摘要
目的研究Eclipse 10.0计划系统中两种不同迭代次数的设置对鼻咽癌调强计划的影响。方法选取2013年12月~2014年12月17例鼻咽癌患者的调强计划,在原有计划的基础上,将优化参数中迭代(Iteration)选项卡中的数值改为100命名为Plan1和500命名为Plan2,然后对两个计划重新计算。统计并比较其靶区的相关剂量学参数、危及器官(Organs at risk,OARs)的剂量学参数、机器总的跳数(Monitor unit,MU)。结果迭代次数对计划肿瘤区(Plan gross tumor volume,PGTV)和计划靶区(Plan target volume,PTV)中D95、D5及靶区剂量均匀性指数(Homogeneity index,HI)的剂量影响较小,差异无统计学意义(P>0.05);迭代次数增加一定程度上能降低危及器官的受量,如两侧腮腺V20、患侧腮腺、两侧视神经、健侧眼球以及喉的平均剂量均有所下降,且差异均具有统计学意义(P<0.05);迭代次数增加,机器总跳数平均增加约100 MU,但差异无统计学意义(P>0.05)。但是迭代次数增加,平均计算时间明显增加,有统计学差异(P<0.05)。结论迭代次数的增加对靶区的影响比较小,但可以改善危及器官所受的剂量。考虑到计划优化时间和工作效率,建议在使用Eclipse 10.0计划系统优化时采用500之内的迭代次数,并且如果优化结果已达到要求则可以尽早结束迭代。
Objective To study the effect of two kinds of dose iteration times on the intensity modulated plan for nasopharyngeal carcinoma（NPC） with Eclipse10.0 planning system. Methods 17 cases of nasopharyngeal carcinoma（NPC）IMRT plans were selected from December 2013 to December 2014. On the basis of the original plan, the optimization iteration times which were changed for 100 and 500 named Plan1 and Plan2, respectively, then the two kinds of plans were recalculated. The dosimetric parameters of the target area and organs at risk（OARs） as well as monitor units（MU）were compared. Results The iteration times had less effect on the D95, D5 and HI（Homogeneity index, HI） of the target area PGTV and PTV with no significant differences（P〉0.05）; However, the increase of iteration times could reduce the dose of organs at risk（OAR）. For example： The V20 of the parotid gland on both sides, the average dose of the ipsilateral side parotid gland, optic nerve on both sides, the contralateral eye and the throat were decreased, and the differences were statistically significant（P〈0.05）; The increase of iteration times increased about 100 MU in the total number of monitor units, but the differences were not statistically significant（P〉0.05）. Even so, the increase of iteration times in creased the optimization time, and the differences were statistically significant（P〈0.05）. Conclusion The increase of iteration times has no much impact on the target area, while it can improve the dose of organs at risk. Considering the planning optimization time and work efficiency, it is recommended that the iterations should be chose within the 500 when using the Eclipse10.0 planning system. Furthermore, if the optimization results have already achieved the requirements, it can be ended as soon as possible.
出处
《中国现代医生》
2017年第16期69-73,共5页
China Modern Doctor
基金
浙江省医药卫生科技计划(2013KYB290)
关键词
鼻咽癌
IMRT
迭代次数
计划优化
Nasopharyngeal carcinoma
IMRT
Iteration
Optimization
