Characterization and use of EBT radiochromic film for IMRT dose verification
Characterization and use of EBT radiochromic film for IMRT dose verification
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DOI：
10.1118/1.2360012
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发表时间：
2006-11-01
期刊：
影响因子：
3.8
通讯作者：
Langen, Katja M.
中科院分区：
文献类型：
--
作者：
Zeidan, Omar A.;Stephenson, Stacy Ann L.;Langen, Katja M.
我们对一种新型改进型放射变色薄膜（EBT 型）进行了评估，以实现 IMRT 剂量验证。使用特征化的平板彩色 CCD 扫描仪，该胶片的剂量灵敏度、均匀性和曝光后显影速度均优于以前类型的放射变色胶片。通过比较深度剂量和横向剂量分布，发现该胶片的剂量响应与水中离子室扫描非常相似。 EBT 胶片偏振对输送剂量和胶片扫描方向的影响对扫描仪的 OD 读数有显着影响。此外，该薄膜的大尺寸、柔韧性以及能够在相对较短的时间内浸入水中的能力使其能够在水和固体水体模中使用，以验证平面和弯曲剂量平面上的 TomoTherapy IMRT 剂量分布。通过将测得的 EBT 剂量分布与 TomoTherapy 治疗计划系统计算的剂量进行比较，对 10 个 IMRT 计划（5 个头颈和 5 个前列腺）进行了 2D 剂量验证。一致性质量通过四组剂量差异和一致性标准距离的伽玛指数进行量化。基于这项研究，我们表明 EBT 胶片具有几个有利的特性，可用于常规 IMRT 患者特定的 QA。 (c) 2006 年美国医学物理学家协会。
We present an evaluation of a new and improved radiochromic film, type EBT, for its implementation to IMRT dose verification. Using a characterized flat bed color CCD scanner, the film's dose sensitivity, uniformity, and speed of development post exposure were shown to be superior to previous types of radiochromic films. The film's dose response was found to be very similar to ion chamber scans in water through comparisons of depth dose and lateral dose profiles. The effect of EBT film polarization with delivered dose and film scan orientation was shown to have a significant effect on the scanner's OD readout. In addition, the film's large size, flexibility, and the ability to submerge it in water for relatively short periods of time allowed for its use in both water and solid water phantoms to verify TomoTherapy IMRT dose distributions in flat and curved dose planes. Dose verification in 2D was performed on ten IMRT plans (five head and neck and five prostate) by comparing measured EBT dose distributions to TomoTherapy treatment planning system calculated dose. The quality of agreement was quantified by the gamma index for four sets of dose difference and distance to agreement criteria. Based on this study, we show that EBT film has several favorable features that allow for its use in routine IMRT patient-specific QA. (c) 2006 American Association of Physicists in Medicine.