各向异性解析算法与先进外照射光子剂量算法在肺癌VMAT计划中的剂量学差异  

Dosimetric differences between Acuros external beam algorithm and anisotropy analysis algorithm in volumetric modulated arc therapy for lung cancer

作　　者：徐诗磊 张九堂[1] 张俊俊[2] 陈旎[1] XU Shilei;ZHANG Jiutang;ZHANG Junjun;CHEN Ni(Department of Radiation Physics and Technology,Hunan Cancer Hospital,Changsha 410013,China;Department of Radiation Oncology,the Third Xiangya Hospital of Central South University,Changsha 410013,China)

机构地区：[1]湖南省肿瘤医院放射物理技术部,湖南长沙410013 [2]中南大学湘雅三医院放射治疗中心,湖南长沙410013

出　　处：《中国医学物理学杂志》2020年第6期676-679,共4页Chinese Journal of Medical Physics

基　　金：湖南省2018年度省级临床重点专科建设项目;湖南省肺癌诊疗能力提升项目。

摘　　要：目的:比较先进外照射光子剂量算法(AXB)和各向异性解析算法(AAA)在肺癌VMAT计划中的剂量学差异。方法:随机选取20例肺癌患者,CT扫描传输图像后勾画靶区及危及器官,采用两弧设计VMAT放疗计划,比较两种算法靶区的剂量分布,肺、心脏和脊髓的受照量。结果:PGTV:最大剂量AXB算法低于AAA算法(P<0.05),最小剂量无统计学意义(P>0.05),平均剂量AXB算法低于AAA算法(P<0.05);PTV:最大剂量和最小剂量无统计学意义(P>0.05),平均剂量AXB算法低于AAA算法(P<0.05);CI:AXB算法优于AAA算法(P<0.05);HI:AXB算法优于AAA算法(P<0.05);脊髓:最大剂量AXB算法低于AAA算法(P<0.05);心脏:V30、V40、DmeanAXB算法均低于AAA算法(P<0.05);肺:V5、V20、DmeanAXB算法均低于AAA算法(P<0.05)。结论:两种算法均满足临床要求,但与AAA算法相比,AXB算法更精确,特别是针对肺组织这种低密度区域。Objective To compare the dosimetric differences in the volumetric modulated arc therapy(VMAT)plans using Acuros external beam(AXB)algorithm versus anisotropy analysis algorithm(AAA)for the treatment of lung cancer.Methods Twenty patients with lung cancer were randomly selected.After the CT images were imported into the planning system,target areas and organs-at-risk(OAR)were delineated,and the VMAT with two arcs was designed for each patient.The two algorithms were used to calculate the dosimetric distributions in target areas and the doses to organs-at-risk(OAR)such as lungs,heart and spinal cord,and the results calculated by AXB algorithm were compared with those calculated by AAA.Results For planning gross target volume,there was no significant difference between AXB algorithm and AAA in the calculation of minimum dose(P>0.05),but the maximum dose and mean dose calculated byAXB algorithm were lower than those calculated byAAA(P<0.05).For planning target volume,there was no significant difference between two algorithms in the calculation of maximum dose and minimum dose(P>0.05),but the mean dose calculated by AXB algorithm was lower than that calculated by AAA(P<0.05).Moreover,AXB algorithm was superior toAAAin conformity index and homogeneity index(P<0.05).The maximum dose of spinal cord,the V30,V40 and mean dose of the heart,and the V5,V20 and mean dose of the lungs which were calculated by AXB algorithm were lower than those obtained by AAA(P<0.05).Conclusion Both AAA and AXB algorithm can satisfy the clinical requirements,but compared withAAA,AXB algorithm is more accurate,especially for low-density areas like the lungs.

关 键 词：肺癌 AXB算法 AAA算法 容积旋转调强放射治疗 

分 类 号：R811.1[医药卫生—放射医学] R734.2[医药卫生—临床医学]