Rink Alexandra, Vitkin I Alex, Jaffray David A
Princess Margaret Hospital/Ontario Cancer Institute, Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9 Canada.
Med Phys. 2007 Feb;34(2):458-63. doi: 10.1118/1.2431425.
The response of radiochromic film, GafChromic EBT, was investigated for dependence on x-ray beam energy using a previously reported real-time optical readout approach. X-ray beams of energy from 75 kVp to 18 MV were employed. The dose-induced change in optical density for the EBT film was compared to values obtained for GafChromic HS and MD-55 films, exposed under the same conditions. All responses were normalized to that obtained for 60Co irradiation. While change in optical density for 1 Gy of applied dose as measured with HS and MD-55 films decreased by approximately 40% at low energies, the mean change in optical density of EBT film remained within 3% of that in the 60Co beam over the entire energy range.
使用先前报道的实时光学读出方法，研究了放射变色薄膜GafChromic EBT对X射线束能量的响应依赖性。采用了能量范围从75 kVp到18 MV的X射线束。将EBT薄膜因剂量引起的光密度变化与在相同条件下曝光的GafChromic HS和MD - 55薄膜所获得的值进行比较。所有响应均相对于60Co辐照所获得的响应进行归一化。虽然用HS和MD - 55薄膜测量的1 Gy施加剂量下的光密度变化在低能量时下降了约40%，但EBT薄膜的光密度平均变化在整个能量范围内保持在60Co束中变化的3%以内。
