A Comparison of Radiobiological Response in Cells Exposed to Low LET Radiation with Different Beam Energies

There is conflicting evidence in the literature on biological effects between different low LET radiations. The aim of this study was to investigate the impact of different low LET radiations on radiobiological response. Chromosomal radiosensitivity was measured in human lymphocytes from healthy donors using the G2 chromosomal radiosensitivity assay. Radiation induced mitotic inhibition was also measured. Cells were irradiated to doses of 0.05 and 0.5 Gy using a Cobalt 60 teletherapy unit and a Linac operating at 6 MV (photons) and 12 MeV (electrons). As expected, a dose response was observed with increasing dose resulting in greater response. No statistically significant differences were observed, however, with different beam energies. Our study shows no statistically significant difference in radiobiological response with beam energy as measured using G2 chromosomal radiosensitivity and radiation induced mitotic inhibition as endpoints.