Ozhasoglu Cihat, Murphy Martin J
Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Int J Radiat Oncol Biol Phys. 2002 Apr 1;52(5):1389-99. doi: 10.1016/s0360-3016(01)02789-4.
To investigate how respiration influences the motion of lung and pancreas tumors and to relate the observations to treatment procedures intended to improve dose alignment by predicting the moving tumor's position from external breathing indicators.
Breathing characteristics for five healthy subjects were observed by optically tracking the displacement of the chest and abdomen, and by measuring tidal air volume with a spirometer. Fluoroscopic imaging of five radiotherapy patients detected the motion of lung and pancreas tumors synchronously with external breathing indicators.
The external and fluoroscopic data showed a wide range of behavior in the normal breathing pattern and its effects on the position of lung and pancreas tumors. This included transient phase shifts between two different external measures of breathing that diminished to zero over a period of minutes, modulated phase shifts between tumor and chest wall motion, and other complex phenomena.
Respiratory compensation strategies that infer tumor position from external breathing signals, including methods of beam gating and dynamic beam tracking, require three-dimensional knowledge of the tumor's motion trajectory as well as the ability to detect and adapt to transient and continuously changing characteristics of respiratory motion during treatment.
研究呼吸如何影响肺部和胰腺肿瘤的运动，并将这些观察结果与旨在通过根据外部呼吸指标预测移动肿瘤的位置来改善剂量对准的治疗程序相关联。
通过光学跟踪胸部和腹部的位移以及用肺活量计测量潮气量来观察五名健康受试者的呼吸特征。对五名放射治疗患者进行荧光透视成像，以与外部呼吸指标同步检测肺部和胰腺肿瘤的运动。
外部和荧光透视数据显示正常呼吸模式及其对肺部和胰腺肿瘤位置的影响具有广泛的行为。这包括两种不同外部呼吸测量之间的瞬态相移，在几分钟内减小到零，肿瘤与胸壁运动之间的调制相移，以及其他复杂现象。
从外部呼吸信号推断肿瘤位置的呼吸补偿策略，包括束门控和动态束跟踪方法，需要肿瘤运动轨迹的三维知识以及在治疗期间检测和适应呼吸运动的瞬态和不断变化特征的能力。
