Dosimetry in the presence of strong magnetic fields

[摘要] Magnetic resonance imaging-guided radiotherapy (MRIgRT) is an emerging technology that requires the use of radiation fields in the presence of magnetic (B) fields. In the presence of B-fields the Lorentz force influences the trajectories of the secondary electrons, which in turn affects both the dose distribution in water and the dose-response of ionization chambers and several other detectors. Thus, dosimetry in the presence of a B-field requires understanding both the B-field effects on the dose distribution and the response of detectors. In this paper we present measured data to show effects of the B-field on the dose distributions, response of ionization chambers, and presence of air-gaps surrounding the sensitive volume of the detector.

[发布机构] Department of Radiation Physics, University of Texas, MD Anderson Cancer Center, Houston; TX; 77030, United States^1;Elekta Software, Elekta A. B., Maryland Heights; MO; 63043, United States^2

[关键词] Air-gaps;Dose distributions;Dose response;Emerging technologies;Radiation field;Secondary electrons;Sensitive volume;Strong magnetic fields