Department of Medical Physics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
BMC Med Imaging. 2020 Jan 29;20(1):9. doi: 10.1186/s12880-020-0415-4.
Organ absorbed doses and effective doses can be used to compare radiation exposure among medical imaging procedures, compare alternative imaging options, and guide dose optimization efforts. Individual dose estimates are important for relatively radiosensitive patient populations such as children and for radiosensitive organs such as the eye lens. Software-based dose calculation methods conveniently calculate organ dose using patient-adjusted and examination-specific inputs.
Organ absorbed doses and effective doses were calculated for 429 pediatric 18F-FDG PET-CT patients. Patient-adjusted and scan-specific information was extracted from the electronic medical record and scanner dose-monitoring software. The VirtualDose and OLINDA/EXM (version 2.0) programs, respectively, were used to calculate the CT and the radiopharmaceutical organ absorbed doses and effective doses. Patients were grouped according to age at the time of the scan as follows: less than 1 year old, 1 to 5 years old, 6 to 10 years old, 11 to 15 years old, and 16 to 17 years old.
The mean (+/- standard deviation, range) total PET plus CT effective dose was 14.5 (1.9, 11.2-22.3) mSv. The mean (+/- standard deviation, range) PET effective dose was 8.1 (1.2, 5.7-16.5) mSv. The mean (+/- standard deviation, range) CT effective dose was 6.4 (1.8, 2.9-14.7) mSv. The five organs with highest PET dose were: Urinary bladder, heart, liver, lungs, and brain. The five organs with highest CT dose were: Thymus, thyroid, kidneys, eye lens, and gonads.
Organ and effective dose for both the CT and PET components can be estimated with actual patient and scan data using commercial software. Doses calculated using software generally agree with those calculated using dose conversion factors, although some organ doses were found to be appreciably different. Software-based dose calculation methods allow patient-adjusted dose factors. The effort to gather the needed patient data is justified by the resulting value of the characterization of patient-adjusted dosimetry.
器官吸收剂量和有效剂量可用于比较医学影像学检查中的辐射暴露，比较替代影像学选择，并指导剂量优化工作。个体剂量估计对于儿童等相对敏感的患者群体以及眼睛晶状体等敏感器官非常重要。基于软件的剂量计算方法可以方便地使用患者调整和检查特定的输入来计算器官剂量。
对 429 名接受 18F-FDG PET-CT 检查的儿科患者进行了器官吸收剂量和有效剂量的计算。从电子病历和扫描仪剂量监测软件中提取了患者调整和扫描特定的信息。分别使用 VirtualDose 和 OLINDA/EXM（版本 2.0）程序计算 CT 和放射性药物的器官吸收剂量和有效剂量。根据扫描时的年龄将患者分为以下几组：<1 岁、1-5 岁、6-10 岁、11-15 岁和 16-17 岁。
平均（+/-标准差，范围）总 PET 加 CT 有效剂量为 14.5（1.9，11.2-22.3）mSv。平均（+/-标准差，范围）PET 有效剂量为 8.1（1.2，5.7-16.5）mSv。平均（+/-标准差，范围）CT 有效剂量为 6.4（1.8，2.9-14.7）mSv。PET 剂量最高的五个器官是：膀胱、心脏、肝脏、肺和脑。CT 剂量最高的五个器官是：胸腺、甲状腺、肾脏、晶状体和性腺。
使用商业软件可以使用实际的患者和扫描数据来估算 CT 和 PET 组件的器官和有效剂量。使用软件计算的剂量通常与使用剂量转换因子计算的剂量一致，尽管发现某些器官剂量明显不同。基于软件的剂量计算方法允许患者调整剂量因素。通过对患者调整剂量特征的描述，收集所需患者数据的工作是合理的。
