摘要
目的比较四维CT(four-dimensional computed tomography,4D-CT)和三维CT(three-dimensional CT,3DCT)模拟定位技术确定食管癌原发肿瘤的位移和体积。方法前瞻性入组22例经病理证实的拟行调强放疗的食管癌患者序贯完成3D-CT和4D-CT模式下胸部模拟定位增强扫描。比较3种不同方法获得的食管肿瘤内在大体肿瘤靶区体积(internal gross tumor target volume,IGTV):4D-CT的10个呼吸时相的GTV得到IGTV_(4D);4D-CT的吸气末和呼气末时相GTV融合得到IGTV_(4D)';基于3D-CT的GTV再依据4D-CT测得的靶区运动范围外扩得到IGTV_(3D)。比较IGTV_(4D)、IGTV_(4D)'和IGTV_(3D)三维方向的位移差异。计算不同段食管癌原发肿瘤靶区IGTV_(4D)与IGTV_(3D)和IGTV_(4D)'的相似度指数(dice similarity coefficient,DSC)和交叉指数(overlap index,OI)。结果胸中段和胸中下段原发肿瘤10个时相上的靶区中心在左右、前后和头足方向的位移比较差异均具有统计学意义(均P<0.01)。食管癌原发肿瘤体积IGTV_(3D)>IGTV_(4D)>IGTV_(4D)'(P<0.05)。设定IGTV_(4D)为食管肿瘤的金标准,IGTV_(3D)有9.1%~24.1%周围正常组织可能受到不必要的照射;IGTV_(4D)'有10.5%~34.5%肿瘤靶区可能被漏照。结论在食管癌调强放疗模拟定位中,4D-CT模拟定位技术优于3D-CT模拟定位技术。
Objective To compare the four-dimensional and three-dimensional computed tomography （4D-CT and 3D-CT） simulation technology in determining the displacement and internal gross target volume of primary esophageal carci- noma. Methods Twenty-two pathologically diagnosed esophageal cancer patients planning to receive intensity modulated radiation therapy （IMRT） were prospectively recruited and sequentially received contrast enhancement free-breathing 3D- CT and respiration-synchronized 4D-CT simulation examinations. Three different internal gross tumor target volume （IGTV） planning methods of esophageal cancer were delineated： all 10 respiratory phases from 4D-CT were merged as IGTV4D＇ only end-inhalation and end-exhalation phases were considered as IGTV4D, and the IGTV3D was acquired by enlarging the 3D-CT- based GTV with the consideration of spatial motion on three orthogonal directions from 4D-CT. Then the target volume and the displacement on three orthogonal directions of these three different ICTV （ including IGTV4D, IGTV4D, and ICTV3D ） were compared. The dice similarity coefficient （DSC） and overlap index （OI） between IGTV4D and IGTV4o,, and between IGTV4D and IGTV3D for different segments of esophagus were also calculated. Results Statistically significant differences were detected for displacement at left-right, anterior-posterior and superior-inferior directions of primary esophageal tumor GTV of the 10 phases originated from medium-thoractic segments and medium-lower-thoractic segments （both P 〈 0.01 ）. Besides, the primary tumor volume was also significantly different ： IGTV3D 〉 IGTV4D 〉 IGTV4D, （ P 〈 0.05 ）. With IGTV4D as the assumed gold standard, IGTVsD may lead to unnecessary radiation of 9.1% to 24.1% of the surrounding normal tis- sues,whereas IGTV4D, may result in 10.5% to 34.5% of target area being uncovered. Conclusion 4D-CT simulation technology is superior to 3D-CT simulation technology for IMRT in esophageal carcinoma.
作者
赖国静
李建成
潘才住
胡彩容
郑德春
Lai Guojing Li Jiancheng Pan Caizhu et al(Radiotherapy Center,Fujian Provincial Cancer Hospital ＆ Fujian Medical University Cancer Hospital, Fuzhou 350014, China Department of Thoracic Radiation Oncology, Fujian Provincial Cancer Hospital ＆ Fujian Medical University Cancer Hospital, Fuzhou 350014, China)
出处
《实用肿瘤杂志》
CAS
2017年第5期444-449,共6页
Journal of Practical Oncology
基金
国家临床重点专科建设项目(2014)
福建省临床重点专科建设项目(2013)
