INTERFRACTION AND INTRAFRACTION CHANGES IN AMPLITUDE OF BREATHING MOTION IN STEREOTACTIC LIVER RADIOTHERAPY
INTERFRACTION AND INTRAFRACTION CHANGES IN AMPLITUDE OF BREATHING MOTION IN STEREOTACTIC LIVER RADIOTHERAPY
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DOI：
10.1016/j.ijrobp.2009.09.008
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发表时间：
2010-07-01
影响因子：
7
通讯作者：
Dawson, Laura A.
中科院分区：
文献类型：
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作者：
Case, Robert B.;Moseley, Douglas J.;Dawson, Laura A.
目的：评价千伏锥束计算机体层摄影(CBCT)引导下立体定向全身放射治疗(SBRT)治疗不能切除的肝癌患者的肝动幅度变化。方法：对29例不能切除的肝癌患者行6段SBRT，其中15例有腹压，14例无腹压，共进行314次CBCT扫描，29次计划4DCT。离线时，CBCT根据呼吸时相被分类到10个箱子里。采用CBCT和四维CT重建的方法测量肝脏的运动幅度。结果：所有患者的平均肝脏运动幅度(范围)分别为1.8(0.1~7.0)mm、8.0(0.1~18.8)mm和4.3(0.1~12.1)mm。平均绝对肝运动幅度变化分别为1.0(ML)、1.7(CC)和1.6(AP)mm和1.3(ML)、1.6(CC)和1.9(AP)mm。未发现分数内振幅变化与分数内时间(范围为4：56-25：37min：s)，以及分数间和分数内振幅变化与肝脏运动幅度之间的相关性。观察者内重复性(Sigma，n=29次)分别为1.3(ML)、1.4(CC)和1.4(AP)mm。结论：大多数肝SBRT患者在整个治疗过程中肝脏运动幅度的变化很小，与肝脏运动的大小和片内时间没有明显关系。(C)2010年爱思唯尔公司。
Purpose: Interfraction and intrafraction changes in amplitude of liver motion were assessed in patients with liver cancer treated with kV cone beam computed tomography (CBCT)-guided stereotactic body radiation therapy (SBRT).Methods and Materials: A total of 314 CBCTs obtained with the patient in the treatment position immediately before and after each fraction, and 29 planning 4DCTs were evaluated in 29 patients undergoing six-fraction SBRT for unresectable liver cancer, with (n = 15) and without (n = 14) abdominal compression. Offline, the CBCTs were sorted into 10 bins, based on phase of respiration. Liver motion amplitude was measured using liver-to-liver alignment from the end-exhale and end-inhale CBCT and four-dimensional CT reconstructions. Inter- and intrafraction amplitude changes were measured from the difference between the pre-SBRT CBCTs relative to the planning four-dimensional CT, and from the pre-SBRT and post-SBRT CBCTs, respectively.Results: Mean liver motion amplitude for all patients (range) was 1.8 (0.1-7.0), 8.0 (0.1-18.8), and 4.3 (0.1-12.1) mm in the mediolateral (ML), craniocaudal (CC), and anteroposterior (AP) directions, respectively. Mean absolute inter- and intrafraction liver motion amplitude changes were 1.0 (ML), 1.7 (CC), and 1.6 (AP) mm and 1.3 (ML), 1.6 (CC), and 1.9 (AP) mm, respectively. No significant correlations were found between intrafraction amplitude change and intrafraction time (range, 4:56-25:37min:sec), and between inter- and intrafraction amplitude changes and liver motion amplitude. Intraobserver reproducibility (sigma, n = 29 fractions) was 1.3 (ML), 1.4 (CC), and 1.4 (AP) mm.Conclusions: For the majority of liver SBRT patients, the change in liver motion amplitude was minimal over the treatment course and showed no apparent relationships with the magnitude of liver motion and intrafraction time. (C) 2010 Elsevier Inc.