Use of a trizonal schema to assess targeting accuracy in prostatic fusion biopsy

Abstract

Objectives: To describe the use of a novel 'trizonal' biopsy schema in which 'near-target' biopsies are taken adjacent to the MRI lesion, in addition to target and systematic biopsies, to determine the accuracy of prostate MRI fusion systems. Participants and Methods: A trizonal biopsy technique was used to evaluate 75 men with small Prostate Imaging Reporting and Data System (PI-RADS) 3–5 MRI lesions (<15 mm) identified from a prospective cohort of 290 men undergoing multiparametric magnetic resonance imaging (MRI) for suspected prostate cancer at a single high-volume institution between September 2017 and May 2019. In addition to target and systematic biopsies, near-target biopsies were taken 4 mm from the apparent border of the MRI lesion. Comparisons were made between highest International Society of Urological Pathology grade and longest tumour length. Results: Fifty-three men with significant prostate cancer in the same quadrant as the target were included in the final analysis. The percentages of positive cores from target, near-target and MRI-negative zones were 66%, 39% and 17%, respectively. Significant cancer was detected in the near-target zone in 77% of cases when the target zone was positive. A total of 17% of participants were upgraded by a median (range) of 1 (1–3) grades through the addition of near-target cores. Notably, 9% of men were diagnosed with clinically significant prostate cancer solely via the near-target biopsy cores when the target cores were negative. Conclusion: The use of near-target biopsies as part of a trizonal biopsy schema provides a novel methodology to optimize clinically significant prostate cancer detection.