Radiation signature on exposed cells: Relevance in dose estimation

Abstract

The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical management. An ideal biomarker to adopt in those situations should be rapid, specific, sensitive, reproducible, and able to categorize the nature of exposure and could provide a reliable dose estimation irrespective of the time of the exposures. Since cytogenetic markers shown to have many advantages relatively than other markers, the origins of various chromosomal abnormalities induced by ionizing radiations along with dose-response curves generated in the laboratory are presented. Current status of the gold standard dicentric chromosome assay, micronucleus assay, translocation measurement by fluorescence in-situ hybridization and an emerging protein marker the γ-H2AX assay are discussed with our laboratory data. With the wide choice of methods, an appropriate assay can be employed based on the net.

Interim In vitro Dose-Response Curve for the Dicentric Biodosimeter Assay from a Philippine Radiotherapy Facility using a Linear Accelerator

“…A higher dose rate means a lower chance for DNA repair. 19 When compared to cytogenetic dose-response curves using x-ray irradiation, the coefficients developed by this study's curves are similar to published data ( Table 5). The calibration curve aims to determine an accurate dose from a set of analyzed cells and dicentric frequencies, ideally within 20% of the actual whole-body dose received by the individual.…”

A statistical framework for radiation dose estimation with uncertainty quantification from the γ-H2AX assay

“…Beside the well–understood dependence on time after exposure due to focus loss [17], the curve parameters may also depend on different scoring mechanisms [13], the laboratory [13, 19], the technician who is carrying out the scoring [21], the temperature at exposure [22], shipment [23], as well as the cell type investigated [16, 24]. Furthermore, it has been reported that H2AX focus counts exhibit considerable inter–individual variation [13, 17], which can be partly attributed to covariates like age, smoking, or genetic factors [23]. However, Moquet et al [19] argued, referring to [24], that this variation only makes a “small contribution” towards the estimation of calibration curve parameters and their uncertainties.…”

Progressive breast fibrosis caused by extreme radiosensitivity: Oncocytogenetic diagnosis and treatment by reconstructive flap surgery

“…This effect was measurable only with more than 2‐Gy irradiation of the blood samples . However, micronucleus method is less sensitive than chromosome aberration technique . In a previously mentioned study with 47 breast cancer cases using 3‐Gy in vitro irradiation before therapy, patients with more translocations (proved by FISH technique) showed less latency period before late skin effects appeared .…”