Puch-Kapst Kathrin, Juran Ralf, Stoever Brigitte, Wauer Roland R
Clinic of Neonatology Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany .
Pediatrics. 2009 Dec;124(6):1556-64. doi: 10.1542/peds.2008-1028.
We determined the frequency and estimated effective radiation dose (E) from conventional diagnostic radiographs for infants who had birth weight of <or=1500 g (very low birth weight [VLBW] infants) and were treated in a NICU.
Entrance skin doses were experimentally measured for all standard weight-dependent exposure settings. For each radiograph in the radiologic file, the exposed area on the film was measured manually. Together with clinical data obtained from the Vermont Oxford Network, medical charts, and radiologic files, we estimated E. E values per radiograph and per child were compared with recommended reference values and annual natural background radiation (NBR). We used reference data to estimate the risk for radiation-induced cancers.
Of 212 VLBW infants, 194 required at least 1 conventional radiograph. Measured entrance skin dose varied between 11.8 and 15.0 microGy. Calculated E received was 16 microsievert (microSv; median) per radiograph and 71.5 microSv (median) per infant for the whole stay. Infants with birth weight <or=750 g, length of stay >or=16 weeks, congenital malformations, or oxygen dependence for >or=36 weeks were at risk for high numbers of radiographs and high radiation dose. Compared with the annual NBR, the median of 4 radiographs per infant contributes 12 days of NBR. We estimated that only 1 of 60000 NICU-treated VLBW infants will develop a fatal malignancy up to 15 years of age.
We found that NICU-treated VLBW infants had low radiation exposure compared with the annual NBR.
我们确定了出生体重≤1500克（极低出生体重[VLBW]婴儿）且在新生儿重症监护病房（NICU）接受治疗的婴儿进行传统诊断性X线摄影的频率，并估算了有效辐射剂量（E）。
对所有标准体重依赖的曝光设置进行了体表入射剂量的实验测量。对于放射学档案中的每张X线片，手动测量胶片上的曝光面积。结合从佛蒙特牛津网络、病历和放射学档案中获取的临床数据，我们估算了E。将每张X线片和每个儿童的E值与推荐参考值及年度天然本底辐射（NBR）进行比较。我们使用参考数据估算辐射诱发癌症的风险。
在212例VLBW婴儿中，194例至少需要进行1次传统X线摄影。测量的体表入射剂量在11.8至15.0微戈瑞之间。计算得出的每次X线摄影的E为16微西弗（μSv；中位数），整个住院期间每个婴儿的E为71.5微西弗（中位数）。出生体重≤750克、住院时间≥16周、患有先天性畸形或需吸氧≥36周的婴儿接受X线摄影的数量较多且辐射剂量较高。与年度NBR相比，每个婴儿4张X线片的中位数相当于12天的NBR。我们估计，在NICU接受治疗的VLBW婴儿中，每60000例中只有1例在15岁之前会发生致命性恶性肿瘤。
我们发现，与年度NBR相比，在NICU接受治疗的VLBW婴儿的辐射暴露较低。
