Individual dosimetry system for targeted alpha therapy based on PHITS coupled with microdosimetric kinetic model.
Individual dosimetry system for targeted alpha therapy based on PHITS coupled with microdosimetric kinetic model.
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DOI：
10.1186/s40658-020-00350-7
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发表时间：
2021-01-12
期刊：
影响因子：
4
通讯作者：
Watabe T
中科院分区：
文献类型：
--
作者：
Sato T;Furuta T;Liu Y;Naka S;Nagamori S;Kanai Y;Watabe T
个体剂量测量系统是核医学精确剂量评价的基础。本研究的目的是开发一个系统，该系统不仅可以计算吸收剂量，还可以根据患者的PET-CT图像计算靶向α治疗（达特）的EQDX（α/β），同时考虑相对生物学有效性的剂量依赖性、剂量率效应和剂量异质性。该系统采用通用的蒙特卡罗粒子输运程序PHITS作为剂量计算引擎，微剂量学动力学模型用于将吸收剂量转换为EQDX（α/β）。使用基于PHITS（RT-PHITS）的放射治疗包的新开发模块，从PET-CT图像自动创建用于描述患者的几何形状和源分布的PHITS输入文件。我们通过使用4名健康志愿者注射18F-NKO-035后的PET-CT图像计算几个器官剂量来检查系统的性能。从我们的系统中获得的沉积能量图似乎是相应PET数据的模糊图像，因为湮灭γ射线将其能量存款在离源位置相当远的地方。计算的器官剂量与OLINDA 2.0的相应数据在20%以内一致，表明我们开发的系统的可靠性。通过将标记的放射性核素从18F替换为211 At进行的试验计算表明，预期达特中靶体积的剂量不均匀性较大，导致高活性注射的EQDX（α/β）显著降低。作为RT-PHITS的扩展，基于PHITS和微剂量学动力学模型，开发了核医学个人剂量学系统。它使我们能够预测达特的治疗和副作用的基础上的临床数据，主要是从传统的外部放射治疗。
An individual dosimetry system is essential for the evaluation of precise doses in nuclear medicine. The purpose of this study was to develop a system for calculating not only absorbed doses but also EQDX(α/β) from the PET-CT images of patients for targeted alpha therapy (TAT), considering the dose dependence of the relative biological effectiveness, the dose-rate effect, and the dose heterogeneity. A general-purpose Monte Carlo particle transport code PHITS was employed as the dose calculation engine in the system, while the microdosimetric kinetic model was used for converting the absorbed dose to EQDX(α/β). PHITS input files for describing the geometry and source distribution of a patient are automatically created from PET-CT images, using newly developed modules of the radiotherapy package based on PHITS (RT-PHITS). We examined the performance of the system by calculating several organ doses using the PET-CT images of four healthy volunteers after injecting 18F-NKO-035. The deposition energy map obtained from our system seems to be a blurred image of the corresponding PET data because annihilation γ-rays deposit their energies rather far from the source location. The calculated organ doses agree with the corresponding data obtained from OLINDA 2.0 within 20%, indicating the reliability of our developed system. Test calculations by replacing the labeled radionuclide from 18F to 211At suggest that large dose heterogeneity in a target volume is expected in TAT, resulting in a significant decrease of EQDX(α/β) for higher-activity injection. As an extension of RT-PHITS, an individual dosimetry system for nuclear medicine was developed based on PHITS coupled with the microdosimetric kinetic model. It enables us to predict the therapeutic and side effects of TAT based on the clinical data largely available from conventional external radiotherapy.
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影响因子：
3.2
作者：
Andersson M;Johansson L;Eckerman K;Mattsson S
通讯作者：
Mattsson S
DOI：
10.1016/0360-3016(82)90459-x
发表时间：
1982-01-01
影响因子：
7
作者：
BARENDSEN, GW
通讯作者：
BARENDSEN, GW
影响因子：
3.4
作者：
Hobbs, Robert F.;Howell, Roger W.;Sgouros, George
通讯作者：
Sgouros, George
影响因子：
9.3
作者：
Prideaux, Andrew R.;Song, Hong;Sgouros, George
通讯作者：
Sgouros, George
影响因子：
1
作者：
Sato, T.;Watanabe, R.;Niita, K.
通讯作者：
Niita, K.