First 3D measurements of proton beams in a deformable silicone-based dosimeter

9th International Conference on 3D Radiation Dosimetry

Høye, E.M.^1 ; Sadel, M.^2 ; Kaplan, L.^2 ; Skyt, P.S.^1 ; Muren, L.P.^1 ; Petersen, J.B.B.^1 ; Swako, J.^3 ; Mierzwiska, G.^3 ; Rydygier, M.^3 ; Malinowski, L.^3 ; Balling, P.^2

Department of Medical Physics, Aarhus University Hospital, Denmark^1

Department of Physics and Astronomy, Aarhus University, Denmark^2

Institute of Nuclear Physics, Polish Academy of Sciences, Poland^3

关键词: 3-D measurement;    Deformation properties;    Entrance region;    High resolution;    Linear energy transfer;    Optical measurement;    Proton treatment;    Spread out Bragg peaks;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/847/1/012021/pdf
DOI  :  10.1088/1742-6596/847/1/012021

来源: IOP

【 摘 要 】

3D dosimetry provides high-resolution dose information of radiation therapy (RT), and is explored to enable and secure high-quality delivery of advanced RT modalities, including proton therapy. We present the first 3D measurements of spot-scanning proton plans in a silicone-based, radiochromic dosimeter with deformation properties. The dose information was read-out by optical CT-scanning. We found that the dosimeter signal was quenched close to the Bragg peak, and that this had a large impact on a measured spread-out Bragg peak. The dose response was linear both in the entrance region and in the Bragg peak, however, the dose response significantly reduced in the Bragg peak. Quenching was attributed to a linear-energy-transfer dependent dose response. Linear energy transfer distributions for each proton treatment plan will provide a means for calibrating the optical measurement to linear energy transfer, as well as dose. This might enable use of the silicone-dosimeter in quality assurance of proton beams.