title: Biodosimetry of Persons Chronically Exposed to Low and Therapeutic Doses of Ionizing Radiation.
abstract: Dynamic changes of the chromosomal aberrations and the DNA damage were analyzed in individuals exposed to low and therapeutic doses of radiation. The investigation included 37 persons living in areas where the radioactive sources were discovered 10-12 years ago. It was established by biodosimetry methods that the examined persons had absorbed dose of 0.2-0.7 Gy or had increased number of chromosomal aberrations, though insufficient to determine a dose. Clinical examination, chromosomal analysis, and assay of DNA damage by the comet (single-cell gel electrophoresis) assay were carried out. There was no correlation between the doses received 10 years ago and the cytogenetic changes with clinical outcome. The effect of the local fractionated gamma-irradiation with doses of 40-70 Gy was studied in cancer patients with localized head and neck tumors. The study of chromosomal abnormalities, the DNA damages by the comet assay, and the micronuclei detection of the buccal cells revealed a statistically significant correlation between the initial cytogenetic indices in cancer patients and their dynamic changes during and after the radiation exposure. In addition, the correlation was detected between the initial cytogenetic parameters and the functional stage of red blood system. Our results allow us to conclude that there is a need for further research to estimate the individual radiation risk to optimize and individualize the subsequent medical management of radiotherapy.
authors.affiliation: Ivane Beritashvili Center of Experimental Biomedicine, Tbilisi, Georgia.
authors.forename: Alla
authors.initials: A
authors.lastname: Zedginidze
authors.affiliation: Tbilisi State University, E. Andronikashvili Institute of Physics, Tbilisi, Georgia.
authors.forename: Ema
authors.initials: E
authors.lastname: Namchevadze
authors.affiliation: Ivane Beritashvili Center of Experimental Biomedicine, Tbilisi, Georgia.
authors.forename: George
authors.initials: G
authors.lastname: Ormocadze
authors.affiliation: Universal Medical Center, Tbilisi, Georgia.
authors.forename: Archil
authors.initials: A
authors.lastname: Kapanadze
authors.affiliation: Ivane Beritashvili Center of Experimental Biomedicine, Tbilisi, Georgia.
authors.forename: Tamara
authors.initials: T
authors.lastname: Nikuradze
authors.affiliation: Medical University Clinic, Tbilisi, Georgia.
authors.forename: Darejan
authors.initials: D
authors.lastname: Lomidze
keywords: Chromosome aberrations; DNA damage; irradiation; micronuclei; radiotherapy