination of targeted and systematic transperineal prostate biopsy. Various mpMRI/PSAd thresholds were assessed based on their accuracy for detecting csPCa, their predictive value, the proportion of avoided biopsies, and net benefit and outcomes from decision curve analysis.

The overall analysis showed that the optimal strategy was to perform biopsy for lesions assessed as PI-RADS 4 and 5 or PI-RADS 3 lesions with PSAd of ≥0.15 ng/mL/mL. This combined approach yielded a negative predictive value (NPV) of 91% and a positive predictive value (PPV) of 43%. Implementing this strategy would have avoided biopsy in 16% (80/511) of the men and reduced the overdiagnosis of insignificant PCa by 9% (15/159) while missing only 4% (7/194) of csPCa cases.

Combining mpMRI with PSAd provides a robust, risk-stratified approach to PCa diagnosis. Men with equivocal mpMRI findings (PI-RADS 3) and low PSAd (<0.15 ng/mL/mL) may safely defer immediate prostate biopsy, reducing unnecessary procedures and the burden of overdiagnosis.