Abstract：
Purpose: This study aims to develop a data-collecting package ExpressMLC and investigate the applicability of MapCHECK2 for multileaf collimator (MLC) modeling and commissioning for complex radiation treatment plans. Materials and methods: The MLC model incorporates realistic parameters to account for sophisticated MLC features. A set of 8 single-beam plans, denoted by ExpressMLC, is created for the determination of parameters. For the commissioning of the MLC model, 4 intensity modulated radiation therapy (IMRT) plans specified by the AAPM TG 119 report were transferred to a computed tomography study of MapCHECK2, recalculated, and compared to measurements on a Varian accelerator. Both per-beam and composite-beam dose verification were conducted. Results: Through sufficient characterization of the MLC model, under 3%/2 mm and 2%/2 mm criteria, MapCHECK2 can be used to accurately verify per beam dose with gamma passing rate better than 90.9% and 89.3%, respectively, while the Gafchromic EBT3 films can achieve gamma passing rate better than 89.3% and 85.7%, respectively. Under the same criteria, MapCHECK2 can achieve composite beam dose verification with a gamma passing rate better than 95.9% and 90.3%, while the Gafchromic EBT3 films can achieve a gamma passing rate better than 96.1% and 91.8%; the p-value from the Mann Whitney test between gamma passing rates of the per beam dose verification using full MapCHECK2 package calibrated MLC model and film calibrated MLC model is .44 and .47, respectively; the p-value between those of the true composite beam dose verification is .62 and .36, respectively. Conclusion: It is confirmed that the 2-dimensional (2D) diode array MapCHECK2 can be used for data collection for MLC modeling with the combination of the ExpressMLC package of plans, whose doses are sufficient for the determination of MLC parameters. It could be a fitting alternative to films to boost the efficiency of MLC modeling and commissioning without sacrificing accuracy.
摘要：
目的：本研究旨在开发一个数据收集包ExpressMLC，并研究MapCHECK2用于多叶准直器（MLC）建模和调试复杂放射治疗计划的适用性。材料和方法:MLC模型包含现实参数以考虑复杂的MLC特征。一套8个单光束计划，用ExpressMLC表示，是为确定参数而创建的。对于MLC模型的调试，AAPMTG119报告指定的4个强度调制放射治疗（IMRT）计划被转移到MapCHECK2的计算机断层扫描研究中，重新计算，并与瓦里安加速器上的测量结果进行了比较。进行了每束和复合束剂量验证。结果：通过对MLC模型的充分表征，在3%/2毫米和2%/2毫米标准下，MapCHECK2可用于精确验证每束剂量，伽马通过率优于90.9%和89.3%，分别,而GafchromeEBT3薄膜可以达到优于89.3%和85.7%的γ通过率，分别。在同样的标准下,MapCHECK2可以实现复合束剂量验证，伽马通过率优于95.9%和90.3%，而GafchromeEBT3薄膜可以达到优于96.1％和91.8％的伽马通过率；使用完整的MapCHECK2包装校准的MLC模型和胶片校准的MLC模型进行的每束剂量验证的伽马通过率之间的MannWhitney测试的p值分别为.44和.47；真实复合束剂量验证之间的p值分别为.62和.36。结论：证实了二维（2D）二极管阵列MapCHECK2可用于MLC建模的数据收集，与ExpressMLC软件包的计划相结合，其剂量足以确定MLC参数。它可以是薄膜的合适替代方案，可以在不牺牲精度的情况下提高MLC建模和调试的效率。
