18F-FDG PET/CT monitoring for early tumor response to cisplatin in VX2 tumor-bearing rabbits / 中华核医学与分子影像杂志

ABSTRACT

Objective To evaluate the value of 18F-FDG PET/CT in early in vivo monitoring of tumor response to cisplatin,and analyze the relationship between 18F-FDG uptake in tumor and the corresponding pathological changes.Methods Thirty VX2 rabbits were divided into 5 groups by random number table with 6 in each group,including 4 treatment groups and 1 control group.18F-FDG PET/CT were performed before and after (6,12,24 and 36 h post-injection respectively) intravenous administration of cisplatin (7 mg/kg) in the treatment groups,respectively.The control group was injected with physiological saline followed by 18F-FDG PET/CT.The ROI was drawn and the SUVmax and T/NT ratio were calculated.The tumor necrosis rate and apoptosis index were observed by histopathologic examination.Paired t test,GamesHowell test and arcuation correlation analysis were used to analyze the data.Results Significant differences were found in SUVmax and T/NT of the control group before and after injection of physiological saline (6.58±1.67 vs 9.77±2.45,52.93±3.90 vs 29.34±3.31;t=-5.480,17.593,both P＜0.05).18F-FDG uptake decreased after 6 h post-injection of cisplatin,with the mean SUVmax decrease rate of (11.83±8.89) ％ and the mean T/NT decrease rate of (59.00±8.22)％.In the 24 h treatment group,18F-FDG uptake decreased most,and the mean SUVmax decrease rate was (42.33±33.80)％,the mean T/NT decrease rate was (83.50± 7.69) ％.The SUVmax and T/NT of those 2 groups were significantly different from those of the control group,and no difference was found between the 2 treatment groups(all P＜0.05).The changes of SUVmax and T/NT were positively correlated with apoptosis index and tumor necrosis rate (r=0.750,0.794,0.804,0.874,all P＜0.05).Conclusion 18F-FDG PET/CT is a sensitive method for monitoring early response to tumor chemotherapy in VX2 tumor-bearing rabbits at 24 h after treatment.