南京 192 Ir放射事故患者照后第4年细胞遗传学随访

Objective To screen the indicators of retrospective dose estimation, based on 5 cytogenetic methods to assess the victim followed-up at 4 year after 192Ir radiation accident in Nanjing. Methods The chromosome aberration (dic + r) assay, cytokinesis block micronucleus (MN) and nucleoplasmic bridge (NPB) assay, fluorescence in situ hybridization (FISH)-based and G banding-based translocation analysis were used to retrospective biological dose estimation. Results The estimated doses of FISH-based and G banding -based analysis were 1.45 and 1.21 Gy respectively, which was similar to the biological dose estimated short time after the accident. However, the estimated doses by chromosome aberration, micronucleus and nucleoplasmic bridge method were 0.56, 0.45 and 0.41 Gy respectively, which were lower than the corresponding biodose. Correction factors were used to adjust the biodose. Conclusions In the 4th years after exposure, the estimated biological doses by FISH-based and G banding-based translocation were consistent with the biodose.Therefore, the two methods were suitable for retrospective dose estimation, while correction factors should be considered in chromosome aberration method for retrospective dose estimation. Key words: Chromosome aberration; Fluorescence in situ hybrdization; G banding; Biological dose estimation; Correction coefficient