摘要
目的:基于不同部位的肺部肿瘤患者四维CT(4DCT)图像,比较最大密度投影图像(MIP)与4DCT图像勾画肺部肿瘤的体积和形状差异。方法:选择肿瘤分别位于肺部中央、靠近胸壁胸椎、紧邻血管、肝脏与心脏或者淋巴结转移并伴随肺不张患者共12例,在平静呼吸状态扫描得到4DCT图像。MIM软件对4DCT图像进行处理得到MIP图像和平均密度投影图像(AIP)。由同一位医生在4DCT的10个呼吸时相图像依次勾画靶区GTV_(0%)、GTV_(10%)、……GTV_(90%),再合成内靶区(ITV_(4D));同时分别在MIP图像和AIP图像勾画ITV_(MIP)和GTV_(AIP)。读取ITV_(MIP)与ITV_(4D)的体积及质心坐标,计算ITV_(MIP)与ITV_(4D)的相似性系数(Dice)以及豪斯多夫距离(Hausdorff)最大值。结果:靶区在肺中央或者靠近胸壁的7位患者,靶区体积比(V_(MIP)/V_(4D))与Dice系数均大于或约等于0.9,两者差值的平均值为0.06。Hausdorff距离最大值、质心位移平均值分别为3.2和0.65 mm。靶区紧邻血管、心脏瓣膜、肝脏或者伴随淋巴结转移及肺不张的5位患者,靶区体积比与Dice系数平均值分别为0.85和0.80,两者差值的平均值为0.13。Hausdorff距离最大值、质心位移平均值分别为9.4和3.0 mm。结论:对于边界清晰的肺部肿瘤,MIP图像和4DCT勾画的ITV相近。肿瘤周围有等密度组织时,MIP图像和4DCT图像勾画靶区差异较大。
Objective To evaluate the differences of the volume and shape of lung tumor delineated from maximum intensity projection（MIP）image and four-dimensional computed tomography（4DCT）image of patients with lung tumors located at different positions.Methods Twelve patients with lung tumor were selected,whose tumor located in the central lungs,near the chest wall,close to the thorax,near the blood vessels and heart,and accompanied with lung atelectasis and lymph node metastasis.MIM software was used to process 4DCT images which were acquired by spiral scanning during free breathing for obtaining MIP images and average intensity projection（AIP）images.After being delineated by the same doctor based on the 4DCT images,the gross tumor target areas（GTV（0%）,GTV（10%）and GTV（90%））were combined as an inner tumor volume（ITV（4D））.Simultaneously,ITV（MIP）and GTV（AIP）were delineated in MIP images and AIP images.The volume and centroid coordinate of ITV（MIP）and ITV（4D）were read;the dice coefficient and maximum Hausdorff distance of ITV（MIP）and ITV（4D）were also calculated.Results Both the dice coefficient and volume ratio between ITV（MIP）and ITV（4D）were beyond 0.9,and the average difference was 0.06 for 7 patients whose tumors were in the central lungs or close to the chest wall;the maximum Hausdorff distance and centroid displacement were 3.20 and 0.65 mm,respectively.The dice coefficient and volume ratio between ITV（MIP）and ITV（4D）were 0.85 and 0.80,and the average difference was 0.13 for the other 5 patients whose tumors were close to the blood vessels,heart,liver and accompanied with lymph node metastasis and lung atelectasis;the maximum Hausdorff distance and cnetroid displacement were 9.4 and 3.0 mm,respectively.Conclusion ITV from MIP images and 4DCT images is similar for distinguishable boundary tumors.Significant volumetric differences exist in the target areas delineated from MIP images and 4DCT images when the tumors are adjoined to tissues with simil
作者
宋孟孟
王运来
黄祥
鞠忠建
戴相昆
吴青南
SONG Mengmeng1, WANG Yunlai2, HUANG Xiang2, JU Zhongjian2, DAI Xiangkun2 WU Qingnan1(1. School of Physics and Technology, Wuhan University, Wuhan 430072, China; 2. Department of Radiotherapy, Chinese PLA General Hospital, Beijing 100853, Chin)
出处
《中国医学物理学杂志》
CSCD
2018年第2期135-140,共6页
Chinese Journal of Medical Physics
基金
国家重点研发计划(2016YFC0105700)
关键词
肺部肿瘤
内靶区
4DCT
最大密度投影图像
相似性系数
豪斯多夫距离最大值
lung tumor
internal target area
four-dimensional computed tomography
maximum intensity projection image
dice coefficient
maximum Hausdorffdistance
