Sánchez-Rubio Patricia, Rodríguez-Romero Ruth, Pinto-Monedero María, Alejo-Luque Luis, Martínez-Ortega Jaime
Medical Physics Department, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain.
J Appl Clin Med Phys. 2024 Dec;25(12):e14510. doi: 10.1002/acm2.14510. Epub 2024 Sep 17.
The aim of this study was to assess the accuracy of a surface-guided radiotherapy (SGRT) system for setup and intra-fraction motion control in frameless non-coplanar stereotactic radiosurgery (fSRS) using actual patient data immobilized with two different types of open-faced masks and employing a novel SGRT systems settings.
Forty-four SRS patients were immobilized with two types of open-faced masks. Sixty lesions were treated, involving the analysis of 68 cone-beam scans (CBCT), 157 megavoltage (MV) images, and 521 SGRT monitoring sessions. The average SGRT translations/rotations and 3D vectors (MAG-Trasl and MAG-Rot) were compared with CBCT or antero-posterior MV images for 0° table or non-coplanar beams, respectively. The intrafraction control was evaluated based on the average shifts obtained from each monitoring session. To assess the association between the SGRT system and the CBCT, the two types of masks and the 3D vectors, a generalized estimating equations (GEE) regression analysis was performed. The Wilcoxon singed-rank test for paired samples was performed to detect differences in couch rotation with longitudinal (LNG) and lateral (LAT) translations and/or yaw.
The average SGRT corrections were smaller than those detected by CBCT (≤0.5 mm and 0.1°), with largest differences in LNG and yaw. The GEE analysis indicated that the average MAG-Trasl, obtained by the SGRT system, was not statistically different (p = 0.09) for both mask types, while, the MAG-Rot was different (p = 0.01). For non-coplanar beams, the Wilcoxon singed-rank test demonstrated no significantly differences for the corrections (LNG, LAT, and yaw) for any table rotation except for LNG corrections at 65° (p = 0.04) and 75° (p = 0.03) table angle position; LAT shifts at 65° (p = 0.03) and 270° (p < 0.001) table angle position, and yaw rotation at 30° (p = 0.02) table angle position. The average intrafraction motion was < 0.1 mm and 0.1° for any table angle.
The SGRT system used, along with the novel workflow performed, can achieve the setup and intra-fraction motion control accuracy required to perform non-coplanar fSRS treatments. Both masks ensure the accuracy required for fSRS while providing a suitable surface for monitoring.
本研究的目的是使用两种不同类型的开放式面罩固定实际患者数据，并采用新型表面引导放射治疗（SGRT）系统设置，评估用于无框架非共面立体定向放射外科（fSRS）中摆位和分次内运动控制的SGRT系统的准确性。
44例SRS患者使用两种类型的开放式面罩进行固定。共治疗60个病灶，涉及分析68次锥形束扫描（CBCT）、157张兆伏（MV）图像和521次SGRT监测。分别将SGRT的平均平移/旋转和三维向量（MAG-Trasl和MAG-Rot）与CBCT或0°治疗床或非共面射束的前后MV图像进行比较。基于每次监测获得的平均位移评估分次内控制情况。为了评估SGRT系统与CBCT、两种面罩类型和三维向量之间的关联，进行了广义估计方程（GEE）回归分析。对配对样本进行Wilcoxon符号秩检验，以检测治疗床在纵向（LNG）和横向（LAT）平移和/或偏航时旋转的差异。
SGRT的平均校正值小于CBCT检测到的值（≤0.5毫米和0.1°），在LNG和偏航方面差异最大。GEE分析表明，对于两种面罩类型，SGRT系统获得的平均MAG-Trasl在统计学上无差异（p = 0.09），而MAG-Rot有差异（p = 0.01）。对于非共面射束，Wilcoxon符号秩检验表明，除了在治疗床角度为65°（p = 0.04）和75°（p = 0.03）时的LNG校正、65°（p = 0.03）和270°（p < 0.001）时的LAT位移以及30°（p = 0.02）时的偏航旋转外，任何治疗床旋转的校正（LNG、LAT和偏航）均无显著差异。对于任何治疗床角度，平均分次内运动均<0.1毫米和0.1°。
所使用的SGRT系统以及所执行的新型工作流程能够实现进行非共面fSRS治疗所需的摆位和分次内运动控制精度。两种面罩在确保fSRS所需精度的同时，还提供了适合监测的表面。
