Rapid rise in FDG uptake in an irradiated human tumour xenograft.
In order to investigate early changes in the glucose metabolism of irradiated tumours, tumour uptake of 2-[18F]fluoro-2-deoxy-d-glucose (18FDG) was studied in human tumour xenografts. Three human tumour lines [ependymoblastoma (NNE), small cell lung cancer (GLS), and glioblastoma (KYG)] showing different radiosensitivities and incidences of radiation-induced apoptosis were subcutaneously transplanted into nude mice, and were irradiated at a single dose of 10 Gy. Then 0.5 mCi of 18FDG was intravenously administered 1 h before sacrifice. The animals were sacrificed at 2, 4 and 6 h following irradiation, and 18FDG accumulation in the tumours was examined. Before irradiation, GLS and KYG tumours showed significantly higher rates of 18FDG accumulation compared with NNE tumours (P <0.004 and P <0.001, respectively). NNE (the most radiosensitive tumour with the highest incidence of radiation-induced apoptosis), however, displayed a 2.3-fold higher rate of 18FDG accumulation at 2 h following irradiation compared with a non-irradiated group (P <0.01), and thereafter showed a plateau up to 6 h. The accumulation did not increase significantly in the other tumours with lower radiosensitivity and much less radiation-induced apoptosis. The rapidity of the increase in 18FDG accumulation in the most radiosensitive tumour line, occurring as early as 2 h following irradiation, suggests that the increase was independent of recovery phenomena following radiation damage.
Furuta
M
M
Department of Radiology and Radiation Oncology, Gunma University School of Medicine, Japan.
Hasegawa
M
M
Hayakawa
K
K
Yamakawa
M
M
Ishikawa
H
H
Nonaka
T
T
Mitsuhashi
N
N
Niibe
H
H
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D004806:Ependymoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011836:Radiation Tolerance; D011877:Radionuclide Imaging; D014018:Tissue Distribution
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D005947:Glucose