Lee Eunsol, Goo Hyun Woo, Lee Jae-Yeong
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Pediatr Radiol. 2015 Aug;45(9):1282-92. doi: 10.1007/s00247-015-3331-y. Epub 2015 Mar 24.
It is necessary to develop a mechanism to estimate and analyze cumulative radiation risks from multiple CT exams in various clinical scenarios in children.
To identify major contributors to high cumulative CT dose estimates using actual dose-length product values collected for 5 years in children.
Between August 2006 and July 2011 we reviewed 26,937 CT exams in 13,803 children. Among them, we included 931 children (median age 3.5 years, age range 0 days-15 years; M:F = 533:398) who had 5,339 CT exams. Each child underwent at least three CT scans and had accessible radiation dose reports. Dose-length product values were automatically extracted from DICOM files and we used recently updated conversion factors for age, gender, anatomical region and tube voltage to estimate CT radiation dose. We tracked the calculated CT dose estimates to obtain a 5-year cumulative value for each child. The study population was divided into three groups according to the cumulative CT dose estimates: high, ≥30 mSv; moderate, 10-30 mSv; and low, <10 mSv. We reviewed clinical data and CT protocols to identify major contributors to high and moderate cumulative CT dose estimates.
Median cumulative CT dose estimate was 5.4 mSv (range 0.5-71.1 mSv), and median number of CT scans was 4 (range 3-36). High cumulative CT dose estimates were most common in children with malignant tumors (57.9%, 11/19). High frequency of CT scans was attributed to high cumulative CT dose estimates in children with ventriculoperitoneal shunt (35 in 1 child) and malignant tumors (range 18-49). Moreover, high-dose CT protocols, such as multiphase abdomen CT (median 4.7 mSv) contributed to high cumulative CT dose estimates even in children with a low number of CT scans.
Disease group, number of CT scans, and high-dose CT protocols are major contributors to higher cumulative CT dose estimates in children.
有必要建立一种机制，用于估计和分析儿童在各种临床情况下多次CT检查的累积辐射风险。
利用收集的5年儿童实际剂量长度乘积值，确定导致高累积CT剂量估计值的主要因素。
2006年8月至2011年7月期间，我们回顾了13803名儿童的26937次CT检查。其中，我们纳入了931名儿童（中位年龄3.5岁，年龄范围0天至15岁；男∶女 = 533∶398），他们接受了5339次CT检查。每个儿童至少接受了三次CT扫描，并且有可获取的辐射剂量报告。剂量长度乘积值从DICOM文件中自动提取，我们使用最近更新的年龄、性别、解剖区域和管电压转换因子来估计CT辐射剂量。我们跟踪计算出的CT剂量估计值，以获得每个儿童的5年累积值。根据累积CT剂量估计值，将研究人群分为三组：高剂量组，≥30 mSv；中剂量组，10 - 30 mSv；低剂量组，<10 mSv。我们回顾临床数据和CT检查方案，以确定导致高累积和中累积CT剂量估计值的主要因素。
累积CT剂量估计值的中位数为5.4 mSv（范围0.5 - 71.1 mSv），CT扫描次数的中位数为4次（范围3 - 36次）。高累积CT剂量估计值在患有恶性肿瘤的儿童中最为常见（57.9%，11/19）。CT扫描频率高归因于脑室腹腔分流术患儿（1名儿童进行了35次扫描）和恶性肿瘤患儿（范围18 - 49次）的高累积CT剂量估计值。此外，高剂量CT检查方案，如多期腹部CT（中位数4.7 mSv），即使在CT扫描次数较少的儿童中也导致了高累积CT剂量估计值。
疾病组类别、CT扫描次数和高剂量CT检查方案是导致儿童累积CT剂量估计值较高的主要因素。
