Hayashi Naoki, Saito Tatsunori, Ouchi Kazuki, Amma Hiroshi, Muraki Yuta, Yasui Keisuke, Nozue Masashi
Division of Medical Physics, School of Medical Sciences, Fujita Health University, Toyoake, Aichi, Japan.
Department of Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan.
J Appl Clin Med Phys. 2025 Jan;26(1):e14517. doi: 10.1002/acm2.14517. Epub 2024 Nov 26.
Radiotherapy devices with multiple image-guidance systems, such as surface-guided radiation therapy (SGRT), have been widely used in recent years. However, in the case of SGRT devices using the light-section method, coordinate coincidence evaluation using a phantom for SGRT devices with patterned light projection is not appropriate. Hence, this study aims to develop a dedicated phantom able to evaluate both the detection accuracy and coordinate coincidence of multiple IGRT configurations, including light-section-based SGRT devices.
First, we developed an end-to-end (E2E) phantom that can be scanned by CT and detected by a light-section-method-based SGRT device. Second, the detection accuracy of the phantom under three reference data acquisition conditions was evaluated using the E2E phantom. The three conditions were a body surface image detected by VOXELAN in the simulation CT room, a body surface image reconstructed from the volume data of the simulation CT room, and a body surface image acquired by VOXELAN in the radiotherapy room. Finally, the coordinate coincidence of the image-guidance system was evaluated using the E2E phantom.
Upon comparing detection accuracy among the three reference data acquisition methods, we found that the reference data generated in the CT room had the largest error (0.58 mm at maximum). The coordinate coincidences of the multiple image-guidance systems were within 1 mm for all components after the maintenance of VOXELAN using E2E phantom. Furthermore, the long-term direction stability was worse in the longitudinal direction.
The new E2E phantom can be used to evaluate the detection accuracy of a light-section-based SGRT system and the coordinate coincidence using a Winston-Lutz-based method in multiple image-guided configurations. The detection accuracy in the three different reference images of VOXELAN using this phantom improved to within 1 mm in all directions.
近年来，具有多种图像引导系统的放射治疗设备，如表面引导放射治疗（SGRT），已被广泛应用。然而，对于采用光截面法的SGRT设备，使用带有图案光投影的SGRT设备体模进行坐标重合评估并不合适。因此，本研究旨在开发一种专用体模，能够评估包括基于光截面的SGRT设备在内的多种图像引导放射治疗（IGRT）配置的检测精度和坐标重合情况。
首先，我们开发了一种端到端（E2E）体模，它可以通过CT扫描，并由基于光截面法的SGRT设备进行检测。其次，使用该E2E体模在三种参考数据采集条件下评估体模的检测精度。这三种条件分别是在模拟CT室中由VOXELAN检测到的体表图像、从模拟CT室的体积数据重建的体表图像以及在放射治疗室中由VOXELAN采集的体表图像。最后，使用E2E体模评估图像引导系统的坐标重合情况。
比较三种参考数据采集方法的检测精度时，我们发现CT室中生成的参考数据误差最大（最大为0.58毫米）。使用E2E体模对VOXELAN进行维护后，所有组件的多个图像引导系统的坐标重合在1毫米以内。此外，纵向的长期方向稳定性较差。
新的E2E体模可用于评估基于光截面的SGRT系统的检测精度，以及在多种图像引导配置中使用基于温斯顿 - 卢茨法的坐标重合情况。使用该体模在VOXELAN的三种不同参考图像中的检测精度在各个方向上均提高到了1毫米以内。
