ADC全容积直方图在直肠癌分期中的应用

Application of whole-volume apparent diffusion coefficient histogram in staging of rectal cancer

目的探讨ADC全容积直方图在直肠癌TN分期中的应用价值。方法前瞻性收集经结肠镜病理证实为直肠癌患者35例,术前行磁共振DWI检查。在ADC直方图软件上勾画肿瘤轮廓,计算ADC直方图参数,采用Spearman法分析ADC直方图参数与肿瘤TN分期相关性,用ROC曲线评价各参数诊断TN分期的效能。采用可靠性检验评估观察者间可重复性。结果参数Histogram width、Skew与肿瘤T分期具有显著相关性(P=0.036,r=0.355;P=0.033,r=0.361);Histogram width、Skew在区分T_3与T_1/T_2期肿块时曲线下面积分别为0.716、0.720。但淋巴结是否转移的指标分析中未发现阳性结果。可靠性检验显示75%的参数组间相关系数在0.8以上。结论大部分ADC全容积直方图参数在直肠癌应用中可靠性高。其中,Histogram width以及Skew与直肠癌T分期具有显著相关性。

Objective To investigate the efficacy of histogram analysis of the whole-volume in apparent diffusion coefficient （ADC） for T and N staging in rectal cancer. Methods Thirty-five patients were enrolled and underwent preoperative DWI exam-ination. Tumors were delineated on each slice of the ADC maps. A series of histogram parameters were calculated and correlated with T and N staging by Spearman correlation analysis. The diagnostic performance of each parameter for distinguishing T and N staging was assessed by using the area under the receiver operating characteristic curve （AUC）. Repeatability test was used to as- sess the repeatability between observers. Results There were significant correlations between histogram parameters （ Histogram width and Skew） and T-staging （P =0.036, r =0.355;P =0.033, r =0. 361）. Among all the histogram parameters, histo- gram width and Skew had larger AUC value in differentiating T3 from T1/T2 tumor, which were 0. 716 and O. 720 respectively. However, we didn＇t find any positive result in whether lymph node metastasis. The intraclass correlation coefficient of 75% histo- gram parameters were more than 0.8 in repeatability test. Conclusion The repeatability of most histogram parameters in rectal cancer is high. Histogram width and Skew correlated significantly with T staging.