Ergen Sefika Arzu, Karacam Songul, Catal Tuba Kurt, Dincbas Fazilet Oner, Oksuz Didem Colpan, Sahinler Ismet
Department of Radiation Oncology, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkiye.
North Clin Istanb. 2024 Apr 17;11(2):120-126. doi: 10.14744/nci.2023.06856. eCollection 2024.
Today, respiratory movement can be monitored and recorded with different methods during a simulation on a four-dimensional (4D) computed tomography (CT) device to be used in radiotherapy planning. A synchronized respiratory monitoring system (RPM) with an externally equipped device is one of these methods. Another method is to create 4D images of the patient's breathing phases without the need for extra equipment, with an anatomy-based software program integrated into the CT device. Our aim is to compare the RPM system and the software system (Deviceless) which are two different respiratory monitoring methods used in tracking moving targets during 4D-CT imaging and to assess their clinical usability.
Ten patients who underwent paraaortic nodal irradiation were enrolled. The simulation was performed using intravenous contrast material on a 4D-CT device with both respiratory monitoring methods. The right/left kidneys and renal arteries were chosen as references to evaluate abdominal organ movement. It was then manually contoured one by one on both sets of images. The images were compared volumetrically and geometrically after rigid reconstruction. The similarity between the contours was determined by the Dice index. Wilcoxon test was used for statistical comparisons.
The motion of the kidneys in all three directions was found to be 0.0 cm in both methods. The shifts in the right/left renal arteries were submillimetric. The Dice index showed a high similarity in both kidney and renal artery contours.
In our study, no difference was found between RPM and Deviceless systems used for tracking and detection of moving targets during simulation in 4D-CT. Both methods can be used safely for radiotherapy planning according to the available possibilities in the clinic.
如今，在用于放射治疗计划的四维（4D）计算机断层扫描（CT）设备上进行模拟时，呼吸运动可用不同方法进行监测和记录。使用外部配备设备的同步呼吸监测系统（RPM）就是其中一种方法。另一种方法是利用集成在CT设备中的基于解剖结构的软件程序，无需额外设备即可创建患者呼吸阶段的4D图像。我们的目的是比较在4D-CT成像期间用于跟踪移动目标的两种不同呼吸监测方法，即RPM系统和软件系统（无设备系统），并评估它们的临床可用性。
招募了10例行腹主动脉旁淋巴结照射的患者。在一台4D-CT设备上使用静脉造影剂，采用两种呼吸监测方法进行模拟。选择右/左肾及肾动脉作为评估腹部器官运动的参考。然后在两组图像上逐一手动勾勒轮廓。在进行刚性重建后，对图像进行体积和几何比较。轮廓之间的相似性由Dice指数确定。采用Wilcoxon检验进行统计学比较。
两种方法中，肾脏在所有三个方向上的运动均为0.0厘米。右/左肾动脉的移位为亚毫米级。Dice指数显示肾脏和肾动脉轮廓具有高度相似性。
在我们的研究中，在4D-CT模拟期间用于跟踪和检测移动目标的RPM系统和无设备系统之间未发现差异。根据临床现有的可能性，这两种方法均可安全地用于放射治疗计划。
