Comprehensive RT-Specific QA for MRI Simulation

MRI simulation is the process of acquiring high fidelity, high contrast resolution magnetic resonance images to identify true disease extent and proximity relative to adjacent organs at risk (OAR) for the purposes of radiation treatment planning. MRI simulation can be performed using dedicated MRI scanners in radiotherapy departments [1] or using MRI scanners sited in other departments as shared resources. As more radiotherapy departments begin incorporating MRI simulation into routine treatment planning, questions often arise regarding what level of quality assurance (QA) activities are required to maintain accuracy and avoid errors. Several well-established references from the American College of Radiology (ACR) [2-3] and American Association of Physicists in Medicine (AAPM) [4-6] provide guidance regarding acceptance testing (AT), commissioning, and routine QA of MRI scanners. However, while these manuals provide procedures and tolerances for general MRI QA, no guidance documents exist that describe the unique radiotherapyspecific QA activities that need to be considered. Radiation therapy presents a new set of challenges and places additional demands on MRI compared to diagnostic radiology that, if not properly addressed, can undermine the advantages MR images offer for treatment planning. The goal of this article is to describe a comprehen-sive MRI simulation QA program to address the RTspecific QA activities required for MRI simulation.