Thyroid dose from common head and neck CT examinations in children: is there an excess risk for thyroid cancer induction?
Thyroid dose from common head and neck CT examinations in children: is there an excess risk for thyroid cancer induction?
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DOI：
10.1007/s00330-006-0417-9
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发表时间：
2007-05-01
影响因子：
5.9
通讯作者：
Gourtsoyiannis, Nicholas
中科院分区：
文献类型：
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作者：
Mazonakis, Michalis;Tzedakis, Antonis;Gourtsoyiannis, Nicholas
本研究旨在评估儿童时期常见的头颈部计算机断层扫描（CT）检查中甲状腺剂量和甲状腺癌诱发的相关风险。采用蒙特卡罗N粒子输运程序模拟在顺序和/或螺旋模式下进行的脑部、鼻窦、内耳和颈部的常规CT扫描。使用代表新生儿和1岁、5岁、10岁和15岁儿童的数学模型计算平均甲状腺剂量。为了验证蒙特卡罗结果，使用热释光剂量计（TLD）对物理拟人模型进行剂量测量。根据扫描区域、儿科患者年龄和使用的采集模式，头部CT检查的甲状腺散射剂量从0.6 mGy到8.7 mGy不等。在颈部CT期间对甲状腺进行的初次照射导致吸收剂量范围为15.2-52.0 mGy。Monte Carlo计算和ESTA测量之间的平均差异为11.8%。甲状腺暴露于头部CT扫描的散射辐射与每百万患者4-65例的低但不可忽略的癌症诱发风险相关。颈部CT可导致甲状腺恶性肿瘤发生风险增加，高达390/100万患者。
This study was conducted to estimate thyroid dose and the associated risk for thyroid cancer induction from common head and neck computed tomography (CT) examinations during childhood. The Monte Carlo N-particle transport code was employed to simulate the routine CT scanning of the brain, paranasal sinuses, inner ear and neck performed on sequential and/or spiral modes. The mean thyroid dose was calculated using mathematical phantoms representing a newborn infant and children of 1year, 5 years, 10 years and 15 years old. To verify Monte Carlo results, dose measurements were carried out on physical anthropomorphic phantoms using thermoluminescent dosemeters (TLDs). The scattered dose to thyroid from head CT examinations varied from 0.6 mGy to 8.7 mGy depending upon the scanned region, the pediatric patient's age and the acquisition mode used. Primary irradiation of the thyroid gland during CT of the neck resulted in an absorbed dose range of 15.2-52.0 mGy. The mean difference between Monte Carlo calculations and TLD measurements was 11.8%. Thyroid exposure to scattered radiation from head CT scanning is associated with a low but not negligible risk of cancer induction of 4-65 per million patients. Neck CT can result in an increased risk for development of thyroid malignancies up to 390 per million patients.