Studies of Populations Exposed to Diagnostic Medical Radiation

血清免疫标记物和脑瘤风险的研究将在一项病例对照研究中对700万美国军事人员的成年胶质瘤进行随访，研究结果表明，过敏史和/或自身免疫性疾病与成人胶质瘤风险降低相关。我们将量化受试者中胶质瘤风险与选定细胞因子、生长因子和免疫相关疾病水平之间的剂量-反应关系。目标是促进参与者之间的跨学科互动，促进长期的研究合作。预计将根据会议记录出版一本专著。拟涵盖的主题包括：低剂量、低剂量率效应；非靶向放射生物学效应；辐射敏感亚群；剂量测定法;子宫内、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；辐射风险与公众。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。放疗器官剂量计算正在开发新的方法，以重建接受常规（Co-60和直线加速器）和先进（调强放射治疗和质子治疗）放疗技术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、剂量不确定性研究和回顾性流行病学研究。我们正在估计可能与当前成人CT使用水平有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年轻时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，一些迹象表明，在子宫内暴露于电离辐射会轻微地、不显著地增加所有儿童癌症和白血病的风险，而在婴儿早期暴露于x射线后，患淋巴瘤的风险可能会增加，这是基于少量数据的。一组接受CT检查的6万名以色列儿童将与国家癌症登记处联系起来，以估计与这些检查产生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发起了一项超过20万儿童的国际队列研究，以评估儿童CT扫描辐射暴露与癌症的潜在风险。为支持一项关于儿童癌症风险和CT暴露的研究，正在开发一个涵盖30个器官和组织的全面器官CT剂量数据库。与辐射有关的脑肿瘤汇总分析已作出初步安排，对与辐射有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对大脑的辐射剂量的信息。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的几十年里显著增加。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。为了提高我们对甲状腺癌病因的认识，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。

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.