Positional repeatability and variation in internal and external markers during volumetric-modulated arc therapy under end-exhalation breath-hold conditions for pancreatic cancer patients
Positional repeatability and variation in internal and external markers during volumetric-modulated arc therapy under end-exhalation breath-hold conditions for pancreatic cancer patients
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DOI：
10.1093/jrr/rraa054
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发表时间：
2020-09-01
影响因子：
2
通讯作者：
Sugimoto, Naozo
中科院分区：
文献类型：
--
作者：
Sasaki, Makoto;Nakamura, Mitsuhiro;Sugimoto, Naozo
本研究的目的是评估内部和外部标记物在多次憋气（BH）期间的位置可重复性，并评估这些标记物在体积调节弧治疗（VMAT）胰腺癌患者的BH期间的位置变化。共有13名具有内部标志物的连续胰腺癌患者入组。在呼气末BH条件下进行单次全弧共面VMAT，同时使用千伏x射线透视监测内部标记物。内部和外部标记的位置可重复性由所有BH过程中基准位置和零位之间的差值确定，位置变化由每一个BH过程中兆伏光束传递过程中基准位置的位移来定义。内部标记物（CoIM）质心在x轴上的位置重复性为0.6 - 1.5 mm， CoIM在y轴上的位置重复性为-0.1 +/- 2.2 mm，外部标记物的位置重复性为0.8 +/- 2.2 mm。内部标记位置出现的频率在y轴上距离参考位置> 2mm，尽管外部标记位置为
The purpose of this study was to assess the positional repeatability of internal and external markers among multiple breath-hold (BH) sessions and evaluate the positional variation of these markers within BH sessions for volumetric-modulated arc therapy (VMAT) for pancreatic cancer patients. A total of 13 consecutive pancreatic cancer patients with an internal marker were enrolled. Single full-arc coplanar VMAT was delivered under end-exhalation BH conditions while monitoring the internal marker with kilovoltage (kV) X-ray fluoroscopy. Positional repeatability of the internal and external markers was determined by the difference between the reference and zero position in all BH sessions, and positional variation was defined by the displacement from the reference position in each BH session during megavolt beam delivery. The overall positional repeatability was 0.6 1.5 mm in the X-axis for the centroid of the internal marker (CoIM), -0.1 +/- 2.2 mm in the Y-axis for the CoIM, and 0.8 +/- 2.2 mm for the external marker. The frequency of an internal marker position appearing > 2 mm from the reference position in the Y-axis, despite the external marker position being