Survival of Human Normal Thyroid Cells after X-ray Irradiation

Publisher Website
Google Scholar
Abstract
Normal thyroid cells from 25 individuals treated surgically for malignant or benign thyroid tumor were cultured in vitro and radiation induced cytotoxicity was studied. The mean lethal dose (D0), quasi-threshold (Dq) and extrapolation number (n) of survival curves of actively dividing thyroid cells assayed by colony formation were estimated to be 92.9 .+-. 2.8 cGy [centigrays] (rad), 58.1 .+-. 6.9 cGy and 2.0 .+-. 0.1, respectively (average for 25 individuals .+-. SE). Proliferating human thyroid cells apparently are more sensitive to X-rays than most other nonhematologic mammalian cells in similar assays. Cell survival was not significantly affected by sex, age, disease or exposure to atomic bomb radiation of the cell donor. However, the number of samples currently available is too small for definite conclusions in this regard.