Advantages and Challenges of Magnetic Resonance Image Guidance for Radiation Therapy

Magnetic Resonance Imaging (MRI) has high soft-tissue contrast and allows for real-time imaging with no ionizing radiation dose to the patient, making it an ideal modality for monitoring patient organ and tumor motion during radiation therapy treatments. However, MRI requires a high-strength, highly homogeneous magnetic field, which is difficult to achieve in proximity to medical linear accelerators, which produce electromagnetic fields of their own and are often in motion during treatment. The result of this pairing is that MRI-guided radiation therapy faces unique challenges and tradeoffs between imaging and treatment capabilities. This talk provides an overview of the complications that arise when combining these two technologies as well as the advantages that make it worth the effort, with a focus on our experience with the Viewray MRIdian platform at New York Presbyterian Hospital.