利用人外周血淋巴细胞染色体畸变估算离体模拟局部照射剂量

摘要/Abstract

摘要： 多数电离辐射事故均为局部照射。对于局部照射剂量估算,国际原子能机构(IAEA)推荐采用Dolphin's 模型,该模型需推算出照射部位染色体畸变率,再代入离体均匀照射情况下建立的剂量效应曲线来估算局部照射剂量。准确推算照射部位染色体畸变率对于估算剂量十分重要,选用合适的剂量效应曲线对估算剂量也同样重要,而对于局部照射,关于不同剂量率剂量效应曲线对估算结果影响的报道还十分有限。基于此本研究利用人外周血淋巴细胞染色体畸变估算离体模拟局部照射剂量,分析不同剂量率剂量效应曲线对估算结果的影响。利用⁶⁰Co γ射线离体照射人外周血样品(样本A和样本B),剂量分别为1 Gy和5 Gy。将照射血与未照射血按25%和75%比例混合以模拟局部照射,分析混合血样中淋巴细胞的双着丝粒染色体(dicentric chromosome,dic)加着丝粒环(r),利用Dolphin's模型估算局部照射dic+r率,并用剂量率不同的两种剂量效应曲线估算局部照射剂量。结果显示,大部分混合血样dic+r分布不符合泊松分布,为过离散分布。利用与实际照射剂量率一致的剂量效应曲线估算的样品受照剂量大多与实际照射剂量比较接近,相对偏差在10%以内,但两样本的1 Gy 25%组的估算受照剂量与实际照射剂量偏差较大。利用与实际照射剂量率不一致的剂量效应曲线估算的样品受照剂量与实际照射剂量相对偏差均超过10%。结果表明dic+r分析用于估算离体模拟局部照射的剂量有可行性,采用剂量率和照射剂量率一致的剂量效应曲线估算的结果更为准确。

关键词: 局部照射, Dolphin's 模型, 染色体畸变, 剂量估算

Abstract: The majority of ionizing radiation accidents is partial exposure. Dolphin's model, recommended by IAEA, is applied to estimate partial exposure dose. Apply this model to calculate the chromosome aberration frequency in exposure area, and then put the chromosome aberration rate into dose-response curve established in vitro to estimate partial exposure dose. For elevating accuracy of partial exposure dose estimation, choosing appropriate dose-response curve is as important as accurately calculating chromosome aberration frequency. However, studies about affection of dose-response curve with different dose rate on partial exposure estimation are limited. Base on this, partial exposure doses were estimated by dic+r frequency and affection of dose-response curve with different dose rate on partial exposure estimation was analyzed in this study. Human peripheral blood lymphocytes (from sample A or sample B) were induced by ⁶⁰Co γ rays at 1 Gy and 5 Gy. Mix the exposed blood with the blood without exposure in 25% or 75% ratio to simulate partial exposure. Analyze dicentric chromosome (dic) plus centromeric ring (r) frequencies in mixed blood via Dolphin's model. Partial doses were estimated by using two curves with different dose rate. As results, dic+r distribution in most of mixed blood samples did not conform to poisson distribution. Based on the dose-response curve consistent with the actual dose rate, most partial doses were close to the actual doses, and the relative deviation was less than 10%. However, the estimated dose of 1 Gy 25% groups of two samples deviate greatly from the actual dose. Applying the dose-response curve inconsistent with the actual dose rate, all the relative deviation between estimated partial doses and actual doses were more than 10%. In conclusion, dic+r can be used to estimate the simulated partial exposure dose in vitro. It is more accuracy for partial exposure dose estimation to apply dose-response curve, which dose rate is same as actual dose rate.

Key words: partial exposure, dolphin's model, chromosomal aberration, dose estimation

中图分类号:

Q691.5

田雪蕾, 陆雪, 蔡恬静, 田梅, 刘青杰. 利用人外周血淋巴细胞染色体畸变估算离体模拟局部照射剂量[J]. 辐射防护, 2021, 41(4): 309-314.

TIAN Xuelei, LU Xue, CAI Tianjing, TIAN Mei, LIU Qingjie. Estimating partial exposure dose by chromosomal aberrations in human peripheral blood lymphocytes in vitro[J]. RADIATION PROTECTION, 2021, 41(4): 309-314.

