基于DWMRI和增强CT勾画胰腺癌GTV对比研究

目的 通过对比研究增强CT及DWMRI在胰腺恶性肿瘤体积大小、肝脏及区域淋巴结转移瘤的差异,指导临床放疗实践。方法 计划入组40例胰腺癌患者,均行增强CT及DWMRI定位扫描,后依据不同图像进行靶区体积勾画、肿瘤最大截面长径测量、肝转移瘤及5~8 mm、>8 mm淋巴结转移瘤的测量。分别使用配对t检验或配对Wilcoxon秩和检验进行分析。结果 基于增强CT、DWMRI所勾画的GTV平均值分别为54.95、41.67 cm³(P=0.000),肿瘤最大界面长径平均值分别为4.18、3.94 cm (P=0.000),其中2例d_CT小于d_DWMRI。依据增强CT、DWMRI图像分别检出肝脏转移瘤83、112个,增强CT检出量占DWMRI检出的74%;>8 mm淋巴结转移瘤分别检出46、56个,5~8 mm淋巴结分别检出103、200个,增强CT检出量分别占DWMRI检出的82%、52%。结论 基于DWMRI测量的GTV及肿瘤最大界面长径较增强CT小,在肝脏及区域淋巴结转移瘤检出较增强CT敏感。然而还需要进一步参照病理对照试验证实。

A comparative analysis of diffusion-weighted magnetic resonance imaging and contrast-enhanced CT in target volume delineation for pancreatic cancer

Objective To investigate the differences in tumor volume and metastatic tumors of the liver and regional lymph nodes between contrast-enhanced computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DWMRI) through a comparative analysis,as well the useful information for target volume delineation,and to guide radiotherapy in clinical practice.Methods A total of 40 patients with pancreatic cancer were enrolled and underwent contrast-enhanced CT and DWMRI in the same position.The target volume was delineated,the major axis of the maximum tumor section was measured,and the numbers of liver metastatic tumors and metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm were measured based on the CT and DWMRI images.The analysis was performed by using paired t-test or paired Wilcoxon rank sum test.Results The mean gross tumor volume (GTV) delineated by contrast-enhanced CT and DWMRI was 54.95 cm3 and 41.67 cm3(P =0.000),and the mean value-different value was 13.28 cm3.The major axis of the maximum tumor section measured by contrast-enhanced CT and DWMRI were 4.18 cm and 3.94 cm (P=0.000),respectively,and in two patients,dCT was smaller than dDWMRI.A total of 83 liver metastatic tumors were identified by contrast-enhanced CT,and 112 were identified by DWMRI;the liver metastatic tumors detected by contrast-enhanced CT accounted for 74％ of those detected by DWMRI.As for the metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm,103 or 46 were detected by contrast-enhanced CT,and 200 or 56 were detected by DWMRI,and the tumors detected contrast-enhanced CT accounted for 52％ or 82％ of those detected by DWMRI.There were significant differences in all data between contrast-enhanced CT and DWMRI.Conclusions GTV and the major axis of the maximum tumor section measured by DWMRI are lower than those measured by contrast-enhanced CT,and contrast-enhanced CT is sensitive in detecting the metastatic tumors of the liver and lymph nodes.However,it is necessary to conduct further controlled experiments with reference to pathology.