MR-Linac-Guided Adaptive Radiotherapy for Brain Tumors

Over the past decade, the integration of magnetic resonance imaging (MRI) technologies into the brain radiotherapy workflow has rapidly expanded, due to increased availability and access to diagnostic and dedicated radiotherapy simulation MRI scanners. In addition to providing anatomic visualization during treatment planning, advanced MRI sequences, such as diffusion and perfusion, can be applied to investigate the physiology and metabolism of CNS tumors. Magnetic resonance-guided radiation therapy (MRgRT) provides a unique advantage by allowing daily visualization of tumors both during treatment (intrafraction) and between treatments (interfraction). This unlocks the potential to use real-time information during the treatment course to potentially affect patient outcomes. The focus of this chapter is to review the potential applications of MRgRT for brain tumors, highlighting the advantages of this technology.