Abstract
1486
Objectives: Small animal PET scanning with 18F-FDG is increasingly used in murine tumor model. Experimental condition of animal handling impacts on the biodistribution of 18F-FDG in mouse study. The aim of this study was to optimize experimental conditions of animal handling for imaging lung metastasis tumor by using 18F-FDG small animal PET. Methods: Female C57BL/6 mice (6 weeks old) were injected intravenously with B16-F10 melanoma cells of 2 × 105. The mice developed metastasis tumors at postinjection 13 day. The experimental conditions for lung metastasis tumor imaging were 20 ± 2 h fasting and warming at 30 celcius degree. Small animal PET image was started 60 min after 18F-FDG (7.4 MBq in 0.1 mL) injection. To determine the impact of anesthesia during the uptake, five groups (n = 4) were studied as follows: no anesthesia, Ketamine 80 mg/kg and Xylazine 7 mg/kg, 0.5%, 1%, and 2% Isoflurane. Glucose levels were measured after anesthesia for scanning. Metastasis tumor was evaluated on glucose standard uptake value (SUVG) images by 2.0 cm3 region of interest. In lung metastasis tumor model, 18FDG image was obtained and fused with anatomical clinical CT image. Results: The average blood glucose level and Lung to Background ratio (L/B) with different anesthesia during 18F-FDG uptake were shown in table below. Ketamine/Xylazine group showed 1.5-fold higher blood glucose concentration than Isoflurane used groups. 0.5% Isoflurane anesthesia group showed the highest L/B ratio. Metastatic tumor (1.5 mm in CT) location in 18F-FDG small animal PET images was confirmed by fusion image using clinical CT. Conclusions: Fused imaging with small animal PET and CT image could be useful for the detection of metastatic tumor. Tumor imaging in animal lung region with 18F-FDG small animal PET should be considered fasting, warming, and Isoflurane anesthesia level for reduction of background artifacts.
- Society of Nuclear Medicine, Inc.