摘要
目的:对比调强放射治疗(IMRT)与容积旋转调强治疗(VMAT)大体积脑转移瘤(BMs)靶区不同增量方式下的剂量学参数,探讨基于直线加速器分次立体定向放射治疗(HSRT)脑转移瘤的更优实现方式。方法:回顾性选取2020年至2023年于海军第九七一医院行固定野调强放射治疗(IMRT)的30例BMs患者,在治疗计划系统(TPS)中分别设计靶区剂量均匀计划(Plan均匀)、靶区内设置均匀增量计划(Plan_(均增))和递增增量计划(Plan_(递增))3种IMRT和容积旋转调强治疗(VMAT)计划。在靶区内部设置高剂量区(GTV_(h)),针对GTV_(h)设计Plan匀增和Plan_(递增)。分析利用IMRT与VMAT分别设计的Plan均匀、Plan_(均增)和Plan_(递增)3种治疗计划的剂量差异。观察对比靶区平均剂量(D_(mean))、50%和2%靶区受照射剂量(D50%和D_(2%));适形指数(CI)、均匀性指数(HI)、梯度指数(GI),以及正常脑组织接受10~40 Gy体积百分占比(V_(10)Gy~V_(40)Gy)。结果:IMRT的Plan_(均增)和Plan_(递增)与Plan均匀相比GTV的D_(mean)提高10.13%和17.9%,差异有统计学意义(t=13.680、12.771,P<0.05),D50%提高8.9%和10.8%,差异有统计学意义(t=15.190、9.929,P<0.05),D_(2%)提高15.2%和46.4%,差异有统计学意义(t=52.320、8.746,P<0.05);IMRT的Plan均匀、Plan_(均增)和Plan_(递增)3种计划正常脑组织V_(10)~V_(40)比较,差异均无统计学意义(P>0.05)。VMAT的Plan_(均增)和Plan_(递增)与Plan均匀相比GTV的D_(mean)提高10.53%和21.23%,差异有统计学意义(t=18.641、15.461,P<0.05),D50%提高9.1%和13.4%,差异有统计学意义(t=11.382、10.952,P<0.05),D_(2%)提高16.4%和48.8%,差异有统计学意义(t=56.471、8.685,P<0.05);VMAT的Plan_(均增)、Plan_(递增)和Plan均匀3种计划正常脑组织V_(10)Gy~V_(40)Gy比较,差异均无统计学意义(P>0.05)。IMRT Plan_(均增)与Plan_(递增)的正常脑组织V20 Gy、V30 Gy和V_(40)Gy均小于VMAT的Plan_(均增)与Plan_(递增),差异均有统计学意义(t_(Plan均增)=2.112、2.215、2.444,t_(Plan递增)=2.323、2.939、3.145,P<0.05);IMRT与VMAT的D2、D_(mean)和D50比较差异均无统计学意义(P>0.05)。结论:在HSRT中,保证靶区边缘正常脑组织安全的前提下,同步提升靶区中心剂量不会显著提高正常脑组织剂量,IMRT与VMAT均能满足靶区内部增量要求,VMAT靶区增量略好,效率更高;递增计划靶区剂量提升效果好于均增计划,VMAT的递增计划更适合BMs的HSRT治疗。
Objective:To compare the dosimetric parameters under different incremental modes between intensity-modulated radiation therapy(IMRT)and volume rotation intensity-modulated therapy(VMAT)for the target area of large volume brain metastases(BMs),and to explore the better way of treating BMs based on hypofractionated stereotactic radiotherapy(HSRT)of linear accelerator.Methods:A total of 30 BMs patients who underwent IMRT at The 971th Hospital of Navy of the CPLA from 2020 to 2023 were selected.In the treatment planning system(TPS),three types of IMRT plans and VMAT plans were designed,which included uniformity plan(Planuniformity)of target area dose,uniform increased plan(Planuniform increased-dose)and incremental plan(Plan_(incremental))within target area.In the inside of the target area,the target area of high dose(GTV_(h))was set,and Planuniform increased-dose and Plan_(incremental)were designed to aim at GTV_(h).The differences of the doses of three types of treatment plans included Plan_(uniformity),Plan_(uniform increased-dose)and Plan_(incremental),which were respectively designed by using IMRT and VMAT,were analyzed.The mean dose(D_(mean))of the target area,the 50%and 2%exposed doses(D50%and D_(2%))of the target area were observed and compared.The conformity index(CI),homogeneity index(HI),gradient index(GI),and the volume percentage(V_(10)Gy-V_(40)Gy)that normal brain tissue received 10 Gy-40 Gy also were observed and compared.Results:Compared with Planuniformity of