Strengthening the Field: Estimating Ontario's MR Simulation Requirements Using RT-QBP Data

Abstract

Purpose/Aim

The use of magnetic resonance simulation (MR-SIM) in Radiation Therapy has increased over the last decade, however there is significant variation in access across the province. MR-SIM is an evolving strategy in radiation treatment planning, deemed essential for some disease sites while not adding value in others. Ontario Health (Cancer Care Ontario) initiated a project to determine when MR-SIM is most beneficial based on clinician feedback identifying disease site groups and specific Radiation Treatment Quality Based Protocols that will benefit from MR-SIM.

Methods/Process

Since the implementation of Radiation Treatment-Quality Based Procedures (RT-QBP) funding in 2019, the Radiation Treatment Program (RTP) at Ontario Health (Cancer Care Ontario) has been receiving protocol level information on every patient receiving radiation treatment in Ontario. RT-QBP data includes significant amounts of information including but not limited to disease site groups, sub-groups, intent (primary or metastatic), treatment modality (external beam, brachytherapy etc.), and even dose and fractionation. In March 2024, RT-QBP protocol lists were shared with various disease site experts to identify protocols that would require or benefit from MR-SIM.

Results or Benefits/Challenges

Upon review of RT-QBP protocols by disease site experts, the top 5 sites that benefit from MR-SIM include Head and Neck, Sarcoma, Central Nervous System, Gynecology and Genitourinary. The percentage of protocols that benefit ranged from 73% to 94%. Currently 4 of 16 radiation treatment facilities in the province have access to dedicated MR-SIM with the remaining sites gaining access through Diagnostic Imaging in various capacities, demonstrating the need for a strategic plan to ensure equitable access to aid improved accuracy in radiation treatment planning. This plan may include increasing MR-SIM access for centres with higher volumes or a shared resource approach for smaller centres that may not be able to fully utilize the capacity on MR-SIM. This work requires support from multiple programs and interprofessional partners.

Conclusions/Impact

This work may lead to new quality indicators for Radiation Therapy treatment, with MR-SIM being one of many possible quality indicators for treatment. A refined approach is necessary to determine the next steps. However, the impact of increasing access to MR-SIM for patients is far reaching and the implementation of RT-QBP reporting can be leveraged to streamline the approach.