ABSTRACT
To assess relative biological effectiveness [RBE] of [131]I radiation relative to [60]Co gamma rays in glioblastoma spheroid cells. In this experimental study, glioblastoma spheroid cells were exposed to [131]I radiation and [60]Co gamma rays. Radiation induced DNA damage was evaluated by alkaline comet assay. Samples of spheroid cells were treated by radiation from [131]I for four different periods of time to find the dose-response equation. Spheroid cells were also exposed by 200 cGy of [60]Co gamma rays as reference radiation to induce DNA damage as endpoint. Resulted RBE of [131]I radiation relative to [60]Co gamma rays in 100 microm giloblastoma spheroid cells was equal to 1.16. The finding of this study suggests that [131]I photons and electrons can be more effective than [60]Co gamma rays to produce DNA damage in glioblastoma spheroid cells