左侧乳腺癌术后放疗无均整器模式剂量学优势分析  

Dosimetric advantages of postoperative radiotherapy in flattening filter-free mode for left-sided breast cancer

作　　者：罗红樱 周剑良[1] 单国平 邵凯南 杨一威 周霞 LUO Hongying;ZHOU Jianliang;SHAN Guoping;SHAO Kainan;YANG Yiwei;ZHOU Xia(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China;Department of Radiation Physics,Cancer Hospital of the University of Chinese Academy of Sciences(Zhejiang Cancer Hospital),Hangzhou 310022,China;Department of Radiotherapy,Cancer Hospital of the University of Chinese Academy of Sciences(Zhejiang Cancer Hospital),Hangzhou 310022,China)

机构地区：[1]南华大学核科学技术学院,湖南衡阳421001 [2]中国科学院大学附属肿瘤医院(浙江省肿瘤医院)放射物理室,浙江杭州310022 [3]中国科学院大学附属肿瘤医院(浙江省肿瘤医院)放疗科,浙江杭州310022

出　　处：《中国医学物理学杂志》2021年第3期281-286,共6页Chinese Journal of Medical Physics

基　　金：浙江省重点科技研发计划(2019C03003);浙江省医药卫生科技计划(2020KY472)。

摘　　要：目的:比较左侧乳腺癌全切术后无均整器(FFF)与均整器(FF)模式下容积旋转调强放疗(VMAT)计划剂量学特点,分析无均整器模式下剂量学优势。方法:随机选取2019~2020年左侧乳腺癌全切术后的患者10例,分别用两种模式对同一患者的计划靶区(PTV)给予相同的处方剂量50 Gy,在RayStation计划系统上设计FFF和FF的VMAT计划,在满足临床要求的情况下,比较两组剂量学特点、机器总跳数、出束总时间。结果:FFF模式靶区PTV的D98%低于FF模式(P=0.007),D95%、D2%、CI、HI两者比较差异均无统计学意义(P>0.05);FFF模式在患侧肺、全肺、心脏、脊髓以及冠状动脉前降支保护上明显优于FF模式(P<0.05),患侧肺平均剂量同比降低9.59%,心脏平均剂量降低12.20%;在健侧肺、臂丛以及正常组织的保护上两者比较差异无统计学意义(P>0.05);FFF模式的机器总跳数相对于FF模式增加1.30倍,出束总时间缩短至FF模式的87.15%。结论:在两组治疗计划均能满足临床治疗要求的前提下,FFF模式可显著减少患者危及器官以及正常组织的受照剂量,虽然机器总跳数增加,但患者的治疗时间反而下降。因此可知FFF模式优于FF模式的治疗效率。Objective To compare the dosimetric characteristics of volumetric modulated arc therapy(VMAT)plan in flattening filter(FF)mode and flattening filter⁃free(FFF)mode,and to analyze the dosimetric advantages of FFF-VMAT.Methods Ten patients with left-sided breast cancer after total resection from 2019 to 2020 were randomly selected.The same prescription dose of 50 Gy was given to the planning target volume(PTV)of the same patient by two modes separately,and two kinds of plans,namely FFF-VMAT plan and FF-VMAT plan,were designed on RayStation planning system.When the clinical requirements were met,the dosimetric characteristics,total monitor units and total delivery time were compared between FFF-VMAT and FF-VMAT.Results Except for the D98%of PTV which was lower in FFF-VMAT than that in FF-VMAT(P=0.007),there was no significant difference between two groups in the D95%,D2%,CI and HI of PTV(P>0.05).FFF mode was superior to FF mode in protection of affected lung,the whole lungs,heart,spinal cord and anterior coronary artery(P<0.05),and compared with those in FF-VMAT,the average dose delivered to the affected lung and heart in FFF-VMAT were decreased by 9.59%and 12.20%,respectively.The differences between FF-VMAT and FFF-VMAT in sparing of the healthy lung,brachial plexus and normal tissues were trivial,without statistical significance(P>0.05).The total monitor units of FFF-VMAT was 1.30 times of that of FF-VMAT,and the total delivery time was shortened to 87.15%of FF-VMAT.Conclusion On the premise that the treatment plans of both groups can meet the clinical treatment requirements,FFF mode can significantly reduce the radiation dose delivered to organs-at-risk and normal tissues.Although the total monitor units in FFF-VMAT is increased,the treatment time is shortened.Therefore,the treatment efficiency of FFF mode is better than that of FF mode.

关 键 词：乳腺癌 无均整器模式 容积旋转调强放疗 剂量学 

分 类 号：R318[医药卫生—生物医学工程] R811.1[医药卫生—基础医学]