Fusion Target Biopsy of the Prostate Using Real-Time Ultrasound and MR Images. A Multicenter RCT on Target Biopsy Techniques in the Diagnosis of Prostate Cancer

Abstract

Background: The current standard technique for prostate cancer detection is trans-rectal ultrasound (TRUS) guided biopsy, and is renowned for its low sensitivity. Developments of multiparametric MRI techniques have increased the detection of significant prostate cancer. Currently there are three techniques utilizing MRI for targeted biopsy; MRI-TRUS fusion; ‘cognitive’ TRUS, and in-bore MRI guided biopsy. There is no consensus which should be preferred. The current study aims to compare prostate cancer detection rates of three target biopsy procedures. Methods: The FUTURE trial is a three-arm randomised controlled, multicentre trial comparing three techniques of MRI targeted biopsy of the prostate amongst subjects with one prior negative TRUS biopsy and a persisting suspicion on prostate cancer. All subjects undergo mpMRI imaging. Images will be centrally reviewed, and evaluated using the ‘Prostate imaging reporting and data system’. An estimated 69% of the subjects will demonstrate tumour suspicious findings on mpMRI, and will be randomised 1:1:1. The primary objective is to compare (significant) tumor detection rates of the three techniques. Secondary objectives include histopathological validation of mpMRI imaging and PI-RADS classification, a cost-effectiveness analysis, and follow-up after a negative mpMRI or negative target biopsy. All biopsy cores will be evaluated by one dedicated uro-pathologists per center. Two sub-investigations were based on the hypothesis that MRI-TRUS fusion and in-bore MRI biopsy demonstrate similar tumor detection, whilst MRI-TRUS fusion demonstrates increased tumor detection compared to ‘cognitive’ TRUS biopsy. A total number 466 of subjects is needed for equal randomization. Assuming that 69% of subjects have tumor suspicious findings on MRI imaging, a total of 675 subjects are required for inclusion. Discussion: For target biopsy procedures of the prostate the ultimate comparator is histopathological examination of radical prostatectomy specimens, though this leads to insurmountable ethical objections and thus to a methodological dilemma concerning validation.