不同算法模型在宫颈癌根治术后固定野调强放射治疗中剂量学分析  

Dosimetric analysis of different algorithms model in fixed field IMRT after radical operation of cervical squamous carcinoma

作　　者：葛双 郗会珍 王寻 叶书成[1] 马俊 陈长建[1] 朱培军[1] 杨君东[1] 程淑媛 GE Shuang;CHI Hui-zhen;WANG Xun(Department of Tumor Radiotherapy, Affiliated Hospital of Jining Medical University Jining 272000, China)

机构地区：[1]济宁医学院附属医院肿瘤放疗科,山东济宁272000 [2]济宁医学院附属医院医学影像中心,山东济宁272000

出　　处：《中国医学装备》2017年第11期34-39,共6页China Medical Equipment

摘　　要：目的:比较宫颈鳞癌根治术后患者在固定野调强放射治疗(FF-IMRT)计划设计时采用各向异性分析算法(AAA)和笔形束卷积(PBC)算法的剂量学差异。方法:随机选取10例术后接受放射治疗的宫颈鳞癌患者的定位CT影像资料,分别采用Varian Eclipse放射治疗计划系统(TPS)提供的AAA和PBC两种剂量算法模型,对七野均分的同一调强计划(IMRT)进行剂量计算,并用电子射野影像装置(EPID)进行剂量验证,比较两种算法模型的剂量-体积直方图(DVH)图上靶区、小肠、结肠、直肠、膀胱、股骨头等危及器官(OARs)的吸收剂量与体积参数和机器跳数(MU)、验证结果γ通过率等参数的差异。结果:两种算法模型得到靶区的平均剂量(D_(mean))与最大剂量(D_(max))PBC算法略高于AAA,适形度指数(CI)和靶区剂量均匀性指数(HI)的AAA结果均好于PBC算法,MU的AAA略高于PBC算法。小肠的V_(15)、D_(mean)、50%的覆盖体积受照的最小剂量(D_(50%)),结肠的D_(mean)、D_(50%),膀胱的V_(30)、V_(40)、V_(45)、D_(mean)、D_(50%),左、右股骨头的D_(mean)的AAA的结果均高于PBC算法;结肠的D_(max),直肠的D_(mean)、D_(max)、D_(50%)和V_(45)的PBC算法略高于AAA。平均差异除直肠的V_(45)和结肠的V_(40)(21.38%,3.59%)较大外,其余参数的偏差在0.07%~1.70%之间,相同角度射野两种算法的γ通过率结果均>98%,差异无统计学意义(t=-0.886,t=0.424,t=0.261,t=-1.426,t=0.284,t=-0.552,t=0;P>0.05)。结论:在宫颈癌根治术后,七野调强放射治疗计划中两种算法获得的靶区和OARs的剂量学参数存在一定的差异,但均可满足临床要求,且剂量验证通过率差异无统计学意义。两种算法均可应用于临床,但在直肠保护、降低放射性直肠损伤发生率方面,AAA要好于PBC算法。Objective:To compare the dosimetric difference of patients with cervical squamous carcinoma in application of fixed-fields IMRT(FF-IMRT)between anisotropic analytical algorithm(AAA)and pencil beam convolution(PBC)algorithm.Methods:The location CT images of10patients with cervical squamous carcinoma who received radiotherapy post-operation were randomly selected in the research.Each IMRT that was averaged by seven-fields was calculated by AAA and PBC,respectively,that were provided by varian eclipse TPS.And the electronic portal imaging device(EPID)was applied to verify the dosage.The adsorbed dose,volume parameter,MU,the passing rate ofγon series of organ at risks(OARs),that included of target region,small intestine,colon,rectum,bladder and femoral head,on the dosevolume histogram(DVH)of the two algorithm model were compared.Results:Dmean and Dmax of the target region of PBC algorithms were slightly higher than those of AAA algorithms,while CI and HI of AAA algorithms were better than that of PBC algorithm,and the MU of AAA was slightly higher than that of PBC algorithm.For V15,Dmean,D50%of small intestine,Dmean,D50%of colon,V30,V40,V45,Dmean,D50%of bladder,Dmean of double femoral head,all of results of AAA are higher than that of PBC algorithm.Dmax of colon,Dmean,Dmax,D50%and V45of rectal of PBC algorithms were slightly higher than that of AAA.The average differences of most of parameters were between0.07%and1.70%exceptV45(21.38%)of rectum and V40(3.59%)of colon.The pass rates ofγof the two algorithms at same field were higher than98%,and the difference between them were not statistically significant(t=-0.886,t=0.424,t=0.261,t=-1.426,t=0.284,t=-0.552,t=0,P>0.05).Conclusion:There are some differences in the dosimetric parameters of the target region and OARs which are obtained from two algorithms in seven fields FF-IMRT of post radical operation of cervical squamous carcinoma,but all of them can meet the clinical requirements and the difference of the pass rate of dose verification is not statistically signific

关 键 词：宫颈癌 各向异性分析算法 笔形束卷积算法 调强放射治疗 剂量学 医用直线加速器 

分 类 号：R814.2[医药卫生—影像医学与核医学]