Photoneutron-induced damage reduction for cardiac implantable electronic devices using neutron-shielding sheets in high-energy X-ray radiotherapy: A phantom study
Photoneutron-induced damage reduction for cardiac implantable electronic devices using neutron-shielding sheets in high-energy X-ray radiotherapy: A phantom study
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DOI：
10.1016/j.ejmp.2021.07.036
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发表时间：
2021-08-06
影响因子：
3.4
通讯作者：
Mizowaki, Takashi
中科院分区：
文献类型：
--
作者：
Kakino, Ryo;Nakamura, Mitsuhiro;Mizowaki, Takashi
目的：评估使用中子屏蔽片（NSS）减少高能X射线放射治疗中光中子对心脏植入式电子设备（CIED）造成的损伤。方法：NSS由厚度为1或2 cm的推注组成（Bls 1或Bls 2）作为减速剂和几种吸收剂（20%、50%或80%B4 C硅酮片[B（4）C20、B4 C50或B4 C80]或40%LiF硅酮片[LiF 40]）。首先，线性加速器（LINAC）与水等效体模的模拟和实验测量。将几个NSS放置在体模上，将Eu：LiCaAlF 6闪烁体放置在体模和NSS之间，并照射X射线。在实验和模拟之间比较相对计数（Cr =当放置NSS或Bls 2时的计数）。其次，在模拟中评估了CIED损伤。比较所有NSS之间的相对损伤（Dr =放置或不放置NSS时的损伤）。此外，γ射线和泄漏的X射线剂量从B4 C测量使用剂量测定膜。在确定最佳NSS组合后，通过改变一侧的长度和厚度进行Dr值分析。结果：模拟和实验的Cr值在30%的百分比差异内一致，除了裸或LiF 40-only。当施加B1 s2 + B4 C80时，Dr值降低了43%。光子剂量小于5 cGy/1500 MU。Dr值较小的B4 C80的一侧的较小的长度和减少的M-层thickness increased.Conclusions：由LINAC产生的光中子引起的CIED损伤有效地减少通过应用最佳NSS。
Purpose: To evaluate damage reduction in cardiac implantable electronic devices (CIEDs) caused by photo-neutrons in high-energy X-ray radiotherapy using a neutron-shielding sheet (NSS).Methods: The NSS consists of a bolus with a thickness of 1 or 2 cm (Bls1 or Bls2) as a moderator and several absorbers (20%, 50%, or 80% B4C silicone sheet [B(4)C20, B4C50, or B4C80] or a 40% LiF silicone sheet [LiF40]). First, a linear accelerator (LINAC) with a water-equivalent phantom was modeled in the simulation and measured experimentally. Several NSSs were placed on the phantom, a Eu:LiCaAlF6 scintillator was placed be-tween the phantom and the NSS, and X-rays were irradiated. The relative counts (Cr = counts when placing the NSS or Bls2) were compared between the experiment and simulation. Second, CIED damage was evaluated in the simulation. The relative damage (Dr = damage when placing or not placing the NSS) was compared among all the NSSs. In addition, the gamma-ray and leaking X-ray dose from B4C was measured using a dosimetric film. After determining the optimal NSS combination, Dr value analysis was performed by changing the length of one side and the thickness.Results: The Cr values of the simulation and experiment agreed within a 30% percentage difference, except for Bare or LiF40-only. The Dr value was reduced by 43% when Bls2 + B4C80 was applied. The photon dose was less than 5 cGy/1500 MU. The Dr values were smaller for the smaller lengths of one side of B4C80 and decreased as the M-layer thickness increased.Conclusions: The CIED damage induced by photoneutrons generated by a LINAC was effectively reduced by applying the optimal NSS.