Lamart Stephanie, Miller Brian W, Van der Meeren Anne, Tazrart Anissa, Angulo Jaime F, Griffiths Nina M
Laboratoire de RadioToxicologie, CEA, Université Paris-Saclay, Arpajon, France.
College of Optical Sciences, The University of Arizona, Tucson, Arizona, United States of America.
PLoS One. 2017 Oct 12;12(10):e0186370. doi: 10.1371/journal.pone.0186370. eCollection 2017.
This work presents a comparison of three autoradiography techniques for imaging biological samples contaminated with actinides: emulsion-based, plastic-based autoradiography and a quantitative digital technique, the iQID camera, based on the numerical analysis of light from a scintillator screen. In radiation toxicology it has been important to develop means of imaging actinide distribution in tissues as these radionuclides may be heterogeneously distributed within and between tissues after internal contamination. Actinide distribution determines which cells are exposed to alpha radiation and is thus potentially critical for assessing absorbed dose. The comparison was carried out by generating autoradiographs of the same biological samples contaminated with actinides with the three autoradiography techniques. These samples were cell preparations or tissue sections collected from animals contaminated with different physico-chemical forms of actinides. The autoradiograph characteristics and the performances of the techniques were evaluated and discussed mainly in terms of acquisition process, activity distribution patterns, spatial resolution and feasibility of activity quantification. The obtained autoradiographs presented similar actinide distribution at low magnification. Out of the three techniques, emulsion autoradiography is the only one to provide a highly-resolved image of the actinide distribution inherently superimposed on the biological sample. Emulsion autoradiography is hence best interpreted at higher magnifications. However, this technique is destructive for the biological sample. Both emulsion- and plastic-based autoradiography record alpha tracks and thus enabled the differentiation between ionized forms of actinides and oxide particles. This feature can help in the evaluation of decorporation therapy efficacy. The most recent technique, the iQID camera, presents several additional features: real-time imaging, separate imaging of alpha particles and gamma rays, and alpha activity quantification. The comparison of these three autoradiography techniques showed that they are complementary and the choice of the technique depends on the purpose of the imaging experiment.
基于乳胶的放射自显影、基于塑料的放射自显影以及一种定量数字技术——iQID相机，该相机基于对闪烁体屏幕发出的光进行数值分析。在放射毒理学中，开发对组织中锕系元素分布进行成像的方法非常重要，因为这些放射性核素在体内污染后可能在组织内和组织间呈非均匀分布。锕系元素的分布决定了哪些细胞会受到α辐射，因此对于评估吸收剂量可能至关重要。通过使用这三种放射自显影技术对被锕系元素污染的相同生物样品生成放射自显影片来进行比较。这些样品是从被不同物理化学形式的锕系元素污染的动物身上采集的细胞制剂或组织切片。主要从采集过程、活性分布模式、空间分辨率和活性定量的可行性等方面对放射自显影片的特性和技术性能进行了评估和讨论。在低倍放大下，所获得的放射自显影片呈现出相似的锕系元素分布。在这三种技术中，乳胶放射自显影是唯一一种能提供固有叠加在生物样品上的锕系元素分布的高分辨率图像的技术。因此，乳胶放射自显影最好在高倍放大下进行解读。然而，该技术对生物样品具有破坏性。基于乳胶和基于塑料的放射自显影都记录α径迹，因此能够区分锕系元素的离子化形式和氧化物颗粒。这一特性有助于评估促排疗法的疗效。最新技术iQID相机具有几个额外的特性：实时成像、α粒子和γ射线的单独成像以及α活性定量。这三种放射自显影技术的比较表明它们是互补的，技术的选择取决于成像实验的目的。
