Lubin Jay H, Adams M Jacob, Shore Roy, Holmberg Erik, Schneider Arthur B, Hawkins Michael M, Robison Leslie L, Inskip Peter D, Lundell Marie, Johansson Robert, Kleinerman Ruth A, de Vathaire Florent, Damber Lena, Sadetzki Siegal, Tucker Margaret, Sakata Ritsu, Veiga Lene H S
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892.
University of Rochester School of Medicine and Dentistry, Department of Public Health Sciences, Rochester, New York 14642.
J Clin Endocrinol Metab. 2017 Jul 1;102(7):2575-2583. doi: 10.1210/jc.2016-3529.
The increased use of diagnostic and therapeutic procedures that involve radiation raises concerns about radiation effects, particularly in children and the radiosensitive thyroid gland.
Evaluation of relative risk (RR) trends for thyroid radiation doses <0.2 gray (Gy); evidence of a threshold dose; and possible modifiers of the dose-response, e.g., sex, age at exposure, time since exposure.
Pooled data from nine cohort studies of childhood external radiation exposure and thyroid cancer with individualized dose estimates, ≥1000 irradiated subjects or ≥10 thyroid cancer cases, with data limited to individuals receiving doses <0.2 Gy.
Cohorts included the following: childhood cancer survivors (n = 2); children treated for benign diseases (n = 6); and children who survived the atomic bombings in Japan (n = 1). There were 252 cases and 2,588,559 person-years in irradiated individuals and 142 cases and 1,865,957 person-years in nonirradiated individuals.
There were no interventions.
Incident thyroid cancers.
For both <0.2 and <0.1 Gy, RRs increased with thyroid dose (P < 0.01), without significant departure from linearity (P = 0.77 and P = 0.66, respectively). Estimates of threshold dose ranged from 0.0 to 0.03 Gy, with an upper 95% confidence bound of 0.04 Gy. The increasing dose-response trend persisted >45 years after exposure, was greater at younger age at exposure and younger attained age, and was similar by sex and number of treatments.
Our analyses reaffirmed linearity of the dose response as the most plausible relationship for "as low as reasonably achievable" assessments for pediatric low-dose radiation-associated thyroid cancer risk.
涉及辐射的诊断和治疗程序使用增加，引发了对辐射影响的担忧，尤其是在儿童和对辐射敏感的甲状腺方面。
评估甲状腺辐射剂量<0.2 格雷（Gy）时的相对风险（RR）趋势；阈值剂量的证据；以及剂量反应的可能调节因素，如性别、暴露时年龄、暴露后时间。
来自九项儿童期外照射与甲状腺癌队列研究的汇总数据，具有个体化剂量估计，≥1000 名受照射受试者或≥10 例甲状腺癌病例，数据限于接受剂量<0.2 Gy 的个体。
队列包括以下人群：儿童癌症幸存者（n = 2）；接受良性疾病治疗的儿童（n = 6）；以及日本原子弹爆炸幸存者儿童（n = 1）。受照射个体中有 252 例病例和 2588559 人年，未受照射个体中有 142 例病例和 1865957 人年。
无干预措施。
甲状腺癌发病情况。
对于<0.2 Gy 和<0.1 Gy 的剂量，RR 均随甲状腺剂量增加（P < 0.01），与线性关系无显著偏差（分别为 P = 0.77 和 P = 0.66）。阈值剂量估计范围为 0.0 至 0.03 Gy，95%置信上限为 0.04 Gy。剂量反应增加趋势在暴露后持续>45 年，在暴露时年龄较小和达到年龄较小时更大，且在性别和治疗次数方面相似。
我们的分析再次确认剂量反应的线性关系是小儿低剂量辐射相关甲状腺癌风险“尽可能合理低”评估中最合理的关系。
