Yamada Kazunari, Soejima Toshinori, Minami Toshiaki, Yoden Eisaku, Watanabe Yuichi, Takenaka Daisuke, Imai Masatake, Okayama Takanobu, Fujii Masahiko, Sugimura Kazuro
Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
Int J Radiat Oncol Biol Phys. 2003 May 1;56(1):235-9. doi: 10.1016/s0360-3016(03)00096-8.
Information concerning the amount and nature of target motion is essential for the determination of internal margin size. However, there are few published reports outlining the motion with heart and aortic pulsation. We introduce a method for three-dimensional radiation treatment planning (3D-RTP) by using electrocardiographically (ECG) gated spiral scanning with a four-section CT system. We describe a new approach to visualize internal organ motion resulting from cardiac motion with ECG gated multidetector row CT.
Five patients with lung or liver tumors were studied with a multidetector row CT system under shallow inspiration breath-holding. With retrospective ECG gating, only data acquired within a predefined interval of the cardiac cycle are used for image reconstruction. All reconstructed image data at diastolic and systolic phases of the cardiac cycle were transferred to the 3D-RTP system. The shift of the internal organs between the cardiac cycles was evaluated.
Cardiac contraction influences anterior thorax, pulmonary peripheral vessels, and liver position, in addition to locations near the heart. Apparent movements more than 5 mm between diastolic and systolic phases were observed in the left ventricle, right atrium, and superior vena cava. Two-phase imaging was useful for showing the movement of internal organs during cardiac contraction under breath-holding.
Spatial information using ECG-gated CT has the potential to determine the planning target volume of moving lung and liver tumors more precisely than conventional CT planning.
有关靶区运动的数量和性质的信息对于确定内部边界大小至关重要。然而，很少有已发表的报告概述心脏和主动脉搏动引起的运动。我们介绍一种使用四排CT系统进行心电图（ECG）门控螺旋扫描的三维放射治疗计划（3D-RTP）方法。我们描述了一种通过ECG门控多层螺旋CT可视化由心脏运动引起的内部器官运动的新方法。
对5例患有肺部或肝脏肿瘤的患者在浅吸气屏气状态下使用多层螺旋CT系统进行研究。采用回顾性ECG门控，仅将在心动周期的预定义间隔内采集的数据用于图像重建。将心动周期舒张期和收缩期的所有重建图像数据传输到3D-RTP系统。评估心动周期之间内部器官的移位。
心脏收缩除了影响心脏附近的位置外，还影响前胸壁、肺外周血管和肝脏位置。在左心室、右心房和上腔静脉中观察到舒张期和收缩期之间明显的运动超过5毫米。双期成像有助于显示屏气时心脏收缩期间内部器官的运动。
使用ECG门控CT的空间信息有可能比传统CT计划更精确地确定移动性肺部和肝脏肿瘤的计划靶体积。
