Chełmiński Krzysztof, Bulski Wojciech, Georg Dietmar, Bodzak Dominika, Maniakowski Zbigniew, Oborska Dominika, Rostkowska Joanna, Kania Małgorzata
Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland.
Division of Medical Radiation Physics, University of Vienna Medical School, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
Rep Pract Oncol Radiother. 2010 Mar 30;15(2):40-6. doi: 10.1016/j.rpor.2010.02.003. eCollection 2010.
The purpose of the study was to examine the energy dependence of Gafchromic EBT radiochromic dosimetry films, in order to assess their potential use in intensity-modulated radiotherapy (IMRT) verifications.
The film samples were irradiated with doses from 0.1 to 12 Gy using photon beams from the energy range 1.25 MeV to 25 MV and the film response was measured using a flat-bed scanner. The samples were scanned and the film responses for different beam energies were compared.
A high uncertainty in readout of the film response was observed for samples irradiated with doses lower than 1 Gy. The relative difference exceeds 20% for doses lower than 1 Gy while for doses over 1 Gy the measured film response differs by less than 5% for the whole examined energy range. The achieved uncertainty of the experimental procedure does not reveal any energy dependence of Gafchromic EBT film response in the investigated energy range.
Gafchromic EBT film does not show any energy dependence in the conditions typical for IMRT but the doses measured for pre-treatment plan verifications should exceed 1 Gy.
本研究旨在检测Gafchromic EBT放射变色剂量测定薄膜的能量依赖性，以评估其在调强放射治疗（IMRT）验证中的潜在用途。
使用能量范围为1.25 MeV至25 MV的光子束对薄膜样品进行0.1至12 Gy的剂量照射，并使用平板扫描仪测量薄膜响应。对样品进行扫描，并比较不同束能量下的薄膜响应。
对于剂量低于1 Gy照射的样品，观察到薄膜响应读出存在高度不确定性。剂量低于1 Gy时，相对差异超过20%，而剂量超过1 Gy时，在整个检测能量范围内，测量的薄膜响应差异小于5%。实验程序所达到的不确定性并未显示在所研究的能量范围内Gafchromic EBT薄膜响应存在任何能量依赖性。
在IMRT的典型条件下，Gafchromic EBT薄膜未显示出任何能量依赖性，但用于治疗前计划验证所测量的剂量应超过1 Gy。
