Effects of neutron, γ-ray, and neutron-γ-ray mixed radiations on chromosomal aberrations in peripheral blood lymphocytes of two males.

This study aimed to explore the relative biological effectiveness (RBE) of monoenergetic neutrons and the interactions of mixed radiation by investigating the biological effects of neutron, 137Cs γ-ray, and neutron-γ-ray mixed radiations on chromosomal aberrations in human peripheral blood lymphocytes. Human peripheral blood lymphocytes were treated with neutrons from the Intensive Deuterium and Tritium Neutron Source Science Facility and a gamma source from the 137Cs γ-ray source of the Chinese Academy of Sciences for follow-up experimental results. The chromosomal aberrations were analyzed in lymphocytes exposed to neutron, 137Cs γ-ray, and mixed radiations, and the RBE values of neutron radiation were calculated. The statistical distribution of chromosomal aberrations was tested using the dispersion index and Mann-Whitney Utest for all doses to conform to a Poisson distribution. The χ2test was used to compare the yields of dicentric and centromeric rings among different radiation groups and evaluate the goodness of fit of the dose-response curve. We used the ztest to evaluate the significance of the equation coefficients. The RBE for 10 dicentrics per 100 cells was 2.8 for neutron radiation. For 20 dicentrics per 100 cells, the respective value was 2.05. The yields of dicentric and centromeric rings significantly increased in the mixed radiation group compared with the 137Cs γ-ray group at the dose of 0.7 Gy. The considerations of the dose dependence of RBE and the intercellular interactions were indispensable for the precise estimation of the biological effect of neutron treatment on tumors.