辐射诱发白血病超额相对危险从日本人群向中国人群的转移

目的 建立辐射诱发白血病超额相对危险(excess relative risk,ERR)从日本人群向中国人群的转移模型并实施.方法 以相加和相乘加权平均模型作为ERR人群间转移模型;选用<五大洲癌症发病率>第9卷计算两人群白血病基线发病率比值;以1994年发表的白血病亚型别ERR为转移起点,演算辐射诱发白血病ERR从日本人群向中国人群的转移.结果 拟定了一组辐射诱发白血病ERR转移的权重系数:所有类型男性的权重系数为0.4;所有类型女性,以及急性淋巴细胞白血病、急性髓系白血病和慢性髓系白血病双性别的权重系数均为0.3.转移的不确定度采用对数正态分布描述.结论 本研究中的相加和相乘加权平均模型及其权重系数充分考虑了日本人群与中国人群的白血病亚型别基线危险差异,适用于辐射诱发白血病ERR从日本人群到中国人群的转移.

Abstract：

Objective To establish a transfer model for excess relative risk (ERR) for radiation-related leukemia from Japanese population to Chinese population.Methods Combined ERR of several subtypes of leukemia published in 1994, with the corresponding leukemia baseline incidence rates obtained from Cancer Incidence in Five Continents Vol.Ⅸ (CI5-Ⅸ) for Japanese population and Chinese population, a weighted risk transfer model was employed between an additive model and a multiplicative model, to execute ERR transfer.Results A range of weighing factors was proposed for risk transfer models:weighing factor was 0.4 for male and 0.3 for female, acute lymphoblastic leukemia, acute myeloid leukemia and chronic myeloid leukemia.The uncertainty for ERR transfer was characterized by lognormal distribution.Conclusions Based on the difference of baseline incidence rate for subtypes of leukemia between Japanese population and Chinese population, the transfer model and these weighing factors discussed in the present study could be applicable to transfer ERR for radiation-related leukemia from Japanese population to Chinese population.     

我国人群辐射致胃癌危险系数估算研究

目的 估算我国人群胃癌辐射致癌危险系数.方法 应用美国电离辐射效应委员会研发的日本原子弹爆炸幸存者胃癌辐射致癌危险模型,估算其辐射致癌超额相对危险和绝对危险系数.综合日本人群辐射致癌危险转移为美国人群危险的多种转移方法,确定由日本人群向我国人群危险转移模型为相乘相加混合模型(算数尺度下,相乘和相加模型权重分别为0.7和0.3).根据我国肿瘤登记年报胃癌基线发病率,利用曲线拟合方法,估算其性别-年龄别基线发病率.综合日本人群胃癌辐射致癌危险系数及我国人群胃癌基线发病率,结合适用于我国人群的危险转移方法,估算我国人群胃癌辐射致癌危险系数.结果 估算获得我国人群胃癌辐射致癌超额相对危险系数值,男性为0.26/Sv,女性为0.64/Sv(30岁受照,60岁患癌).受照年龄越小,患癌年龄越小此系数越大.结论 我国人群胃癌辐射致癌危险系数高于日本原子弹爆炸幸存者,二者随性别-年龄变化趋势相同.     

辐射致癌危险预测模型的改进

对辐射致癌危险度的计算，足基于特定肿瘤的危险预测模型。最近，对原有模型中使用的一些参数进行了改进，包括采用两种危险系数即死亡率危险系数和发病率危险系数、提出年龄和性别特异性的致癌危险系数等，应用这些改进的危险系数，计算并给出了不同核素和不同暴露方式下组织和器官的辐射致癌危险度估计值。     

辐射致癌危险预测模型的改进

对辐射致癌危险度的计算,是基于特定肿瘤的危险预测模型。最近,对原有模型中使用的一些参数进行了改进,包括采用两种危险系数即死亡率危险系数和发病率危险系数、提出年龄和性别特异性的致癌危险系数等。应用这些改进的危险系数,计算并给出了不同核素和不同暴露方式下组织和器官的辐射致癌危险度估计值。     