参考文献

[1] 卞晓璐,韩贞琳,张晓强,等. 1例¹⁹²Ir源致外照射轻度骨髓型急性放射病的临床观察与随访[J]. 中国辐射卫生, 2018,27(4): 318-321.
BIAN X L, HAN Z L, ZHANG X Q, et al. Medical follow up and clinical observation of a case exposed to ¹⁹²Ir source with mild bone marrow from of ARS[J]. Chin J Radio Health, 2018,27(4): 318-321.
[2] 戴宏,刘玉龙,王优优,等. 南京“5.7”¹⁹²Ir 源放射事故患者的生物剂量估算[J]. 中华放射医学与防护志, 2016,36(5):350-354.
DAI H,LIU Y L,WANG Y Y,et al. Biological dosimetry for the victim accidentally exposed to ¹⁹²Ir radiation source at “5.7” in Nanjing[J]. China J Radiol Med Prot, 2016, 36(5):350-354.
[3] 陈维,王进,王福如,等. 一起¹⁹²Ir源丢失事故导致人员意外受照的调查与分析[J]. 中国辐射卫生, 2016, 25(1): 64-66.
CHEN W, WANG J, WANG F R, et al. An investigation and analysis of accidental exposure of personnel resulting from a ¹⁹²Ir source loss accident[J]. Chin J Radio Health, 2016, 25(1): 64-66.
[4] Voisin P, Assaei R G, Heidary A, et al. Mathematical methods in biological dosimetry: the 1996 Iranian accident[J]. Int J Radiat Biol, 2000, 76(11): 1545-1554.
[5] Mònica P,Leonardo B, Pedro P, et al. A new model for biological dose assessment in cases of heterogeneous exposures to ionizing radiation[J]. Radiation Research, 2016, 185(2):151-162.
[6] Roch-lefevre S, Pouzoulet F, Giraudet A L, et al. Cetogenetic assessment of heterogeneous radiation doses in cancer patients treated with fractionated radiotherapy[J]. The British Journal of Radiology, 2010, 83:759-766.
[7] Mariana E Mendes, Julyanne C G Mendonca, Joan F Barquinero, et al. Comparative study of micronucleus assays and dicentric plus ring chromosomes for dose assessment in particular cases of partial-body exposure[J]. Int J Radiat Biol, 2019, 95(8): 1058-1071.
[8] 韩保光,陈迪,金璀珍,等. 染色体畸变分析用于离体模拟与活体局部照射剂量估计的实验研究[J]. 辐射防护,1993,13(6):401-412.
HAN B G,CHEN D,JIN C Z,et al. Study of using chromosomal aberreation analysis to estimate partial exposure dose in vitro and in vivo[J]. Radiation Protection, 1993,13(6): 401-412.
[9] International Atomic Energy Agency. Cytogenetic dosimetry: applications in preparedness for and response to radiation emergensis[R]. Vienna: IAEA, 2011.
[10] Pham N D, Nguyen M H, Tran Que, et al. Determination of spontaneous dicentric frequencies and establishment of dose-response curves after expose of human peripheral blood lymphocytes to low- and high-dose rate ⁶⁰Co gamma rays—the basis for cytogenetic biodosimetry in Vietnam[J]. Int J Radiat Biol, 2019, 95(3): 307-313.
[11] 中国疾病预防控制中心辐射防护与核安全医学所. 染色体畸变估算生物剂量方法:GB/T 28236—2011 [S]. 北京:中国标准出版社,2012.
National Institute for Radiological Protection,Chinese Center for Disease Control and Prevention. Method for chromosomal aberreation estimating biological dose:GB/T 28236—2011 [S]. Beijing: Standards Press of China,2012.
[12] 金璀珍, 刘秀林, 张泽云. 一例¹⁹²Ir源辐射事故病人受照生物剂量的估算[J]. 中华放射医学与防护杂志, 1997, 17(1):34-36.
JIN C Z, LIU X Y, ZHANG Z Y. Cytogenetic dosimetry for a victim accidentally exposed to ¹⁹²Ir gamma-rays[J]. China J Radiol Med Prot, 1997, 17(1):34-36.
[13] Prasanna P G, Moroni M, Pellmar C. Triage dose assessment for partial-body exposure: dicentric analysis[J]. Health Phys, 2010, 98(2): 244-251.
[14] Vaurijoux A, Gregoire E, Roch-lefevre S, et al. Detection of partial-body exposure to ionizing radiation by the automatic detection of dicentrics[J]. Radiat Res, 2012, 177:357-364.
[15] Romm H, Ainsbury E, Barnad S, et al. Validation of semi-automatic scoring of dicentric chromosomes after simulation of three different irradiation scenarios[J]. Health Phys, 2014, 106(6): 764-771.