Combining Prostate-Specific Antigen Density With PI-RADS to Improve the Detection of Clinically Significant Prostate Cancer at MRI/TRUS Fusion-Targeted Re-Biopsy.

BACKGROUND

The diagnostic reliability of magnetic resonance imaging (MRI)/transrectal ultrasound (TRUS) fusion-targeted re-biopsy for prostate cancer (PCa) remains limited. Therefore, additional predictive markers are needed to improve patient selection. This study aimed to identify factors predictive of clinically significant PCa (csPCa) to develop a risk stratification model. The role of systematic biopsies was also investigated.

METHODS

We retrospectively analyzed 194 patients who underwent MRI/TRUS fusion-targeted re-biopsies between 2017 and 2024. Lesions were scored according to the Prostate Imaging Reporting and Data System (PI-RADS) version 2.0 or 2.1. Univariate and multivariate logistic regression analyses were conducted to identify predictors of csPCa, defined as Gleason score ≥ 3 + 4. Detection rates for csPCa were compared between groups. The diagnostic contribution of systematic biopsies was assessed separately.

RESULTS

Of the 194 patients, 82 (42.3%) were diagnosed with csPCa. Multivariate analysis identified prostate-specific antigen density (PSAD) ≥ 0.20 (odds ratio (OR): 6.56) and PI-RADS ≥ 4 (OR: 12.38) as independent predictors of csPCa. Based on the PI-RADS category and PSAD, patients were stratified into high-, intermediate-, and low-risk groups. These risk stratification factors led to the classification of 83 (42.8%) patients as high-risk, 77 (39.7%) as intermediate-risk, and 34 (17.5%) as low-risk, with csPCa detection rates of 74.7% (62/83), 24.7% (19/77), and 2.9% (1/34), respectively. Of the 82 patients with csPCa, 21 were diagnosed exclusively via systematic biopsies.

CONCLUSIONS

Combining PSAD with PI-RADS improved risk stratification for csPCa in men who underwent MRI/TRUS fusion re-biopsies, while systematic biopsies added diagnostic value. These findings support individualized evidence-based re-biopsy strategies.