#1343

Evaluating PI-RADS mpMRI Diagnostic Accuracy Using Transperineal and TRUS Biopsy Histology: Are We Detecting Every Clinically Significant Cancer?

J. Connor¹, K. Siddiqui¹, D. O'Sullivan¹

¹Hermitage Medical Clinic, Department of Urology, Dublin, Ireland

Introduction:

The PROMIS and PRECISION trials have redefined prostate cancer diagnostics by advocating for pre-biopsy multiparametric MRI (mpMRI), interpreted using the Prostate Imaging Reporting and Data System (PI-RADS), to guide biopsy decisions. These studies support omitting biopsy in patients with negative MRI (PI-RADS ≤2), thereby reducing unnecessary procedures. This audit evaluated the diagnostic performance of PI-RADS scoring in patients undergoing either transperineal biopsy (TPB) or transrectal ultrasound-guided biopsy (TRUS).

Material and methods:

Patients with prior prostate cancer treatment were excluded. Data collected included age, PSA, PI-RADS score, and histological outcomes. Cancer was classified as benign, clinically insignificant (Gleason 3+3), or clinically significant (Gleason >3+3). Diagnostic accuracy was assessed via sensitivity, specificity, and positive/negative predictive values (PPV/NPV).

Results:

A total of 51 patients were included: 47 underwent TPB and 14 TRUS. Clinically significant cancer detection rates for PI-RADS 3, 4, and 5 were 23%, 36.4%, and 52.9%, respectively. Sensitivity for detecting clinically significant cancer in PI-RADS ≥4 was 92.9% (95% CI 66.1–99.8) in the TPB group and 90.0% (95% CI 55.5–99.8) in the TRUS group. Specificity was 21.1% (TPB) and 25.0% (TRUS). PPV and NPV were 46.4% and 80.0% (TPB), and 80.0% and 50.0% (TRUS).