Universidade de São Paulo, Ribeirão Preto, Brazil.
J Radiol Prot. 2020 Mar;40(1):215-224. doi: 10.1088/1361-6498/ab55ca. Epub 2019 Nov 8.
The reduction in the occupational dose limit of the eye lens has created the need for optimising eye protection and dose assessment, in particular for interventional clinicians. Lead glasses are one of the protection tools for shielding the eyes, but assessing the eye lens dose when these are in place remains challenging. In this study, we evaluated the impact of the position of H (3) dosemeters on the estimated eye lens dose when lead glasses are used in interventional settings. Using the Monte Carlo method (MCNPX), an interventional cardiology setup was simulated for two models of lead glasses, five beam projections and two patient access routes. H (3) dosemeters were placed at several positions on the operator and the obtained dose was compared to the dose to the sensitive part of the eye lens (H ). Furthermore, to reproduce an experimental setup, a reference dosemeter, H (3), was placed on the surface of the eye. The dose measured by H (3) was, on average, only 60% of H . Dosemeters placed on the glasses, under their shielding, underestimated H for all parameters considered, by from 10% up to 90%. Conversely, dosemeters placed on the head or on the glasses, over their shielding, overestimated H , on average, up to 60%. The presence or lack of side shielding in lead glasses affected mostly dosemeters placed on the forehead, at the left side. Results suggest that both use of a correction factor of 0.5 to account for the presence of lead glasses in doses measured outside their shielding and placing an eye lens dosemeter immediately beneath the lenses of lead glasses may lead to the underestimation of the eye lens dose. Most suitable positions for eye lens dose assessment were on the skin, unshielded by the glasses or close to the eye, with no correction to the dose measured.
眼晶体职业剂量限值的降低使得优化眼部防护和剂量评估变得尤为必要，尤其是对于介入临床医生而言。铅眼镜是屏蔽眼部的防护工具之一，但当这些眼镜到位时，评估眼晶体剂量仍然具有挑战性。在这项研究中，我们评估了在介入环境中使用铅眼镜时，H （3）剂量计位置对估计眼晶体剂量的影响。使用蒙特卡罗方法（MCNPX），模拟了两种铅眼镜、五个射束投影和两种患者进入途径的介入心脏病学设置。将 H （3）剂量计放置在操作员的几个位置，并将获得的剂量与眼晶体敏感部分（H ）的剂量进行比较。此外，为了再现实验设置，在眼睛表面放置了参考剂量计 H （3）。H （3）测量的剂量平均仅为 H 的 60%。置于眼镜下方屏蔽下的剂量计，对于所有考虑的参数，低估了 H ，低估幅度从 10%到 90%不等。相反，置于眼镜上方屏蔽上方的剂量计，平均高估了 H ，高估幅度高达 60%。铅眼镜中是否存在侧屏蔽对置于额头、左侧的剂量计影响最大。结果表明，在未屏蔽的情况下，使用 0.5 的校正因子来考虑铅眼镜的存在，并将眼晶体剂量计直接置于铅眼镜镜片下方，可能会导致眼晶体剂量的低估。进行眼晶体剂量评估的最合适位置是在皮肤、眼镜未屏蔽的位置或靠近眼睛的位置，无需对测量的剂量进行校正。
