造影剂对上段食管癌VMAT放疗计划剂量的影响  

The effect of contrast agents on the planned dose of VMAT radiotherapy for upper esophageal cancer

作　　者：严维江 周杰 李明 杨云云 马兆明 马建华 Yan Weijiang;Zhou Jie;Li Ming;Yang Yunyun;Ma Zhaoming;Ma Jianhua(Department of Radiotherapy,The Second People's Hospital of Lianyungang,Kangda College,Nanjing Medical University,Lianyungang 222023,China)

机构地区：[1]南京医科大学康达学院附属连云港市第二人民医院放疗科,连云港222023

出　　处：《现代仪器与医疗》2024年第1期91-96,共6页Modern Instruments & Medical Treatment

基　　金：南京医科大学康达学院科研发展基金(KD2023KWJJ084)。

摘　　要：目的 探讨上臂静脉到上腔静脉中残留的造影剂对上段食管癌VMAT放疗计划剂量影响。方法 选取10例上段食管癌患者,定位时对每例患者静脉注射造影剂并行CT模拟定位扫描,把图像传输至瓦里安Eclipse 11.0计划系统,测量造影血管的CT值,然后将造影血管CT值用赋值方法改为40HU,采用在增强CT上做VMAT计划1,然后在增强CT上赋值修正,腋静脉至上腔静脉的大血管的CT值,做VMAT计划2。计算赋值前和赋值后的靶区PGTV和PTV的D_(2)和D_(98)、适形度指数(CI)、均匀性指数(HI),以及正常器官肺、脊髓和肱骨头的剂量分布,并比较两种计划对加速器治疗跳数(MU)的影响。通过秩和检验来判断注射造影剂所造成的高CT值对靶区和危及器官剂量的影响。结果 对于靶区PTV的D_(2)和PGTV的D_(98)差异具有统计学意义(P<0.05);PTV的D_(98)和PGTV的D_(2)差异无统计学意义(P>0.05);适形度指数(CI)和均匀性指数(HI)差异无统计学意义(P>0.05)。对于危及器官肺的V_(5)、V_(10)和正常器官左、右肱骨头的平均剂量差异具有统计学意义(P<0.05),但肺的V_(20)、V_(30)差异无统计学意义(P>0.05)。两种计划加速器治疗跳数(MU)具有统计学意义(P<0.05)。结论 上臂静脉到上腔静脉中残留的造影剂对上段食管癌VMAT计划的靶区剂量有一定的影响,但影响在可接受范围内。造影剂导致了肺的低剂量区V_(5)和V_(10)增加,以及增加了肱骨头的平均剂量。同时,造影剂还导致了加速器治疗跳数增加(MU)。Objective To explore the impact of residual contrast agent in the brachial vein to superior vena cava on VMAT radiotherapy dose planning for upper esophageal cancer.Methods Ten patients with upper esophageal cancer were selected.Contrast agent was intravenously injected during positioning,and CT simulation scans were performed.The images were transferred to the Varian Eclipse 11.0 planning system.The CT values of the contrast-enhanced vessels were measured and then converted to 40HU using a assigning method.VMAT plan 1 was created on the enhanced CT,and then the CT values of the major vessels from the axillary vein to the superior vena cava were assigned and corrected on the enhanced CT to create VMAT plan 2.The D_(2) and D_(98) of the target area PGTV and PTV,conformity index(CI),homogeneity index(HI),as well as the dose distribution of normal organs such as lung,spinal cord,and humeral heads were calculated before and after assignment,and the effects of the two plans on the number of accelerator treatments(MU)were compared.The impact of high CT values caused by contrast agent injection on the dose of target area and organs at risk was assessed using rank sum test.Results There were statistically significant differences in D_(2) of PTV and D_(98) of PGTV(P<0.05).However,there were no statistically significant differences in D_(98) of PTV and D_(2) of PGTV(P>0.05).There were no statistically significant differences in conformity index(CI)and homogeneity index(HI)(P>0.05).Statistically significant differences were observed in V_(5) and V_(10) of lung,as well as the average dose of the left and right humeral heads(P<0.05),but no statistically significant differences were found in V_(20) and V_(30) of the lung(P>0.05).The number of accelerator treatments(MU)in both plans showed statistically significant differences(P<0.05).Conclusion Residual contrast agent from the brachial vein to the superior vena cava has a certain impact on the target area dose of VMAT planning for upper esophageal cancer,but the impact is with

关 键 词：食管癌 放射治疗 造影剂 CT值 适形度指数 

分 类 号：TH77[机械工程—仪器科学与技术] R730.55[机械工程—精密仪器及机械]