ABSTRACT
The advent of magnetic resonance-guided radiation therapy (MRgRT) has introduced new considerations for the management of radiation dosimetry in the presence of a magnetic field. This chapter begins with a description of the fundamental physics interactions, such as the electron return effect and its dependencies with magnetic field strength, beam energy, and the presence of heterogeneities. The next section describes the impact of the magnetic field on dosimetry equipment such as ion chambers, film, and thermoluminescent dosimeters that may be adversely impacted and may require corrections when used in a magnetic field. New dosimetry technologies are also described. Finally, treatment planning considerations are provided along with a discussion of clinical management scenarios to highlight the major considerations when considering clinical implementation.
