Perilesional Biopsy in-Systematic Out? Comparative Analysis of Targeted, Perilesional, and Systematic Core Yield by...

To characterize prostate cancer (Pca) detection rates by Gleason Grade Group (GG) in targeted, perilesional, and systematic cores sampling the remaining prostate using robotic-assisted transperineal magnetic resonance imaging (MRI) /ultrasound fusion biopsy (RA-TP-FBx), enabling precise spatial documentation of every core relative to MRI-lesions and the prostate.

We analyzed prospectively collected RA-TP-FBx cases between 2020 and 2024. Biopsies were performed with the iSR'obot Mona Lisa (Biobot). Sampling included a traditional targeted + systematic strategy and a Trizonal approach: targeted + perilesional + systematic. Perilesional cores were defined at biopsy as samples within 10 mm of the MRI-lesion margin and systematic cores as samples outside the targeted-perilesional areas. Individualized 3D prostate maps were correlated with per-core histopathology. Clinically significant PCa (csPCa) was defined as GG ≥ 2.

The full cohort included 566 RA-TP-FBx cases. Diagnosis of csPCa (n=131 in the Trizonal cohort) was exclusively due to perilesional sampling in 6.1% (8/131). Systematic biopsy detected csPCa not captured by targeted or perilesional cores in 3.8% (5/131), but only 1.5% (2/131) originated from MRI-negative lobes. Overdetection of GG 1 (n = 58 in the Trizonal cohort) would be reduced by 24.1% (14/58) by omitting systematic cores when targeted and perilesional cores were negative.

Robotic-assisted mapping demonstrated that perilesional sampling effectively complemented targeted biopsy, while systematic cores yielded minimal additional csPCa detection but increased GG 1 overdetection. These data support adopting targeted + perilesional sampling and omitting or deintensifying the routine addition of systematic cores in the remaining prostate.