摘要
目的]探讨半弧（semi-arc,SA）和剪刀形切线弧（tangent-arc,TA）技术在左侧乳腺癌根治术后放疗中的应用研究及剂量学优势。[方法]选取15例根治术后的左侧乳腺癌病例,在Monaco计划系统上分别采用SA和TA两组射野方式进行容积旋转调强（VMAT）计划设计,比较两组计划的靶区平均剂量、最大剂量、适形性指数（HI）、均匀性指数（CI）等,以及危及器官（OAR）的相关受照剂量体积参数。[结果]对于胸壁靶区PTV-T,TA射野组的Dmean和D2均小于SA组（P〈0.05）,且HI和CI值优于SA组;对于锁骨淋巴结靶区PTV-N,虽然在HI和CI上两组差异无统计学意义,但Dmean、D98和D2均呈现TA〈SA（P〈0.05）。对于危及器官的受量,TA组的射野方式对降低健侧肺V5、V10和Dmean的效果明显好于SA组（P〈0.05）,且更进一步地保护了心脏、脊髓、对侧乳腺和左侧肱骨头。[结论]对于乳腺癌的VMAT计划,两组射野方式都能满足临床应用要求,但TA组在得到相同靶区处方剂量覆盖率、平均剂量、最大剂量、HI、CI等的前提下,能够进一步改善危及器官的受照剂量与受照体积,认为TA组射野方式是一种更适合左侧乳腺癌放疗的VMAT技术。
[Objective]To compare the dosimetry advantage of semi-arc（SA）and forficiform tangentarc（TA）techniques in volumetric modulated arc therapy（VMAT）for the left breast cancer after radical operation.[Methods]For 15 postoperative patients with left breast cancer,SA and TA beam fields for VMAT plans were designed on Monaco plan system,respectively.The mean dose,maximum dose,homogeneity index（HI）and conformity index（CI）of the targets were compared.The corresponding radiation doses of organs at risk（OAR）were also compared.[Results]For chest wall target PTV-T,the Dmeanand D2of TA group were less than those of SA（P〈0.05）,HI and CI were better than SA.For clavicle lymph node target PTV-N,the HI and CI of two groups had no significant difference,but the Dmean,D（98）and D2of TA were significantly lower than those of SA（P〈0.05）.For the OARs,the V5,Vand Dmeanof contralateral lung in TA group were significantly reduced,and better than those in SA group（P〈0.05）,and further protected the heart,spinal cord,the contralateral breast and the left head of the humerus.[Conclusion]Two beam modalities can meet the requirements of clinical application with VMAT plan for breast cancer,but under the premise of the same target coverage,the mean dose,maximum dose,HI,CI in TA group can further protect OARs,it was more suitable for the left breast cancer in VMAT.
作者
郑明志
胡彩容
程燕铭
陆军
张秀春
吴君心
ZHENG Ming-zhi;HU Cai-rong;CHENG Yah-ruing(Fujian Cancer Hospital ＆ Fujian Medical University Cancer Hospital, Fuzhou 350014, China)
出处
《肿瘤学杂志》
CAS
2018年第5期470-475,共6页
Journal of Chinese Oncology
基金
福建省医学创新课题(2014-CXB-5)
2013-2014年度国家临床重点专科建设项目(国卫办医函[2013]544号)
福建省2012年临床重点专科(西医类别)建设项目(闽卫科教[2012]149号)
关键词
乳腺肿瘤
半弧
切线弧
剂量学
breast neoplasm
semi-arc
tangent-arc
dosimetric
