Shore R E, Beck H L, Boice J D, Caffrey E A, Davis S, Grogan H A, Mettler F A, Preston R J, Till J E, Wakeford R, Walsh L, Dauer L T
New York University School of Medicine, New York, United States of America. Radiation Effects Research Foundation, Hiroshima, Japan.
J Radiol Prot. 2018 Sep;38(3):1217-1233. doi: 10.1088/1361-6498/aad348. Epub 2018 Jul 13.
The recently published NCRP Commentary No. 27 evaluated the new information from epidemiologic studies as to their degree of support for applying the linear nonthreshold (LNT) model of carcinogenic effects for radiation protection purposes (NCRP 2018 Implications of Recent Epidemiologic Studies for the Linear Nonthreshold Model and Radiation Protection, Commentary No. 27 (Bethesda, MD: National Council on Radiation Protection and Measurements)). The aim was to determine whether recent epidemiologic studies of low-LET radiation, particularly those at low doses and/or low dose rates (LD/LDR), broadly support the LNT model of carcinogenic risk or, on the contrary, demonstrate sufficient evidence that the LNT model is inappropriate for the purposes of radiation protection. An updated review was needed because a considerable number of reports of radiation epidemiologic studies based on new or updated data have been published since other major reviews were conducted by national and international scientific committees. The Commentary provides a critical review of the LD/LDR studies that are most directly applicable to current occupational, environmental and medical radiation exposure circumstances. This Memorandum summarises several of the more important LD/LDR studies that incorporate radiation dose responses for solid cancer and leukemia that were reviewed in Commentary No. 27. In addition, an overview is provided of radiation studies of breast and thyroid cancers, and cancer after childhood exposures. Non-cancers are briefly touched upon such as ischemic heart disease, cataracts, and heritable genetic effects. To assess the applicability and utility of the LNT model for radiation protection, the Commentary evaluated 29 epidemiologic studies or groups of studies, primarily of total solid cancer, in terms of strengths and weaknesses in their epidemiologic methods, dosimetry approaches, and statistical modelling, and the degree to which they supported a LNT model for continued use in radiation protection. Recommendations for how to make epidemiologic radiation studies more informative are outlined. The NCRP Committee recognises that the risks from LD/LDR exposures are small and uncertain. The Committee judged that the available epidemiologic data were broadly supportive of the LNT model and that at this time no alternative dose-response relationship appears more pragmatic or prudent for radiation protection purposes.
最近发表的美国国家辐射防护与测量委员会（NCRP）第27号评论评估了流行病学研究的新信息，以确定这些信息在多大程度上支持将致癌效应的线性无阈（LNT）模型用于辐射防护目的（NCRP 2018《近期流行病学研究对线性无阈模型及辐射防护的影响》，第27号评论（马里兰州贝塞斯达：美国国家辐射防护与测量委员会））。其目的是确定近期关于低传能线密度（LET）辐射的流行病学研究，尤其是那些低剂量和/或低剂量率（LD/LDR）的研究，是否广泛支持致癌风险的LNT模型，或者相反，是否有充分证据表明LNT模型不适用于辐射防护目的。由于自国家和国际科学委员会进行其他主要综述以来，已经发表了大量基于新数据或更新数据的辐射流行病学研究报告，因此需要进行一次更新的综述。该评论对最直接适用于当前职业、环境和医疗辐射暴露情况的LD/LDR研究进行了批判性审查。本备忘录总结了第27号评论中审查的一些更重要的LD/LDR研究，这些研究纳入了实体癌和白血病的辐射剂量反应。此外，还概述了乳腺癌和甲状腺癌以及儿童期暴露后癌症的辐射研究。还简要提及了非癌症情况，如缺血性心脏病、白内障和遗传遗传效应。为了评估LNT模型在辐射防护中的适用性和实用性，该评论从流行病学方法、剂量测定方法和统计建模的优缺点，以及它们支持在辐射防护中继续使用LNT模型的程度等方面，对29项流行病学研究或研究组（主要是关于实体癌总数）进行了评估。概述了如何使辐射流行病学研究更具信息量的建议。NCRP委员会认识到LD/LDR暴露带来的风险很小且不确定。委员会判断，现有的流行病学数据广泛支持LNT模型，目前对于辐射防护目的而言，没有其他替代剂量反应关系显得更务实或谨慎。
