Harms W B, Low D A, Wong J W, Purdy J A
Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, Missouri 63110, USA.
Med Phys. 1998 Oct;25(10):1830-6. doi: 10.1118/1.598363.
Current methods for evaluating modern radiation therapy treatment planning (RTP) systems include the manual superposition of calculated and measured isodose curves and the comparison of a limited number of calculated and measured point doses. Both techniques have significant limitations in providing quantitative evaluations of the large number of dose data generated by modern RTP systems. More sophisticated comparison techniques have been presented in the literature, including dose-difference and distance-to-agreement (DTA) analyses. A software tool has been developed that uses superimposed isodose plots, dose-difference, and DTA distributions to quantify errors in computed dose distributions. Dose-difference and DTA analyses are overly sensitive in regions of high- and low-dose gradient, respectively. The logical union of locations that fail both dose-difference and DTA acceptance criteria, termed the composite evaluation, is calculated and displayed. The composite evaluation provides a method for the physicist to efficiently identify regions that fail both the dose-difference and DTA acceptance criteria. The tool provides a computer platform for the quantitative comparison of calculated and measured dose distributions.
当前评估现代放射治疗治疗计划(RTP)系统的方法包括手动叠加计算出的和测量得到的等剂量曲线,以及比较有限数量的计算点剂量和测量点剂量。这两种技术在对现代RTP系统生成的大量剂量数据进行定量评估时都存在显著局限性。文献中已经提出了更复杂的比较技术,包括剂量差异分析和距离一致性(DTA)分析。已经开发出一种软件工具,该工具使用叠加的等剂量图、剂量差异和DTA分布来量化计算剂量分布中的误差。剂量差异分析和DTA分析分别在高剂量梯度和低剂量梯度区域过于敏感。计算并显示同时不符合剂量差异和DTA验收标准的位置的逻辑并集,即复合评估。复合评估为物理学家提供了一种有效识别同时不符合剂量差异和DTA验收标准的区域的方法。该工具为计算剂量分布和测量剂量分布的定量比较提供了一个计算机平台。