CT-on-Rails Versus In-Room CBCT for Online Daily Adaptive Proton Therapy of Head-and-Neck Cancers.
CT-on-Rails Versus In-Room CBCT for Online Daily Adaptive Proton Therapy of Head-and-Neck Cancers.
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DOI：
10.3390/cancers13235991
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发表时间：
2021-11-28
期刊：
影响因子：
5.2
通讯作者：
Paganetti H
中科院分区：
文献类型：
--
作者：
Nesteruk KP;Bobić M;Lalonde A;Winey BA;Lomax AJ;Paganetti H
每日适应性质子治疗将使质子的独特特性得到充分利用。锥束 CT (CBCT) 因其成本低、结构紧凑且可用性广泛而成为日常适应的主要成像方式。然而，有些质子治疗中心配备了轨道式 CT 或考虑安装此类扫描仪以进行所谓的“近治疗位置”成像。我们的研究解决了一个关键问题：轨道 CT 是否适合日常适应性质子治疗。尽管轨道上 CT 声称具有高精度，但尚未对治疗执行不确定性增加的适应效果进行定量研究。在本文中，我们证明预期的不确定性不会影响基于室内 CT 的适应头颈癌的剂量学疗效，因此应用于“近治疗位置”成像的轨道 CT 是在线自适应质子治疗的合适方式。目的：比较每日适应性质子治疗中轨道 CT 与室内 CBCT 的疗效。方法：我们分析了 10 名头颈患者的每日 CBCT 和相应的虚拟 CT 图像。 CT 扫描后移动患者的必要性是适应工作流程中最显着的差异，导致治疗执行不确定性 σ 增加。它是等中心匹配 σi 和床运动 σm 引起的随机患者运动的组合。假设前者永远不会超过 1 毫米。对于后者，我们研究了 σm = 1、2 和 3 mm 的三种不同情况。因此，为了模拟轨道上 CT 的适应工作流程，我们在基于蒙特卡罗的适应之后但在交付适应计划之前引入了随机偏移。结果：对于 σm = 1 和 2 mm，累积剂量体积直方图和剂量分布没有显着差异。 σm = 3 mm 的偏移导致 CTV 剂量不足和体积相当大的热点。结论：由于室内 CT 的 σm 通常不超过 2 mm，因此头颈患者在线自适应治疗的两种方式之间不存在临床上显着的剂量差异。因此，室内轨道 CT 可以被认为是适应性质子治疗中 CBCT 的良好替代方案。
Daily adaptive proton therapy will allow the unique properties of protons to be fully exploited. Cone-beam CT (CBCT) is the primary imaging modality considered for daily adaptation due to its low cost, compactness, and thus wide availability. However, there are proton therapy centers equipped with CT-on-rails or considering the installation of such scanners for the so-called “near-treatment-position” imaging. Our study addresses the critical question, whether CT-on-rails is a suitable modality for daily adaptive proton therapy. Although high precision accuracies have been claimed for CT-on-rails, no quantitative study of the adaptation efficacy with increased treatment execution uncertainties has ever been performed. In this paper, we demonstrate that the expected uncertainties will not affect the dosimetric efficacy of the adaptation based on in-room CT for head and neck cancers, and thus CT-on-rails applied to “near-treatment-position” imaging is a suitable modality for online adaptive proton therapy. Purpose: To compare the efficacy of CT-on-rails versus in-room CBCT for daily adaptive proton therapy. Methods: We analyzed a cohort of ten head-and-neck patients with daily CBCT and corresponding virtual CT images. The necessity of moving the patient after a CT scan is the most significant difference in the adaptation workflow, leading to an increased treatment execution uncertainty σ. It is a combination of the isocenter-matching σi and random patient movements induced by the couch motion σm. The former is assumed to never exceed 1 mm. For the latter, we studied three different scenarios with σm = 1, 2, and 3 mm. Accordingly, to mimic the adaptation workflow with CT-on-rails, we introduced random offsets after Monte-Carlo-based adaptation but before delivery of the adapted plan. Results: There were no significant differences in accumulated dose-volume histograms and dose distributions for σm = 1 and 2 mm. Offsets with σm = 3 mm resulted in underdosage to CTV and hot spots of considerable volume. Conclusion: Since σm typically does not exceed 2 mm for in-room CT, there is no clinically significant dosimetric difference between the two modalities for online adaptive therapy of head-and-neck patients. Therefore, in-room CT-on-rails can be considered a good alternative to CBCT for adaptive proton therapy.
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影响因子：
3.8
作者：
Haelga, Roger A.;Besserer, Juergen;Schneider, Uwe
通讯作者：
Schneider, Uwe
影响因子：
3.5
作者：
Jia, Xun;Gu, Xuejun;Jiang, Steve B.
通讯作者：
Jiang, Steve B.
影响因子：
3.1
作者：
Nenoff, Lena;Matter, Michael;Albertini, Francesca
通讯作者：
Albertini, Francesca
DOI：
10.1016/j.ijrobp.2005.07.957
发表时间：
2006-02-01
影响因子：
7
作者：
Hansen, EK;Bucci, MK;Xia, P
通讯作者：
Xia, P
影响因子：
3.5
作者：
Castadot, Pierre;Lee, John A.;Gregoire, Vincent
通讯作者：
Gregoire, Vincent