Development of Dose-Response Calibration Curve for Dicentric Chromosome Induced by X-Rays

Abstract

Chromosome aberration is a biomarker that has been used as a standard tool in biological dosimetry (biodosimetry) of individuals after exposure to ionizing radiation. It is based mainly on the induction of dicentric chromosomes – one of the radiation-induced biological effects, in order to correlate them with radiation dose. In this study, a dose calibration curve for X-rays was generated by using the dicentric assay and by fitting the data to both Chromosomal Aberration Calculation Software and Dose Estimate programs to compare the output of each method. Peripheral blood samples from four nonsmoker healthy donors were irradiated with various doses ranging from 0 to 4 Gy with 250 kV or 122 keV X-rays at a dose rate of 0.17 Gy/min. The irradiated blood was cultured, harvested, and analyzed according to the standard procedure as described by the International Atomic Energy Agency with slight modifications. The dose-response calibration data for dicentrics were fitted with the linear-quadratic model (Y dic = 0.03987D 2 + 0.00651D). The dose-response calibration curve obtained in this research was comparable to other estimations with similar radiation quality and dose rates. The results in this research convinced us in sustaining a biodosimetry using a dose-response calibration curve in our laboratory.

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

“…Along with the high significance of the fitted C, α and β coefficients (z-test, P < 0.0001), the close to 1.0 p-value of the Poisson-based goodness of fit (χ 2 = 3.51, DF = 7, P = 0.83) indicates clearly excellent fitting of the data with no trend toward lack of fit (12). The comparison between our dose-response relationship for DC induction with those from similar published studies that used X-ray irradiation (19,26,(28)(29)(30)(31)(32)(33)(34)(35) showed quite large range of DC yields (Figure 6). These interlaboratory differences could emanate from the energy of the X-ray irradiation used, the dose rate, technical or methodical variances, metaphases and DC scoring criteria, and the professional experience of the scorers.…”

“…These interlaboratory differences could emanate from the energy of the X-ray irradiation used, the dose rate, technical or methodical variances, metaphases and DC scoring criteria, and the professional experience of the scorers. For examples, although most authors used X-rays of 220-250 kVp (26,28,29,(32)(33)(34), others used 100-180 kVp (19,30,31,35). In addition, the dose rate varied from 1 Gy/min (26,30,32), to about 0.5 Gy/min (31,34), to 0.27 Gy/min or less (19,35) (Figure 6).…”

“…The DCA has many advantages, such as a high specificity to ionizing radiation, the slow DC decay with the possibility of assessing exposure even months after irradiation, the potential to detect partial body exposure, and its sensitivity to doses down to 20 mGy when scoring a few thousand metaphases (14). Consequently, many countries have established specialized cytogenetic biodosimetry laboratories as part of the radiation protection program and the first medical responders to radiological and nuclear threats (15)(16)(17)(18)(19). We have previously described the establishment of a cytogenetic biodosimetry laboratory in Saudi Arabia along with producing a preliminary calibration curve composed of four volunteers (20).…”

The Use of Image Processing and Analysis in Automated Biological Dosimetry

“…The National Biodosimetry Laboratory in Indonesia was established in 2005 by the National Nuclear Energy Agency of Indonesia, known locally as Badan Tenaga Nuklir Nasional (BATAN). Our research group within BATAN established the national standard dose-response calibration curves for DCA and MN in 2013, 2016, 2017, and 2019 [30][31][32][33][34]. The establishment of a national standard dose-response calibration curve for γH2AX is currently in progress in the laboratory.…”

Chronic exposure to low doses of ionizing radiation impacts the processing of glycoprotein N-linked glycans in Medaka (Oryzias latipes)

“…Effects of high/moderate ionizing radiation such as cell death, chromosomal aberrations, DNA damage, mutagenesis, and carcinogenesis are well understood and extensively studied (Barber et al 2002;Dubrova 2003;Joseph et al 2004;Saha 2012;Perumal et al 2015;Lusiyanti et al 2019), and the linear relationship between high doses of radiation and biological effects are well accepted. Research on how to improve radiotherapy has played an important role in the understanding of these relationships when a chronic exposure occurs.…”