Development and characterization of a three-dimensional film stack dosimeter

7th International Conference on 3D Radiation Dosimetry

McCaw, T.J.^1 ; Micka, J.A.^1 ; DeWerd, L.A.^1

Department of Medical Physics, University of Wisconsin, Madison, WI 53705, United States^1

关键词: Depth dose measurements;    Energy dependence;    External beam radiotherapy;    Measurement uncertainty;    Measurement volume;    Orientation dependence;    Thermoluminescent dosimeters;    Three-dimensional (3D) films;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012018/pdf
DOI  :  10.1088/1742-6596/444/1/012018

来源: IOP

【 摘 要 】

A three-dimensional (3D) film stack dosimeter (FSD) using Gafchromic® EBT2 film was characterized for use in external-beam radiotherapy. The FSD was found to have negligible energy dependence and orientation dependence less than 2% using Monte Carlo simulations. Percent-depth-dose measurements with the FSD aligned parallel and perpendicular to the beam axis agreed with Monte Carlo simulations within 2%. Measurements of a60Co slit field with the FSD and thermoluminescent dosimeters agreed with a gamma passing rate of 97.6% using 1.5%/1.5 mm criteria. Edge artifacts were smaller than 2 mm, minimally affecting the usable measurement volume. The FSD is water equivalent, energy independent and orientation independent within measurement uncertainty at60Co energies, providing a 3D dosimeter that can be analyzed with a desktop scanner.