摘要
目的评估乳腺癌改良根治术后三种常用调强照射技术的靶区及其周围正常组织受照剂量的差异,为术后临床最佳治疗计划的选择提供科学理论依据。方法随机选取左侧20例乳腺癌改良根治术后患者,经CT扫描后将图像传至Pinnacle^39. 6治疗计划系统中并由同一医生进行靶区勾画。针对每例患者靶区分别设计临床常用的IMRT6野计划、IMRT7野计划和VMAT 3种调强计划。利用剂量体积直方图评价3种调强照射方法的靶区和周围正常组织照射剂量体积和靶区适形指数及剂量不均匀性指数。结果 (1)VMAT靶区PTV的D_(mean)较6F、7F小,VMAT的靶区适形度最高,7F次之,6F最差。3种计划靶区均匀性指数无差异。(2)VMAT心脏最小受量要稍大于6F、7F;但心脏最大受量及平均剂量三者间无差异。VMAT心脏V_(30),V_(40)等高剂量受照体积明显小于6F、7F,而低剂量V_5～V_(20)三者间无明显差异。(3)患肺最大剂量、最小剂量及平均剂量三者并无明显差别。6F左肺中高剂量照射体积V_(15)、V_(20)、V_(30)、V_(40)、V_(50)较VMAT明显高。7F左肺的中高剂量照射体积V_(15)、V_(20)、V_(30)也显著高于VMAT,但在其余体积处两者无明显差别。6F与7F 2种计划差异不明显。(4)6F右肺平均剂量D_(mean)明显低于7F和VMAT,但低剂量区域V_5、V_(10)等处三者间差异不具有统计学意义。(5)右侧乳腺的D_(mean)、V_5、V_(10)等处三者之间差异不具有统计学意义。结论与常规固定野放疗6F与7F相比,VMAT计划在满足乳腺癌改良根治术后靶区剂量分布适形度和均匀性临床要求的同时还可以更好的降低肺组织和心脏、脊髓等危及器官的照射剂量和照射体积进而减少其并发症的发生率,具有重要实际临床意义和推广应用价值。
Objective To evaluate the dosimetric difference between IMRT in target and normal tissues receiving post-mastectpmy.Methods 20 patients that have received post-mastectpmy of left breast cancer were chosen randomly.CT images were inputted into the Pinnacle 3 9.6 treatment planning system.Three six-field IMRT plans(6F IMRT),seven-field IMRT plans(7F IMRT),and volumetric modulated arc therapy(VMAT)plans were designed for each patient.The irradiation dosed at the target region and surrounding normal tissues,as well as the conformity index and heterogeneity index of the target region under three IMRT plans,were evaluated by the dose volume histogram.Results ①The average PTV of VMAT plan is smaller than those of 6F and 7F plans.The conformity index(CI)of VMAT plan is the highest,followed by the 7F mode and the worst 6F mode.Three plans exhibit no statistical difference in the heterogeneity index(HI)of the target region.②VMAT Plan shows larger minimum dose in heart,but three plans exhibit no statistical difference in the maximum and average dose of heart.VMAT Plan exhibits statistical difference with 6F plans and 7F plans in terms of high-level irradiation volumes(V30,V40).But three plans exhibit no statistical difference n terms of low-level irradiation volumes(V5~V20).③Three plans present no statistically difference in terms of the maximum dose,minimum dose and mean dose of left lung.The VMAT plan has smaller irradiation dose high-level irradiation volumes(V15、V20、V30、V40、V50)than 6F plans and the same as(V15、V20、V30)than 7F plans with respect to left lung protection.However,there is no statistical difference between 6F plans and 7F plans.④For right lung protection,6F plans exhibits lower mean,maximum,and minimum irradiation doses to the right lung(Dmean,Dmax,and Dmin),and three plans show no statistically difference in low-level volume(V5、V10).⑤For right breast protection,All three plans exhibit no statistically significant difference with respect to V5,V10,and mean,maximum,and minimum irradia
作者
谢琛
张怀文
洪潮
胡海芹
XIE Chen;ZHANG Huaiwen;HONG Chao(Jiangxi Cancer Hospital,Nanchang,330029)
出处
《实用癌症杂志》
2018年第12期1941-1946,共6页
The Practical Journal of Cancer
基金
江西省卫计委科技计划项目(编号:20171114)
关键词
乳腺癌改良根治术
调强放射治疗
旋转调强放射治疗
剂量学
Breast cancer receiving post-mastectomy
Intensity-modulated radiation therapy
Volumetric modulated arc therapy
Dosimetry
