Dosimetry in the presence of strong magnetic fields

9th International Conference on 3D Radiation Dosimetry

O'Brien, D.J.^1 ; Schupp, N.^2 ; Pencea, S.^2 ; Dolan, J.^1,2 ; Sawakuchi, G.O.^1

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;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/847/1/012055/pdf
DOI  :  10.1088/1742-6596/847/1/012055

来源: IOP

【 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.