星形细胞瘤相对脑血容量与肿瘤血管生成的相关性研究

Correlation of relative cerebral blood volume with tumor angiogenesis in astrocytomas

目的通过对脑星形细胞瘤磁共振灌注成像(PWI)与MVD、VEGF免疫组织化学对照研究,旨在探讨星形细胞瘤相对脑血容量(rCBV)与肿瘤血管生成的相关性。方法对42例星形细胞瘤术前行常规T1WI和T2WI,然后采用对比剂首过动态增强自旋回波平面回波成像序列进行灌注成像扫描,最后行常规增强扫描。以灌注原始图像重建出rCBV图,依据rCBV图分别计算出肿瘤实质最大rCBV比值。术后取病理分别进行HE染色、MVD、VEGF免疫组化染色,分别用于病理分级并计算每一标本的MVD和VEGF表达程度。分别将MVD、VEGF表达与肿瘤实质最大rCBV比值进行相关分析。结果肿瘤实质最大rCBV比值与MVD呈明显正相关,r=0.686(P<0.01)。VEGF不同表达程度的星形细胞瘤之间的肿瘤实质最大rCBV比值的差异有统计学意义(P<0.05),随着VEGF表达程度增高,肿瘤实质最大rCBV比值增大。结论星形细胞瘤肿瘤实质最大rCBV比值与MVD及VEGF表达存在显著相关,灌注成像与肿瘤血管生成存在相关性。灌注成像可用于活体上评价星形细胞瘤的血管生成程度。

Objective To investigate the correlations of relative cerebral blood volume （rCBV） with vascular endothelial growth factor （VEGF） expression and microvessel density （MVD） in astrocytomas. Methods MR perfusion weighted imaging （PWI） was performed preoperatively on 42 patients with histologically confirmed astrocytoma. Color maps of rCBV were reconstructed from the perfusion data. The maximum rCBV ratios in solid portion were calculated using contralateral normal white matter as reference. The expression levels of VEGF were obtained after all specimens were immunostained. This technique was also used to detect the MVD. The correlation coefficients were used to determine the strength of the correlations between the maximum rCBV ratio and MVD together with VEGF expression levels. Results The maximum rCBV ratio in the solid portion was correlated well with MVD （r=0. 686, P〈0. 01）. Significant difference （P〈0.05） in the maximum rCBV ratio of the solid portion was found between different VEGF expression levels. The maximum rCBV ratio of the solid portion increased gradually with VEGF expression upgrading. Conclusion MR PWI may reflect the extent of tumor angiogenesis. It is feasible for evaluating the angiogenesis of astrocytomas.