勾画标准培训对乳腺癌保乳术后放疗靶区勾画的作用

The influence of delineating criteria training on the delineation of tumor bed and whole breast target after breast-conserving surgery

目的探讨勾画标准培训对保乳术后瘤床靶区和全乳靶区勾画的影响。方法选择12例保乳术后患者，5位勾画者先对每位患者依据金属夹勾画瘤床靶区（GTV，）、依据术腔血清肿勾画瘤床靶区（GTV2）、勾画全乳靶区（cTV），随后参照勾画标准重复勾画GTV1、GTV2、CTV，比较5位勾画者间差异和参照标准前后差异并行单因素方差分析或配对t检验。结果5位勾画者参照标准前的GTV1、GTV2、CTV均不同（F=11．16、7．54、3．78，P=0．000、0．000、0．009），参照勾画标准后的GTV1、GTV2不同（F=4．78、4．24，P=0．002、0．005），但cTV相似（F=1．52，P=0．209）。参照勾画标准前后的GTV1、GTV2、CTV变异系数不同（t=3．14、2．81、2．70，P=0．009、0．017、0．021），匹配指数也不同（F=16．08、8．61、8．48，P=0．000、0．000、0．000）。结论乳腺癌靶区勾画标准的制订可降低勾画者之间荠异．尤其是对伞乳靶区的勾画匿为明显。

Objective To explore the influence of delineator and contouring criteria training on the delineation of the tumor bed and whole breast target after breast-conserving surgery. Methods Twelve breast cancer patients after breast conserving surgery were selected. Tumor bed marked by clips was defined as gross target volume 1 （ GTV1 ）, tumor bed formed by seroma was defined as GTV2 and the whale breast was defined as clinical target volume （CTV）. Five junior radiation oncologists first delineated GTV1 , GTV2 and CTV for each patient following their own criteria. After contouring criteria training, they then delineated GTV1 , GTV2 and CTV for the same group of patients again. The differences of the volumes of GTV1 , GTV2 and CTV before and after training among different delineators were compared. One-way ANOVA or matching t-test was performed. Results The inter-delineator variability on GTV1 , GTV~ and CTV delineation before training was statistically significant （ F = 11.16,7.54 and 3.78, P = 0. 000,0. 000 and 0. 009 ）. After training, the inter-delineator variability on GTV~ and GTV2 delineation had statistical significance （t = 4. 78 and 4. 24 ,P =0. 002 and 0. 005 ）, but the inter-delineator variability on CTV delineation had no statistical significance （ t = 1.52 ,P = 0. 209 ）. The coefficient of variance of the GTV1 , GTV2 and CTV before and after training was significantly different （ t = 3.14, 2. 81, 2.70, P = 0. 009, 0. 017 and 0. 021 ）. The matching index of GTV1, GTV2 and CTV before and after training was significantly different （F= 16. 08, 8. 61, 8. 48, P = 0. 000, 0. 000 and 0. 000）. Conclusions In delineating the target of breast cancer, application of the criteria of target delineation can reduce the difference among the delineators, especially for CTV.