RESUMEN
BACKGROUND/AIM: Altered fractionation is an area of intense clinical research in radiation oncology. Estimation of the α/ß ratio of individual carcinomas after establishment of primary cell cultures from tumor biopsies may prove of importance in the individualization of radiotherapy schemes. MATERIALS AND METHODS: Here we proposed a simple method to estimate the α/ß ratio in cultured cell lines (two lung carcinomas: A549 and H1299; one lung fibroblast cell line: MRC5), using viability assays. RESULTS: For the A549 cell line, the α/ß ratio ranged from 14-25 Gy, for H1299 from 11-43 Gy and for the MRC5 fibroblast cell line this was far lower, ranging from 0.69 to 6 Gy. The α/ß ratio decreased when extracted from comparisons of lower dose per fraction schemes. CONCLUSION: The α/ß ratio of a cell line can be easily defined after simple viability/dose fractionation experiments.