Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study.
Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study.
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DOI：
10.1016/s0140-6736(12)60815-0
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发表时间：
2012-08-04
期刊：
影响因子：
168.9
通讯作者：
de Gonzalez, Amy Berrington
中科院分区：
文献类型：
--
作者：
Pearce, Mark S.;Salotti, Jane A.;Little, Mark P.;McHugh, Kieran;Lee, Choonsik;Kim, Kwang Pyo;Howe, Nicola L.;Ronckers, Cecile M.;Rajaraman, Preetha;Craft, Alan W.;Parker, Louise;de Gonzalez, Amy Berrington
尽管 CT 扫描在临床上非常有用，但相关的电离辐射存在潜在的癌症风险，特别是对于比成人对放射更敏感的儿童。我们的目的是评估一组儿童和年轻人接受 CT 扫描后患白血病和脑肿瘤的额外风险。在我们的回顾性队列研究中，我们纳入了 1985 年至 2002 年间在英格兰、威尔士或苏格兰（英国）的国家医疗服务 (NHS) 中心首次接受 CT 检查的患者，当时他们的年龄还不到 22 岁。我们从 NHS 中央登记处获得了 1985 年 1 月 1 日至 2008 年 12 月 31 日期间癌症发病率、死亡率和失访的数据。我们估计了每次 CT 扫描吸收的大脑和红骨髓剂量（以 mGy 为单位），并使用泊松相对风险模型评估了白血病和脑肿瘤的过度发病率。为了避免纳入与癌症诊断相关的 CT 扫描，白血病的随访在第一次 CT 后 2 年开始，脑肿瘤的随访在第一次 CT 后 5 年开始。随访期间，178 604名患者中有74名被诊断患有白血病，176 587名患者中有135名被诊断患有脑肿瘤。我们注意到 CT 扫描的辐射剂量与白血病（相对风险 [ERR] 每 mGy 0·036，95% CI 0·005–0·120；p=0·0097）和脑肿瘤（0·023、0·010–0·049；p<0·0001）呈正相关。与接受剂量低于5 mGy的患者相比，接受累积剂量至少30 mGy（平均剂量51·13 mGy）的患者患白血病的相对风险为3·18（95% CI 1·46–6·94），接受累积剂量50–74 mGy（平均剂量60·42 mGy）的患者患脑癌的相对风险为3·18（95% CI 1·46–6·94）。 2·82（1·33–6·03）。对儿童使用 CT 扫描提供约 50 mGy 的累积剂量可能会使患白血病的风险几乎增加三倍，而约 60 mGy 的剂量可能会使患脑癌的风险增加三倍。由于这些癌症相对罕见，累积的绝对风险很小：在 10 岁以下患者第一次扫描后的 10 年内，每 10000 次头部 CT 扫描估计会出现 1 例过量的白血病病例和 1 例脑肿瘤病例。尽管如此，尽管临床获益应大于较小的绝对风险，但 CT 扫描的辐射剂量应尽可能保持在较低水平，并且在适当的情况下应考虑不涉及电离辐射的替代程序。美国国家癌症研究所和英国卫生部。
Although CT scans are very useful clinically, potential cancer risks exist from associated ionising radiation, in particular for children who are more radiosensitive than adults. We aimed to assess the excess risk of leukaemia and brain tumours after CT scans in a cohort of children and young adults. In our retrospective cohort study, we included patients without previous cancer diagnoses who were first examined with CT in National Health Service (NHS) centres in England, Wales, or Scotland (Great Britain) between 1985 and 2002, when they were younger than 22 years of age. We obtained data for cancer incidence, mortality, and loss to follow-up from the NHS Central Registry from Jan 1, 1985, to Dec 31, 2008. We estimated absorbed brain and red bone marrow doses per CT scan in mGy and assessed excess incidence of leukaemia and brain tumours cancer with Poisson relative risk models. To avoid inclusion of CT scans related to cancer diagnosis, follow-up for leukaemia began 2 years after the first CT and for brain tumours 5 years after the first CT. During follow-up, 74 of 178 604 patients were diagnosed with leukaemia and 135 of 176 587 patients were diagnosed with brain tumours. We noted a positive association between radiation dose from CT scans and leukaemia (excess relative risk [ERR] per mGy 0·036, 95% CI 0·005–0·120; p=0·0097) and brain tumours (0·023, 0·010–0·049; p<0·0001). Compared with patients who received a dose of less than 5 mGy, the relative risk of leukaemia for patients who received a cumulative dose of at least 30 mGy (mean dose 51·13 mGy) was 3·18 (95% CI 1·46–6·94) and the relative risk of brain cancer for patients who received a cumulative dose of 50–74 mGy (mean dose 60·42 mGy) was 2·82 (1·33–6·03). Use of CT scans in children to deliver cumulative doses of about 50 mGy might almost triple the risk of leukaemia and doses of about 60 mGy might triple the risk of brain cancer. Because these cancers are relatively rare, the cumulative absolute risks are small: in the 10 years after the first scan for patients younger than 10 years, one excess case of leukaemia and one excess case of brain tumour per 10 000 head CT scans is estimated to occur. Nevertheless, although clinical benefits should outweigh the small absolute risks, radiation doses from CT scans ought to be kept as low as possible and alternative procedures, which do not involve ionising radiation, should be considered if appropriate. US National Cancer Institute and UK Department of Health.