Patient training in respiratory-gated radiotherapy.
Patient training in respiratory-gated radiotherapy.
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DOI：
10.1016/s0958-3947(02)00136-x
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发表时间：
2003-01-01
期刊：
影响因子：
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通讯作者：
Mohan, Radhe
中科院分区：
文献类型：
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作者：
Kini, Vijay R;Vedam, Subrahmanya S;Mohan, Radhe
呼吸门控用于抵消胸部肿瘤放射治疗期间器官运动的影响。患者在单一治疗期间和每天的呼吸模式变化的影响尚不清楚。我们评估了在呼吸门控放射治疗中使用患者训练工具的可行性及其对呼吸周期规律性和重复性的影响。为了监测呼吸模式，我们使用了商用呼吸门控放射治疗系统的一个组件(实时位置管理系统，瓦里安肿瘤系统，帕洛阿尔托，CA 94304)。这种被动标记视频跟踪系统由放置在患者胸部或腹部的反射标记组成，由安装在墙上的摄像机检测到。安装在与此摄像头接口的PC上的软件以数字方式检测标记器的运动并记录下来。作为时间函数的标记位置用作可用于触发成像或治疗的运动信号。使用的训练工具是音频提示和视觉反馈，并以自由呼吸为对照。这种音频提示方法使用指令，根据患者自己的呼吸模式，以周期性的间隔“吸气”或“呼气”。在视觉反馈方法中，患者可以看到由于呼吸而产生的腹壁运动的实时轨迹。利用这一点，他们被要求保持恒定的运动幅度。记录每个患者的腹壁运动轨迹，进行不同的动作。自由呼吸表现出不同的幅度和频率。音频提示导致频率可重复；然而，变异性和幅度的大小增加。视觉反馈对幅度有更好的控制，但在频率上有微小的变化。我们的结论是，训练提高了患者呼吸周期的幅度和频率的重复性。这可能会提高呼吸门控放射治疗的准确性。
Respiratory gating is used to counter the effects of organ motion during radiotherapy for chest tumors. The effects of variations in patient breathing patterns during a single treatment and from day to day are unknown. We evaluated the feasibility of using patient training tools and their effect on the breathing cycle regularity and reproducibility during respiratory-gated radiotherapy. To monitor respiratory patterns, we used a component of a commercially available respiratory-gated radiotherapy system (Real Time Position Management (RPM) System, Varian Oncology Systems, Palo Alto, CA 94304). This passive marker video tracking system consists of reflective markers placed on the patient's chest or abdomen, which are detected by a wall-mounted video camera. Software installed on a PC interfaced to this camera detects the marker motion digitally and records it. The marker position as a function of time serves as the motion signal that may be used to trigger imaging or treatment. The training tools used were audio prompting and visual feedback, with free breathing as a control. The audio prompting method used instructions to "breathe in" or "breathe out" at periodic intervals deduced from patients' own breathing patterns. In the visual feedback method, patients were shown a real-time trace of their abdominal wall motion due to breathing. Using this, they were asked to maintain a constant amplitude of motion. Motion traces of the abdominal wall were recorded for each patient for various maneuvers. Free breathing showed a variable amplitude and frequency. Audio prompting resulted in a reproducible frequency; however, the variability and the magnitude of amplitude increased. Visual feedback gave a better control over the amplitude but showed minor variations in frequency. We concluded that training improves the reproducibility of amplitude and frequency of patient breathing cycles. This may increase the accuracy of respiratory-gated radiation therapy.