目的:比较Acuros XB(AXB)算法与AAA算法在肺癌调强放疗(IMRT)计划中的剂量学差异.方法:选取10例接受放射治疗的肺癌患者,CT图像扫描后勾画靶区和危及器官,分别用两种优化算法设计IMRT计划,比较两种算法所得计划的靶区剂量分布、危及器官受量及正常组织受量的差异.结果:应用AXB算法的计划中PTV最大剂量和平均剂量分别为(66.37±1.94)和(61.5±3.88) Gy;应用AAA算法的计划中分别为(64.56±1.75)和(62.02±4.77)Gy.前者PTV最大剂量高于后者,但平均剂量低于后者,两者差异均有统计学意义(P＜0.05).两种计划在靶区的均匀性和适形度差异无统计学意义(P＞0.05).两种计划的双肺剂量Dmax、Dmean和V20差异有统计学意义(P＜0.05),前者双肺Dmax和V20高于后者,但双肺的平均剂量Dmean低于后者.两种计划在正常组织的体积剂量差异无统计学意义(P＞0.05).结论:虽然应用两种算法的计划均满足临床要求,但是与AXB算法相比,AAA算法低估了靶区最大剂量,高估了靶区平均剂量,同时也低估了正常肺部的体积剂量.%Objective To compare the dosimetric differences between anisotropic analytical algorithm (AAA) and Acuros XB (AXB) algorithm in intensity-modulated radiotherapy (IMRT) plans for lung cancer.Methods The CT images of 10 patients with lung cancer were imported into the planning system,and the planning target volume (PTV) and organs-at-risk (OAR) were delineated.Different IMRT plans were generated with AAA and AXB algorithm,respectively,and the dosimetric distributions in PTV,OAR and normal tissue were evaluated.Results The maximum dose and mean dose of PTV in IMRT plan generated with AXB algorithm were (66.37±1.94) and (61.50±3.88) Gy,while those in IMRT plan generated with AAA were (64.56±1.75) and (62.02±4.77) Gy.The former had a higher maximum dose,but a lower mean dose than the latter,with significant differences (P＜0.05).The comparison between the two plans showed no significant difference in conformity index,homogeneity index,and the volume dose of normal tissue (P＞0.05),but some significant differences in the V20,maximum dose and mean dose ofthe whole lung (P＜0.05).The IMRT plan generated with AXB algorithm had a higher V20 and maximum dose of the whole lung than the other plan,but a lower mean dose of whole lung.Conclusion Though,both Aeuros XB algorithm and AAA could satisfy the clinical requirements,AAA underrates the maximum dose of target area,and overrates the mean dose of target area,and underestimates the volume dose of the normal lung.
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