Sen Hasan Tutkun, Bell Muyinatu A Lediju, Zhang Yin, Ding Kai, Boctor Emad, Wong John, Iordachita Iulian, Kazanzides Peter
IEEE Trans Biomed Eng. 2017 Jul;64(7):1608-1618. doi: 10.1109/TBME.2016.2612229. Epub 2016 Oct 3.
We are developing a cooperatively controlled robot system for image-guided radiation therapy (IGRT) in which a clinician and robot share control of a 3-D ultrasound (US) probe. IGRT involves two main steps: 1) planning/simulation and 2) treatment delivery. The goals of the system are to provide guidance for patient setup and real-time target monitoring during fractionated radiotherapy of soft tissue targets, especially in the upper abdomen. To compensate for soft tissue deformations created by the probe, we present a novel workflow where the robot holds the US probe on the patient during acquisition of the planning computerized tomography image, thereby ensuring that planning is performed on the deformed tissue. The robot system introduces constraints (virtual fixtures) to help to produce consistent soft tissue deformation between simulation and treatment days, based on the robot position, contact force, and reference US image recorded during simulation. This paper presents the system integration and the proposed clinical workflow, validated by an in vivo canine study. The results show that the virtual fixtures enable the clinician to deviate from the recorded position to better reproduce the reference US image, which correlates with more consistent soft tissue deformation and the possibility for more accurate patient setup and radiation delivery.
我们正在开发一种用于图像引导放射治疗（IGRT）的协同控制机器人系统，其中临床医生和机器人共同控制一个三维超声（US）探头。IGRT包括两个主要步骤：1）计划/模拟和2）治疗实施。该系统的目标是在软组织靶区的分次放射治疗期间，特别是在上腹部，为患者摆位提供指导并进行实时靶区监测。为了补偿探头造成的软组织变形，我们提出了一种新颖的工作流程，即在获取计划计算机断层扫描图像时，机器人将US探头固定在患者身上，从而确保在变形组织上进行计划制定。机器人系统引入约束（虚拟夹具），基于模拟过程中记录的机器人位置、接触力和参考US图像，帮助在模拟和治疗期间产生一致的软组织变形。本文介绍了该系统集成和所提出的临床工作流程，并通过一项体内犬类研究进行了验证。结果表明，虚拟夹具使临床医生能够偏离记录位置，以更好地重现参考US图像，这与更一致的软组织变形以及更准确的患者摆位和放射治疗实施的可能性相关。
