Observation of xenoplanted VX2 tumors in rabbits by 18F-FDG PET/CT imaging / 肿瘤

ABSTRACT

Objective: To study the changes in metabolism of (18F-fluoro-2-deoxyglucose) by positron emission tomography over computed tomography (PET/CT) imaging at different time points after inoculation of VX2 tumor cells into rabbits and determine the difference in FDG metablism between various inoculation regions. Methods: VX2 tumor cells were inoculated into rabbits. PET/CT imaging was performed at d 14 and d 19 postinoculation. The tumor growth and SUV (standard uptake value) changes were recorded. Tumor volume was defined in CT images. SUVmax was used in the calculation of retention index (RI). The distribution of 18F-FDG was observed in tumor samples and pathological examination was performed. The correlations of tumor volume and SUV value at various time points was analyzed. Results: Continuous dynamic PET/CT imaging found that VX2 tumor grew rapidly and the volume of tumor body gradually increased with the prolongation of postinoculation time. A linear increase in SUV was observed when the postinoculation time was prolonged. The tumor volume and SUV value had significant correlation with postinoculation time (r = 0.89, r = 0.93, P 0.05). SUV value was not associated with tumor volume at different time points (P > 0.05). Pathological examination validated that the tissues with accumulation of 18-FDG were enriched with tumor cells. Conclusion: VX2 xenografted model in rabbit is an ideal animal model for PET/CT imaging. Similar tumor growth and invasion style are observed regardless of different postinoculation days and body part. The efficacy of radiochemothery should be mornitored by PET/CT imaging in the period when the metablism of 18-FDG increases in linear.