MRI GUIDED RADIATION THERAPY

Introduction: Radiation therapy (RT) remains to be one of the mainstays in the treatment of cancer. Recently many efforts have been made to integrate MRI into clinical RT planning and monitoring. This integration is known as MRI-guided radiotherapy. MRI-guided RT includes superior soft-tissue contrast, organ motion visualization. This recent advance is able to monitor tumor and tissue physiologic changes by the use of MRI compared with other modalities such as computed tomography. One of the common modalities used among these is Offline MRI which is already in use at many institutions. But further, MRI-guided linear accelerator systems allow the use of MRI during treatment as well, which has the advantage of improved adaptation to anatomic changes between RT fractions. Such a development in MRI guidance provides the basis for a paradigm change in treatment planning, monitoring, and adaptation. The major changes include real-time volumetric anatomic imaging, reproducible quantitative imaging across different MRI systems, and biologic validation of quantitative imaging, as well as addressing the disadvantage of image distortion because of magnetic field inhomogeneities.

Aim of the Study: This review describes promising inventions in offline and online MRI-guided RT and further opportunities they offer for advancing research and clinical care, including various hurdles to be overcome and the need for a multidisciplinary approach for the same.

Methodology: The review is all-inclusive research of PUBMED since the year 2011 to 2021

Conclusion: MRI-guided radiation therapy (RT) can be the next big step in RT, overcoming various disadvantages of CT guidance and offering better opportunities for the treatment of cancer. There is an improved interaction and intrafraction adaptation, dose accumulation mapping, and the use of MRI biomarkers. This kind of advancement needs a multidisciplinary approach with strong collaboration among radiologists, radiation oncologists, physicists, other imaging researchers, engineers, and data scientists. This collaboration and multidisciplinary clinical research in advanced clinical radiation oncology may provide an efficient result in treatment outcomes. The MRI-guided Linear Accelerator Consortium can be proven as an ideal platform to validate the potential benefits of MRI-guided RT.

Keywords: Magnetic resonance imaging; MR-guided radiation therapy; radiation oncology; radiation oncology imaging.