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.

Application of a semi-automated dicentric scoring system in triage and monitoring occupational radiation exposure

“…A limitation of scoring systems with DCScore is that metaphase images that are poor quality are rejected and few images that are good quality are accepted for scoring. The quality of metaphase spreads is an important factor that affects DC scoring using DCScore ( 9 , 21 ). As our study utilized images generated in previous studies for validating the semi-automated scoring method, we could not adjust the image quality and used a smaller number of metaphase images in the semi-automated scoring method than in the manual scoring method.…”

“…The performance of manual DCA has been well-studied for radiation biodosimetry ( 17 – 20 ), but relatively few studies have validated DCScore. In most of these studies, the performance of DCScore has been evaluated in triage using ex vivo irradiated blood ( 9 , 21 , 22 ); however, the application of DCScore in estimating the accurate radiation dose in in vivo irradiated humans has not been reported.…”

Metaphase Cells Enrichment for Efficient Use in the Dicentric Chromosome Assay

“…To accelerate the speed of DCA analysis for dose estimation, automated tools were developed. The automated tools included harvesters [Subramanian 2020], metaphase nders [Weber et al 1992 with automatic dicentric scoring was found to be close to the dose obtained with manual dicentric scoring of 500 metaphases [Vaurijoux et al 2009].…”

Establishing a Reference Dose–Response Calibration Curve for Dicentric Chromosome Aberrations to Assess Accidental Radiation Exposure in Saudi Arabia

“…Acknowledging that the DCA is currently the best-established cytogenetic technique for absorbed radiation dose assessment, it is somewhat impractical for triage of mass casualty events owing to its labor-intensive and time-consuming procedures. While lymphocyte culture for 48 h is inevitable, many research is directed to streamline DCA processes by automating DC scoring in metaphase images using machine learning image processing techniques (36)(37)(38)(39)(40). Hence, many image training classifiers were created to improve the specificity of automated DC analysis algorithm.…”