INSERM, UMR1101, LaTIM, University of Brest, Brest, France.
Hamad Medical Corporation OHS, PET/CT Center, Doha, Qatar.
Med Phys. 2021 Dec;48(12):8037-8044. doi: 10.1002/mp.15300. Epub 2021 Oct 29.
In the last few years, there has been a growing interest in surface imaging for patient positioning in external radiation therapy. The aim of this study is to evaluate the accuracy of daily patient positioning using the Azure Kinect surface imaging.
A total of 50 fractions in 10 patients including lung, pelvic, and head and neck tumors were analyzed in real time. A rigid registration algorithm, based on the iterative closest point (ICP) approach, is employed to estimate the patient position in 6 degrees of freedom (DOF). This position is compared to the reference values obtained by the radiograph imaging. The mean setup error and its standard deviation were calculated for all measured fractions.
The positioning error showed 1.1 ± 1.1 mm in lateral, 1.8 ± 2.1 mm in longitudinal, and 0.8 ± 1.1 mm in vertical, and 0.3°± 0.4° in yaw, 0.2°± 0.2° in pitch, and 0.2°± 0.2° in roll directions. The larger setup error occurred in pelvic regions.
We have evaluated in a radiotherapy set-up considering different patient anatomical locations, a depth measurement based surface imaging solution for patient positioning considering the 6 DOF couch motion. We showed that the proposed solution allows an accurate patient positioning without the need for patient markings or the use of additional radiation dose.
在过去的几年中，人们对外照射治疗中使用表面成像进行患者定位越来越感兴趣。本研究旨在评估使用 Azure Kinect 表面成像进行日常患者定位的准确性。
对 10 名患者的 50 个分次进行实时分析，包括肺部、骨盆和头颈部肿瘤。采用基于迭代最近点（ICP）方法的刚性配准算法来估计 6 自由度（DOF）中的患者位置。将该位置与射线照相成像获得的参考值进行比较。计算所有测量分次的平均设置误差及其标准差。
定位误差在侧方为 1.1±1.1mm，在前后方向为 1.8±2.1mm，在垂直方向为 0.8±1.1mm，在偏航方向为 0.3°±0.4°，在俯仰方向为 0.2°±0.2°，在滚转方向为 0.2°±0.2°。在骨盆区域出现较大的设置误差。
我们在考虑不同患者解剖位置的放射治疗设置中评估了一种基于深度测量的表面成像解决方案，用于考虑 6 DOF 床运动的患者定位。我们表明，该解决方案允许进行精确的患者定位，而无需患者标记或使用额外的辐射剂量。
