Improvement of tracking accuracy and stability by recursive image processing in real-time tumor-tracking radiotherapy system
Improvement of tracking accuracy and stability by recursive image processing in real-time tumor-tracking radiotherapy system
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实时肿瘤跟踪放疗系统中递归图像处理提高跟踪精度和稳定性
DOI：
10.1117/12.912734
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Masayori Ishikawa
中科院分区：
文献类型：
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作者：
Naoki Miyamoto;Kenneth Sutherland;Ryusuke Suzuki;Taeko Matsuura;Chie Toramatsu;Seishin Takao;Hideaki Nihongi;Rumiko Kinoshita;Shinichi Shimizu;Rikiya Onimaru;Kikuo Umegaki;Hiroki Shirato;Masayori Ishikawa
在实时肿瘤跟踪放射治疗（RTRT）系统中，将基准标记物插入靶肿瘤中或附近，以监测放射性诱导的肿瘤运动。在放射治疗期间，通过以30帧/秒操作的连续荧光透视检测标记。通过基于归一化互相关的模板模式匹配技术来确定标记位置。在高管电压、大电流和长时间曝光的情况下，基准标记将被准确地识别，然而，由于X射线透视导致的辐射剂量增加。另一方面，通过降低荧光透视参数设置，基准标记可能会丢失，因为统计噪声的影响增加。在门控放射治疗中，图像引导的误差会导致照射效率和准确性的降低。为了在低剂量透视中稳定准确地跟踪标记，我们提出了递归滤波器的应用。通过对静态标记和动态标记的跟踪验证了图像处理的有效性。结果表明，在低剂量成像中应用递归图像滤波器可以提高标记跟踪的稳定性和准确性。
In the real-time tumor-tracking radiotherapy (RTRT) system, the fiducial markers are inserted in or near the target tumor in order monitor the respiratory-induced motion of tumors. During radiation treatment, the markers are detected by continuous fluoroscopy operated at 30 frames/sec. The marker position is determined by means of a template pattern matching technique which is based on the normalized cross correlation. With high tube voltage, large current and long exposure, the fiducial marker will be recognized accurately, however, the radiation dose due to X-ray fluoroscopy increases. On the other hand, by decreasing the fluoroscopy parameter settings, the fiducial marker could be lost because the effect of statistical noise is increased. In the respiratory-gated radiotherapy, the error of the image guidance will induce the reduction of the irradiation efficiency and accuracy. In order to track the marker stably and accurately in low dose fluoroscopy, we propose the application of a recursive filter. The effectiveness of the image processing is investigated by tracking the static marker and the dynamic marker. The results suggest that the stability and the accuracy of the marker tracking can be improved by applying the recursive image filter in low dose imaging.