中文摘要：

目的比较部分乳腺外照射患者四维CT（4DCT）测得的基于金属夹与血清肿所确定的术腔体积及位置关系。方法在15例乳腺癌患者4DCT图像上分别基于术腔各边界金属夹、血清肿、结合金属夹和血清肿勾画大体肿瘤体积并定义为GTVc、GTVs和GTVc＋s。测定GTVc、GTVs和GTVc＋s的体积、适形指数（cI）及三者间包含度（DI）。三者间体积、CI值比较行方差分析，DI值比较采用配对t检验，DI、CI值与靶区中心间距相关分析用Pearson法。结果GTVc、GTVs和GTVc＋s的体积分别为23．15、19．27cm^3和24．60cm^3（P=0．000）。GTVc与GTVs、GTVc与GTVc＋s、GTVs与GTVc＋s间的CI分别为0．36、0．60、0．53（P=0．000）。DI显示GTVs对GTVc的优于GTVc对GTVs的（0．67比0．48，P=0．000），GTVc对GTVc＋s的优于GTVc＋s对GTVc的（0．82比0．71，P=0．000），GTVs对GTVc＋s的优于GTVc＋s对GTvs的（0．91比0．52，P=0．000）。DI、CI值与靶区中心间距均呈负相关（所有P=0．000）。结论基于金属夹与血清肿及结合金属夹和血清肿勾画术腔靶区既存在体积差异又存在空间错位。

英文摘要：

Objective To conduct a comparative study of the volume and location of the lumpectomy cavity delineated by metal clips and/or seroma on four-dimensional computed tomography （4DCT） for external-beam partial breast irradiation. Methods On 10 respiratory phases of 4DCT images with 15 breast cancer patients, gross tumor volumes （GTVs ） were delineated based on the metal clips at the boundaries of surgical cavity, seroma, and metal clips plus seroma to obtain GTVc, GTVs, and GTVc＋s, respectively. The volumes of GTVc, GTVs, and GTVc＋s were measured, and the conformity index （CI） , degree of inclusion （DI） , and centroid distance between each two GTVs were calculated. One-way analysis of variance was used to compare volume and CI between GTVc, GTVs, and GTVc＋s ;the paired t-test was used for comparison of DI;the Pearson correlation test was used to investigate the relationship of CI and DI with centroid distance. Results The volumes of GTVc , GTVs, and GTVc＋s were 23.15 ~±13.34 cm3 , 19.27± 17.53 em3 , and 24.60 ±16. 72 em3 , respectively （P =0. 000）. The CIs of GTVc vs GTVs, GTVc vs GTVc ＋s, and GTVs vs GTVc＋s were 0.36 ±0. 14, 0.60 ±0. 14, and 0.53 ±0. 20, respectively （ P = 0. 000）. The DI of GTVs in GTVc was significantly higher than that of GTVc in GTVs （0.67 ±0. 21 vs 0.48 ±0. 20, P =0. 000） ;the DI of GTVc in GTVc＋s was significantly higher than that of GTVc＋s in GTVc （0.82 ±0. 11 vs 0.71 ±0. 19, P =0. 000） ;the DI of GTVs in GTVc＋s was significantly higher than that of GTVc＋s in GTVs （0.91 ±0. 14 vs 0.52 ±0. 22 ;P = 0. 000）. The Dis and CIs of GTVc vs GTVs, GTVc vs GTVc＋s, and GTVs vs GTVc＋s were negatively correlated with their centroid distances （P = 0. 000 for all comparisons）. Conclusions There are volume differences and spatial mismatches between the GTVs delineated based on metal clips, seroma, and metal clips plus seroma.