Usefulness of Prostate-Specific Antigen Density as an Indicator for Recommending Prebiopsy Magnetic Resonance Imaging to Prevent Missed Prostate Cancer Diagnoses

Purpose: To identify the indication for recommending prebiopsy magnetic resonance imaging (MRI) to prevent prostate cancer missed diagnoses in cases without prebiopsy MRI.Materials and Methods: Between January 2017 and September 2020, 585 patients suspected with prostate cancer underwent prostate biopsy after MRI. For patients with visible lesions, MRI-targeted biopsy using an image-based fusion program was performed in addition to the 12- core systematic biopsy. Patients for whom MRI was performed in other institutions (n=4) and patients who underwent target biopsy alone (n=7) were excluded.Results: Of 574 patients (median prostate-specific antigen [PSA] level, 6.88 ng/mL; mean age, 68.2 years), 342 (59.6%) were diagnosed with prostate cancer (visible lesions=312/449 [69.5%]; nonvisible lesions=30/123 [24.0%]). The detection rates of visible lesions stratified using the Prostate Imaging Reporting and Data System score (3 vs. 4 vs. 5) were 30.9% (54 of 175), 61.2% (150 of 245), and 90.1% (127 of 141), respectively. Multivariate analysis showed that PSA density was a significant factor for presence of visible lesions, prostate cancer, and significant prostate cancer diagnosis. Among patients with positive lesions, 27 (8.2%) were diagnosed with prostate cancer concomitant with negative systematic biopsy results. A PSA density of 0.15 ng/mL/cm³ was identified as the significant cutoff value for predicting positive target biopsy in groups with negative systematic biopsy. Sixty of the negative target lesions (26.1%) were diagnosed using systematic biopsy.Conclusions: To maximize cancer detection rates, both targeted and systematic biopsies should be implemented. PSA density was identified as a useful factor for recommending prebiopsy MRI to patients suspected with prostate cancer.