Experimental Analysis of Advanced Radiotherapy Dosimetry

描述(申请人提供)：本项目的总体目标是了解非平凡的系统误差在基于多叶准直器(MLC)的兆伏(MV)光子束强度调制放射治疗(IMRI-)传输和剂量计算的总体精度中的作用。根据我们的初步数据，在调强放射治疗的实施和计划计算中存在着相当大的系统误差，并且有可能在临床上产生显著的误差。提出了基于静态和动态MLC的调强放射治疗的完整实验特征。这一实验特征包括使用一种新型的辐射变色胶片剂量成像系统同时准确地测量调强放射治疗产生的剂量分布，以及使用高速闪烁摄像系统来测量传输场的形状和通量。这项工作的结果将提供不同误差源的重要性排名，以制定将IMRT交付错误降至最低的策略。来自该特征的数据将允许通过将这些测量参数的反馈纳入治疗规划算法来补偿机械对准和剂量传递误差。从这一优势出发，将评估调强放射治疗剂量计算算法的准确性。这项工作的结果将为结束临床治疗计划系统和MLC调强放疗交付系统之间的循环提供一个范例。

DESCRIPTION (provided by applicant): The overall aim of this project is to understand the role of nontrivial systematic errors in the overall accuracy of multileaf collimator (MLC) -based megavoltage (MV) photon-beam intensity modulated radiation therapy (IMRI-) delivery and dose calculation. According to our preliminary data, nontrivial systematic errors in IMRT delivery and plan calculation exist with significant frequency and have the potential to conspire to be clinically significant. A complete experimental characterization of static and dynamic MLC-based IMRT delivery is proposed. This experimental characterization includes the accurate simultaneous measurement of the dose distributions produced by IMRT using a novel radiochromic film dose-imaging system, and the delivered field shapes and fluences using a high-speed scintillation camera system. Results from this work will provide a ranking of the importance of the different sources of error for the development of strategies to minimize IMRT delivery errors. The data from this characterization will allow mechanical misalignment and dose delivery errors to be compensated for by incorporating the feedback of these measured parameters into a treatment-planning algorithm. From this vantage, the accuracy of the IMRT dose calculational algorithms will be assessed. Results from this work will provide a paradigm for closing the loop between the clinical treatment planning system and the MLC IMRT delivery system.