Secondary neutron dose during proton therapy using spot scanning
Secondary neutron dose during proton therapy using spot scanning
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DOI：
10.1016/s0360-3016(01)02826-7
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发表时间：
2002-05-01
影响因子：
7
通讯作者：
Besserer, J
中科院分区：
文献类型：
--
作者：
Schneider, U;Agosteo, S;Besserer, J
目的：在质子放射治疗期间，在进入患者之前和之后，通过束线中的材料中的核相互作用产生次级中子。在常规治疗计划中通常不考虑这些中子沉积的剂量当量。在这项研究中，我们估计病人的中子剂量从一个点扫描束线，进行测量和Monte Carlo simulation.Methods和材料：测量的二次中子剂量进行了照射过程中的水幻影与177 MeV的质子使用邦纳球和CR39蚀刻探测器。此外，Monte Carlo模拟进行了使用FLUKA代码。结果：我们的测量与测量在一个束线使用的散射箔技术的比较表明，至少10点扫描技术的剂量优势。在布拉格峰的区域中，中子剂量当量对于中等大小的靶体积可以达到治疗剂量的大约1%。中子剂量预期在健康组织的病人（在未处理的体积）是大和中等的目标体积，约0.004 Sv和0.002 Sv每治疗戈伊，分别：我们得出结论，从测量和模拟的剂量沉积的二次中子在质子放射治疗过程中使用的点扫描技术可以忽略不计的治疗区域。在健康组织中，来自中子的剂量（每次治疗0.002 Sv戈伊）大约是光子治疗期间（0.001 Sv）的两倍。与使用质子束而不是光子可以实现的剂量节省相比，中子对积分剂量的贡献仍然非常低。(C)2002年爱思唯尔科技有限公司
Purpose: During proton radiotherapy, secondary neutrons are produced by nuclear interactions in the material in the beam line before and after entering the patient. The dose equivalent deposited by these neutrons is usually not considered in routine treatment planning. In this study, we estimated the neutron dose in patients from a spot scanning beam line by, performing measurements and Monte Carlo simulations.Methods and Materials: Measurements of the secondary neutron dose were performed during irradiation of a water phantom with 177-MeV protons using a Bonner sphere and CR39 etch detectors. Additionally, Monte Carlo simulations were performed using the FLUKA code.Results: A comparison of our measurements with measurements taken at a beam line using the scatter foil technique shows a dose advantage of at least 10 for the spot scanning technique. In the region of the Bragg peak, the neutron dose equivalent can reach for a medium-sized target volume approximately 1% of the treatment dose. Neutron doses expected in healthy tissues of the patient (in the not-treated volume) are for large and medium target volumes, approximately 0.004 Sv and 0.002 Sv per treatment Gy, respectively.Conclusions: We conclude from the measurements and simulations that the dose deposited by secondary neutrons during proton radiotherapy using the spot scanning technique can be neglected in the treatment region. In the healthy tissue, the dose coming from neutrons (0.002 Sv per treatment Gy) is approximately a factor of two larger than during photon treatment (0.001 Sv). These contributions to the integral dose from neutrons are still very low when compared to the dose sparing that can be achieved by using a proton beam instead of photons. (C) 2002 Elsevier Science Inc.