Application of a PAGAT/MgCl2 gel for dose measurements in a 150 MeV proton beam

7th International Conference on 3D Radiation Dosimetry

Tominaga, T.^1 ; Hayashi, S.^1 ; Usui, S.^1 ; Kawamura, H.^2 ; Katahira, K.^3

Hiroshima International University, Department of Clinical Radiology, Higashi-Hiroshima, Hiroshima, Japan^1

Ibaraki Prefectural University of Health Sciences, Inashiki, Ibaraki, Japan^2

Hyogo Ion Beam Medical Center, Tatsuno, Hyogo, Japan^3

关键词: Clinical proton beams;    Dose measurement;    Dose sensitivity;    Inorganic salts;    Irradiation conditions;    Radiation sensitivity;    Response curves;    Spin-spin relaxation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012057/pdf
DOI  :  10.1088/1742-6596/444/1/012057

来源: IOP

【 摘 要 】

The purpose of this study is to evaluate the dose response of polyacrylamide-based gel (PAGAT) when irradiated with clinical proton beams. Recently inorganic salt additive in gel has been reported to improve dose sensitivity substantially. We attempted to add MgCl2(0.5M) to regular PAGAT gel in order to compensate its lower radiation sensitivity. The spin-spin relaxation rates (R2) as dose readout was calculated from MR imaging after irradiation with 150MeV proton beam. The dose sensitivity was discussed from the slope at dose-R2response curve. As the result, the sensitivity of the gel with MgCl2is approximately 3 times higher than that of regular PAGAT gel without spoiling dose response stability under the various irradiation conditions such as dose rate and dose integration.