Thierens H, Vral A, de Ridder L
Medical Physics Laboratory, University of Gent, Belgium.
Health Phys. 1991 Nov;61(5):623-30. doi: 10.1097/00004032-199111000-00005.
The dose response of the number of micronuclei in cytokinesis-blocked lymphocytes after in-vitro irradiation of whole blood with x rays in the dose range 0-4 Gy was studied for a heterogeneous population of 10 donors. One thousand binucleated cells were systematically scored for micronuclei. A linear-quadratic dose dependency of the micronucleus yields was observed. The data were used to derive the accuracy of the dose assessment with the technique in case of a radiation accident. It was shown that for doses of 2 Gy and higher, the uncertainty of the dose was predominantly due to interindividual differences in the x-ray-induced micronucleus yields. At the 95% confidence level, doses lower than 0.3 Gy could not be unequivocally detected with the cytokinesis-blocked micronucleus assay due to the variability of the baseline micronucleus frequency within the donor population and the poor statistical accuracy when scoring 1,000 cells. The precision and sensitivity of the method in the low-dose range could be improved by the knowledge of individual pre-irradiation baseline values and an increase of the number of cells scored by automation of the technique.
对10名供血者的异质群体进行了研究，在0 - 4 Gy剂量范围内用X射线对全血进行体外照射后，观察胞质分裂阻滞淋巴细胞中微核数量的剂量反应。系统地对1000个双核细胞进行微核计数。观察到微核产额呈线性二次剂量依赖性。这些数据用于推导在辐射事故情况下该技术剂量评估的准确性。结果表明，对于2 Gy及更高剂量，剂量的不确定性主要归因于X射线诱导的微核产额的个体间差异。在95%置信水平下，由于供血者群体中基线微核频率的变异性以及对1000个细胞进行计数时统计准确性较差，胞质分裂阻滞微核试验无法明确检测到低于0.3 Gy的剂量。通过了解个体照射前的基线值以及通过技术自动化增加计数细胞的数量，可以提高该方法在低剂量范围内的精度和灵敏度。
