Jenkins Cesare H, Naczynski Dominik J, Yu Shu-Jung S, Xing Lei
Department of Mechanical Engineering and Department of Radiation Oncology, Stanford University, Stanford, California 94305.
Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305.
Med Phys. 2015 Jan;42(1):5-13. doi: 10.1118/1.4901255.
To characterize the performance of a novel radiation therapy monitoring technique that utilizes a flexible scintillating film, common optical detectors, and image processing algorithms for real-time beam visualization (RT-BV).
Scintillating films were formed by mixing Gd2O2S:Tb (GOS) with silicone and casting the mixture at room temperature. The films were placed in the path of therapeutic beams generated by medical linear accelerators (LINAC). The emitted light was subsequently captured using a CMOS digital camera. Image processing algorithms were used to extract the intensity, shape, and location of the radiation field at various beam energies, dose rates, and collimator locations. The measurement results were compared with known collimator settings to validate the performance of the imaging system.
The RT-BV system achieved a sufficient contrast-to-noise ratio to enable real-time monitoring of the LINAC beam at 20 fps with normal ambient lighting in the LINAC room. The RT-BV system successfully identified collimator movements with sub-millimeter resolution.
The RT-BV system is capable of localizing radiation therapy beams with sub-millimeter precision and tracking beam movement at video-rate exposure.
表征一种新型放射治疗监测技术的性能，该技术利用柔性闪烁膜、普通光学探测器和图像处理算法进行实时束流可视化（RT-BV）。
通过将Gd2O2S:Tb（GOS）与硅酮混合并在室温下浇铸混合物来形成闪烁膜。将这些膜放置在医用直线加速器（LINAC）产生的治疗束流路径中。随后使用CMOS数码相机捕获发出的光。使用图像处理算法在各种束流能量、剂量率和准直器位置下提取辐射场的强度、形状和位置。将测量结果与已知的准直器设置进行比较，以验证成像系统的性能。
RT-BV系统实现了足够的对比度噪声比，能够在LINAC机房正常环境光下以20帧/秒的速度实时监测LINAC束流。RT-BV系统成功地以亚毫米分辨率识别准直器的移动。
RT-BV系统能够以亚毫米精度定位放射治疗束流，并以视频速率曝光跟踪束流移动。
