Assessment of the Minimal Targeted Biopsy Core Number per MRI Lesion for Improving Prostate Cancer Grading Prediction.

Guillaume Ploussard,Jean-Baptiste Beauval,Guillaume Loison,Michel Soulié,Mathieu Roumiguié,Christophe Almeras,Cécile Manceau,Bernard Malavaud,Marine Lesourd,Ambroise Salin,Jean-Romain Gautier,Daniel Portalez,Christophe Tollon,Raphaële Renard-Penna

doi:10.3390/jcm9010225

Abstract

Background: To study the impact of MRI characteristics and of targeted biopsy (TB) core number on the final grade group (GG) prediction. Materials and Methods: The cohort was 478 consecutive patients who underwent radical prostatectomy (RP) after positive mpMRI (multiparametric magnetic resonance imaging) followed by fusion TB. Endpoints were the upgrading and concordance rates between TB and RP specimens. Results: Upgrading rate after TB was 40.6%. Patients with upgrading had lower PIRADS (Prostate Imaging-Reporting and Data System) scores (p < 0.001), smaller lesion size (p = 0.017), fewer TB cores (p < 0.001), and lower TB density (p = 0.015) compared with cases with grade concordance. There was a significant continuous improvement in upgrading rate when TB core number per lesion increased from 56.3% to 25.6% when <2 or ≥5 TB cores were taken, respectively (p = 0.002). The minimal TB number per lesion to reduce upgrading risk to approximately 30%was 4 in PIRADS 3, and 3 in PIRADS 4–5 cases. Conclusions: Grade group prediction by TB is significantly improved by higher PIRADS score, larger lesion size, and increased TB per lesion. At least four TB cores should be taken in PIRADS 3 score lesions, whereas three cores seem enough in PIRADS 4–5 cases to improve GG prediction and limit upgrading risk.

Highlights

Actual prostate cancer guidelines recommend the realization of a multiparametric MRI prior to biopsies [1,2,3,4,5]
How many targeted biopsy (TB) cores should be taken per lesion to reduce the risk of upgrading? How do MRI characteristics (PIRADS score, maximum diameter of lesions, number of lesions) and the concomitant realization of systematic biopsy (SB) impact this TB core number? Given the lack of evidence answering these daily practice questions, we aimed to assess the impact of MRI characteristics, and TB core number on final grade group (GG) prediction and upgrading risk in this cohort of consecutive patients undergoing radical prostatectomy (RP) after software-based elastic fusion TB
Does the TB core number impact on this upgrading rate? We found an incremental utility of performing additional TB cores for improving grading prediction and reducing the risk of upgrading

Summary

Introduction

Actual prostate cancer guidelines recommend the realization of a multiparametric MRI prior to biopsies [1,2,3,4,5]. The minimal TB core number to be taken could be modified according to the MRI characteristics of the lesion in terms of PIRADS (Prostate Imaging-Reporting and Data System) score and number, location, and size of visible lesions, and these stratifications have not been thoroughly evaluated [8]. To study the impact of MRI characteristics and of targeted biopsy (TB) core number on the final grade group (GG) prediction. Patients with upgrading had lower PIRADS (Prostate Imaging-Reporting and Data System) scores (p < 0.001), smaller lesion size (p = 0.017), fewer TB cores (p < 0.001), and lower TB density (p = 0.015) compared with cases with grade concordance. At least four TB cores should be taken in PIRADS 3 score lesions, whereas three cores seem enough in PIRADS 4–5 cases to improve GG prediction and limit upgrading risk

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