18^F-FDG11C-MET和11^C-CHOPET／CT对大鼠C6胶质瘤和炎性病变的鉴别诊断价值及与HIF-1α、VEGF的相关性研究

Differential diagnosis of rat C6 glioma and inflammation with 1^F-FDG, 11^C-MET and IIC-CHO PET/CT imaging and their correlations with HIF-1α and VEGF

目的比较18^F-FDG、11^C-MET和11^C-CHOPET／CT对大鼠C6胶质瘤和炎性病变的鉴别诊断价值，并探讨其与HIF-1α、VEGF的相关性。方法选取32只Wistar大鼠同时构建右腹股沟区C6胶质瘤和左上肢急性炎性病变模型，分2组行11^C-MET、11^C-CHO和18^F-FDGPET／CT显像，单因素方差分析比较2种病变间3种显像剂的肿瘤SUVmax／对侧脊柱旁肌肉SUVmax（T／M）及急性炎性病变SUVmax／M（AIfM）是否存在差异，同时计算肿瘤选择指数（SI）。Spearman相关分析观察不同显像剂在C6胶质瘤中的摄取程度与HIF-1α、VEGF的相关性。结果C6胶质瘤18^F．FDGT／M为6．89±2．53，11^C-MET为2．75±0．87，11^C-CHO为2．73±1．01；急性炎性病变三者AIfM分别为4．77±2．21、1．75±0．66和2．23±0．90。18^F-FDG和”C-MET在C6胶质瘤和急性炎性病变问的摄取差异有统计学意义（tFDG=2．133，tMET=3．267，均P〈0．05），且SI㈣、〉SIrDG（t=2．600，P〈0．05）；11^C-CHO在C6胶质瘤和急性炎性病变间的摄取差异无统计学意义（t=1．537，P〉0．05）。C6胶质瘤对18^F-FDG的摄取程度与HIF-1α、VEGF均相关（rs=0．725和0．637，均P〈0．05）；C6胶质瘤对11^C-MET的摄取程度与HIF-1α、VEGF均相关（rs=0．621和0．764，均P〈0．05）；C6胶质瘤对11^C-CHO的摄取程度仅与VEGF相关（r。=0．682，P〈0．05）。结论11^C-MET和18^F-FDG能够鉴别胶质瘤和炎性病变，且“C-MET更具肿瘤特异性，11^C-CHO价值有限；18^F．FDG和11^C-MET可用于评价胶质瘤的乏氧状态，且18^F-FDG更敏感：18^F-FDG、11^C-MET、11^C-CHO均可评价胶质瘤的血管生成，但敏感性不同。

Objective To compare 18^F-FDG,11^C-MET and HC-CHO PET/CT in rat C6 glioma and inflammation models and observe their correlations with HIF-1α and VEGF expressions. Methods Thirty- two male Wistar rats were included to bear both C6 glioma and turpentine oil-induced acute inflammation （AI）. 18^F-FDG, 11^C-MET and 11^C-CHO PET/CT were performed on rats. The SUVmax= ratios of tumor-to- muscle （T/M） , Al-to-muscle （AI/M） and tumor selectivity index （SI） were calculated. One-way analysis of variance and two-sample t test were used for statistical analyses. HIF-1α and VEGF expression was detec- ted by immunohistochemical staining. Spearman correlation analysis was performed to evaluate the relationshipbetween T/M ratios and the expressions of HIF-1α or VEGF. Results T/M ratios of 18^F-FDG, 11^ C-MET and 11^C-CHO in C6 glioma were 6.89±2.53, 2.75±0.87, 2.73±1.01, and the AI/M were 4.77±2.21, 1.75± 0. 66, 2.23±0.90 respectively. The 18^F-FDG and 11^C-MET uptake between C6 glioma and AI were signifi- cantly different（tFDG = 2.133, tMET = 3.267, both P〈0.05）. The SIMET was significantly higher than SIFDG（t = 2.600, P〈0.05）. The 11^C-CHO uptake between tumor and inflammation showed no significant difference（t= 1.537, P〉0.05）. T/M ratios of 18^F-FDG and 11^C-MET were positively related to HIF-1α and VEGF expres- sions（r = 0.725, 0.637, 0.621, 0.764, all P〈0.05）. The T/M ratio of HC-CHO related only to VEGF （r = 0. 682, P〈0.05）. Conclusions 18^F-FDG and 11^C-MET PET/CT may differentiate C6 glioma from AI, and n C：MET PET/CT seems more tumor-selective. 11^C-CHO PET is less valuable for the differential diagnosis. The 18^F-FDG and 11^ C-MET uptake of C6 glioma may be related to tumor hypoxia. All the three tracers could reflect tumor angiogenesis, but with different sensitiveness.