Studies of Populations Exposed to Diagnostic Medical Radiation

计算机断层扫描器官剂量计算-正在开发新的工具和方法，利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。器官剂量估计值被用于回顾性流行病学队列研究和病例对照研究。美国CT扫描使用的癌症风险-我们正在估计可能与成人当前CT使用水平相关的潜在辐射相关癌症风险，并对CT筛查检查进行辐射风险-收益分析。生命早期的辐射和儿童癌症的风险——研究生命早期的辐射暴露是特别重要的，因为许多组织在子宫内和更年轻的时候更容易受到辐射的影响。我们在2011年2月发表的分析结果显示，有一些迹象表明，在子宫内暴露于电离辐射下，所有儿童癌症和白血病的风险都有轻微的、不显著的增加，儿科CT扫描：REB发起了一项国际队列研究，对18万名儿童进行了研究，以评估儿童CT扫描辐射暴露与癌症的潜在风险。建立了一个全面的器官CT剂量数据库，以支持儿童癌症风险和CT暴露的研究。2012年发表的这项研究的结果首次表明，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总分析-已初步安排对辐射相关的恶性和良性脑肿瘤的风险进行汇总分析，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。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着增加。我们正在评估乳头状癌的分子标记和组织病理学变化是否在过去三十年中发生了变化，使用从一家美国医院收集的甲状腺肿瘤组织。研究的分子标记有BRAF、N-RAS、K-Ras、H-Ras和RET/PTC。放射相关甲状腺癌的综合分析-为了提高我们对甲状腺癌病因的了解，REB的科学家们建立了一个国际联盟来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、照射时年龄、达到年龄和照射后时间的潜在相互作用。儿童研究结果于2012年提交发表。

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.