A novel range-verification method using ionoacoustic wave generated from spherical gold markers for particle-beam therapy: a simulation study
A novel range-verification method using ionoacoustic wave generated from spherical gold markers for particle-beam therapy: a simulation study
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一种利用球形金标记物产生的离子声波进行粒子束治疗的新型范围验证方法：模拟研究
DOI：
10.1038/s41598-019-38889-w
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
T. Matsuura
中科院分区：
文献类型：
--
作者：
T. Takayanagi;T. Uesaka;M. Kitaoka;MB.Unlu;K.Umegaki;H. Shirato;L. Xing;T. Matsuura
本研究提出一种新的替代质子束的范围验证方法与声波产生的球形金属标记。当质子束入射到金属标记物上时，由于金属和组织之间的声阻抗差异很大，因此产生的大部分压力波被限制在标记物中。然而，频率等于标记的共振频率的声波逃脱了这种限制;标记短暂地充当声学发射器。在此，利用这种现象来测量质子束的范围。我们在3-D模拟中测试所提出的策略，结合剂量计算与建模的声波传播。将一个直径为2.0mm的球形金标记物置于水中，用60 MeV质子束入射到其上，研究了压力波与束脉冲宽度和标记物位置的关系。在短束脉冲下，在波模拟中观察到源自标记的1.62 MHz的特定高频声波，其幅度与标记和布拉格峰之间的距离相关。结果表明，布拉格峰的位置可以通过测量从标记的声波振幅估计，使用一个单独的探测器适当设计的谐振频率。
This study proposes a novel alternative range-verification method for proton beam with acoustic waves generated from spherical metal markers. When proton beam is incident on metal markers, most of the resulting pressure waves are confined in the markers because of the large difference in acoustic impedance between the metal and tissue. However, acoustic waves with frequency equal to marker’s resonant frequency escape this confinement; the marker briefly acts as an acoustic transmitter. Herein, this phenomenon is exploited to measure the range of the proton beam. We test the proposed strategy in 3-D simulations, combining the dose calculations with modelling of acoustic-wave propagation. A spherical gold marker of 2.0 mm diameter was placed in water with a 60 MeV proton beam incident on it. We investigated the dependence of pressure waves on the width of beam pulse and marker position. At short beam pulse, specific high-frequency acoustic waves of 1.62 MHz originating from the marker were observed in wave simulations, whose amplitude correlated with the distance between the marker and Bragg peak. Results indicate that the Bragg peak position can be estimated by measuring the acoustic wave amplitudes from the marker, using a single detector properly designed for the resonance frequency.