Proton FLASH effects on mouse skin at different oxygen tensions.
Proton FLASH effects on mouse skin at different oxygen tensions.
复制标题
质子闪光在不同氧张力下对小鼠皮肤的影响。
DOI：
10.1088/1361-6560/acb888
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发表时间：
2023
影响因子：
3.5
通讯作者：
Schuemann,Jan
中科院分区：
文献类型：
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作者：
Zhang,Qixian;Gerweck,LeoE;Cascio,Ethan;Yang,Qingyuan;Huang,Peigen;Niemierko,Andrzej;Bertolet,Alejandro;Nesteruk,KonradPawel;McNamara,Aimee;Schuemann,Jan
目的FLASH剂量率（> 40 Gy s−1）照射因其对正常组织的保护作用而受到极大关注。闪光效应最初是在电子辐射中观察到的，但后来证明光子束和质子束也会发生这种效应。已经提出了几种机制来解释高剂量率下的组织保护，包括涉及氧气的效应，例如受照射细胞内的氧气耗尽。在本研究中，我们研究了改变氧浓度时FLASH质子照射对皮肤的保护作用。方法我们的双散射质子系统提供了1.2×1.6 cm 2 椭圆场，剂量率为~ 130 Gy s− 1。常规剂量率为~ 0.4 Gy s− 1。FVB/N小鼠的腿部标记有两个纹身点并固定在支架上进行曝光。为了改变皮肤氧气浓度，小鼠呼吸纯氧或绑腿以限制血液流动。测量两个点之间的距离，以分析皮肤随时间的收缩情况。 主要结果 与传统剂量率照射相比，闪光照射可减轻 15% 的皮肤收缩。 25 至 30 Gy 照射后 75 天的表皮厚度和胶原沉积表明皮肤对 FLASH 照射具有长期保护功能。为小鼠提供氧气或降低皮肤氧气浓度消除了剂量率依赖性的反应差异。 意义 与标准剂量率照射相比，FLASH 质子照射减少了皮肤收缩、表皮厚度和胶原蛋白沉积。观察到的 FLASH 效应的氧依赖性与暴露期间的快速氧消耗一致，但不是结论性的。
ObjectiveIrradiation at FLASH dose rates (> 40 Gy s− 1) has received great attention due to its reported normal tissue sparing effect. The FLASH effect was originally observed in electron irradiations but has since been shown to also occur with both photon and proton beams. Several mechanisms have been proposed to explain the tissue sparing at high dose rates, including effects involving oxygen, such as depletion of oxygen within the irradiated cells. In this study, we investigated the protective role of FLASH proton irradiation on the skin when varying the oxygen concentration.ApproachOur double scattering proton system provided a 1.2× 1.6 cm 2 elliptical field at a dose rate of∼ 130 Gy s− 1. The conventional dose rate was∼ 0.4 Gy s− 1. The legs of the FVB/N mice were marked with two tattooed dots and fixed in a holder for exposure. To alter the skin oxygen concentration, the mice were breathing pure oxygen or had their legs tied to restrict blood flow. The distance between the two dots was measured to analyze skin contraction over time.Main resultsFLASH irradiation mitigated skin contraction by 15% compared to conventional dose rate irradiation. The epidermis thickness and collagen deposition at 75 d following 25 to 30 Gy exposure suggested a long-term protective function in the skin from FLASH irradiation. Providing the mice with oxygen or reducing the skin oxygen concentration removed the dose-rate-dependent difference in response.SignificanceFLASH proton irradiation decreased skin contraction, epidermis thickness and collagen deposition compared to standard dose rate irradiations. The observed oxygen-dependence of the FLASH effect is consistent with, but not conclusive of, fast oxygen depletion during the exposure.