Comparison between in-beam and offline positron emission tomography imaging of proton and carbon ion therapeutic irradiation at synchrotron- and cyclotron-based facilities
Comparison between in-beam and offline positron emission tomography imaging of proton and carbon ion therapeutic irradiation at synchrotron- and cyclotron-based facilities
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DOI：
10.1016/j.ijrobp.2008.02.033
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发表时间：
2008-07-01
影响因子：
7
通讯作者：
Haberer, Thomas
中科院分区：
文献类型：
--
作者：
Parodi, Katia;Bortfeld, Thomas;Haberer, Thomas
目的：在治疗室中使用专用束内正电子发射断层扫描（PET）探测器而不是附近的商业断层扫描仪的好处是一个悬而未决的问题。这项工作定量地比较了可测量的信号在束和离线PET成像，考虑到现实的采集策略，在不同的离子束设施。脉冲和连续照射从同步加速器和回旋加速器的两种情况被认为是，因为它们的广泛使用，在大多数碳离子和质子therapy centers.Methods和Materials：一个数学框架被引入到比较的时间依赖性的量和空间分布的衰变从辐射诱导的同位素生产。后者是用蒙特卡罗技术计算的真实的质子治疗头颈部和椎旁肿瘤。碳离子照射的外推是基于之前体模实验的结果。生物清除率建模考虑到现有的数据从以前的动物和临床study.Results：可用于光束和离线检测范围从40%到60%的回旋加速器为基础的设施，65%至110%（碳离子）和94%至166%（质子）在同步加速器为基础的设施的物理衰变量之间的比率，并增加时，包括生物清除。在辐照过程中的衰变的空间分布表现出更好的相关性与剂量输送和减少的影响biologicalprocesss.Conclusions：在束成像可以是有利的同步加速器为基础的设施，提供有效的PET系统，使检测同位素衰变在束提取实施。非常短（
Purpose: The benefit of using dedicated in-beam positron emission tomography (PET) detectors in the treatment room instead of commercial tomographs nearby is an open question. This work quantitatively compares the measurable signal for in-beam and offline PET imaging, taking into account realistic acquisition strategies at different ion beam facilities. Both scenarios of pulsed and continuous irradiation from synchrotron and cyclotron accelerators are considered, because of their widespread use in most carbon ion and proton therapy centers.Methods and Materials: A mathematical framework is introduced to compare the time-dependent amount and spatial distribution of decays from irradiation-induced isotope production. The latter is calculated with Monte Carlo techniques for real proton treatments of head-and-neck and paraspinal tumors. Extrapolation to carbon ion irradiation is based on results of previous phantom experiments. Biologic clearance is modeled taking into account available data from previous animal and clinical studies.Results: Ratios between the amount of physical decays available for in-beam and offline detection range from 40% to 60% for cyclotron-based facilities, to 65% to 110% (carbon ions) and 94% to 166% (protons) at synchrotron-based facilities, and increase when including biologic clearance. Spatial distributions of decays during irradiation exhibit better correlation with the dose delivery and reduced influence of biologic processes.Conclusions: In-beam imaging can be advantageous for synchrotron-based facilities, provided that efficient PET systems enabling detection of isotope decays during beam extraction are implemented. For very short (