基于Halcyon加速器左乳腺癌不同旋转弧数VMAT计划比较  

Comparison of VMAT plan with different arcs for left breast cancer based on Halcyon accelerator

作　　者：梅国建 尹楚欧 刘江[1] 邓娟 何迎盈[1] 叶程伟 MEI Guo-jian;YIN Chu-ou;LIU Jiang;DENG Juan;HE Ying-ying;YE Cheng-wei(Department of Oncology,The People’s Hospital of Deyang,Deyang 618000,Sichuan,China)

机构地区：[1]德阳市人民医院肿瘤科,四川德阳618000

出　　处：《生物医学工程与临床》2023年第5期587-593,共7页Biomedical Engineering and Clinical Medicine

基　　金：德阳市科学技术局科技计划项目(重点研发)(2021SZ008)。

摘　　要：目的基于Halcyon加速器比较左乳腺癌改良根治术后2弧、3弧、4弧和5弧的容积调强放射治疗(VMAT)计划的剂量学差异。方法选择德阳市人民医院肿瘤科行左侧乳腺癌改良根治术后患者20例,均为女性;年龄32~69岁,中位年龄51岁;肿瘤分期均为T3~T4、N1;位置为非内象限。基于Halcyon加速器为每位患者分别设计2弧、3弧、4弧和5弧4组VMAT计划。比较4组计划的计划靶区体积(PTV)和危及器官的剂量学指标、跳数(MU)、出束时间和γ通过率的差异。结果4弧组和5弧组VMAT计划在PTV的适形度指数(CI)、均匀性指数(HI)、D_(98)、D_(50)、D_(2)和Dmean上均优于2弧组和3弧组,而5弧组仅在PTV的D_(2)稍低于4弧组[(5311.9±30.74)cGy vs(5332.5±31.13)cGy。P<0.05]。危及器官,4弧组和5弧组左肺(患侧肺)V_(5)、V_(20)、V_(30)、V_(40)和Dmean最低,V_(10)亦低于3弧组[(33.09±2.60)%vs(32.98±2.65)%vs(34.23±2.53)%。P<0.05]。4弧组和5弧组右肺(健侧肺)Dmean低于2弧组[435(339,464)cGy vs 435(394,462)cGy vs 447(417,490)cGy。P<0.05]。4弧组和5弧组心脏V_(20)[(7.96±4.17)%、(7.99±4.19)%]和V_(30)[(3.60±2.58)%、(3.41±2.46)%]最低,V_(10)和Dmean亦低于2弧组[22.8(17.7,25.7)%vs 22.6(18.3,25.7)%vs 23.75(19.0,27.5)%、836(705,898)cGy vs 835(708,931)cGy vs 857(741,959)cGy。P<0.05]。4弧组和5弧组食管Dmean[(1362.0±370.4)cGy、(1363.2±367.3)cGy]最低,右乳Dmax亦低于2弧组[(901.4±162.9)cGy vs(900.4±170.4)cGy vs(973.9±181.5)cGy。P<0.05]。5弧组与4弧组各危及器官的剂量差异均无统计学意义(P>0.05)。4弧组MU和出束时间较2弧组和3弧组有少量增加,分别增加26.15 MU、0.05 min和28.9 MU、0.04 min,5弧组较4弧组也分别增加31.8 MU和0.05 min(P<0.05)。4组计划的γ通过率均>95%,组间差异无统计学意义(P>0.05)。结论4弧的乳腺癌VMAT计划可获得更优的剂量学分布。因此推荐左乳腺癌改良根治术后在Halcyon加速器上采用4弧的VMAT计划。Objective To compare the dosimetric difference of volumetric modulated arc therapy(VMAT)plans with 2-,3-,4-and 5-arc on the Halcyon accelerator followed by modified radical mastectomy(MRM)in patient with left breast cancer.Methods A total of 20 female patients with left breast cancer after MRM were enrolled,which aged 32-69 years old with median age of 51 years old.The tumor stages were T3-T4 and N1,position was non-inner quadrant.Four VMAT plans of 2-arc,3-arc,4-arc and 5-arc were designed for each patient based on Halcyon accelerator,and the differences of planning target volume(PTV),dosimetric parameters of organs at risk(OAR),monitor unit(MU),beam delivery time andγpass rate among 4 groups were compared.Results The conformity index(CI),homogeneity index(HI),D_(98),D_(50),D_(2)and Dmean of PTV in 4-arc group and 5-arc group were better than those in 2-arc group and 3-arc group,while D_(2)of PTV in 5-arc group was slightly lower than that in 4-arc group[(5311.9±30.74)cGy vs(5332.5±31.13)cGy.P<0.05].In OAR,the V_(5),V_(20),V_(30),V_(40)and Dmean of the left lung(affected lung)in 4-arc group and 5-arc group were the lowest among 4 groups,and V_(10)was also lower in 4-arc and 5-arc group than that in 3-arc group[(33.09±2.60)%vs(32.98±2.65)%vs(34.23±2.53)%.P<0.05].Moreover,the Dmean of right lung(healthy lung)in 4-arc group and 5-arc group was lower than that in 2-arc group[435(339,464)cGy vs 435(394,462)cGy vs 447(417,490)cGy.P<0.05].The V_(20)[(7.96±4.17)%,(7.99±4.19)%]and V_(30)[(3.60±2.58)%,(3.41±2.46)%]of heart in 4-arc group and 5-arc group were lowest among 4 groups,V_(10)and Dmean were also lower in 4-arc and 5-arc group than those in 2-arc group[22.8(17.7,25.7)%vs 22.6(18.3,25.7)%vs 23.75(19.0,27.5)%,836(705,898)cGy vs 835(708,931)cGy vs 857(741,959)cGy.P<0.05].The Dmean of esophagus in 4-arc group and 5-arc group were lowest among 4 groups[(1362.0±370.4)cGy,(1363.2±367.3)cGy],Dmax of right breast were also lower in 4-arc and 5-arc group than that in 2-arc group[(901.4±162.9)cGy vs(900.4±170.

关 键 词：乳腺癌 容积调强放疗 Halcyon加速器 剂量学 危及器官 

分 类 号：R730.55[医药卫生—肿瘤] R737.9[医药卫生—临床医学]