Ostyn Mark, Kim Siyong, Yeo Woon-Hong
Radiation Oncology, Medical Physics Graduate Program, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA.
Department of Mechanical and Nuclear Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA.
Sensors (Basel). 2016 Apr 13;16(4):534. doi: 10.3390/s16040534.
One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF) localization system designed to track intrafraction motion (target motion during the radiation treatment). This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range) for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a localization estimate and angular resolution of sensors (signal receivers) in a simulated room. The results indicate that the external sensor needs an angular resolution of about 0.03 degrees to achieve millimeter-level localization accuracy in a treatment room. This fundamental study of a novel RF localization system offers the groundwork to design a radiotherapy-compatible patient positioning system for active motion compensation.
外照射放疗是癌症治疗中使用最广泛的工具之一。然而，放疗涉及的主要风险是对健康组织的辐射剂量过高，而患者的运动又会加剧这种情况。在此，我们展示了一项针对潜在射频（RF）定位系统的模拟研究，该系统旨在跟踪分次内运动（放射治疗期间的靶区运动）。该系统包括可穿戴在皮肤上的射频信标和一个外部跟踪系统。我们开发了一个用于到达方向测量的分析模型，该模型使用射频（GHz范围）进行定位估计。我们使用蒙特卡罗模拟来研究在模拟房间中定位估计与传感器（信号接收器）角度分辨率之间的关系。结果表明，外部传感器需要约0.03度的角度分辨率才能在治疗室中实现毫米级的定位精度。这项对新型射频定位系统的基础研究为设计用于主动运动补偿的放疗兼容患者定位系统奠定了基础。
