The Role of MR-Guided Radiation Therapy in the Management of Liver Malignancies

Radiation therapy (RT) has continued to be a mainstay of treatment for cancer, serving as either an alternative or adjunct to chemotherapy and surgery. While computerized tomography (CT) has traditionally been used as the imaging for RT, magnetic resonance-guided RT (MRgRT) has emerged as a novel treatment method with many advantages over CT. A shortened list includes providing superior localization of the tumor and surrounding organs, enabling on-table adaptation of patient treatment plans, and allowing for dose escalation to the target of interest. As with any novel treatment, there is a learning curve in using the available platforms—ViewRay MRIdian system and the Elekta Unity system. There are also specifications regarding dosing, organs at risk, contouring, target volumes, and on-table adaptation that have to be further delineated to account for the different technology and the specific target organ—the liver. While future studies must be conducted to validate current findings, previously published studies have shown varying levels of success with MRgRT and promise a bright future for the technology. In this review, the authors present an overview for clinicians describing MRgRT, its advantages, specifications, and its clinical implications.