Kilovoltage intrafraction monitoring (KIM) is a method allowing to precisely infer the tumour trajectory based on cone beam computed tomography (CBCT) 2D-projections. However, its accuracy is deteriorated in the case of highly mobile tumours involving hysteresis. A first adaptation of KIM consisting of a prior amplitude based binning step has been developed in order to minimize the errors of the original model (phase-KIM). In this work, we propose enhanced methods (KIM sub-arc optim and phase-KIM sub-arc optim ) to improve the accuracy of KIM and phase-KIM which relies on the selection of the optimal starting CBCT gantry angle. Aiming at demonstrating the interest of our approach, we carried out a simulation study and an experimental study: we compared the accuracy of the conventional versus sub-arc optim methods on simulated realistic tumour motions with amplitudes ranging from 5 to 30 mm in 1 mm increments. The same approach was performed using a lung dynami...

中文翻译：

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通过龙门角度选择提高千伏分次内监测精度

千伏分割内监测 (KIM) 是一种允许基于锥形束计算机断层扫描 (CBCT) 2D 投影精确推断肿瘤轨迹的方法。然而，在涉及滞后的高度移动的肿瘤的情况下，其准确性会下降。为了最小化原始模型的误差（相位-KIM），已经开发了由先前基于幅度的分箱步骤组成的 KIM 的第一个改编版本。在这项工作中，我们提出了增强的方法（KIM sub-arc optim 和 phase-KIM sub-arc optim ）来提高 KIM 和 phase-KIM 的准确性，这依赖于最佳起始 CBCT 龙门角度的选择。为了展示我们方法的兴趣，我们进行了模拟研究和实验研究：我们比较了传统与亚弧优化方法在模拟真实肿瘤运动上的准确性，幅度范围为 5 到 30 毫米，增量为 1 毫米。使用肺动力执行相同的方法...