BACKGROUND: It is well known that blood glucose level affects the uptake of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) in tumours. Thus, the action of steroids on glucose metabolism may alter blood glucose levels and may affect FDG uptake in tumours in patients treated with steroids. To clarify this point, we determined the effects of steroids on FDG uptake in tumours in a rat model of a malignant tumour. METHODS: Rats were inoculated with allogenic hepatoma cells (KDH-8) into the left calf muscle. They were fasted overnight and divided into three groups (n=5 in each group): (1) dexamethasone (DEX) pretreated (0.8 mg.kg(-1) body weight, i.m. injection 4 h before FDG i.v. injection); (2) prednisolone (PRE) pretreated (8 mg.kg(-1) body weight, i.m. injection 20 h before FDG i.v. injection); and (3) control (untreated) groups. Radioactivity in tissues was determined 1 h after i.v. injection of FDG. FDG uptake in the tumour was expressed as the percentage of injected dose per gram of tissue after normalization to animal's weight (%ID/g tissue/kg body weight). RESULTS: DEX and PRE pretreatments significantly increased the blood glucose levels to 128% and 145% of the control value. The levels of FDG uptake in the tumour were not significantly affected by DEX and PRE pretreatment (90% and 87% of the control value, respectively) (P=NS). CONCLUSIONS: These results demonstrate that FDG uptake in the tumour was not affected by pretreatment with steroids, in spite of a slight elevation in blood glucose level.
BACKGROUND: It is well known that blood glucose level affects the uptake of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) in tumours. Thus, the action of steroids on glucose metabolism may alter blood glucose levels and may affect FDG uptake in tumours in patients treated with steroids. To clarify this point, we determined the effects of steroids on FDG uptake in tumours in a rat model of a malignant tumour. METHODS:Rats were inoculated with allogenic hepatoma cells (KDH-8) into the left calf muscle. They were fasted overnight and divided into three groups (n=5 in each group): (1) dexamethasone (DEX) pretreated (0.8 mg.kg(-1) body weight, i.m. injection 4 h before FDG i.v. injection); (2) prednisolone (PRE) pretreated (8 mg.kg(-1) body weight, i.m. injection 20 h before FDG i.v. injection); and (3) control (untreated) groups. Radioactivity in tissues was determined 1 h after i.v. injection of FDG. FDG uptake in the tumour was expressed as the percentage of injected dose per gram of tissue after normalization to animal's weight (%ID/g tissue/kg body weight). RESULTS:DEX and PRE pretreatments significantly increased the blood glucose levels to 128% and 145% of the control value. The levels of FDG uptake in the tumour were not significantly affected by DEX and PRE pretreatment (90% and 87% of the control value, respectively) (P=NS). CONCLUSIONS: These results demonstrate that FDG uptake in the tumour was not affected by pretreatment with steroids, in spite of a slight elevation in blood glucose level.