Tumor location, cirrhosis, and surgical history contribute to tumor movement in the liver, as measured during stereotactic irradiation using a real-time tumor-tracking radiotherapy system
Tumor location, cirrhosis, and surgical history contribute to tumor movement in the liver, as measured during stereotactic irradiation using a real-time tumor-tracking radiotherapy system
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DOI：
10.1016/s0360-3016(03)00082-8
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发表时间：
2003-05-01
影响因子：
7
通讯作者：
Miyasaka, K
中科院分区：
文献类型：
--
作者：
Kitamura, K;Shirato, H;Miyasaka, K
目的：目的：研究实时肿瘤跟踪放疗（RTRT）中肝脏肿瘤的三维运动规律。治疗前，在肿瘤附近植入一个2 mm的金标记。RTRT系统使用荧光透视图像处理器单元确定植入标记的3D位置。只有当标记物位于允许区域内时，才触发线性加速器照射肿瘤。分析自动记录的肿瘤运动数据，以确定肿瘤运动的幅度、肿瘤运动的曲线形状、治疗效率、运动频率和滞后。评估以下每个临床因素以确定其对运动幅度的贡献：肿瘤位置、肝硬化的存在、手术史、肿瘤体积以及等中心点与标记之间的距离。20例患者肿瘤运动的平均幅度为4 ± 4 mm在左右、头尾和前后（AP）方向上，分别为9 ± 5 mm（范围1-12）、9 ± 5 mm（范围2-19）和5 ± 3 mm（范围2-12）。在左右和AP方向上，右叶的肿瘤运动明显大于左叶（p = 0.01）。肝硬化患者肿瘤在左右和前后方向的运动明显大于非肝硬化患者（p < 0.004）。肝部分切除组肿瘤左右及前后方向的运动明显小于无手术史组（p < 0.03）。因此，检查的五个临床因素中的三个（即，肿瘤在肝脏中的位置、肝硬化和肝脏手术史）显著影响立体定向照射期间肝脏在横轴方向上的肿瘤运动。频率分析显示，对于20个肿瘤中的9个（45%），心跳引起可测量的运动。肿瘤的3D轨迹显示20个肿瘤中的4个（20%）具有滞后。结论：肿瘤部位、肝硬化程度、手术史等因素均影响术中肿瘤轴向运动。这一发现应有助于确定最小的边缘在个别情况下放射治疗肝脏恶性肿瘤。(C)2003年爱思唯尔公司
Purpose: To investigate the three-dimensional (3D) intrafractional motion of liver tumors during real-time tumor-tracking radiotherapy (RTRT).Methods and Materials: The data of 20 patients with liver tumors were analyzed. Before treatment, a 2-mm gold marker was implanted near the tumor. The RTRT system used fluoroscopy image processor units to determine the 3D position of the implanted marker. A linear accelerator was triggered to irradiate the tumor only when the marker was located within a permitted region. The automatically recorded tumor-motion data were analyzed to determine the amplitude of the tumor motion, curve shape of the tumor motion, treatment efficiency, frequency of movement, and hysteresis. Each of the following clinical factors was evaluated to determine its contribution to the amplitude of movement: tumor position, existence of cirrhosis, surgical history, tumor volume, and distance between the isocenter and the marker.Results: The average amplitude of tumor motion in the 20 patients was 4 +/- 4 mm (range 1-12), 9 +/- 5 mm (range 2-19), and 5 +/- 3 mm (range 2-12) in the left-right, craniocaudal, and anterior-posterior (AP) direction, respectively. The tumor motion of the right lobe was significantly larger than that of the left lobe in the left-right and AP directions (p = 0.01). The tumor motion of the patients with liver cirrhosis was significantly larger than that of the patients without liver cirrhosis in the left-right and AP directions (p < 0.004). The tumor motion of the patients who had received partial hepatectomy was significantly smaller than that of the patients who had no history of any operation on the liver in the left-right and AP directions (p < 0.03). Thus, three of the five clinical factors examined (i.e., tumor position in the liver, cirrhosis, and history of surgery on the liver) significantly affected the tumor motion of the liver in the transaxial direction during stereotactic irradiation. Frequency analysis revealed that for 9 (45%) of the 20 tumors, the cardiac beat caused measurable motion. The 3D trajectory of the tumor showed hysteresis for 4 (20%) of the 20 tumors. The average treatment efficiency of RTRT was 40%.Conclusion: Tumor location, cirrhosis, and history of surgery on the liver all had an impact on the intrafractional tumor motion of the liver in the transaxial direction. This finding should be helpful in determining the smallest possible margin in individual cases of radiotherapy for liver malignancy. (C) 2003 Elsevier Inc.