Damilakis John, Stratakis John, Raissaki Maria, Perisinakis Kostas, Kourbetis Nikiforos, Gourtsoyiannis Nicholas
Department of Medical Physics, Faculty of Medicine, University of Crete, Iraklion 71003, Crete, Greece.
Med Phys. 2006 Apr;33(4):1033-40. doi: 10.1118/1.2181297.
The aim of the current study was to (a) provide normalized dose data for the estimation of the radiation dose from upper gastrointestinal tract contrast (UGIC) studies carried out to infants and (b) estimate the average patient dose and risks associated with radiation from UGIC examinations performed in our institution. Organ and effective doses, normalized to entrance skin dose (ESD) and dose area product (DAP) were estimated for UGIC procedures utilizing the Monte Carlo N-particle (MCNP) transport code and two mathematical phantoms, one corresponding to the size of a newborn and one to the size of a 1-year-old child. The validity of the MCNP results was verified by comparison with dose data obtained in physical anthropomorphic phantoms simulating a newborn and a 1-year-old infant using thermoluminescence dosimetry (TLD). Data were also collected from 25 consecutive UGIC examinations performed to infants. Study participants were (a) 12 infants aged from 0.5 to 5.9 months (group 1) and (b) 13 infants aged from 6 to 15 months (group 2). For each examination, ESD and dose to comforters were measured using TLD. Patient effective doses were estimated using normalized dose data obtained in the simulation study. The risk for fatal cancer induction was estimated using appropriate coefficients. The results consist of tabulated dose data normalized to ESD or DAP for the estimation of patient dose. Conversion coefficients were estimated for various tube potentials and beam filtration values. The mean total fluoroscopy time was 1.26 and 1.62 min for groups 1 and 2, respectively. The average effective dose was 1.6 mSv for group 1 and 1.9 mSv for group 2. The risk of cancer attributable to the radiation exposure associated with a typical UGIC study was found to be up to 3 per 10 000 infants undergoing an UGIC examination. The mean radiation dose absorbed by the hands of comforters was 47 microGy. In conclusion, estimation of radiation doses associated with UGIC studies performed to infants can be made using the normalized dose data provided in the current study. Radiation dose values associated with UGIC examinations carried out to infants are not low and should be minimized as much as possible.
(a) 提供标准化剂量数据，用于估算对婴儿进行上消化道造影（UGIC）检查时的辐射剂量；(b) 估算在本机构进行的UGIC检查中患者的平均剂量以及与辐射相关的风险。利用蒙特卡罗N粒子（MCNP）输运代码和两个数学体模（一个对应新生儿大小，一个对应1岁儿童大小），估算了UGIC检查中各器官和有效剂量相对于体表入射剂量（ESD）和剂量面积乘积（DAP）的归一化值。通过与使用热释光剂量测定法（TLD）模拟新生儿和1岁婴儿的物理拟人化体模所获得的剂量数据进行比较，验证了MCNP结果的有效性。还收集了对婴儿进行的连续25次UGIC检查的数据。研究参与者为：(a) 12名年龄在0.5至5.9个月的婴儿（第1组）和(b) 13名年龄在6至15个月的婴儿（第2组）。每次检查时，使用TLD测量ESD和对辅助人员的剂量。利用模拟研究中获得的标准化剂量数据估算患者的有效剂量。使用适当的系数估算诱发致命癌症的风险。结果包括以ESD或DAP归一化的剂量数据表格，用于估算患者剂量。估算了各种管电压和束流过滤值的转换系数。第1组和第2组的平均总透视时间分别为1.26分钟和1.62分钟。第1组的平均有效剂量为1.6 mSv，第2组为1.9 mSv。发现与典型UGIC检查相关的辐射暴露导致的癌症风险高达每10000名接受UGIC检查的婴儿中有3例。辅助人员手部吸收的平均辐射剂量为47微戈瑞。总之，利用本研究提供的标准化剂量数据可以估算与对婴儿进行的UGIC检查相关的辐射剂量。与对婴儿进行的UGIC检查相关的辐射剂量值并不低，应尽可能将其降至最低。
