A Prospective, Blinded Comparison of Magnetic Resonance (MR) Imaging–Ultrasound Fusion and Visual Estimation in the Performance of MR-targeted Prostate Biopsy: The PROFUS Trial
Mené sur 77 patients, cet essai prospectif évalue la performance d'une technique de biopsie à l'aide d'images échographiques et IRM fusionnées pour détecter un cancer de la prostate
Background : Increasing evidence supports the use of magnetic resonance (MR)–targeted prostate biopsy. The optimal method for such biopsy remains undefined, however.
Objective : To prospectively compare targeted biopsy outcomes between MR imaging (MRI)–ultrasound fusion and visual targeting.
Design, setting, and participants : From June 2012 to March 2013, prospective targeted biopsy was performed in 125 consecutive men with suspicious regions identified on prebiopsy 3-T MRI consisting of T2-weighted, diffusion-weighted, and dynamic-contrast enhanced sequences.
Intervention : Two MRI–ultrasound fusion targeted cores per target were performed by one operator using the ei-Nav|Artemis system. Targets were then blinded, and a second operator took two visually targeted cores and a 12-core biopsy.
Outcome measurements and statistical analysis : Biopsy information yield was compared between targeting techniques and to 12-core biopsy. Results were analyzed using the McNemar test. Multivariate analysis was performed using binomial logistic regression.
Results and limitations : Among 172 targets, fusion biopsy detected 55 (32.0%) cancers and 35 (20.3%) Gleason sum ≥7 cancers compared with 46 (26.7%) and 26 (15.1%), respectively, using visual targeting (p=0.1374, p=0.0523). Fusion biopsy provided informative nonbenign histology in 77 targets compared with 60 by visual (p=0.0104). Targeted biopsy detected 75.0% of all clinically significant cancers and 86.4% of Gleason sum ≥7 cancers detected on standard biopsy. On multivariate analysis, fusion performed best among smaller targets. The study is limited by lack of comparison with whole-gland specimens and sample size. Furthermore, cancer detection on visual targeting is likely higher than in community settings, where experience with this technique may be limited.
Conclusions : Fusion biopsy was more often histologically informative than visual targeting but did not increase cancer detection. A trend toward increased detection with fusion biopsy was observed across all study subsets, suggesting a need for a larger study size. Fusion targeting improved accuracy for smaller lesions. Its use may reduce the learning curve necessary for visual targeting and improve community adoption of MR-targeted biopsy.
Take Home Message : Magnetic resonance–ultrasound (MR-US)-guided biopsy improves biopsy information yield compared with visual estimation but does not improve cancer detection. MR-US guidance may have a role in biopsy of smaller targets, for which visual estimation is more complex.
European urology , résumé, 2012