Studies of Populations Exposed to Diagnostic Medical Radiation

免疫和脑瘤风险的血清标记物表明过敏和/或自身免疫性疾病史与成人胶质瘤风险降低有关的证据将在一项病例对照研究中进行，该研究嵌套在700万名美国军事人员中，具有诊断前的血清样本。我们将量化受试者中胶质瘤风险与选定的细胞因子和生长因子水平以及免疫相关疾病之间的剂量-反应关系。放射生物学外展的目标是促进参与者之间的跨学科互动，并促进长期研究合作。预计将从会议记录中编写一本专著。将涵盖的专题包括：低剂量、低剂量率效应；非靶向放射生物学效应；辐射敏感亚组；剂量学；宫内、职业性和环境性癌症；非癌症疾病，如甲状腺、白内障、心血管疾病；辐射风险和公众。计算机断层扫描器官剂量计算利用蒙特卡罗传输技术，正在开发新的工具和方法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。器官剂量估计值正用于回溯性流行病学队列和病例对照研究。放射治疗器官剂量计算正在开发新的方法来重建接受常规(Co-60和直线加速器)和先进(调强放射治疗和质子治疗)放射治疗的患者的器官剂量。这些方法用于与常规方法的剂量比较、剂量不确定度研究和回顾性流行病学研究。美国使用CT扫描的癌症风险我们正在评估与辐射相关的潜在癌症风险，这可能与目前成人使用CT的水平有关，并对CT筛查检查进行辐射风险-益处分析。早期生命辐射和儿童癌症的风险研究早期生命中的辐射暴露具有特别重要的意义，因为许多组织在子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，有一些迹象表明，在子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、非显著地增加，根据少数病例，在婴儿早期暴露于X射线后，患淋巴瘤的风险可能会增加。以色列的儿科CT检查接受CT检查的60,000名以色列儿童将与国家癌症登记处联系起来，以评估与这些检查的辐射暴露有关的所有癌症，特别是脑癌和白血病的风险。儿科CT扫描REB发起了一项对20多万名儿童进行的国际队列研究，以评估与儿科CT扫描的辐射暴露相关的潜在癌症风险。目前正在为总共30个器官和组织开发一个全面的器官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。辐射相关脑肿瘤的综合分析已经作出初步安排，对与辐射相关的恶性和良性脑肿瘤的风险进行综合分析，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着增加。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。正在研究的分子标记有BRAF、N-RAS、K-RAS、H-RAS和RET/PTC。辐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。

Serum Markers of Immunity and Risk of Brain Tumors Evidence that a history of allergy and/or autoimmune diseases is associated with a reduced risk of gliomas in adults will be followed up in a case-control study of adult gliomas nested within 7 million United States military personnel with pre-diagnostic serum samples. We will quantify the dose-response relationship between risk of gliomas and levels of selected cytokines and growth factors and immune-related disorders in the subjects. Radiobiology Outreach The goal is to stimulate interdisciplinary interactions between the participants and to foster long-term research collaboration. It is expected that a monograph will be produced from the proceedings of the conference. Topics to be covered include the following: low dose, low-dose-rate effects; non-targeted radiobiological effects; radiation sensitive subgroups; dosimetry; in utero, occupational and environmental cancers; non-cancer diseases, such as thyroid, cataracts, cardiovascular disease; radiation risk and the public. 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 studies. Radiotherapy Organ Dose Calculations New methods are being developed to reconstruct organ dose for patients treated by conventional (Co-60 and linear accelerator) and advanced (intensity modulated radiation therapy and proton therapy) radiotherapy techniques. The methods are used for dose comparison with conventional method, dose uncertainty study, and retrospective epidemiologic studies. Cancer 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 numbers. Pediatric CT Examinations in Israel A cohort of 60,000 Israeli children who received CT examinations will be linked with the national cancer registry to estimate the risk of all cancers, especially brain and leukemia, associated with radiation exposure from these examinations. Pediatric CT Scans REB initiated an international cohort study of over 200,000 children to evaluate the potential risk of cancer associated with radiation exposure from pediatric CT scans. A comprehensive organ CT dose database for a total of 30 organs and tissues is being developed in support of a study of pediatric cancer risk and CT exposure. 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 individuals. Molecular 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.