食管癌调强放疗计划中AAA算法与PBC算法的对比研究

A Comparison of Anisotropic Analytical Algorithm(AAA) and Pencil Beam Convolution(PBC) Algorithm for IMRT Treatment Planning of Esophageal Carcioma

目的:比较Varian治疗计划系统Eclipse中AAA算法和PBC算法在食管癌调强放疗中的剂量学差异。方法:选择22例中段食管癌患者,分别采用AAA算法与PBC算法设计两种调强计划,比较靶区的剂量分布,肺、脊髓和心脏等危及器官受照剂量的差异。结果:PGTV最大剂量、PTV平均剂量和左肺的平均剂量两种算法无显著性差异(P>0.05),PGTV和PTV最小剂量、PTV最大剂量、参考剂量所包靶区的体积(V95)和其他危及器官的受量,两种算法均有显著性差异(P<0.05)。结论:与PBC算法相比,AAA算法对不均匀组织的修正更加精确,对于食管癌这种与肺相关的剂量计算采用AAA算法更准确一些。

Objective： The aim of the study was to investigate the difference of Anisotropic Analytical Algorithm （AAA） and Pencil Beam Convolution （PBC） Algorithm in the Eclipse planning system（Varian Medical Systems） for Esophageal Carcioma IMRT Treatment Planning. Methods： For 22 patients with esophageal carcioma, IMRT Treatment Plannings with AAA and PBC were preformed respectively. The difference of dose distribution to target and organs at risk （OAR） was compared. Results ： There was no significant difference in the maximum doses of the PGTV, the mean doses of the PTV and left lung （P〉0. 05）, while there was significant difference in the minimum doses of the PGTV and PTV, the maximum doses of the PTV, the percentage volume of the target receiving a dose greater than 95% of the prescription dose （V95）, and the dose of other OAR （P〈0.05）. Conclusions： Compared with the PBC algorithm, AAA algorithm is more exactitude to correct the asymmetry tissue, so for the esophageal carcioma, AAA algorithm is more accurate.