Abstract PET/CT tests are becoming increasingly important imaging tools in the noninvasive evaluation and children monitoring with known or suspected malignant diseases. This equipment allows the functional images overlapping obtained from the radiopharmaceuticals administration and anatomical images generated by X-ray beam attenuation. Although the immediate benefit to the individual patient can be substantial, the relatively high radiation doses associated with PET/CT compared with conventional exams have raised health care. This is especially concerning for children, who are more sensitive to radiation-induced carcinogenesis and have many remaining years to develop cancer. The aim of this study is evaluating and compare the doses generated by the CT scan and incorporated by the radionuclide 18F-FDG administration for 2 and 10-years old phantoms. To evaluate the CT dose, radiochromic film strips were positioned into two body phantoms, built by PMMA volumes. Two CT protocols were performed, one only for anatomical mapping and another for diagnosis. The Effective Dose from 18F-FDG was evaluated using the biokinetic model proposed by ICRP 106. The effective doses averages from CT were approximately double for 2-year phantom. The CT diagnostic protocol provides absorbed doses on average five times as high as the anatomical mapping protocol. The diagnostic CT scan is responsible for almost 60% of the effective dose in the PET/CT test, hence the importance of the tomographic protocol optimization, reducing the dose values to the minimum achievable. It is important to emphasize the importance of using the specific size of the patient when estimating the exposure dose for 18F-FDG PET/CT.

中文翻译：

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使用不同体模的儿科 PET/CT 扫描剂量学研究

摘要 PET/CT 检测在无创评估和儿童监测已知或疑似恶性疾病中正成为越来越重要的成像工具。该设备允许从放射性药物管理中获得的功能图像与由 X 射线束衰减生成的解剖图像重叠。尽管对个体患者的直接好处可能是巨大的，但与传统检查相比，与 PET/CT 相关的相对较高的辐射剂量提高了医疗保健水平。这对儿童来说尤其令人担忧，他们对辐射诱发的致癌作用更敏感，并且还有很多年会患上癌症。这项研究的目的是评估和比较 CT 扫描产生的剂量，并通过放射性核素 18F-FDG 给药纳入 2 岁和 10 岁的体模。为了评估 CT 剂量，将放射变色薄膜条放置在由 PMMA 体积构建的两个人体模型中。执行了两种 CT 协议，一种仅用于解剖映射，另一种用于诊断。使用 ICRP 106 提出的生物动力学模型评估了 18F-FDG 的有效剂量。 CT 的有效剂量平均值大约是 2 年假体的两倍。CT 诊断协议提供的吸收剂量平均是解剖映射协议的五倍。在 PET/CT 测试中，诊断性 CT 扫描几乎占有效剂量的 60%，因此优化断层扫描协议的重要性，将剂量值降低到可达到的最小值。在估算 18F-FDG PET/CT 的暴露剂量时，必须强调使用患者具体体型的重要性。