摘要
目的:为提高左乳癌保乳术后患者的静态调强放疗(intensity-modulated radiotherapy,IMRT)计划质量,本文提出一种内切等中心IMRT计划(inner tangent isocenter IMRT,In_(iso)-IMRT)设计方法,并与常规等中心IMRT计划(normal isocenter IMRT,Nor_(iso)-IMRT)进行比较,探讨等中心设置对靶区和危及器官的剂量差异,为临床上设计精准化个体化物理计划提供参考依据。方法:回顾性随机选择33例左乳癌保乳术后患者,利用Monaco 6.11计划系统同一个患者分别设计Nor_(iso)-IMRT和In_(iso)-IMRT计划,其中,Nor_(iso)-IMRT组将照射野等中心设置为计划靶区(planning target volume,PTV)的几何中心点,In_(iso)-IMRT组则是在Noriso-IMRT组的基础上再沿乳头方向平移至PTV与肺组织的交界处形成等中心。比较两组计划的剂量学参数。结果:In_(iso)-IMRT组PTV的D_(98)、均匀性指数、适形性指数和机器跳数均优于Nor_(iso)-IMRT组,差异有统计学意义(P<0.05),D_(50)、D_(2)两组计划差异无统计学意义(P>0.05)。In_(iso)-IMRT组L-lung的V_(5)、V_(10)、V_(20)、V_(30)、V_(40)、D_(mean);Heart的V_(5)、V_(10)、V_(20)、D-(mean);R-lung的D_(mean)和Cord的D_(2)均明显低于Nor_(iso)-IMRT组,差异有统计学意义(P<0.05);In_(iso)-IMRT组R-breast的Dmean略高于Nor_(iso)-IMRT组[(376.07±156.11)cGy vs(250.87±102.61)cGy],差异有统计学意义(P<0.05)。结论:与Noriso-IMRT计划相比,本文提出的Iniso-IMRT计划设计方法不仅在靶区上获益,同时心肺的受照剂量也明显降低,而对侧乳腺的略微牺牲在可接受范围内,值得医学物理师和肿瘤医师参考。
Objective:To improve the quality of static intensity-modulated radiotherapy(IMRT)plan for patients with left breast cancer after breast-conserving surgery by comparing the dosimetric differences in targets and organs at risk between the inner tangent isocenter IMRT(In_(iso)-IMRT)and the normal isocenter IMRT(Nor_(iso)-IMRT),in order to provide ev-idence for designing precise and personalized physics plans in clinical work.Methods:Thirty-three patients with left breast cancer after breast-conserving surgery were retrospectively and randomly selected.Nor_(iso)-IMRT and In_(iso)-IMRT plans were respectively designed by Monaco 6.11 treatment plan-ning system for the same patient.For Nor_(iso)-IMRT,the center of irradiation field was set as the geometric center of planning target volume(PTV),while In_(iso)-IMRT then moved along the papillary direction to the junction between PTV and lung tissue based on the setting of Nor_(iso)-IMRT.The dosimetric parameters of the two groups were compared.Results:For PTV,In_(iso)-IMRT was better than Nor_(iso)-IMRT in Dgs,homogeneity index,conformity index and monitor units,and the differences were statistically significant(P<0.05),while there were no statistically significant differences in Dso and D,between two groups(P>0.05).In_(iso)-IMRT were significantly lower than Nor_(iso)-IMRT in V_(5),V_(10),V_(20),V_(30),V_(40)and D_(mean) of L-lung,V_(5),V_(10),V_(20) and D_(mean) of heart,Dmean of R-lung and D,of cord(P<0.05).In_(iso)-IMRT was slightly higher than Nor_(iso)-IMRT in the Dmean of R-breast[(376.07±156.11)cGy us(250.87±102.61)cGy],and the difference was statistically significant(P<0.05).Conclusion:Compared with Nor_(iso)-IMRT,the design of In_(iso)-IMRT proposed in this paper not only benefits the target area but also significantly reduces the radiation dose of L-lung,R-lung and Heart,while the slight increase of radiation dose in the R-breast is within an acceptable range,which is valuable for medical physicists and oncologists.
作者
袁美芳
赵彪
孙朝细
蒲琴
李静
Yuan Meifang;Zhao Biao;Sun Chaoxi;Pu Qin;Li Jing(Department of Radiation Oncology,the Third Affiliated Hospital of Kunming Medical University&Yunnan Cancer Hospital,Kunming 650118,Yunnan,China;Intensive Care Unit,the Third Affiliated Hospital of Kunming Medical University&Yunnan Cancer Hospital,Kunming 650118,Yunnan,China)
出处
《肿瘤预防与治疗》
2024年第6期505-511,共7页
Journal of Cancer Control And Treatment
基金
国家自然科学基金—地区科学基金项目(编号:32360114)。
关键词
等中心
左乳癌保乳术后
静态调强放疗
优化策略
Isocenter
Left breast cancer after breast conserving surgery
Static intensity modulated radiotherapy
Op-timized strategy
