EVALUATION OF NEUTRON AMBIENT DOSE EQUIVALENT IN CARBON-ION RADIOTHERAPY WITH ENERGY SCANNING
EVALUATION OF NEUTRON AMBIENT DOSE EQUIVALENT IN CARBON-ION RADIOTHERAPY WITH ENERGY SCANNING
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DOI：
10.1093/rpd/ncaa166
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发表时间：
2020-09-01
影响因子：
1
通讯作者：
Yonai, Shunsuke
中科院分区：
文献类型：
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作者：
Matsumoto, Shinnosuke;Yonai, Shunsuke
在碳离子放射治疗(CIRT)中，二次中子是由束线装置或患者体内的核相互作用产生的。在此，用能量扫描(ES)方法评价了CIRT中次级中子的特性。用WENDI-II测量了中子环境剂量当量(H*(10))。用蒙特卡罗模拟方法计算了中子能谱。测量和计算是在实际情况下进行的，最大束流能量(E-max)分别为290、350和400 MeV u(-1)。此外，在距离移位扫描(RS)和混合扫描(HS)中，比较了ES中的H*(10)和H*(10)。H*(10)在E-max=290 MeV u(-1)时比E-max=400 MeV u(-1)时减少65%。当E_(Max)=350 MeV u(-1)时，E_s中的H~*(10)在θ=120时是θ=60时的42%。在距束轴50 cm处，ES CIRT的中子剂量分别约为RS和HS CIRT的60%和70%。
In carbon-ion radiotherapy (CIRT), secondary neutrons are produced by nuclear interactions in the beamline devices or patient. Herein, the characteristics of secondary neutrons in CIRT with energy scanning (ES) were evaluated. Neutron ambient dose equivalents (H*(10)) were measured using WENDI-II. The neutron energy spectrum was calculated using the Monte Carlo simulation. Measurement and calculation were performed under realistic case scenarios using maximum beam energies (E-max) of 290, 350 and 400 MeV u(-1). Moreover, H*(10) in ES was compared with H*(10) in range-shifter scanning (RS) and hybrid scanning (HS). H*(10) in E-max = 290 MeV u(-1) was 65% less than that in E-max = 400 MeV u(-1). At E-max = 350 MeV u(-1), H*(10) in ES at theta = 120 was 42% of that at theta = 60. The neutron dose in ES CIRT decreased to approximately 60 and 70% of that in RS and HS CIRT, respectively, at 50-cm distance from the beam axis.