Magnetic Resonance-Guided Adaptive Radiotherapy: Technical Concepts

Abstract

The excellent soft-tissue contrast of magnetic resonance (MR) images, and the speed and frequency with which the patient can be imaged, allow clear visualization of the target and nearby organs at risk at multiple time points over the course of each treatment. This imaging capability enables adaptation of the treatment plan and delivery to the patient’s anatomy throughout the treatment, which thus allows greater accuracy of dose delivery to the targets whilst sparing healthy tissue. This chapter describes the technological components required to facilitate fast, online adaptation of treatment plans, including the designs of the commercially available MR-guided adaptive radiotherapy systems, image acquisition, treatment planning and delivery, as well as the quality assurance measures put in place to ensure that these plans can be safely and accurately delivered.