整合素αvβ3分子探针18^F-Alfatide在肺癌患者中的生物学分布

Biodistribution of the αvβ3-targeted tracer 18^F-Alfatide in lung cancer patients

目的研究18^F-氟化铝螯合的聚乙二醇环RGD二肽（Alfatide）在肺癌患者体内的生物学分布及肿瘤组织对18^F-Alfatide的摄取。方法选取15例疑拟肺癌患者，其中男12例，女3例，平均年龄（56＋9）岁，按体质量静脉注射18^F-Alfatide3．7MBq／kg，静卧60min后行体部及头部PET／CT扫描，扫描范围从颅顶至股骨上端，勾画ROI并计算SUVmax和SUVmean。对肿瘤石蜡标本切片后进行整合素仅。αvβ3免疫染色分析。采用Spearson等级相关分析18^F-Alfatide摄取和αvβ3表达的相关性。结果15例患者中腺癌7例，鳞状细胞癌7例，小细胞肺癌1例。体内生物学分布结果显示，18^F-Alfatide主要通过肾脏排泄，血液清除快，肌肉及血液本底低，肝、脾及肾脏放射性摄取较高，肺部肿瘤组织具有较高的放射性摄取，肿瘤组织的SUVmax与SUVmean。分别为4．27±1．32与2．75±0．77，T／NT为15．19±9．33；肿瘤组织18^F-Alfatide摄取水平随αvβ3，表达水平的升高而增加（rs=0．765，P〈0．05）。结论18^F-Alfatide具有较好的体内生物学分布特性，相应的PET显像可以反映肿瘤组织的αvβ3，表达水平。

Objective To study the biodistribution of 18^F-Alfatide in lung cancer patients. Meth- otis Fifteen patients （ 12 males, 3 females, average age： （56±9） years） with suspicious lung cancer under- went PET/CT imaging. Images were acquired for each patient 60 min after injection of lSF-Alfatide （3.7 MBq/ kg）, coveting a field of view from the thigh to the skull. SUVmax and SUV were calculated with ROI meth- od. Immunohistochemistry test of tumor samples was performed to confirm the expression of integrin αvβ3. The relationship between the accumulation of 18^F-Alfatide and the expression of αvβ3 was analyzed by Spear- son rank correlation. Results There were 7 patients with squamous cell carcinoma, 7 patients with adeno- carcinoma and 1 patient with small cell lung cancer, lSF-Alfatide was excreted by the kidneys. The radioac- tivity was quickly eliminated from plasma. The high accumulation of radioactivity was found in the liver, spleen and kidneys, lSF-Alfatide PET imaging identified all tumors. The SUVmax and SUV of tumors were 4.27±1.32 and 2.75±0.77 respectively. T/NT ratio was 15.19±9.33. The uptake of iSF-Alfatide in tumor tis- sues correlated with the expression level of integrin αvβ3（ r = 0.765, P〈0.05）. Conclusion lS F-Alfatide has a favorable property of tissue biodisttibution and can be effectively used for αvβ3-positive tumor imaging.