Knutson Nels C, Schmidt Matthew C, Belley Matthew D, Nguyen Ngoc, Price Michael, Mutic Sasa, Sajo Erno, Li H Harold
Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
Medical Physics Program, University of Massachusetts Lowell, Lowell, MA, 01852, USA.
J Appl Clin Med Phys. 2018 Nov;19(6):60-67. doi: 10.1002/acm2.12444. Epub 2018 Sep 6.
This work shows the feasibility of collecting linear accelerator beam data using just a 1-D water tank and automated couch movements with the goal to maximize the cost effectiveness in resource-limited clinical settings. Two commissioning datasets were acquired: (a) using a standard of practice 3D water tank scanning system (3DS) and (b) using a novel technique to translate a commercial TG-51 complaint 1D water tank via automated couch movements (1DS). The Extensible Markup Language (XML) was used to dynamically move the linear accelerator couch position (and thus the 1D tank) during radiation delivery for the acquisition of inline, crossline, and diagonal profiles. Both the 1DS and 3DS datasets were used to generate beam models (BM and BM ) in a commercial treatment planning system (TPS). 98.7% of 1DS measured points had a gamma value (2%/2 mm) < 1 when compared with the 3DS. Static jaw defined field and dynamic MLC field dose distribution comparisons for the TPS beam models BM and BM had 3D gamma values (2%/2 mm) < 1 for all 24,900,000 data points tested and >99.5% pass rate with gamma value (1%/1 mm) < 1. In conclusion, automated couch motions and a 1D scanning tank were used to collect commissioning beam data with accuracy comparable to traditionally acquired data using a 3D scanning system. TPS beam models generated directly from 1DS measured data were clinically equivalent to a model derived from 3DS data.
这项工作展示了仅使用一维水箱和自动治疗床移动来收集直线加速器束流数据的可行性，目的是在资源有限的临床环境中实现成本效益最大化。获取了两个调试验证数据集：(a) 使用标准的三维水箱扫描系统 (3DS)，以及 (b) 使用一种新技术，通过自动治疗床移动来平移符合商业TG-51标准的一维水箱 (1DS)。在放射治疗过程中，使用可扩展标记语言 (XML) 动态移动直线加速器治疗床位置（从而移动一维水箱），以获取轴向、横向和对角线剂量分布曲线。1DS和3DS数据集均用于在商业治疗计划系统 (TPS) 中生成束流模型 (BM 和BM )。与3DS相比，1DS测量点中有98.7% 的伽马值（2%/2毫米）<1。TPS束流模型BM 和BM 的静态准直器界定野和动态多叶准直器野剂量分布比较中，对于所有测试的24900000个数据点，三维伽马值（2%/2毫米）<1，伽马值（1%/1毫米）<1时的通过率>99.5%。总之，自动治疗床移动和一维扫描水箱用于收集调试验证束流数据，其准确性与使用三维扫描系统传统获取的数据相当。直接从1DS测量数据生成的TPS束流模型在临床上等同于从3DS数据导出的模型。
