Studies of Populations Exposed to Diagnostic Medical Radiation

计算机断层扫描器官剂量计算-通过使用蒙特卡罗传输技术来计算接受计算机断层扫描检查的儿童和成人患者的器官剂量，正在开发新的工具和方法。器官剂量估计被用于回顾性流行病学队列和病例对照研究美国使用CT扫描的癌症风险-我们正在估计可能与成人当前CT使用水平有关的潜在辐射相关癌症风险，并为CT筛查进行辐射风险-益处分析。早期生命辐射和儿童癌症风险-研究早期生命中的辐射暴露特别重要，因为许多组织在宫内和较年轻的暴露年龄更容易受到辐射影响。我们在2011年2月发表的分析结果显示，一些迹象表明，在宫内暴露于电离辐射的所有儿童癌症和白血病的风险略有、非显著增加，以及在婴儿早期暴露于x射线后患淋巴瘤的潜在风险增加。开发了一个全面的器官CT剂量数据库，以支持一项关于儿童癌症风险和CT暴露的研究。2012年发表的这项研究结果首次表明，儿童时期进行CT扫描后，患白血病和脑肿瘤的风险增加。辐射相关脑肿瘤的汇集分析-已做出初步安排，对与辐射相关的恶性和良性脑肿瘤的风险进行汇集分析，包括来自世界各地的研究数据，这些研究提供了个人大脑辐射剂量的信息了解甲状腺癌发病率的分子和组织病理学线索-甲状腺癌发病率在过去几十年中显著增加。我们正在使用从美国一家医院收集的甲状腺肿瘤组织来评估乳头状癌的分子标志物和组织病理学的变化在过去30年中是否发生了变化。正在研究的分子标志物是BRAF、N-RAS、K-RAS、H-RAS和RET/PTC。与辐射相关的甲状腺癌的池分析-为了提高我们对甲状腺癌病因的了解，REB的科学家们成立了一个国际联盟，研究儿童和成人的放射性甲状腺癌。将评估辐射剂量-反应的统计模型，以及与性别、暴露年龄、达到的年龄和暴露以来的时间的潜在相互作用。2012年提交了针对儿童的研究结果以供发表。

Computed Tomography Organ Dose Calculations - New tools and methods are being developed by using Monte Carlo transport technique to calculate organ dose for pediatric and adult patients undergoing computed tomography examinations. The organ dose estimates are being used for retrospective epidemiologic cohort and case-control studiesCancer Risks from CT Scan Use in the United States - We are estimating the potential radiation-related cancer risks that may be related to current levels of CT use in adults, and also conducting radiation risk-benefit analyses for CT screening examinations.Early Life Radiation and the Risk of Child Cancer - Studying radiation exposure during early life is of particular importance, given that many tissues are more susceptible to radiation effects in utero and at younger age of exposure. Results of our analysis, published in February 2011, showed some indication of a slight, non-significant increase in risk for all childhood cancer and leukemia with exposure to ionizing radiation in utero, and potential increased risk of lymphoma following exposure to x-rays in early infancy based on small numbersPediatric CT Scans - REB initiated an international cohort study of 180,000 children to evaluate the potential risk of cancer associated with radiation exposure from pediatric CT scans. A comprehensive organ CT dose database was developed in support of a study of pediatric cancer risk and CT exposure. The results from this study published in 2012 suggested for the first time that there are increased risks of leukemia and brain tumors after CT scans in childhood.Pooled Analysis of Radiation-Related Brain Tumors - Preliminary arrangements have been made to conduct a pooled analysis of the risk of radiation-related malignant and benign brain tumors, including data from studies worldwide that have information on radiation dose to the brain for individualsMolecular and Histopathologic Clues to the Understanding of Thyroid Cancer Incidence - Thyroid cancer incidence has increased significantly over the last few decades. We are evaluating whether alterations in molecular markers and histopathology of papillary carcinoma have changed over the last three decades, using thyroid tumor tissue collected from one US hospital. Molecular markers under investigation are BRAF, N-RAS, K-Ras, H-Ras, and RET/PTC.Pooled analysis of Radiation-Related Thyroid Cancer- To improve our understanding of the etiology of thyroid cancer, REB scientists have set up an international consortium to study radiogenic thyroid cancer in children and adults. Statistical models of the radiation dose-response will be assessed as well as potential interaction with gender, age at exposure, attained age, and time since exposure. Results for children were submitted for publication in 2012.