Magnetic resonance imaging/ultrasound-fusion biopsy significantly upgrades prostate cancer versus systematic 12-core transrectal ultrasound biopsy

Abstract

Background: Gleason scores from standard, 12-core prostate biopsies are upgraded historically in 25-33% of patients. Multiparametric prostate magnetic resonance imaging (MP-MRI) with ultrasound (US)-targeted fusion biopsy may better sample the true gland pathology.

Objective: The rate of Gleason score upgrading from an MRI/US-fusion-guided prostate-biopsy platform is compared with a standard 12-core biopsy regimen alone.

Design, setting, and participants: There were 582 subjects enrolled from August 2007 through August 2012 in a prospective trial comparing systematic, extended 12-core transrectal ultrasound biopsies to targeted MRI/US-fusion-guided prostate biopsies performed during the same biopsy session.

Outcome measurements and statistical analysis: The highest Gleason score from each biopsy method was compared.

Interventions: An MRI/US-fusion-guided platform with electromagnetic tracking was used for the performance of the fusion-guided biopsies.

Results and limitations: A diagnosis of prostate cancer (PCa) was made in 315 (54%) of the patients. Addition of targeted biopsy led to Gleason upgrading in 81 (32%) cases. Targeted biopsy detected 67% more Gleason ≥4+3 tumors than 12-core biopsy alone and missed 36% of Gleason ≤3+4 tumors, thus mitigating the detection of lower-grade disease. Conversely, 12-core biopsy led to upgrading in 67 (26%) cases over targeted biopsy alone but only detected 8% more Gleason ≥4+3 tumors. On multivariate analysis, MP-MRI suspicion was associated with Gleason score upgrading in the targeted lesions (p<0.001). The main limitation of this study was that definitive pathology from radical prostatectomy was not available.

Conclusions: MRI/US-fusion-guided biopsy upgrades and detects PCa of higher Gleason score in 32% of patients compared with traditional 12-core biopsy alone. Targeted biopsy technique preferentially detects higher-grade PCa while missing lower-grade tumors.

Trial registration: ClinicalTrials.gov NCT00102544.

Keywords: Image-guided biopsy; Magnetic resonance imaging; Prostate cancer; Prostatic neoplasms/diagnosis; Prostatic neoplasms/pathology; Prostatic neoplasms/ultrasonography; Targeted biopsy.

Conflict of interest statement

Financial disclosures

Peter A. Pinto certifies that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: J. Kruecker is affiliated with Philips Research North America. The other authors have nothing to disclose.

Copyright © 2013. Published by Elsevier B.V.

Figures

Fig. 1

Schematic demonstrating steps to obtaining a magnetic resonance imaging/ultrasound (MRI/US)-fusion guided biopsy. ERC = endorectal coil; T2W = T2 weighted; DWI = diffusion-weighted imaging; DCE = dynamic contrast enhanced; TRUS = transrectal ultrasound; 3D = three dimensional.

Fig. 2

(a) Distribution of Gleason scores seen (a) on target biopsies for each given 12-core biopsy diagnosis and (b) on 12-core biopsy for each given target biopsy diagnosis.

Fig. 3

Distribution of cases missed by 12-core biopsy and targeted biopsy.