Minimal Added Value of Targeted Transperineal Biopsy for Larger MRI-Detected Prostate Lesions

Overview

This study evaluated the benefit of MRI-targeted transperineal prostate biopsies compared to systematic background sector biopsies in patients with larger MRI-detected lesions. Findings suggest that for larger lesions, targeted biopsy cores provide minimal additional diagnostic value beyond standard background cores.

Background

Prostate cancer diagnosis traditionally relies on non-targeted transrectal ultrasound-guided biopsies, which have significant sampling errors and can miss up to 30% of cancers. Multi-parametric MRI (mp-MRI) has improved tumor detection and risk stratification by enabling targeted biopsies. The transperineal approach offers advantages over transrectal biopsy, including lower infection risk and better access to anterior prostate regions. However, the optimal number and type of biopsy cores, especially the added value of targeted cores for different lesion sizes, remain uncertain.

Data Highlights

Seventy-six patients with high-probability MRI lesions (Likert score 4 or 5) underwent MRI–TRUS fusion transperineal biopsy, including 24–36 background sector cores and additional targeted cores. Biopsy cores were categorized as background sector biopsy cores (BSB), target biopsy cores (TB), and target sector biopsy cores (TSB). Data collected included prostate and target volumes, core histopathology, and cancer detection rates.

Key Findings

• Targeted biopsy cores showed higher detection rates for clinically significant cancer compared to systematic cores in general.
• For larger MRI-detected lesions, targeted cores added minimal diagnostic benefit beyond standard background sector cores.
• Systematic background sector biopsies remain important to detect MRI-occult tumors and reduce false negatives.
• Increasing the number of targeted cores increases procedure time, cost, and potential morbidity without proportional diagnostic gain.
• The transperineal approach facilitates sampling of anterior and apical prostate regions with reduced infection risk.

Clinical Implications

Clinicians should consider that for larger MRI-visible prostate lesions, extensive targeted biopsies may not significantly improve cancer detection beyond systematic background cores. Balancing the number of biopsy cores is essential to minimize patient morbidity, procedure time, and healthcare costs. The transperineal approach remains advantageous for comprehensive prostate sampling, especially in challenging anatomical locations.

Conclusion

MRI-targeted transperineal biopsy adds limited value over systematic background biopsies for larger prostate lesions detected on MRI. Optimizing biopsy strategies to minimize cores while ensuring accurate diagnosis is crucial for patient care.

References

1. Ginsburg et al. 2019 -- Standards of reporting for MRI-targeted biopsy studies (START)
2. PI-RADS Steering Committee 2015 -- Prostate Imaging-Reporting and Data System