Initial Experience with a Mid-Field MR Simulator

Document Type

Conference Proceeding

Publication Date

9-30-2025

Publication Title

Med Phys

Keywords

conference abstract, human, image quality, image reconstruction, immobilization device, magnet, magnetic field, MRI guided linear accelerator, MRI scanner, nuclear magnetic resonance imaging, radiotherapy, simulation, treatment planning, work environment, workflow

Abstract

The use of MRI in radiation therapy (RT) is on the rise. As a result, there is a need for the radiation therapy clinics to enhance their MRI skillset in areas pertaining to its use for treatment planning and delivery. This session will focus on the following aspects of MR guided radiation therapy (MRgRT). • Low- and mid-field MRI for MRgRT With the increase of low- and mid-field MRI use for diagnostic applications, these fields are also making their way to the radiation therapy clinics. An important aspect of using these fields is the less nuanced safety considerations, specifically for departments that rely on RadOnc professionals to run the MR machine with only limited input from Radiology colleagues. These magnets have a relatively smaller footprint and hence allow to repurpose unused MR space to perform brachy and other simulation procedures nearby. However, lower field strength also means inherently lower SNR, and hence a concern about image quality comes up. With modern technology, and the use of AI in image reconstruction, these lower field MRI platforms can produce images with clinically acceptable quality. For this part of the session, representative use cases with mid-field magnet where images with image quality comparable to that of the radiology images have been acquired, will be highlighted. Lastly, the improvement in the ability to incorporate immobilization devices with a larger bore magnet will also be highlighted. • MR safety for MRgRT There has been strong interest in integrating MRI into the radiation therapy workflow either as a stand-alone unit or in new radiation delivery technologies. MR safety is one of the major challenges in incorporating MRI in therapy since most therapy physicists are not yet accustomed to a working environment with high magnetic fields. Many medical and immobilization devices used in radiotherapy also lack clear labels regarding MR safety. The lecture in this session provides practical guidance for the physicist tasked with conducting MRI safety program as well as discusses strategies and provides guidance for establishing MR safety programs in the radiation oncology environment. • On-line adaptive with 1.5T MR-Linac (MRL) system The 1.5 Tesla MR-Linac system allows on-line adaptive RT. Recently, the system has been upgraded to include continuous motion management using MR-cine. This part of the session will focus on advancements in online adaptive RT with MRL. Learning Objectives: 1. Learn the advantages of using a low- or mid-field MR system for radiation therapy 2. Appreciate the comparability of a low- or mid-field MR system to that of typical, clinical MR system (e.g., 1.5 T) 3. Identify the safety challenges of integration of MRI into radiation therapy 4. Describe the strategies and references for establishing MR safety programs in radiotherapy 5. Identify the advancements in the field of online adaptive RT with 1.5 Tesla MRL.

Volume

52

Issue

10

First Page

18

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