Schweikard Achim, Shiomi Hiroya, Adler John
Informatik, Universitaet Lübeck, 23538 Lübeck, Germany.
Med Phys. 2004 Oct;31(10):2738-41. doi: 10.1118/1.1774132.
Respiratory motion is difficult to compensate for with conventional radiotherapy systems. An accurate tracking method for following the motion of the tumor is of considerable clinical relevance. We investigate methods to compensate for respiratory motion using robotic radiosurgery. In this system the therapeutic beam is moved by a robotic arm, and follows the moving target through a combination of infrared tracking and synchronized x-ray imaging. Infrared emitters are used to record the motion of the patient's skin surface. The position of internal gold fiducials is computed repeatedly during treatment, via x-ray image processing. We correlate the motion between external and internal markers. From this correlation model we infer the placement of the internal target during time intervals where no x-ray images are taken. Fifteen patients with lung tumors have recently been treated with a fully integrated system implementing this new method. The clinical trials confirm our hypothesis that internal motion and external motion are indeed correlated. In a preliminar study we have extended our work to tracking without implanted fiducials, based on algorithms for computing deformation motions and digitally reconstructed radiographs.
传统放疗系统很难对呼吸运动进行补偿。一种精确跟踪肿瘤运动的方法具有相当大的临床意义。我们研究了使用机器人放射外科来补偿呼吸运动的方法。在该系统中，治疗束由机器人手臂移动，并通过红外跟踪和同步X射线成像的组合来跟踪移动目标。红外发射器用于记录患者皮肤表面的运动。在治疗过程中，通过X射线图像处理反复计算内部金标靶的位置。我们将外部和内部标记之间的运动进行关联。从这个关联模型中，我们推断出在未拍摄X射线图像的时间间隔内内部靶标的位置。最近，15名肺癌患者接受了采用这种新方法的完全集成系统的治疗。临床试验证实了我们的假设，即内部运动和外部运动确实相关。在一项初步研究中，我们基于计算变形运动和数字重建射线照片的算法，将工作扩展到了无植入标记的跟踪。
