Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Canada.
Pediatr Radiol. 2013 Sep;43(9):1108-16. doi: 10.1007/s00247-013-2674-5. Epub 2013 Mar 26.
There is a need for updated radiation dose estimates in pediatric fluoroscopy given the routine use of new dose-saving technologies and increased radiation safety awareness in pediatric imaging.
To estimate effective doses for standardized pediatric upper gastrointestinal (UGI) examinations at our institute using direct dose measurement, as well as provide dose-area product (DAP) to effective dose conversion factors to be used for the estimation of UGI effective doses for boys and girls up to 10 years of age at other centers.
Metal oxide semiconductor field-effect transistor (MOSFET) dosimeters were placed within four anthropomorphic phantoms representing children ≤10 years of age and exposed to mock UGI examinations using exposures much greater than used clinically to minimize measurement error. Measured effective dose was calculated using ICRP 103 weights and scaled to our institution's standardized clinical UGI (3.6-min fluoroscopy, four spot exposures and four examination beam projections) as determined from patient logs. Results were compared to Monte Carlo simulations and related to fluoroscope-displayed DAP.
Measured effective doses for standardized pediatric UGI examinations in our institute ranged from 0.35 to 0.79 mSv in girls and were 3-8% lower for boys. Simulation-derived and measured effective doses were in agreement (percentage differences <19%, T > 0.18). DAP-to-effective dose conversion factors ranged from 6.5 ×10(-4) mSv per Gy-cm(2) to 4.3 × 10(-3) mSv per Gy-cm(2) for girls and were similarly lower for boys.
Using modern fluoroscopy equipment, the effective dose associated with the UGI examination in children ≤10 years at our institute is < 1 mSv. Estimations of effective dose associated with pediatric UGI examinations can be made for children up to the age of 10 using the DAP-normalized conversion factors provided in this study. These estimates can be further refined to reflect individual hospital examination protocols through the use of direct organ dose measurement using MOSFETs, which were shown to agree with Monte Carlo simulated doses.
鉴于新的剂量节约技术在儿科透视中的常规应用以及儿科影像中对辐射安全意识的提高，有必要更新儿科透视的辐射剂量估算。
使用直接剂量测量来估算我们研究所标准化小儿上消化道（UGI）检查的有效剂量，并提供剂量面积乘积（DAP）与有效剂量的转换因子，以便在其他中心估算 10 岁以下男孩和女孩的 UGI 有效剂量。
将金属氧化物半导体场效应晶体管（MOSFET）剂量计放置在代表≤10 岁儿童的四个人体模型内，并使用远大于临床使用的曝光量进行模拟 UGI 检查，以最大程度减少测量误差。使用 ICRP 103 权重计算测量的有效剂量，并根据患者日志中确定的我们机构的标准化临床 UGI（3.6 分钟透视、四个点曝光和四个检查射束投影）进行缩放。结果与蒙特卡罗模拟进行比较，并与透视器显示的 DAP 相关联。
我们研究所标准化小儿 UGI 检查的测量有效剂量在女孩中为 0.35 至 0.79 mSv，男孩中低 3-8%。模拟和测量的有效剂量一致（差异百分比<19%，T>0.18）。DAP 至有效剂量的转换因子在女孩中范围为 6.5×10(-4) mSv 每 Gy-cm(2)至 4.3×10(-3) mSv 每 Gy-cm(2)，男孩中类似较低。
使用现代透视设备，我们研究所≤10 岁儿童 UGI 检查的有效剂量<1 mSv。可以使用本研究中提供的 DAP 归一化转换因子，对 10 岁以下儿童的 UGI 检查的有效剂量进行估算。通过使用 MOSFET 进行器官直接剂量测量，可以进一步细化这些估算，以反映个别医院的检查方案，且结果与蒙特卡罗模拟剂量一致。
