MR-targeted TRUS prostate biopsy using local reference augmentation: initial experience.

Wendy J M Van De Ven,Henkjan J Huisman,Jeroen Veltman,Erik B Cornel,Jurgen J Fütterer,J P Michiel Sedelaar,Wulphert Venderink,Jelle O Barentsz

doi:10.1007/s11255-016-1283-2

Abstract

Purpose To evaluate MR-targeted TRUS prostate biopsy using a novel local reference augmentation method.Patients and methodsTracker-based MR–TRUS fusion was applied using local reference augmentation. In contrast to conventional whole gland fusion, local reference augmentation focuses the highest registration accuracy to the region surrounding the lesion to be biopsied. Pre-acquired multi-parametric MR images (mpMRI) were evaluated using PIRADS classification. T2-weighted MR images were imported on an ultrasound machine to allow for MR–TRUS fusion. Biopsies were targeted to the most suspicious lesion area identified on mpMRI. Each target was biopsied 1–5 times. For each biopsied lesion the diameter, PIRADS and Gleason scores, visibility during fusion, and representativeness were recorded.ResultsIncluded were 23 consecutive patients with 25 MR suspicious lesions, of which 11 patients had a previous negative TRUS-guided biopsy and 12 were biopsy naïve. The cancer detection rate was 64 % (Gleason score ≥6). Biopsy was negative (i.e., no Gleason score) in seven patients confirmed by follow-up in all of them (up to 18 months). After MR–TRUS fusion, 88 % of the lesions could be visualized on TRUS. The cancer detection rate increases with increasing lesion size, being 73 % for lesions larger than 10 mm.ConclusionTracker-based MR–TRUS fusion biopsy with local reference augmentation is feasible, especially for lesions with an MR maximum diameter of at least 10 mm or PIRADS 5 lesions. If this is not the case, we recommend in-bore MR-guided biopsy.

Highlights

An elevated or rising PSA followed by systematic transrectal ultrasound (TRUS)-guided biopsy (USgBx) is the currently internationally accepted diagnostic procedure to detect prostate cancer and determine patient management [1]
We propose a novel protocol to augment the accuracy locally by selecting reference landmarks on both MR and TRUS images that are close to the biopsy target [21], which we refer to as local reference augmentation in analogy to all-weather aircraft landing systems
During MR–TRUS fusion, 88 % of the lesions could be visualized on TRUS alone, allowing targeted biopsies to be optimized using live TRUS guidance

Summary

Introduction

An elevated or rising PSA followed by systematic (on average 12 core) transrectal ultrasound (TRUS)-guided biopsy (USgBx) is the currently internationally accepted diagnostic procedure to detect prostate cancer and determine patient management [1]. USgBx has a low sensitivity (40 %) [2,3,4], causing three problems: (1) Significant cancers can be missed or underestimated; (2) there is unnecessary overtreatment due to overdiagnosis [5,6,7]; and (3) it may lead to repeat biopsies inducing increased infection rates [8]. In-bore MR-guided MR biopsy (MRgMRBx) has been shown to (1) reduce the detection of low-risk cancer and (2) increase the detection rate of intermediate- and high-risk cancer, while using fewer cores [11]. The associated cost, relative complexity, and inconvenience of MRgMRBx may

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