兔VX2移植瘤PET—CT的显像研究

目的：研究兔VX2移植瘤的PET／CT显像及其应用前景。方法：48只日本大白兔种植VX2肿瘤，随机分为4组，分别于2、4、6和8周进行PET／CT显像，获得注射^18F-FDG后不同时间（20、40、60、80、100和120min）PET／CT图像，以及肿瘤组织和正常组织的SUV值。显像后处死大白兔，进行病理检查，观察肿瘤细胞的核分裂像及平均肿瘤微血管密度。结果：VX2移植瘤总成活率为80％；注射^18F-FDG后40～100min的SUV值与20和120min的SUV值相比，差异有统计学意义，P≤0．001。种植VX2肿瘤细胞后2、4、6和8周的肿瘤组织和正常组织的SUV值差异均有统计学意义，P均〈0．05。肿瘤大小的增殖、病理性核分裂像和平均肿瘤微血管密度与注射^18F-FDG后60min的SUV值密切相关。结论：PET／CT还可以清楚地显示肿瘤的解剖部位、形态、大小和肿瘤细胞的代谢状况，及时发现转移，是一项可靠和有价值的检查手段。

^18F-FDG PET/CT in experimental VX2 rabbit tumors

OBJECTIVE： To explore imaging and applicative prospect of ^18 F-FDG PET/CT in experimental VX2 rabbit tumors. METHODS： Forty-eight Japanese white rabbits were successfully implanted with VX2 tumors in livers and thighs and randomly divid ed into 4 groups. Four groups respectively imaged with PET/CT in two, four, six, eight weeks later and obtained PET/CT imaging of rabbits in different time （20, 40, 60, 80, 100 and 120 min）. In addition, SUVs of the tumor tissue and the normal tissue were measured. The rabbits were killed after imaging. The pathological mitosis and mean microvessel density of tumor tissue were observed. RESULTS： The general survival rate of implanted VX2 tumors was 80%. The SUV of the tumor tissue in 40-100 min after injected ^18F-FDG were significantly higher than those in 20 and 120 min （P≤0. 001）. There were significant between the SUV of tumor tis sue in 2, 4, 6 and 8 weeks after implanted VX2 tumors and those of the normal tissue （P〈 0.05）. The SUV in 60rain after injected ^18F-FDG was correlated with growth rate of size and pathological mitosis and mean microvessel density of tumor tissue. CONCLUSIONS： PET/CT imaging can clearly show the shape, size, anatom ical regions and metabolic condition of tumors and immediately dis cover metastasis. PET/CT is a very valuable and reliable examination.