ABSTRACT
To evaluate the feasibility of using radiosensitivity of peripheral leukocytes as a predictor of clinical therapeutic responses to radiosurgery in individuals with cerebral arteriovenous malformation (AVM), we enrolled 18 patients years after they had received Gamma Knife radiosurgery for their cerebral AVM. The AVMs were shown with different degrees of regression in size in posttherapeutic periods. The peripheral leukocytes of these patients were collected at the last neuroimaging follow-ups. The leukocytes, before and 1 and 2 h after 8 Gy external gamma-irradiation, were evaluated for the amounts of DNA double-strand breaks (DSB) in 50 randomly selected individual nuclei by the neutral single cell gel electrophoresis, or so-called comet analysis. After being adjusted for gender and age at radiosurgery, the individuals with less posttherapeutic regression in AMV sizes or relatively poor or inadequate responses to radiosurgery were shown to have significantly higher DSB repair capacity on their leukocytes by comet analysis. These results suggested that in vitro radiosensitivity of peripheral leukocytes may provide valuable information for predicting therapeutic response or for adjusting irradiation doses in AVM radiosurgery.
Subject(s)
DNA Damage , DNA Repair/radiation effects , Intracranial Arteriovenous Malformations/diagnosis , Intracranial Arteriovenous Malformations/radiotherapy , Leukocytes/radiation effects , Outcome Assessment, Health Care/methods , Radiosurgery/methods , Adolescent , Adult , Child , DNA/radiation effects , DNA/ultrastructure , Feasibility Studies , Female , Follow-Up Studies , Humans , Intracranial Arteriovenous Malformations/pathology , Leukocytes/ultrastructure , Male , Middle Aged , Statistics as Topic , Treatment OutcomeABSTRACT
(137)Cs contamination in living or agricultural environments may contribute to significant human internal exposure and cause adverse health effects. Contamination by (137)Cs and other radionuclides was detected in a river valley in northern Taiwan, in the 1990s. Given that the radioactivity appeared to be widely distributed in soil, rice and several other food plants in the areas surrounding several communities in the late 1990s [Y.B. Nabyvanents, T.F. Gesell, M.H. Jen, W.P. Chang, Distribution of (137)Cs in soil along Ta-han River Valley in Tau-Yuan County in Taiwan, J. Environ. Radioact. 54 (2001) 391], its possible impact on local occupants was further studied. Ten subjects in three families residing continuously in the highly contaminated valley and 10 non-exposed subjects matched for age, sex, and cigarette smoking habits from neighboring communities were evaluated for micronucleus frequencies and for degenerative nuclear changes in urinary exfoliated epithelial cells (EE cells). Micronucleus frequencies ( per thousand ) were significantly higher in the exposed subjects (4.79+/-1.21 per thousand ) than in the reference subjects (2.73+/-0.59 per thousand; Wilcoxon 2-sample test, P value 0.0004). There were also higher frequencies of EE cells with karyolysis and condensed chromatin in the exposed subjects than in reference subjects. These results indicate that genotoxic and/or mutagenic effects on urinary epithelial cells occur in human subjects who have resided for a long time in a radioactively contaminated environment.
