Dependence of micronuclei assay on the depth of absorbed dose.

Aim: The purpose of the present study is to investigate the dependence of micronuclei response on the depth of absorbed dose.

Background: One of the most common cytogenetic methods used for radiation dosimetry is micronuclei (MN). Being less complex and faster than other methods are two remarkable advantages of the MN method which make it suitable for monitoring of population. In biological dosimetry based on the micronuclei method, the investigation into the dependence of response on the depth in which dose is absorbed is significant, though has received less attention so far.

Materials And Methods: Blood samples were poured in separate vials to be irradiated at different depths using a linear accelerator system.

Results: According to the results, MN, as a function of the absorbed dose, had the best fitness with the linear-quadratic model at all depths. Furthermore, the results showed the dependence of MN response on the depth of absorbed dose. For doses up to 2 Gy, the maximum difference from the reference depth of 1.5 cm was related to the depth of 10 cm; however, by increasing the absorbed dose, the response associated with the depth of 20 cm showed the maximum deviation from the reference depth.

Conclusions: Consequently, it is necessary to apply a correction factor to the biological dosimetry. The correction factor is dependent on the depth and the absorbed dose.