辐射致癌危险模型及人群危险转移研究概况

对日本原子弹爆炸幸存者队列的流行病学研究,是各国进行辐射危害评价及赔偿的主要依据。依据流行病学数据建立模型,定量计算辐射危险,使该结果的应用更加明确。近年来随着日本原子弹爆炸幸存者队列数据资料的进一步搜集、方法学的不断完善,模型的研究也取得了新的进展。该文对迄今为止各个主要致力于辐射致癌研究的机构给出的辐射致癌模型及人群危险转移进行综述,简要介绍建立模型及转移时考虑的因素,以期为我国辐射致癌赔偿相关应用提供参照。     

辐射致癌危险评估的现状、问题及展望

辐射致癌危险评估的现状、问题及展望吴德昌辐射危害的评估中起主导作用的是有关辐射致癌的危险估计，本文将仅就辐射致癌危险的现状、存在问题及未来展望提出些分析。现状自１９７７年基本建议书发表以来的数年中，出现了一些有关辐射在人群中诱发癌症危险的新资料，并获...     

ICRP辐射遗传效应危险系数的估算程序

基于辐射防护目的,ICRP需要确定单位剂量性腺照射引起的遗传效应的发生概率,即辐射遗传效应危险系数．     

阳江高本底地区辐射致癌危险分析(1979-2002年)

目的 分析1999-2002年随访资料,并与既往1979-1998年资料合并分析,以期进一步提高辐射致癌危险估计的统计效能;调整个体吸烟因素,重新估计高本底地区小剂量电离辐射的致癌危险。 方法 高本底地区和对照地区居民癌症研究采用队列研究方法,分阶段对研究对象进行随访。本研究阶段首先搜集1999-2002年的癌症死亡资料,并初步分析1999-2002年高本底地区居民癌症死亡危险;其次通过ID号连接记录,将1999-2002年研究数据与1979-1998年研究数据进行合并,分析1979-2002年高本底地区居民的癌症死亡危险及调整吸烟后高本底地区居民的辐射致癌死亡危险。用Epicure软件中的DATAB模块计算人年数,用AMFIT模块的Poisson回归模型估算高本底地区居民癌症死亡的相对危险(RR)、超额相对危险系数(ERR/Sv)和可信区间(CI)。 结果 高本底地区和对照地区队列研究1999-2002年共随访76 264人,累积观察300 523人年,期间共死亡2 267例,其中癌症死亡239例。1979-2002年合并资料共随访125 079人,累积观察2 293 463人年,死亡14 711例,其中癌症死亡1 441例。1979-2002年癌症死亡分析结果显示,经性别、年龄调整后,高本底地区全癌症死亡的相对危险RR=0.99 (95%CI:0.89~1.11),高本底地区和对照地区相比癌症死亡,结果差异无统计学意义(P>0.05);1979-2002年高本底地区全部癌症死亡的超额相对危险系数(ERR/Sv)为-0.01(95%CI:-0.50~0.64)。调整吸烟后,1987-2002年高本底地区全癌症死亡相对危险RR=1.00(95%CI:0.87~1.15),差异无统计学意义(P>0.05);高本底地区全部癌症死亡的ERR/Sv为0.01(95%CI:-0.56~0.81)。 结论 未发现高本底地区小剂量电离辐射引起居民癌症死亡危险的增加。调整吸烟后,高本底地区全部癌症死亡与对照地区相比,差异仍无统计学意义,但超额相对危险(ERR)较调整前稍增大。     

急性白血病合并医院感染的危险因素及预防措施分析

白血病是临床常见的造血系统恶性肿瘤,发病率及病死率较高。根据白血病细胞的成熟程度及病程,白血病分为急性白血病(AL)和慢性白血病(CL)两类,前者发病急、病情进展快,病死率更高。AL发病时骨髓中大量白血病细胞增殖,抑制正常的造血功能,并广泛浸润肝脏、脾脏及淋巴结等,引发感染、出血、贫血等临床症状,其中感染会降低患者免疫力,是导致病情加重甚至死亡的重要原因。因此,根据AL患者医院感染的临床特征,深     

Biological effects of low-dose radiation from computed tomography scanning

Abstract

Purpose: With the widespread use of computed tomography (CT), the risks of low-dose radiation from CT have been increasingly highlighted. This study aims to illustrate the CT-induced biological effects and analyze the potential beneficial or harmful outcomes so as to provide radiologists with reasonable advice on CT usage.

