Construction of In vitro Dose-response Curve for Human Peripheral Blood Exposed to High-energy Clinical 6 MV X-rays

A BSTRACT Introduction: High-energy LINAC X-rays are used instead of the traditional modality (γ-rays) in cancer radiotherapy. Health professionals may be exposed to these high-energy X-rays owing to mishandling or mechanical failure, and using a low-energy X-rays calibration curve may not yield a meaningful dose estimate. This study aimed to obtain a dose calibration curve by scoring dicentric chromosomes (DC) in peripheral blood cells exposed to a high-energy clinical 6 MV X-ray in vitro . Materials and Methods: The peripheral blood samples from healthy donors ( n = 2) were irradiated with 6 MV energy (5.78 Gy/min) of X-ray and induced biological damage was quantified as DC formation, as it is considered the gold standard biodosimetry. Results: Compared to the unexposed sample, the observed DC frequency in the X-irradiated samples reveals a significant ( P < 0.0001) dose-dependent increase. There is no significant ( P > 0.05) difference in DC analysis for intrascorer variances. The dose-response curve was fitted with a linear-quadratic fit. Conclusion: The established dose-response curve generated (c = 0.0007 ± 0.001, αD = 0.035 ± 0.013, βD 2 = 0.045 ± 0.005) for peripheral blood subjected to high energy clinical 6 MV X-irradiation could be used for biological dosimetry readily.