Evaluation of the MIM SymphonyTM Predictive Fusion Registration Methodology for HDR Prostate Brachytherapy

Abstract

Traditionally, radiotherapy for prostate cancer involves irradiation of the entire gland to the prescription dose. In recent years, interest has mounted in instead pursuing focal therapy, to either boost the lesions of disease within the prostate to a higher dose than the rest of the gland or to exclusively treat these disease sites. Such a treatment strategy is an ideal setting for the use of high-dose-rate (HDR) prostate brachytherapy, which allows precise dose targeting. Visualization of these lesions, however, is not feasible on ultrasound during transrectal ultrasound (TRUS)-guided HDR brachytherapy procedures. Focal therapy therefore relies on the registration of a pretreatment magnetic resonance image (MRI) to the TRUS image to define the lesions. The accuracy of this registration will be paramount to the success of the treatment. Many different registration algorithms have recently been introduced to fuse the MRI and the TRUS, including both rigid and deformable solutions. In this study, we evaluate the MIM SymphonyTM predictive fusion workflow in combination with several registration algorithms to determine the optimal workflow for MRI-TRUS fusion for HDR prostate brachytherapy at our centre.