Shimizu Hidetoshi, Murasawa Satoshi, Okudaira Kuniyasu, Aoyama Takahiro, Anai Shigeo, Nishitani Kazuharu, Kitagawa Tomoki, Sasaki Koji
Department of Radiation Oncology, Aichi Cancer Center Hospital.
MU-lab.
Igaku Butsuri. 2021;41(1):1-9. doi: 10.11323/jjmp.41.1_1.
The in-room laser which is used for patient positioning in radiotherapy is generally projected on the radiation isocenter determined by the Winston-Lutz test and so on. In this study, a couch-mounted verification device was developed that could evaluate all in-room lasers' alignment including the horizontality and verticality at one time. The device has the function to perform the light/radiation field coincidence test and the Winston-Lutz test at the same time. The aim of this report was to introduce the verification procedure for two tests, using the newly developed software and device, and to present the tuning flow of the in-room laser. Moreover, the analysis accuracy of the developed software was evaluated in comparison with commercial software.
First, the light/radiation field was evaluated by using tungsten markers on the central surface of the device. Next, after aligning the long-carved lines on the front and sides of the device with the in-room lasers, the Winston-Lutz test was carried out by using the tungsten sphere in the center of the device. The acquired images were collectively analyzed using the developed software equipped with the reporting function. Additionally, the result of this Winston-Lutz test was compared with the result from commercial software.
A series of the light/radiation field coincidence test and the Winston-Lutz test were analyzed using the developed device and software. The results could be easily confirmed using the reporting function of the software. Regarding the result of the Winston-Lutz test, most of the analysis differences between the developed software and commercially available software were within the pixel size (0.22 mm).
Since the accuracy of the radiation field affects the result of the Winston-Lutz test, the presented procedure of performing the light/radiation coincidence field test in advance facilitates the interpretation of the error of the Winston-Lutz test. Based on the results of the Winston-Lutz test, we were able to demonstrate the tuning flow of all in-room lasers including the horizontality and verticality by using the developed device.
We have developed a couch-mounted verification device and software that can evaluate the light/radiation coincidence field test and the alignment including the horizontality and verticality of the in-room laser used for patient positioning in radiotherapy, and reported its usefulness. The analysis accuracy of the developed software was comparable to that of commercially available software. The use of this device and the developed software would contribute to not only the efficiency of adjusting all in-room lasers' alignment including the horizontality and verticality but also reflect accurately the result of the Winston-Lutz test.
放射治疗中用于患者定位的室内激光通常投射在由温斯顿-卢茨测试等确定的辐射等中心上。在本研究中，开发了一种安装在治疗床上的验证装置，该装置可以一次性评估所有室内激光的对准情况，包括水平度和垂直度。该装置具有同时进行光/辐射野重合测试和温斯顿-卢茨测试的功能。本报告的目的是介绍使用新开发的软件和装置进行这两项测试的验证程序，并展示室内激光的调整流程。此外，将开发的软件的分析精度与商业软件进行了比较评估。
首先，通过使用装置中心表面上的钨标记来评估光/辐射野。接下来，将装置正面和侧面的长刻线与室内激光对齐后，使用装置中心的钨球进行温斯顿-卢茨测试。使用配备报告功能的开发软件对采集的图像进行综合分析。此外，将此温斯顿-卢茨测试的结果与商业软件的结果进行比较。
使用开发的装置和软件对一系列光/辐射野重合测试和温斯顿-卢茨测试进行了分析。使用软件的报告功能可以轻松确认结果。关于温斯顿-卢茨测试的结果，开发的软件与市售软件之间的大多数分析差异在像素尺寸（0.22毫米）范围内。
由于辐射野的精度会影响温斯顿-卢茨测试的结果，因此预先进行光/辐射重合场测试的程序有助于解释温斯顿-卢茨测试的误差。基于温斯顿-卢茨测试的结果，我们能够使用开发的装置展示所有室内激光包括水平度和垂直度的调整流程。
我们开发了一种安装在治疗床上的验证装置和软件，该装置和软件可以评估光/辐射重合场测试以及放射治疗中用于患者定位的室内激光的对准情况，包括水平度和垂直度，并报告了其有用性。开发的软件的分析精度与市售软件相当。使用该装置和开发的软件不仅有助于提高调整所有室内激光包括水平度和垂直度的对准效率，还能准确反映温斯顿-卢茨测试的结果。
