Devic Slobodan, Seuntjens Jan, Sham Edwin, Podgorsak Ervin B, Schmidtlein C Ross, Kirov Assen S, Soares Christopher G
Medical Physics Department, McGill University Health Centre, Montréal, Québec H3G 1A4, Canada.
Memorial Sloan-Kettering Cancer Center, New York, New York.
Med Phys. 2005 Jul;32(7Part1):2245-2253. doi: 10.1118/1.1929253.
In this study, a measurement protocol is presented that improves the precision of dose measurements using a flat-bed document scanner in conjunction with two new GafChromic® film models, HS and Prototype A EBT exposed to 6MV photon beams. We established two sources of uncertainties in dose measurements, governed by measurement and calibration curve fit parameters contributions. We have quantitatively assessed the influence of different steps in the protocol on the overall dose measurement uncertainty. Applying the protocol described in this paper on the Agfa Arcus II flat-bed document scanner, the overall one-sigma dose measurement uncertainty for an uniform field amounts to 2% or less for doses above around 0.4Gy in the case of the EBT (Prototype A), and for doses above 5Gy in the case of the HS model GafChromic® film using a region of interest 2×2mm2 in size.
在本研究中，提出了一种测量方案，该方案结合两种新型GafChromic® 胶片型号HS和原型A EBT，在6MV光子束照射下，利用平板文档扫描仪提高剂量测量的精度。我们确定了剂量测量中的两个不确定度来源，它们由测量和校准曲线拟合参数的贡献决定。我们已经定量评估了该方案中不同步骤对总体剂量测量不确定度的影响。将本文所述方案应用于爱克发Arcus II平板文档扫描仪，对于EBT（原型A）胶片，在剂量高于约0.4Gy时，对于大小为2×2mm2的感兴趣区域，均匀野的总体单标准差剂量测量不确定度为2%或更低；对于HS型号的GafChromic® 胶片，在剂量高于5Gy时也是如此。
