ACRF Image X Institute, Central Clinical School, The University of Sydney, Sydney, NSW, Australia.
Phys Med Biol. 2019 May 21;64(10):105021. doi: 10.1088/1361-6560/ab1935.
In this study we develop and characterise a six degree-of-freedom (6 DoF) robotic motion system for quality assurance of real-time image-guided radiotherapy techniques. The system consists of a commercially available robotic arm, an acrylic phantom with embedded Calypso markers, a custom base plate to mount the robot to the treatment couch, and control software implementing the appropriate sequence of transformations to reproduce measured tumour motion traces. The robotic motion system was evaluated in terms of the set-up and motion trace repeatability, static localization accuracy and dynamic localization accuracy. Four prostate, two liver and three lung motion traces, representing a range of tumor motion trajectories recorded in real patient treatments, were executed using the robotic motion system and compared with motion measurements from the clinical Calypso motion tracking system. System set-up and motion trace repeatability was better than 0.5 deg and 0.3 mm for rotation and translation, respectively. The static localization accuracy of the robotic motion system in the LR, SI and AP directions was 0.09 mm, 0.08 mm and 0.02 mm for translations, respectively, and 0.2°, 0.06° and 0.06° for rotations, respectively. The dynamic localization accuracy of the robotic motion system was <0.2 mm and <0.6° for translations and rotations, respectively. Thus, we have demonstrated the ability to accurately mimic rigid-body tumor motion using a robotically controlled phantom to provide precise geometric QA for advanced radiotherapy delivery approaches.
在这项研究中，我们开发并描述了一种六自由度（6 DoF）机器人运动系统，用于实时图像引导放射治疗技术的质量保证。该系统由商业可用的机器人手臂、带有嵌入式 Calypso 标记的丙烯酸体模、一个定制的底座，用于将机器人安装到治疗床，以及实现适当变换序列的控制软件组成，以再现测量的肿瘤运动轨迹。机器人运动系统的评估包括设置和运动轨迹重复性、静态定位精度和动态定位精度。使用机器人运动系统执行了四个前列腺、两个肝脏和三个肺部运动轨迹，这些轨迹代表了在实际患者治疗中记录的一系列肿瘤运动轨迹，并与临床 Calypso 运动跟踪系统的运动测量结果进行了比较。系统设置和运动轨迹重复性优于 0.5 度和 0.3 毫米，分别用于旋转和平移。机器人运动系统在 LR、SI 和 AP 方向的静态定位精度分别为平移 0.09 毫米、0.08 毫米和 0.02 毫米，旋转分别为 0.2°、0.06°和 0.06°。机器人运动系统的动态定位精度分别为平移和旋转的 <0.2 毫米和 <0.6°。因此，我们已经证明了使用机器人控制的体模准确模拟刚体肿瘤运动的能力，为先进的放射治疗提供精确的几何 QA 方法。
