Robot-assisted 3D-TRUS guided prostate brachytherapy: System integration and validation
Robot-assisted 3D-TRUS guided prostate brachytherapy: System integration and validation
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DOI：
10.1118/1.1645680
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发表时间：
2004-03-01
期刊：
影响因子：
3.8
通讯作者：
Fenster, A
中科院分区：
文献类型：
--
作者：
Wei, ZP;Wan, G;Fenster, A
目前的经会阴前列腺近距离放射治疗使用经直肠超声(TRUS)引导和固定位置的模板来引导针沿平行轨迹进行。然而，植入路径的耻骨弓形干扰(PAI)阻碍了部分前列腺沿平行轨迹被近距离放射治疗针靶向。为了解决PAI问题，一些研究人员探索了除平行插入轨迹外的其他插入轨迹，即倾斜插入轨迹。然而，在当前的近距离放射治疗程序中，平行轨迹约束不允许倾斜插入。在本文中，我们描述了一种机器人辅助的三维(3D)TRUS引导方法来解决这一问题。我们的原型由一个商用机器人和一个三维TRUS成像系统组成，该系统包括超声机、图像采集设备和三维TRUS图像重建，并显示软件。在我们的方法中，我们使用机器人作为可移动的针头导向器，即机器人在插入之前定位针，但医生将针插入患者的前列腺。在我们工作的后一阶段，我们将包括机器人插入。通过统一机器人、超声换能器和3D TRUS图像坐标系，模板孔的位置可以准确地与3D TRUS图像坐标系相关联，从而允许通过模板孔将针准确和一致地插入到前列腺中的目标位置。各个坐标系的统一包括两个步骤，即三维图像标定和机器人标定。我们对系统的测试表明，机器人系统在患者皮肤位置的针头放置精度为0.15 mm×0.06 mm，平均针角误差为0.07度。用于图像标定的尼龙线交点定位的基准定位误差为0.13 mm，用于机器人标定的草皮定位的基准定位误差为0.37 mm。图像标定的基准配准误差为0.12 mm，机器人标定的基准配准误差为0.52 mm。图像标定的目标配准误差为0.23 mm，机器人标定的目标配准误差为0.68 mm。对整个系统的评估表明，针可以用于琼脂模体中的目标位置，平均误差为0.79 mm+/-0.32 mm。(C)2004年美国医学物理学家协会。
Current transperineal prostate brachytherapy uses transrectal ultrasound (TRUS) guidance and a template at a fixed position to guide needles along parallel trajectories. However, pubic arch interference (PAI) with the implant path obstructs part of the prostate from being targeted by the brachytherapy needles along parallel trajectories. To solve the PAI problem, some investigators have explored other insertion trajectories than parallel, i.e., oblique. However, parallel trajectory constraints in current brachytherapy procedure do not allow oblique insertion. In this paper, we describe a robot-assisted, three-dimensional (3D) TRUS guided approach to solve this problem. Our prototype consists of a commercial robot, and a 3D TRUS imaging system including an ultrasound machine, image acquisition apparatus and 3D TRUS image reconstruction, and displays software. In our approach, we use the robot as a movable needle guide, i.e., the robot positions the needle before insertion, but the physician inserts the needle into the patient's prostate. In a later phase of our work, we will include robot insertion. By unifying the robot, ultrasound transducer, and the 3D TRUS image coordinate systems, the position of the template hole can be accurately related to 3D TRUS image coordinate system, allowing accurate and consistent insertion of the needle via the template hole into the targeted position in the prostate. The unification of the various coordinate systems includes two steps, i.e., 3D image calibration and robot calibration. Our testing of the system showed that the needle placement accuracy of the robot system at the "patient's" skin position was 0.15 mm 0.06 mm, and the mean needle angulation error was 0.07degrees. The fiducial localization error (FLE) in localizing the intersections of the nylon strings for image calibration was 0.13 mm, and the FLE in localizing the divots for robot calibration was 0.37 mm. The fiducial registration error for image calibration was 0.12 mm and 0.52 mm for robot calibration. The target registration error for image calibration was 0.23 mm, and 0.68 mm for robot calibration. Evaluation of the complete system showed that needles can be used to target positions in agar phantoms with a mean error of 0.79 mm+/-0.32 mm. (C) 2004 American Association of Physicists in Medicine.