IMRT,the D_(mean)of GTV of Planuniform increased-dose and Plan_(incremental)of IMRT increased by 10.13%and 17.9%,with statistically significant differences(t=13.680,12.771,P<0.05).D50%increased by 8.9%and 10.8%,with statistically significant differences(t=15.190,9.929,P<0.05).D_(2%)increased by 15.2%and 46.4%,with statistically significant differences(t=52.320,8.746,P<0.05).There were no statistically significant differences in normal brain tissue V_(10)Gy-V_(40)Gy among Plan_(uniformity),Plan_(uniform increased-dose)and Plan_(incremental)of IMRT(P>0.05).Compared with Plan_(uniformity)of VMAT,the D_(mean)of GTV of Planuniform increased-dose and Plan_(incremental)of VMAT increased by 10.53%and 21.23%,with statistically significant differences(t=18.641,15.461,P<0.05),and D50%increased by 9.1%and 13.4%,with statistically significant differences(t=11.382,10.952,P<0.05),and D_(2%)increased by 16.4%and 48.8%,with statistically significant differences(t=56.471,8.685,P<0.05),respectively.There were no statistically significant differences in normal brain tissue V_(10)Gy-V_(40)Gy among Planuniformity,Plan_(uniform increased-dose) and Plan_(incremental)of VMAT(P>0.05).The normal brain tissue V_(20 Gy),V_(30 Gy) and V_(40Gy) of Planuniform increased-dose and Plan_(incremental)of IMRT were respectively less than those of VMAT,and the differences of them between IMRT and VMAT were significantt (Plan uniform increased-dose=2.112,2.215,2.444,tPlan incremental=2.323,2.939,3.145,P<0.05).There were no statistically significant difference in D_(2%),D_(mean),and D50%between IMRT and VMAT(P>0.05).Conclusion:On the premise of ensuring the safety of normal brain tissue at the edge of the target area,the synchronously increasing of the central dose of the target area will not significantly increase the dose for normal brain tissue.Both IMRT and VMAT can meet the requirements of increment in the inside of the target area,and VMAT has slightly better increment and higher efficiency within target area.The incremental of VMAT target area is slightly better,which also has better efficiency,while the enhancement effect of the dose of target area of Plan_(incremental)is better than that of the Plan_(uniform increased-dose).The Plan_(incremental) of VMAT is more suitable for HSRT treatment for BMs.
作者
吕海鹏
刘晓
陈嘉炜
石明明
徐红岩
侯晓玮
解传滨
Lyu Haipeng;Liu Xiao;Chen Jiawei;Shi Mingming;Xu Hongyan;Hou Xiaowei;Xie Chuanbin(Ward of Radiotherapy,Oncology Department,The 971th Hospital of Navy of the CPLA,Qingdao 266000,China;Oncology Department,The 971th Hospital of Navy of the CPLA,Qingdao 266000,China;Department of Radiotherapy,The First Medical Center,Chinese PLA General Hospital,Beijing 100853,China)
出处
《中国医学装备》
2025年第4期6-12,共7页
China Medical Equipment
基金
国家重点研发计划(2022YFC2409503)
青岛市科技计划(19-6-1-29-nsh)。
作者简介
通信作者:侯晓玮,Email:bluesky5581@126.com。
