title: The effect of tumor size on F-18-labeled fluorodeoxyglucose and fluoroerythronitroimidazole uptake in a murine sarcoma model.
abstract: The purpose of this study was to evaluate the effect of tumor size on the uptake of 18F-fluorodeoxyglucose (FDG) and fluoroerythronitroimidazole (FETNIM) in a murine sarcoma model. ICR mice were xenografted with sarcoma 180 cell line and tumors were allowed to grow to a weight of 0.26-5.82 grams. 18F-FDG and 18F-FETNIM were injected intravenously in separate groups of mice, and after 1 hr, the tumors were excised and radiotracer uptake was measured. In another group of mice tumors were autoradiographically analyzed and subjected to H & E staining. In both the FDG and FETNIM group, per-gram radiotracer uptake by a tumor was inversely proportional to tumor weight. 18F-FETNIM correlated more (r = -0.593, p < 0.05) than 18F-FDG (r = -0.447, p < 0.05). Autoradiographic studies revealed that FDG accumulated in viable tumor areas, whereas FETNIM accumulated in both viable and partially necrotic areas. In the case of 18F-FETNIM, a direct correlation between tumor weight and the no-uptake-area to total-tumor-area was demonstrated. We concluded that increased tumor size is associated with decreased uptake of 18F-FDG and FETNIM, though this depends on the type of radiotracers and distribution of necrosis.
authors.affiliation: Department of Nuclear Medicine, and Cancer Research Institute, Seoul National University College of Medicine, Chongno-gu, Korea. jkchung@plaza.snu.ac.kr
authors.forename: J K
authors.initials: JK
authors.lastname: Chung
authors.forename: Y S
authors.initials: YS
authors.lastname: Chang
authors.forename: Y J
authors.initials: YJ
authors.lastname: Lee
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.forename: J M
authors.initials: JM
authors.lastname: Jeong
authors.forename: D S
authors.initials: DS
authors.lastname: Lee
authors.forename: J J
authors.initials: JJ
authors.lastname: Jang
authors.forename: M C
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000818:Animals; D001345:Autoradiography; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009336:Necrosis; D009593:Nitroimidazoles; D012510:Sarcoma 180 / Q000000981:diagnostic imaging* / Q000473:pathology*; D014055:Tomography, Emission-Computed
chemical_list: D005462:Fluorine Radioisotopes; D009593:Nitroimidazoles; C092114:fluoroerythronitroimidazole; D019788:Fluorodeoxyglucose F18