保乳患者术前诊断MRI与术后俯卧位定位CT基于形变配准的靶区比较研究  

A comparative study of target volumes based on deformation registration using preoperative prone magnetic resonance imaging and postoperative prone computed tomography imaging for patients undergoing breast-conserving surgery

作　　者：于婷 李建彬 王玮 徐敏 邵倩 张英杰 刘希军 Yu Ting;Li jianbin;Wang Wei;Xu Min;Shao Qian;Zhang Yingjie;Liu Xijun(School of Medicine and Life Sciences,University of Jinan,Shandong Academy of Medical Sciences,Jinan 250022,China（Yu T;Department of Radiation Oncology,Shandong Cancer Hospital Affiliated to Shandong University,Jinan 250117,China（Li JB,Wang W,Xu M,Shao Q,Zhang YJ,Liu XJ)

机构地区：[1]济南大学山东省医学科学院医学与生命科学学院,250022 [2]山东大学附属山东省肿瘤医院放疗科,济南250117

出　　处：《中华放射医学与防护杂志》2018年第7期499-504,共6页Chinese Journal of Radiological Medicine and Protection

基　　金：国家重点研发计划项目（2016YFC0904700）;国家自然基金青年基金（81703038）;山东省重点研发计划项目（2017GSF18102）;山东省自然科学基金（ZR2017PH006）

摘　　要：目的 基于形变配准比较保乳患者术前诊断MRI与术后俯卧位定位CT相应靶区间体积和位置的关联与差异。方法 18例早期乳腺癌保乳术后拟行俯卧位部分乳腺外照射（EB-PBI）患者入组，所有患者保乳术前均行俯卧位诊断MRI扫描并行术后俯卧位定位CT扫描。基于术前MRI勾画肿瘤靶区（GTVMRI），边界外扩10和20 mm构建CTVMRI＋1和CTVMRI＋2，边界外扩15和25 mm构建PTVMRI＋1和PTVMRI＋2，勾画患侧全乳靶区CTVBreast-MRI；在定位CT图像上，基于术腔金属夹勾画瘤床GTV（GTVTB），边界外扩10和15 mm构建CTVTB和PTVTB，勾画患侧全乳靶区CTVBreast-CI。在MIM系统中，将MRI与CT图像进行形变配准。结果 基于术后定位CT所得GTVTB、CTVTB、PTVTB分别大于基于术前诊断MRI所得GTVMRI、CTVMRI＋1、PTVMRI＋1 （Z=-3.593、-3.593、-2.983， P〈0.05）。基于GTVTB与GTVMRI靶区中心点形变配准时GTVTB-GTVMRI、GTVTB-CTVMRI＋1、CTVTB-GTVMRI、CTVTB-GTVMRI＋1的适形指数（CI）和包含度（DI）较基于胸廓形变配准有所改善（Z=-3.724、-3.724、-2.591、-3.593， P〈0.05；Z=-3.724、-3.724、-3.201、-3.724，P〈0.05）。结论 对早期乳腺癌患者，基于术前俯卧位MRI所得EB-PBI靶区体积显著小于基于术后俯卧位CT所得EB-PBI靶区体积，但对应靶区体积间呈正相关。即使采用形变配准，术前MRI与术后定位CT间，无论全乳靶区间还是肿瘤靶区与瘤床靶区间的空间对应性仍然较差，因此，基于术前MRI与术后瘤床进行俯卧位EB-PBI靶区融合性勾画是不合理。Objective To explore the differences and correlation between the target volumes based on deformation registration （DIR） using preoperative prone diagnostic magnetic resonance （MR） imaging and postoperative prone computed tomography （CT） simulation imaging for patients undergoing breast-conserving surgery （BCS）. Methods Eighteen breast cancer patients suitable for external-beam partial breast irradiation （EB-PBI） after BCS were enrolled. Preoperative prone diagnostic MR and postoperative prone CT scan sets were acquired during free breathing for all patients. The gross tumor volume （GTV） delineated on the preoperative diagnostic MR images was defined as GTVMRI, the clinical target volumes （CTVMRI＋1 and CTVMRI＋2） were defined as 10 and 20 mm margins around the GTVMRI, and the planning target volume （PTVMRI＋1 and PTVMRI＋2） were defined as 15 and 25 mm margins around the GTVMRI,respectively. Tumor bed （TB） delineated on the postoperative prone CT simulation images acquired during free breathing was defined as GTVTB, CTV and PTV were defined as 10 and 15 mm margins around the GTVTB, respectively. The target volume of the whole breast contoured on the MR and CT images were defined as CTVBreast-MRI and CTVBreast-CI, respectively. The MR and CT images were registered deformably in MIM software system. Results The GTVTB, CTVTB and PTVTB were significantly greater than GTVMRI, GTVMRI＋1 and PTVMRI＋1, respectively （Z=-3.593, -3.593, -2.983, P〈0.05）. Meanwhile, the CTVTB and PTVTB were significantly less than the CTVMRI＋2 and PTVMRI＋2,respectively（Z=-2.722, -2.853, P〈0.05）. The conformal index （CI） and degree of inclusion （DI） of GTVTB-GTVMRI, GTVTB-CTVMRI＋1, CTVTB-GTVMRI and CTVTB-GTVMRI＋1 based on center-coincidence of the compared targets were better than those based on DIR of the thorax（Z=-3.724、-3.724、-2.591、-3.593, P〈0.05;Z=-3.724、-3.724、-3.201、-3.724,P〈0.05）. Conclusions For the patients enrolled for prone EB-PBI, target vol

关 键 词：术前诊断磁共振 术后俯卧位定位CT 形变配准 靶区比较 部分乳腺外照射 

分 类 号：R445.2[医药卫生—影像医学与核医学]