乳腺癌保乳术后基于体表标记和触诊范围以及CT图像显示腺体勾画全乳靶区的比较

Comparison of the whole breast target volume delineated according to surface marks, palpation and glandular tissue on CT images after breast-conserving surgery

目的 对比基于体表标记和触诊范围以及CT图像显示腺体勾画全乳临床靶区（CTV）的差异,探讨全乳CTV勾画的合理方法.方法 选择15例乳腺癌保乳术后放疗的患者,在三维CT模拟定位扫描图像上,分别基于体表标记所界定乳腺解剖范围、触诊范围所界定乳腺解剖范围和CT图像显示腺体范围勾画全乳CTV,并分别定义为CTVan、CTVpa和CTVgl,比较3种方法所勾画全乳CTV的体积大小、相互包含度（DI）和适形指数（CI）.结果 CTVan的体积为（792.23 ± 282.25） cm3,CTVpa的体积为（618.33 ±295.90）cm3,CTVgl的体积为（196.83±117.62）cm3,3组间差异有统计学意义（P ＜0.001）,CTVan和CTVpa间的差异无统计学意义（P=0.080）,而CTVan与CTVgl间、CTVpa与CTVgl间的差异则均有统计学意义（均P＜0.001）.CTVan与CTVpa的CI为0.644±0.122,明显大于CTVan与CTVgl以及CTVpa与CTVgl的CI（分别为0.264±0.108和0.328±0.115,均P＜0.001）.CTVpa对CTVan的DI为0.890±0.080,CTVan对CTVpa的DI为0.709±0.144,CTVgl对CTVan的DI为0.994±0.005,CTVgl对CTVpa的DI分别为0.989±0.008.CTVpa与CTVan的内界、外界、上界和下界的差值分别为（3.35 ±7.23） mm、（5.57±13.37） mm、（1.75±11.62） mm和（11.25±4.07） mm,而且上界与内界的差值与CTVpa的体积呈负相关（均P＜0.05）.结论 基于体表标记和触诊范围以及CT图像显示腺体勾画的全乳CTV的差异有统计学意义,其中基于CT显示的腺体勾画的CTV明显小于另外两个靶区.基于触诊范围所界定乳腺范围并参考体表解剖标记进行全乳CTV的勾画是相对合理的.

Objective To compare the methods of delineating the whole breast target volume based on surface marks,palpation and glandular tissue on CT images,and to explore the contouring criteria after breast-conserving surgery.Methods In 15 patients with breast cancer after breast-conserving surgery,the whole breast target was delineated in 3D CT simulation images each by three different methods.The target volume delineated according to anatomical marks were named CTVan,according to breast palpation named CTVpa,and according to glandular mammary tissue showing by CT images named CTVgl.The volumes of CTVan,CTVpa and CTVgl,and the degree of inclusion （DI） and conformal index （CI） between the targets were measured.Results The mean volumes of CTVan,CTVpa and CTVgl were （792.23 ± 282.25） cm3,（618.33 ± 295.90） cm3 and （196.83 ± 117.62） cm3,respectively.The differences among the three methods were statistically significant （P 〈 0.001）.The difference between CTVan and CTVpa had no statistical significance （P =0.08）,and both the differences between CTVan and CTVgl,and between CTVpa and CTVgl had statistical significance （both P 〈 0.001）.The CI between CTVan and CTVpa （0.644 ±0.122） was significantly larger than the CI between CTVan and CTVgl （0.264 ±0.108）,and the CI between CTVpa and CTVgl （0.328 ±0.115） （P 〈0.001）.The DI of CTVan to CTVpa was 0.709 ± 0.144,DI of CTVgl to CTVan was 0.994 ± 0.005 and DI of CTVgl to CTVpa was 0.989 ± 0.008.The differences of inner,outer,upper and lower boundaries of CTVpa and CTVan were （3.35 ± 7.23） mm,（5.57 ±13.37） mm,（1.75 ±11.62） mm,and （11.25 ± 4.07） mm,respectively.The cranial and medial boundaries had a negative correlation with CTVpa （P 〈 0.05 for all）.Conclusions The differences among the three methods in the delineation of whole breast target volume are statistically significant.The target volume delineated according to the glandular mammary tissue displayed by CT scan is significantly smaller than that by the other two methods.Combination of breast palpation and anatomical marks may be helpful in delineating the whole breast target volume is relatively reasonable at present.