Maxim Peter G, Loo Billy W, Shirazi Haider, Thorndyke Brian, Luxton Gary, Le Quynh-Thu
Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA.
Int J Radiat Oncol Biol Phys. 2007 Dec 1;69(5):1395-401. doi: 10.1016/j.ijrobp.2007.05.016. Epub 2007 Sep 14.
To assess the respiratory motion of different thoracic nodal locations and its dependence on the presence of enlarged nodes; to assess the respiratory motion of different parenchymal tumor locations; and to determine the appropriate margins to cover the respiratory motion of targets at these locations.
We reviewed the four-dimensional computed tomography scans of 20 patients with thoracic tumors treated at our institution. The motion of four central thoracic locations (aortic arch, carina, and bilateral hila), parenchymal tumor locations (upper vs. lower, and anterior vs. middle vs. posterior thorax), and bilateral diaphragmatic domes was measured.
For the central thoracic locations, the largest motion was in the superoinferior (SI) dimension (>5 mm for bilateral hila and carina, but <4 mm for aortic arch). No significant difference was found in the motion of these locations in the absence or presence of enlarged nodes. For parenchymal tumors, upper tumors exhibited smaller SI motion than did lower tumors (3.7 vs. 10.4 mm, p = 0.029). Similarly, anterior tumors exhibited smaller motion than did posterior tumors in both the SI (4.0 vs. 8.0 mm, p = 0.013) and lateral (2.8 vs. 4.6 mm, p = 0.045) directions. The margins that would be needed to encompass the respiratory motion of each of the evaluated locations in 95% of patients were tabulated and range from 3.4 to 37.2 mm, depending on the location and direction.
The results of our study have provided data for appropriate site-specific internal target volume expansion that could be useful in the absence of four-dimensional computed tomography-based treatment planning. However, generalizing the results from a small patient population requires discretion.
评估不同胸部淋巴结位置的呼吸运动及其对肿大淋巴结存在与否的依赖性；评估不同实质肿瘤位置的呼吸运动；并确定覆盖这些位置靶区呼吸运动的合适边界。
我们回顾了在本机构接受治疗的20例胸部肿瘤患者的四维计算机断层扫描。测量了四个胸部中央位置（主动脉弓、隆突和双侧肺门）、实质肿瘤位置（上叶与下叶，以及前胸壁与中胸壁与后胸壁）和双侧膈肌圆顶的运动。
对于胸部中央位置，最大运动在上下（SI）维度（双侧肺门和隆突>5mm，但主动脉弓<4mm）。在有无肿大淋巴结的情况下，这些位置的运动未发现显著差异。对于实质肿瘤，上叶肿瘤的SI运动比下叶肿瘤小（3.7对10.4mm，p = 0.029）。同样，在前胸壁肿瘤在SI（4.0对8.0mm，p = 0.013）和侧方（2.8对4.6mm，p = 0.045）方向的运动均比后胸壁肿瘤小。列出了95%的患者中涵盖每个评估位置呼吸运动所需的边界，范围为3.4至37.2mm，具体取决于位置和方向。
我们的研究结果为特定部位的合适内部靶区体积扩展提供了数据，这在缺乏基于四维计算机断层扫描的治疗计划时可能有用。然而，从小规模患者群体中推广结果需要谨慎。
