Romanyukha Alexander, Trompier François, Reyes Ricardo A, Christensen Doran M, Iddins Carol J, Sugarman Stephen L
Naval Dosimetry Center, Bethesda, MD, USA,
Radiat Environ Biophys. 2014 Nov;53(4):755-62. doi: 10.1007/s00411-014-0553-6. Epub 2014 Jun 24.
In this paper, we report results of radiation dose measurements in fingernails of a worker who sustained a radiation injury to his right thumb while using 130 kVp X-ray for nondestructive testing. Clinically estimated absorbed dose was about 20-25 Gy. Electron paramagnetic resonance (EPR) dose assessment was independently carried out by two laboratories, the Naval Dosimetry Center (NDC) and French Institut de Radioprotection et de Sûreté Nucléaire (IRSN). The laboratories used different equipments and protocols to estimate doses in the same fingernail samples. NDC used an X-band transportable EPR spectrometer, e-scan produced by Bruker BioSpin, and a universal dose calibration curve. In contrast, IRSN used a more sensitive Q-band stationary spectrometer (EMXplus) with a new approach for the dose assessment (dose saturation method), derived by additional dose irradiation to known doses. The protocol used by NDC is significantly faster than that used by IRSN, nondestructive, and could be done in field conditions, but it is probably less accurate and requires more sample for the measurements. The IRSN protocol, on the other hand, potentially is more accurate and requires very small amount of sample but requires more time and labor. In both EPR laboratories, the intense radiation-induced signal was measured in the accidentally irradiated fingernails and the resulting dose assessments were different. The dose on the fingernails from the right thumb was estimated as 14 ± 3 Gy at NDC and as 19 ± 6 Gy at IRSN. Both EPR dose assessments are given in terms of tissue kerma. This paper discusses the experience gained by using EPR for dose assessment in fingernails with a stationary spectrometer versus a portable one, the reasons for the observed discrepancies in dose, and potential advantages and disadvantages of each approach for EPR measurements in fingernails.
在本文中，我们报告了一名工人指甲辐射剂量测量的结果。该工人在使用130 kVp X射线进行无损检测时右手拇指受到辐射损伤。临床估计吸收剂量约为20 - 25 Gy。电子顺磁共振（EPR）剂量评估由两个实验室独立进行，即海军剂量测定中心（NDC）和法国核辐射防护与安全研究所（IRSN）。这两个实验室使用不同的设备和方案来估计同一指甲样本中的剂量。NDC使用一台X波段便携式EPR光谱仪、布鲁克生物Spin公司生产的e - scan以及一条通用剂量校准曲线。相比之下，IRSN使用一台更灵敏的Q波段固定式光谱仪（EMXplus），采用一种新的剂量评估方法（剂量饱和法），该方法通过对已知剂量进行额外的剂量照射得出。NDC使用的方案比IRSN使用的方案速度快得多，具有无损性，并且可以在现场条件下完成，但可能不太准确，测量时需要更多样本。另一方面，IRSN的方案可能更准确，所需样本量非常小，但需要更多时间和人力。在两个EPR实验室中，均在意外受照的指甲中测量到了强烈的辐射诱导信号，且所得的剂量评估结果不同。右手拇指指甲上的剂量在NDC估计为14±3 Gy，在IRSN估计为19±6 Gy。两个EPR剂量评估结果均以组织比释动能表示。本文讨论了使用EPR通过固定式光谱仪与便携式光谱仪对指甲进行剂量评估所获得的经验、观察到的剂量差异的原因以及每种指甲EPR测量方法的潜在优缺点。
