VX2肿瘤MSCT灌注与缺氧状态关系的研究

The Relationship Among MSCT Perfusion And Hypoxia in The VX2 Tumor Model

目的研究VX2肿瘤MSCT血流灌注与缺氧状态之间的关系。材料与方法8只腿部肌肉种植VX2肿瘤的新西兰大白兔,分别于肿瘤生长第7、14、21、28天行MSCT灌注扫描,分别测量肿瘤及正常肌肉组织内血流量(BF)、最大强化指数(PEI)、峰值到达时间(TTP)及血容量(BV)作为灌注指标。肿瘤组织行HIF-1α免疫组织化学染色,根据肿瘤细胞着色深度和阳性细胞百分比统计HIF-1α表达等级。不同时间段HIF-1α等级分布分别进行χ2检验,HIF-1α表达等级之间行χ2检验,HIF-1α与CT灌注值行Spearman等级相关分析。结果肿瘤第7、14、21、28天HIF-1α等级由低到高再降低,但其变化差异无统计学意义(χ2=1.49,P=0.22),不同时间段CT灌注BF值与HIF-1α表达存在相关性(r=0.87,P<0.05),其他CT灌注值与HIF-1α表达无明显相关性。结论VX2肿瘤生长过程中均存在缺氧,缺氧状态与CT灌注BF值相关,表明VX2肿瘤血流灌注与肿瘤缺氧状态之间存在依存关系。

Objective To study the relationship of tumor hypoxia and MSCT perfusion parameters of VX2 soft-tissue tumor in the rabbit model during the process of tumor growth. Materials and Methods 8 rabbits were implanted with VX2 tumor tissue in proximal thighs. MSCT perfusion scan were performed on those rabbits with Mx8000 Quad CT in the 7, 14,21,28 days after implant respectively. The 45s-perfusion CT examination was underwent and perfusion maps were produced automatically. Blood flow（BF） , peak enhancement index （ PEI ） , time to peak （TTP） and blood volume （ BV ） were measured by the manually defined ROI within tumor. 2 rabbits were sacrificed every 7 days after CT perfusion, and the resected specimens were stained immunohistochemieally to identified HIF-α for assessment of their stage. Results The HIF-1α staging of 7th, 14th,21st,28th day increase gradually with time and then following decrease. The HIF-1α staging of vary time have no significance difference （ X^2 = 1.49, P = 0.22 ）. Significant correlation were observed between BF with HIF- 1α（r =0. 87,P 〈0.05） ,There were no significant associations between PEI,TTP,BV and HIF-1α. Conclusion HIF-1α is an important factor in the regulation of angiogenesis and tumor growth in VX2 soft-tissue tumor. Blood perfusion values correlate positively with HIF-1α and they may reflect the regulation of hypoxia and perfusion partially in tumor.