肺癌患者重复性CT检查剂量水平调查与影响因素分析

Investigation and analysis of dose level from recurrent CT scans in patients with lung cancer

目的:调查和分析肺癌患者重复性CT检查所致辐射剂量水平的影响因素,为后续累积剂量优化研究提供参考。方法:应用PACS系统,检索2015年10月至2018年10月一直在滨州医学院附属医院随诊的26例症状稳定且不可手术的Ⅲ期原发性非小细胞肺癌患者的CT检查数据。依据《中国临床肿瘤学会(CSCO)原发性肺癌诊疗指南》判断临床医师对诊疗规范的依从性;计算26例患者的有效剂量,统计非胸部CT检查的有效剂量占比;依据《医学影像检查技术学》判断非电离辐射检查替代的可行性,从影像检查策略方面分析剂量影响因素。依据《X射线计算机断层摄影成年人诊断参考水平》设计剂量核查方案,结合《CT检查技术专家共识》从CT检查操作方面分析剂量影响因素。结果:影像检查策略方面,26例患者以肺癌随访为目的的CT扫描次数范围为4~38次,检查策略符合诊疗规范的建议;26例患者的CT检查所致有效剂量的范围为19.04~470.73 mSv;非胸部CT检查所致有效剂量的范围为0~202.35 mSv,占总有效剂量的比例范围为0%~53%,存在非电离辐射检查替代的可行性。检查操作方面,不同设备的各检查部位CTDIvol、DLP数值均存在超过规定诊断参考水平的情况;胸部CT扫描范围不符合建议范围的占比为31.67%。结论:全面、系统的CT检查辐射剂量数据分析有助于后续CT累积剂量优化研究。

Objective:To investigate and analyze the factors affecting the radiation dose of recurrent CT scans for lung cancer patients,and to provide reference for subsequent studies on the cumulative dose optimization.Methods:Applying the PACS system to retrieve CT examination data for patients with primary non-small cell lung cancer in PhaseⅢand inoperable stage with stable symptoms,which were followed up by the affiliated hospital of Binzhou medical college from October 2015 to October 2018,judging the compliance of clinical physicians to the diagnosis and treatment norms according to the Guidelines of Chinese society of clincial oncology(CSCO)primary lung cancer.Calculating the effective dose of 26 patients,counting the proportion of the effective dose of non-chest CT examination,judging the feasibility of non-ionizing radiation examination substitution based on the medical imaging examination technology,and analyzing the dose influencing factors in terms of image examination strategies.Design a dose verification scheme based on the diagnostic reference levels for adults in X-ray computed tomography,and analyze the dose impact factors from the CT examination operation in conjunction with the CT examination technical expert consensus.Results:In terms of image examination strategy,the number of CT scans for the purpose of follow-up lung cancer in 26 patients ranged from 4 to 38.The examination strategy is in line with the Guidelines of Chinese society of clincial oncology(CSCO)primary lung cancer.The range of effective doses of CT examinations for 26 patients is 19.04~470.73mSv;the range of effective doses of non-chest CT examination is 0~202.35mSv,which accounted for 0%to 53%of the total effective dose,suggesting that there is a feasibility of replacing the non-chest CT examination with non-ionizing radiation examination.The CTDIvol and DLP values of each scanning site in different equipment all exceed the prescribed diagnostic reference level,which is specified in the diagnostic reference levels for adults in X-ray computed tomography.The proportion of chest CT scans that do not meeting the recommended range is 31.67%.Conclusion:Comprehensive and systematic analysis of radiation metrics of CT examination can be helpful for subsequent CT cumulative dose optimization studies.