Thoracic tumours are increasingly considered indications for pencil beam scanned proton therapy (PBS-PT) treatments. Conservative robustness settings have been suggested due to potential range straggling effects caused by the lung micro-structure. Using proton radiography (PR) and a 4D porcine lung phantom, we experimentally assess range errors to be considered in robust treatment planning for thoracic indications. A human-chest-size 4D phantom hosting inflatable porcine lungs and corresponding 4D computed tomography (4DCT) were used. Five PR frames were planned to intersect the phantom at various positions. Integral depth-dose curves (IDDs) per proton spot were measured using a multi-layer ionisation chamber (MLIC). Each PR frame consisted of 81 spots with an assigned energy of 210 MeV (full width at half maximum (FWHM) 8.2 mm). Each frame was delivered five times while simultaneously acquiring the breathing signal of the 4D phantom, using an ANZAI load cell. The synchronised A...

中文翻译：

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猪肺部幻影和质子射线照相术评估肺样组织中的范围不确定性

胸腔肿瘤越来越被认为是笔形束扫描质子治疗（PBS-PT）治疗的适应症。由于肺微结构引起的潜在范围散乱效应，已经提出了保守的稳健性设置。使用质子射线照相（PR）和4D猪肺部幻影，我们通过实验评估了针对胸骨适应症的稳健治疗计划中要考虑的范围误差。使用了具有人胸大小的4D幻像，该幻像容纳可充气的猪肺，并使用了相应的4D计算机断层扫描（4DCT）。计划使用五个PR框架在各个位置与模型相交。使用多层电离室（MLIC）测量每个质子点的积分深度-剂量曲线（IDD）。每个PR框架由81个光点组成，分配的能量为210 MeV（半高全宽（FWHM）8.2 mm）。使用ANZAI称重传感器，每帧交付五次，同时获取4D体模的呼吸信号。同步机