Automated Dicentric Aberration Scoring for Triage Dose Assessment: ⁶⁰Co Gamma Ray Dose-response at Different Dose Rates

Abstract

The objective of this study was to establish radiation dose-response calibration curves using automated dicentric scoring to support rapid and accurate cytogenetic triage dose-assessment. Blood was drawn from healthy human volunteers and exposed to ⁶⁰Co gamma rays at several dose rates (i.e., 1.0, 0.6, and 0.1 Gy min⁻¹). After radiation, the blood was placed for 2 h in a 37 °C incubator for repair. Blood was then cultured in complete media to which a mitogen (i.e., phytoghemagglutinin, concentration 4%) was added for 48 h. Colcemid was added to the culture at a final concentration of 0.2 μg mL⁻¹ after 24 h for the purpose of arresting first-division metaphase mitotics. Cells were harvested at the end of 48 h. Samples were processed using an automated metaphase harvester and automated microscope metaphase finder equipped with a suite of software including a specialized automated dicentric scoring application. The data obtained were used to create dose-response tables of dicentric yields. The null hypothesis that the data is Poisson-distributed could not be rejected at the significance level of α = 0.05 using results from a Shiny R Studio application (goodness-of-fit Poisson). Calibration curves based on linear-quadratic fits for ⁶⁰Co gamma rays at the three different dose rates were generated using these data. The calibration curves were used to detect blind test cases. In conclusion, using the automated harvester and automated microscope metaphase finder with associated automated dicentric scoring software demonstrates high-throughput with suitable accuracy for triage radiation dose assessment.