Materials and methods: The related literature was analyzed according to the topics of stochastic effect, hereditary effect, deterministic effect, accumulative injuries, hormesis and adaptive response; population epidemiology data were also analyzed.

Results: CT accounts for 9% of X-ray examinations and approximately 40–67% of medical-related radiation, the dose is within the range of low-dose radiation (LDR). Two opposite viewpoints exist nowadays regarding the biological effects of CT scanning: They are either harmful or harmless. Approximately 0.6% and 1.5% of the cumulative cancer risk could be attributed to diagnostic X-rays in the UK and Germany, respectively. The probability of CT scans induced-cancer is about 0.7% and CT angiography's risk is around 0.13%. It is estimated that approximately 29,000 cancers could be related to CT scans in the USA every year. Meanwhile, another investigation of 25,104 patients who underwent 45,632 CT scans in 4 years showed that the majority of CT-induced cancers were accidents rather than certainties of frequent CT scans.

Conclusion: Although the LDR effects of CT are still controversial, the current problems include the high frequency-use and abuse of CT scans, the increase of radiation dose and accumulative dose in high-accuracy CT, and the poor understanding of carcinogenic risks. The underlying biological basis needs further exploring and the ratio of risks and benefits should be considered.     

Dose quantities for characterization of patients' exposure to radiation in computed tomography and their significance for risk estimation

Summary In order to evaluate patients' exposure to radiation in computed tomography, dose quantities such as the computed tomography dose index (CTDI), multiple scan average dose (MSAD) and dose free in air on the axis of rotation are used. The CTDI and the MSAD, derivable from the CTDI, are a good measure for the absorbed doses in the examined volume, but they do not take the biological sensitivity of the organs into account and do not describe the radiogenic risk that is actually relevant for patients and doctors. The dose on the axis of rotation is not an accurate measure of the effective dose and the radiogenic risk. The declaration of a limit for the dose on the axis of rotation should take the different regions into account, in order to guarantee acceptable image quality on one hand and to avoid an unnecessarily high risk on the other side. As physical dose quantities, the CTDI, MSAD and dose on the axis of rotation are useful to characterize and differentiate between programs and systems concerning radiation exposure. Eingegangen am 16. Dezember 1996 Nach überarbeitung angenommen am 14. M?rz 1997     

Effective doses to members of the public from the diagnostic application of ionizing radiation in Germany

The exposure of the German population to man-made radiation results mainly from diagnostic X-ray and nuclear medical examinations. Data are presented about the annual frequency and the average dose of the various examination types for West Germany in the years 1990–1992. According to these data a yearly average of approximately 1550 diagnostic examinations using ionizing radiation were performed per 1000 inhabitants resulting in an annual per caput effective dose of 1.9 mSv. Despite the frequent use of alternative examination techniques, such as sonography, nuclear magnetic resonance and endoscopy, the frequency of X-ray and nuclear medical examinations is still increasing. If collective risk assessments are done using the per caput effective dose, at least the age distribution of the patients must be considered. This leads to a “risk-modifying factor“ of 0.6–0.7 for patients to be applied to the ICRP risk coefficient of 5 % per Sv valid for the general population. However, radiation risk must always be viewed in context with disease- and therapy-related risks and balanced against the benefit of the diagnostic examination, which should always exceed the risk for a well-indicated procedure. Received 12 June 1996; Revision received 21 October 1996; Accepted 8 November 1996