Assessment of simulated high-dose partial-body irradiation by PCC-R assay

The estimation of the dose and the irradiated fraction of the body is important information in the primary medical response in case of a radiological accident. the pcc-r assay has been developed for high-dose estimations,but little attention has been given to its applicability for partial-body irradiations. in the present work we estimated the doses and the percentage of the irradiated fraction in simulated partial-body radiation exposures at high doses using the pcc-r assay. peripheral whole blood of three healthy donors was exposed to doses from 0-20 gy,with 60co gamma radiation. to simulate partial body irradiations,irradiated and nonirradiated blood was mixed to obtain proportions of irradiated blood from 10-90%. lymphocyte cultures were treated with colcemid and calyculin-a before harvest. conventional and triage scores were performed for each dose,proportion of irradiated blood and donor. the papworth's u test was used to evaluate the pccr distribution per cell. a dose-response relationship was fitted according to the maximum likelihood method using the frequencies of pcc-r obtained from 100% irradiated blood. the dose to the partially irradiated blood was estimated using the contaminated poisson method. a new d0 value of 10.9 gy was calculated and used to estimate the initial fraction of irradiated cells. the results presented here indicate that by pcc-r it is possible to distinguish between simulated partial- and whole-body irradiations by the u-test,and to accurately estimate the dose from 10-20 gy,and the initial fraction of irradiated cells in the interval from 10-90%. © the author 2013. published by oxford university press on behalf of the japan radiation research society and japanese society for therapeutic radiology and oncology.