Initial clinical experience with real‐time transrectal ultrasonography‐magnetic resonance imaging fusion‐guided prostate biopsy

Abstract

with a commercial needle guide and custom modified with two embedded miniature orthogonal five-degrees of freedom sensors to enable spatial tracking and registration with MR images in six degrees of freedom. The MRI sequence of choice was registered manually to the US using custom software for real-time navigation and feedback. The interface displayed the actual and projected needle pathways superimposed upon the real-time US blended with the prior MR images, with position data updating in real time at 10 frames per second. The registered MRI information blended to the real-time US was available to the physician who performed targeted biopsies of highly suspicious areas. RESULTSFive patients underwent limited focal biopsy and fiducial marker placement with real-time TRUS-MRI fusion. The Gleason scores at the time of enrolment on study were 8, 7, 9, 9, and 6. Of the 11 targeted biopsies, eight showed prostate cancer. Positive biopsies were found in all patients. The entire TRUS procedure, with fusion, took ≈ 10 min. CONCLUSIONThe fusion of real-time TRUS and prior MR images of the prostate is feasible and enables MRI-guided interventions (like prostate biopsy) outside of the MRI suite. The technique allows for navigation within dynamic contrast-enhanced maps, or T2-weighted or MR spectroscopy images. This technique is a rapid way to facilitate MRIguided prostate therapies such as external beam radiation therapy, brachytherapy, cryoablation, high-intensity focused ultrasound ablation, or direct injection of agents, without the cost, throughput, or equipment compatibility issues that might arise with MRI-guided interventions inside the MRI suite.

MRI-directed cognitive fusion-guided biopsy of the anterior prostate tumors

“…Another promising technique is electronic fusion of magnetic resonance and TRUS images to guide biopsy. With this technique, software is used to coregister prior MRI data and real-time TRUS images (14). This makes use of spatial positioning sensors attached to the endorectal ultrasound probe.…”

“…Where TRUS is used to guide targeted biopsy, electronic fusion of magnetic resonance images with TRUS images can be performed to guide biopsy (14,15), or "cognitive fusion" can be used (16), by which the operator prospectively reviews the MRI appearances and uses TRUS to guide targeted sampling of the area of suspected tumor in the prostate gland.…”

MR-guided biopsy of the prostate: correlation of cancer detection rate with number of previous negative TRUS biopsies

“…Part of the solution may be to utilize MRI in routine, diagnostic imaging for patients with suspected prostate cancer. Combining MRI and real time TRUS-guided biopsy using fusion techniques in selected patients might prove to be an effective diagnostic strategy for optimizing diagnostic accuracy and cost-effectiveness (34). A recently introduced real-time MRI/US fusion technique has been reported to yield promising prostate cancer detection rates of up to 34% (35).…”

Transcranial color coded sonography: advanced approach using ultrasound fusion imaging

“…Its first clinical use was reported for analysis of lesions or tumours of the liver [3], breast [4], and prostate [5]. Since then an increasing number of reports have been published, primarily aiming to use a combined image modality approach for improvement of ultrasound-guided biopsies [6].…”