基于锥形束计算机断层扫描的呼气屏气状态下肝分次运动
Interfractional Liver Positional Motion Under Exhaled Breath Holding Based on Cone Beam Computed Tomography.
机构信息
Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan;
Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.
出版信息
In Vivo. 2023 Jul-Aug;37(4):1822-1827. doi: 10.21873/invivo.13273.
BACKGROUND/AIM: We measured interfractional liver positional motion in liver stereotactic body radiotherapy (SBRT) with exhaled breath holding (BH) based on kilovoltage (kV) cone-beam computed tomography (CBCT) images.
PATIENTS AND METHODS
We collected 528 pre-treatment kV-CBCT images from 132 patients who underwent liver SBRT under exhaled BH using the Abches system, a non-electronic contact-based respiratory monitoring device, and analyzed them to investigate interfractional liver positional motion. Planning computed tomography (CT) scans were obtained using the Abches system when the patients were under exhaled BH. Translational 3-degree-of-freedom (DOF) soft-tissue-based image registration was performed using the kV-CBCT images under exhaled BH after 6-DOF vertebral bone image registration. Interfractional liver positional motions in the left-right (LR), anteroposterior (AP), and craniocaudal (CC) directions were defined based on the differences in the position of the liver relative to the vertebral bones.
RESULTS
For all fractions, the absolute mean±standard deviation for the interfractional liver positional motion in the LR, AP, and CC directions was 0.7±1.0 mm, 1.0±1.5 mm, and 2.8±3.1 mm, respectively. The liver interfractional systematic/random positional motions in the LR, AP, and CC directions were 0.9/1.2 mm, 1.4/1.8 mm, and 2.9/3.9 mm, respectively. For all fractions, 100.0%, 98.3%, and 86.9% of the interfractional liver positional motions in the LR, AP, and CC directions, respectively, were less than 5 mm.
CONCLUSION
CBCT-guided online correction should be used to correct interfractional liver positions errors present in liver SBRT with exhaled BH.
背景/目的：我们通过千伏（kV）锥形束计算机断层扫描（CBCT）图像测量了基于呼气屏气（BH）的肝脏立体定向体放射治疗（SBRT）中的肝区间位置运动。
患者和方法
我们收集了 132 名接受呼气 BH 下肝脏 SBRT 的患者的 528 次预处理 kV-CBCT 图像，这些患者使用 Abches 系统（一种非电子接触式呼吸监测设备）进行了治疗，并对其进行了分析以研究肝区间位置运动。当患者处于呼气 BH 下时，使用 Abches 系统获取计划计算机断层扫描（CT）扫描。在进行 6 自由度（DOF）椎骨图像配准后，使用呼气 BH 下的 kV-CBCT 图像进行了基于软组织的 3 自由度（DOF）的平移图像配准。基于肝相对于椎骨的位置差异，定义了肝在左右（LR）、前后（AP）和头尾（CC）方向上的肝区间位置运动。
结果
对于所有分次，LR、AP 和 CC 方向上肝区间位置运动的绝对值平均值±标准差分别为 0.7±1.0mm、1.0±1.5mm 和 2.8±3.1mm。LR、AP 和 CC 方向上肝区间系统/随机位置运动分别为 0.9/1.2mm、1.4/1.8mm 和 2.9/3.9mm。对于所有分次，LR、AP 和 CC 方向上的肝区间位置运动分别有 100.0%、98.3%和 86.9%小于 5mm。
结论
对于基于呼气 BH 的肝脏 SBRT，应使用 CBCT 引导的在线校正来校正肝区间位置误差。
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