Simulation of organ-specific patient effective dose due to secondary neutrons in proton radiation treatment
Simulation of organ-specific patient effective dose due to secondary neutrons in proton radiation treatment
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DOI：
10.1088/0031-9155/50/18/007
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发表时间：
2005-09-21
影响因子：
3.5
通讯作者：
Paganetti, H
中科院分区：
文献类型：
--
作者：
Jiang, HY;Wang, B;Paganetti, H
接受放射治疗的癌症患者会暴露于目标（肿瘤）的高剂量、邻近组织的中等剂量以及身体各部位的散射辐射的低剂量。在质子治疗的情况下，在加速器头部和患者体内产生的次级中子到达患者体内的许多区域。由于对癌症患者的管理效率的提高，放射治疗后长期存活的人数大幅增加。这导致人们担心在治疗后期出现辐射诱发癌症的风险。本文介绍了一个案例研究，以确定有效剂量的次级中子在病人接受质子治疗。采用全身患者模型VIP-Man作为患者模型。从VIP-Man研究中生成的几何数据集被实施到GEANT4 Monte Carlo代码中。两个质子治疗计划的肿瘤在肺和鼻窦进行了模拟。使用器官剂量和ICRP-60辐射和组织加权因子计算有效剂量。结果表明，两个质子计划的全身有效剂量分别为0.162 Sv和0.0266 Sv，主要贡献者是来自质子治疗喷嘴的中子。根据治疗部位的不同，器官之间存在显著差异。
Cancer patients undergoing radiation treatment are exposed to high doses to the target (tumour), intermediate doses to adjacent tissues and low doses from scattered radiation to all parts of the body. In the case of proton therapy, secondary neutrons generated in the accelerator head and inside the patient reach many areas in the patient body. Due to the improved efficacy of management of cancer patients, the number of long term survivors post-radiation treatment is increasing substantially. This results in concern about the risk of radiation-induced cancer appearing at late post-treatment times. This paper presents a case study to determine the effective dose from secondary neutrons in patients undergoing proton treatment. A whole-body patient model, VIP-Man, was employed as the patient model. The geometry dataset generated from studies made on VIP-Man was implemented into the GEANT4 Monte Carlo code. Two proton treatment plans for tumours in the lung and paranasal sinus were simulated. The organ doses and ICRP-60 radiation and tissue weighting factors were used to calculate the effective dose. Results show whole body effective doses for the two proton plans of 0.162 Sv and 0.0266 Sv, respectively, to which the major contributor is due to neutrons from the proton treatment nozzle. There is a substantial difference among organs depending on the treatment site.