双源CT双能量单期增强扫描检查对食管癌患者辐射剂量影响的前瞻性研究

Effect of radiation dose of dual-source computed tomography dual energy single-phase enhanced scan inpatients with esophageal cancer： a perspective study

目的：探讨双源CT.辐射剂量的影响。 方法：采用前瞻性研究方法。选取2015年1月至2016年12月浙江大学丽水医院收治的56例食管癌患者的临床病理资料。采用随机区组法将患者分为试验组（行双源CT双能量单期增强扫描检查）和对照组（行常规双期增强CT扫描检查）。肿瘤TNM 分期标准参照2009年美国癌症联合会（AJCC）第7版食管癌TNM分期标准。由两名观察者独立阅片。参照2009年AJCC第7版食管癌治疗标准，患者行根治性手术或姑息性手术，术后辅助放、化疗。采用门诊和电话方式进行随访，了解患者治疗后生存情况。随访时间截至 2017年3月。观察指标：（1）肿瘤T、N、M分期一致性。（2）肿瘤T、N、M分期准确率（以病理学检查结果为金标准）。（3）CT扫描辐射剂量。（4）治疗及随访情况。采用κ检验一致性。κ≥0.75为一致性较好，0.40≤κ〈0.75为一致性一般，κ〈0.40为一致性较差。计数资料和率的比较采用x2检验。计量资料比较采用t检验。 结果：筛选出符合研究条件的患者50例，试验组和对照组各25例。（1）肿瘤T、N、M分期一致性：试验组和对照组患者均顺利完成CT检查。两名观察者对50例患者行肿瘤T、N、M分期一致性均为一般（κ=0.452，0.618，0.729，P〈0.05）。其中肿瘤N、M分期一致性优于T分期。（2）以病理学检查结果为金标准，试验组和对照组患者术前行CT检查肿瘤T分期准确率分别为72%和76%，N分期准确率分别为88%和84%，M分期准确率分别为92%和88%。两组上述指标比较，差异均无统计学意义（x2=0.10，0.37，0.50，P〉0.05）。（3）CT扫描辐射剂量：试验组和对照组患者 CTDIvol分别为（10.35±2.01）mGy和（3.55±0.60）mGy，DLP分别为（400.63±34.13）mGy·cm和（140.66±10.89）mGy·cm，有效辐射剂量E分别为（5.61±0.47）mSv和（1.98±0.17）mSv。两组患者CTDIvol和有效辐射剂量E比较，差异均有统计学意义（t=16.23，36.30，P〈0.05）。（4）治疗及随访情况：50例患者中，43例在我院接受治疗，其中32例行根治性手术（11例术后行辅助化疗），6例行姑息性手术，3例单纯行放疗，2例单纯行化疗。43例患者中，36例获得治疗后随访，随访时间为3-18个月，中位随访时间为6个月。随访期间，患者1年生存率为61.1%。 结论：食管癌患者行双源CT双能量单期增强扫描检查，不降低肿瘤TNM分期准确率，可明显降低辐射剂量。

Objective：To investigate the effect of radiation dose of dualsource computed tomography （CT） dual energy singlephase enhanced scan in patients with esophageal cancer. Methods：The prospective study was conducted. The clinicopathological data of 56 patients with esophageal cancer who were admitted to the Lishui Hospital of Zhejiang University between January 2015 and December 2016 were collected. All the patients were divided into the experimental group （undergoing dualsource CT dual energy singlephase enhanced scan） and control group （undergoing dualphase CT enhanced scan） by randomised block method. TNM classification of esophageal cancer （Seventh Edition） published by American Joint Committee on Cancer （AJCC） was used as a standard TNM staging. Two observers independently read films. All the patients underwent radical resection of esophageal cancer or palliative surgery, and then received adjuvant radiochemotherapy. Followup using outpatient examination and telephone interview was performed to detect postoperative survival of patients up to March 2017. Observation indicators： （1） consistencies of T staging, N staging and M staging; （2） accuracies of T staging, N staging and M staging （pathological results as a gold standard）; （3） radiation dose of CT scan; （4） treatment and followup situations. The Kappa test was used for evaluating the consistency, κ≥0.75 as a good consistency, 0.40≤κ〈0.75 as a normal consistency and κ〈0.40 as a poor consistency. Comparisons of count data and ratio were done by the chisquare test. Comparisons of measurement data were analyzed by the t test. Results：A total of 50 patients were enrolled in the study, including 25 in the experimental group and 25 in the control group. （1） Consistencies of T staging, N staging and M staging： all the 50 patients finished successfully CT scans. Two observers considered that consistencies of T staging, N staging and M staging in the 2 groups were normal （κ=0.452, 0.618, 0.729, P〈0.05）. Consistencies of N staging and M staging were superior to T staging. （2） The pathological results were used as a gold standard. Accuracies of T staging, N staging and M staging in the experimental and control groups were 72%, 76% and 88%, 84% and 92%, 88%, respectively, with no statistically significant difference between the 2 groups （x2=0.10, 0.37, 0.50, P〉0.05）. （3） Radiation dose of CT scan： volume CT dose index （CTDIvol）, dose length production （DLP） and effective radiation dose （E） were （10.35±2.01）mGy, （400.63±34.13）mGy·cm, （5.61±0.47）mSv in the experimental group and （3.55±0.60）mGy, （140.66±10.89）mGy·cm, （1.98±0.17）mSv in the control group, respectively. There were statistically significant differences in CTDIvol and E between the 2 groups （t=16.23, 36.30, P〈0.05）. （4） Treatment and followup situations： of 50 patients, 43 patients received treatments, including 32 undergoing radical resection （11 receiving postoperative adjuvant chemotherapy）, 6 undergoing palliative surgery, 3 receiving single radiotherapy and 2 receiving single chemotherapy. Thirtysix of 43 patients were followed up for 3- 18 months, with a median time of 6 months. During followup, 1year survival rate was 61.1%. Conclusion：Dualsource CT dual energy singlephase enhanced scan in patients with esophageal cancer cannot reduce accuracy of TNM staging, but decreased effectively radiation dose.