Utility of prostate-specific antigen derivatives to minimize unnecessary magnetic resonance imaging in patients with prior negative prostate biopsy.

Magnetic resonance imaging (MRI) has become an important tool for recommending prostate biopsy (PB) in prostate cancer (PCa) detection. However, the routine use of MRI in patients with previous negative PB remains debatable. This study aimed to evaluate the utility of prostate-specific antigen (PSA) derivatives to guide MRI use and reduce unnecessary scans in such cases. Receiver operating characteristic analysis identified a Prostate Imaging Reporting and Data System score ≥ 4 as the optimal threshold for predicting clinically significant PCa (Gleason score ≥ 7). A cohort of 251 patients with at least one prior negative PB who underwent serum PSA testing, free PSA, and MRI between October 2015 and June 2024 were analyzed. The optimal cutoff values for PSA, PSA density (PSAD), and free-to-total PSA ratio (%fPSA) were 11.87 ng/mL, 0.19 ng/mL2, and 18.76%, respectively (all p < 0.001). Restricting MRI to patients with PSA < 11.87 ng/mL, PSAD < 0.19 ng/mL2, or %fPSA > 18.76% could induce MRI use by 22.7% while missing only 9.1% of significant PCa cases on MRI-targeted PB.