Lewis肺癌^(99m)Tc-EC-MN乏氧显像与VEGF表达相关性的实验研究

Experimental study of the correlation between hypoxia image by SPECT and the expression of VEGF in tumor tissue of Lewis lung carcinoma

目的:初步探讨用99mTc-EC-MN对Lewis肺癌行SPECT显像,所得参数T/NT(肿瘤放射性计数与对侧放射性计数比值)和血管内皮生长因子(VEGF)的表达水平之间的相关性。方法:用99mTc标记EC-MN,制备12个Lewis肺癌昆明小鼠模型,采用乏氧显像剂99mTc-EC-MN对其进行SPECT显像,通过划感兴趣区技术计算肿瘤与对侧肌肉放射性计数比值(T/NT)。显像结束后即刻颈动脉放血处死小鼠,取出肿瘤瘤体,用免疫组化方法测定肿瘤组织VEGF的表达水平。结果:12个荷Lewis肺癌小鼠在注射显像剂99mTc-EC-MN后3小时的SPECT显像示T/NT值为1.42-2.06(均数为1.78±0.22);VEGF的表达0.25%-2.05%(中位数为1.1%);Lewis肺癌的T/NT值与VEGF的表达呈直线相关关系(t=2.557,P=0.0285)。结论:99mTc-EC-MN SPECT乏氧显像的T/NT值与VEGF表达水平之间存在一定的相关性。

Objective：To evaluate the correlation between T/NT （the radioactivity ratio of tumor to the opposite muscle） by SPECT hypoxia image with 99mTc - EC - metronidazaole（ ^99mTc - EC - MN） and the expression of vascular endothelial growth factor（VEGF） in Lewis lung cancer animal model. Methods： EC -MN was labeled with ^99mTc. 12 mice bearing Lewis lung cancer were used for SPECT imaging and ROI technique was adopted to measure T/NT. Tumor biopsies were collected immediately after SPECT imaging. The expression of VEFR was detected by immunohistochemistry. Results： The T/NT value of Lewis lung sarcoma at 3h after injection of ^99mTc - EC -MN ranges from 1.42 to 2.06 with mean value of 1.78 ± 0.22. The expression of VEGF was 0.25% - 2.05% with the median of 1.1% , there was a significant linear correlation between VEGF expression and T/NT（ t = 2. 557, P = 0. 0258 ）. Conclusion ： There is a correspondence between T/NT value by SPECT and the expression of VEGF by immunohistochemistry.