How many cores are enough? Optimizing the transperineal prostate biopsy template

Area of Science:

• Urology
• Oncology
• Medical Imaging

Background:

• Transrectal ultrasound guided prostate biopsy (TRUS-B) typically uses 10-12 cores.
• A standardized template for transperineal prostate biopsy (TP-B) is lacking.
• Optimal core number and location for TP-B require investigation.

Purpose of the Study:

• To develop an optimal systematic biopsy template for TP-B.
• To compare cancer detection rates between different core numbers in TP-B.
• To evaluate TP-B template effectiveness against TRUS-B.

Main Methods:

• Prospective analysis of 200 free-hand TP-B procedures with 20 cores each.
• Systematic breakdown of 20-core TP-B into 10, 12, and 16 core templates for comparison.
• Comparison of Grade Group (GG) detection, focusing on clinically significant cancer (≥GG2).
• Subgroup analyses including biopsy-naïve men and PSA density stratification.
• Comparison with an historic cohort of 10-12 core TRUS-B.

Main Results:

• 20-core TP-B detected clinically significant cancer in 49% of men.
• 12 and 16 core templates showed similar detection rates to 20 cores (46% and 47%).
• 20 cores detected more clinically significant cancers than 10 cores (49% vs. 41%, P=0.02).
• Higher core numbers did not increase GG1 detection but improved detection of ≥GG2 cancers.
• 12-core TP-B detected more cancers than 12-core TRUS-B (46% vs. 38%, P<0.001).

Conclusions:

• A 20-core TP-B template detected more clinically significant prostate cancers than a 10-core template.
• Cancer detection rates were comparable for 12, 16, and 20 core TP-B templates.
• A minimum of 12 cores is proposed for systematic TP-B to optimize detection of clinically significant prostate cancer.