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.
Phys Med. 2018 Jan;45:146-155. doi: 10.1016/j.ejmp.2017.12.013. Epub 2017 Dec 22.
Estimate organ and effective doses from computed tomography scans of pediatric oncologic patients using patient-specific information.
With IRB approval patient-specific scan parameters and patient size obtained from DICOM images and vendor-provided dose monitoring application were obtained for a cross-sectional study of 1250 pediatric patients from 0 through 20 y-olds who underwent head, chest, abdomen-pelvis, or chest-abdomen-pelvis CT scans. Patients were categorized by age. Organ doses and effective doses were estimated using VirtualDose™ CT based on patient-specific information, tube current modulation (TCM), and age-specific realistic phantoms. CTDIvol, DLP, and dose results were compared with those reported in the literature.
CTDIvol and DLP varied widely as patient size varied. The 75th percentiles of CTDIvol and DLP were no greater than in the literature with the exception of head scans of 16-20 y-olds and of abdomen-pelvis scans of larger patients. Eye lens dose from a head scan was up to 69 mGy. Mean organ doses agreed with other studies at maximal difference of 38% for chest and 41% for abdomen-pelvis scans. Mean effective dose was generally higher for older patients. The highest effective doses were estimated for the 16-20 y-olds as: head 3.3 mSv, chest 4.1 mSv, abdomen-pelvis 10.0 mSv, chest-abdomen-pelvis 14.0 mSv.
Patient-specific organ and effective doses have been estimated for pediatric oncologic patients from <1 through 20 y-olds. The effect of TCM was successfully accounted for in the estimates. Output parameters varied with patient size. CTDIvol and DLP results are useful for future protocol optimization.
利用患者特定信息，估算小儿肿瘤科患者 CT 扫描的器官剂量和有效剂量。
经机构审查委员会批准，本研究为回顾性研究，共纳入 1250 例 0 至 20 岁行头、胸、腹-盆或胸-腹-盆 CT 扫描的小儿肿瘤科患者，从 DICOM 图像和供应商提供的剂量监测应用程序中获取患者特定的扫描参数和患者体型，并获得患者的同意。根据患者体型、管电流调制（TCM）和年龄特异性逼真体模，使用 VirtualDose CT 估算器官剂量和有效剂量。基于患者特定信息、TCM 和年龄特异性逼真体模估算 CT 容积剂量指数（CTDIvol）、剂量长度乘积（DLP）和剂量结果，并与文献报道的结果进行比较。
随着患者体型的变化，CTDIvol 和 DLP 变化较大。除 16-20 岁头扫描和较大患者的腹-盆扫描外，头、胸和腹-盆扫描的 CTDIvol 和 DLP 的第 75 百分位数不大于文献报道的结果。头扫描时眼晶体剂量最高可达 69 mGy。各器官剂量的平均值与其他研究一致，最大差异为 38%（胸部）和 41%（腹部-骨盆）。有效剂量通常随年龄增长而升高。16-20 岁患者的有效剂量最高：头部 3.3 mSv，胸部 4.1 mSv，腹部-骨盆 10.0 mSv，胸部-腹部-骨盆 14.0 mSv。
本研究利用患者特定信息估算了 1 至 20 岁小儿肿瘤科患者的器官和有效剂量。在估算中成功考虑了 TCM 的影响。输出参数随患者体型而变化。CTDIvol 和 DLP 结果可用于未来方案的优化。
