Introduction: Brachytherapy is a preferred choice of radiotherapy in the treatment of sensitive tissues cancer like intestine and gonad. The treatment is expensive because of the frequent replacement of radionuclide sources. A better understanding of cell killing and the cellular responses at different dose rates, might aid in tumor cell killing with fewer doses thereby enhancing a better prognosis.
Methods: The cervix cancer cell line was irradiated with doses ranging from 2Gy-10 Gy at three different dose-rates as used in brachytherapy along with unexposed sample as control. The biological effects of different doses and dose rate of the cells was assessed by measuring its cytotoxicity,genotoxicity and clonogenic ability of exposed cells. The bystander effect was examined by co-culturing the exposed tumor cells with the unexposed normal blood lymphocyte and vice-versa.
Results: A significant and dose dependent changes in cell viability (trypan blue exclusion), genotoxicity (Micronucleus assay) and colony forming ability (Clonogenic assay) was observed in the cells exposed to different doses of radiation (p<0.0001); however, the changes were dose-rate independent.urthermore, the bystander study results show an enhanced cell killing in the tumor cells which suggest a beneficial bystander effects.
Conclusion: The observed elevated bystander response in the tumour cells compared to that of normal blood lymphocytes suggest that if it happens under in-vivo situation, could results in has a therapeutic gain.
Published on: Nov 15, 2015 Pages: 7-13