基于保乳术前MRI、术后标本及定位CT所构建大体肿瘤体积的比较研究

发布时间：2018-06-13 16:54

  本文选题：磁共振成像 + 部分乳腺外照射　； 参考：《济南大学》2017年硕士论文

【摘要】：目的探讨保乳患者术前MRI肿瘤体积与术后标本测量体积及基于金属夹勾画的瘤床体积之间的差异性与相关性,同时探讨基于4DCT的0时相(CT0)与50时相(CT50)刚性配准与形变配准基础上所构建保乳术后瘤床体积及位置的差异性。方法1.50例早期乳腺癌患者入组,基于保乳术前MRI勾画大体肿瘤体积(gross tumor volume,GTV)并定义为GTVMRI,其边界外扩1.0 cm得到GTVMRI+1。测量切除标本体积并测量和计算病理体积,分别定义为GTVES和GTVPAT。在定位CT图像上基于术腔边界金属夹勾画GTV,并定义为GTVTB。2.44例保乳术后已行4DCT模拟定位扫描的患者入组。由同一位放疗科医生分别基于4DCT的0时相和50时相勾画GTV及选定金属夹。将CT0与CT50分别运行刚性配准(rigid image registration,RIR)与形变配准(deformable image registration,DIR),并将基于CT0图像勾画的GTV及金属夹分别通过形变配准与刚性配准映射到CT50图像上。以相似度指数(Dice similarity coefficient,DSC)、三维空间方向上靶区中心点位移的差异评估不同图像配准技术对CT0与CT50图像之间靶区体积及位置的差异。结果1.GTVMRI、GTVMRI+1、GTVPAT、GTVES、GTVTB中位数(范围)分别为0.97(0.01~6.88)cm3、12.58(3.90~34.13)cm3、0.97(0.01~2.36)cm3、15.46(1.15~70.69)cm3、19.24(4.72~54.33)cm3。GTVMRI与GTVPAT、GTVMRI+1与GTVES、GTVTB与GTVES差异均无统计学意义(P=0.188,0.07,0.264)。GTVTB、GTVES与GTVMRI均无相关性(P=0.378,0.071),GTVTB、GTVES与GTVMRI+1也均无相关性(P=0.375,0.068),而GTVTB与GTVES呈正相关(r=0.488,P=0.004)。2.RIR与DIR靶区的平均DSC分别为0.860±0.042与0.870±0.040(P=0.000)。RIR在三维空间方向上靶区中心点的位移明显大于DIR(分别为1.22 mm和1.10 mm,P=0.000)。而且在前后方向上,GTV及金属夹通过RIR的位移明显大于DIR(P=0.000)。但是,在左右及上下方向上,RIR与DIR对GTV及金属夹位移的差异均没有统计学意义(均P0.050)。结论在非影像引导情况下,保乳治疗的患者基于触诊范围行局部肿瘤扩大切除术时,切除标本体积及基于金属夹勾画的术腔体积与基于术前MRI图像所勾画与构建的肿瘤体积均无相关性。形变配准可以显著改善4DCT的0时相与50时相配准时靶区的重合度。同时,基于形变配准测量呼吸运动所致的靶区及选定金属夹在前后方向上的位移明显优于刚性配准。
[Abstract]:Objective to investigate the difference and correlation between preoperative MRI tumor volume and postoperative measurement volume and tumor bed volume based on metal clip in breast conserving patients. At the same time, the difference of volume and location of tumor bed after breast conserving operation was discussed on the basis of rigid registration and deformation registration based on 0time phase CT0 (4DCT) and CT50 (50time phase). Methods 1.Fifty patients with early breast cancer were enrolled in the study. Gross tumor volume was defined as GTV MRI based on the gross tumor volume before breast conserving. The volume of excision specimen was measured and the pathological volume was measured and calculated, which were defined as GTVES and GTVPATrespectively. GTV was delineated on the localization CT image based on the metal clip of the surgical cavity boundary, and was defined as GTVTB.2.44 patients who had undergone 4DCT analog localization scanning after breast conserving surgery were included in the group. The GTV and the selected metal clip were delineated by the same radiotherapy doctor based on the 4 DCT 0 and 50 time phases, respectively. The rigid image registration and deformable image registration based on CT0 and CT50 are respectively applied to CT50 images, and the GTVs and metal clips based on CT0 images are mapped to CT50 images by deformation registration and rigid registration respectively. The difference of the center displacement of target in 3D direction is evaluated by using the similarity index (Dice similarity efficient) and the difference of target volume and position between CT0 and CT50 images by different image registration techniques. 缁撴灉1.GTVMRI,GTVMRI 1,GTVPAT,GTVES,GTVTB涓�浣嶆暎�

本文编号：2014711