A Propensity Score-matched Comparison of Micro-ultrasound-guided Transrectal and Magnetic Resonance Imaging/Transrectal Ultrasound Fusion-guided Transperineal Prostate Biopsies for Detection of Clinically Significant Prostate Cancer

Abstract

Background and objective: High-resolution micro-ultrasound (microUS) is an advanced imaging tool. Our objective was to determine whether systematic microUS use for transrectal biopsy (TRBx) improves the detection rate for clinically significant prostate cancer (csPCa) in comparison to transperineal biopsy (TPBx) performed with magnetic resonance imaging (MRI)/conventional transrectal ultrasound (TRUS) fusion software.

Methods: We retrospectively analyzed data for men who underwent prostate biopsies, including those on active surveillance (AS). TRBx was performed under microUS guidance, while MRI/TRUS fusion was consistently used to guide TPBx. Patients were matched according to propensity score matching (PSM). The primary endpoint was comparison of the csPCa detection rate with the two approaches. Secondary endpoints included predictors of csPCa (International Society of Urological Pathology grade group ≥2, assessed via multivariable logistic regression) and complication rates.

Key findings and limitations: Overall, 1423 patients were enrolled. After applying PSM we identified an analytical cohort of 1094 men, 582 in the TRBx group and 512 in the TPBx group. There was no significant difference in the csPCa detection rate between the TRBx (45%) and TPBx (51%) groups (p = 0.07). Complications occurred in nine of 1094 patients (1%). On adjusted multivariable analysis, TPBx had a similar csPCa detection rate to TRBx (adjusted odds ratio [aOR] 1.26;p = 0.09). Predictors of csPCa detection were a positive family history (aOR 1.68; 95% confidence interval [CI] 1.20-2.35; p = 0.002); age (aOR 1.04, 95% CI 1.02-1.06; p < 0.001); positive digital rectal examination (aOR 2.35, 95% CI 1.70-3.25; p < 0.001); prostate-specific antigen density ≥0.15 ng/ml/cm³ (aOR 3.23, 95% CI 2.47-4.23; p < 0.001); and a Prostate Imaging-Reporting and Data System score ≥3 (aOR 2.46; 95% CI 1.83-3.32; p < 0.001). Limitations include the retrospective nature of the study, the risk of underestimating the complication rate, and the heterogeneity of biopsy indications.

Conclusions and clinical implications: TRBx using microUS alone showed a comparable csPCa detection rate to TPBx guided by MRI/TRUS fusion software. Given the better visualization and real-time detection of suspicious zones with microUS, the potential for improvement in the csPCa detection rate with greater integration of microUS in the TPBx setting warrants further investigation.

Patient summary: We compared the ability of two different prostate biopsy approaches to detect clinically significant prostate cancer. We found that transrectal biopsy guided by micro-ultrasound had similar detection rates to transperineal biopsy guided by a combination of magnetic resonance imaging and conventional ultrasound. More research is needed to confirm the potential of micro-ultrasound for transperineal biopsy.

Keywords: Diagnosis, Micro-ultrasound; Magnetic resonance imaging; Multiparametric; Prostate biopsy; Transrectal ultrasound.