Anesthesia condition for (18)F-FDG imaging of lung metastasis tumors using small animal PET.
Small animal positron emission tomography (PET) with (18)F-FDG has been increasingly used for tumor imaging in the murine model. The aim of this study was to establish the anesthesia condition for imaging of lung metastasis tumor using small animal (18)F-FDG PET.


METHODS
To determine the impact of anesthesia on (18)F-FDG distribution in normal mice, five groups were studied under the following conditions: no anesthesia, ketamine and xylazine (Ke/Xy), 0.5% isoflurane (Iso 0.5), 1% isoflurane (Iso 1) and 2% isoflurane (Iso 2). The ex vivo counting, standard uptake value (SUV) image and glucose SUV of (18)F-FDG in various tissues were evaluated. The (18)F-FDG images in the lung metastasis tumor model were obtained under no anesthesia, Ke/Xy and Iso 0.5, and registered with CT image to clarify the tumor region.


RESULTS
Blood glucose concentration and muscle uptake of (18)F-FDG in the Ke/Xy group markedly increased more than in the other groups. The Iso 2 group increased (18)F-FDG uptake in heart compared with the other groups. The Iso 0.5 anesthesized group showed the lowest (18)F-FDG uptake in heart and chest wall. The small size of lung metastasis tumor (2 mm) was clearly visualized by (18)F-FDG image with the Iso 0.5 anesthesia.


CONCLUSIONS
Small animal (18)F-FDG PET imaging with Iso 0.5 anesthesia was appropriate for the detection of lung metastasis tumor. To acquire (18)F-FDG PET images with small animal PET, the type and level of anesthetic should be carefully considered to be suitable for the visualization of target tissue in the experimental model.
Woo
Sang-Keun
SK
Division of Nuclear Medicine and RI Application, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706, South Korea.
Lee
Tae Sup
TS
Kim
Kyeong Min
KM
Kim
June-Youp
JY
Jung
Jae Ho
JH
Kang
Joo Hyun
JH
Cheon
Gi Jeong
GJ
Choi
Chang Woon
CW
Lim
Sang Moo
SM
D000758:Anesthesia / Q000379:methods*; D000818:Animals; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008546:Melanoma, Experimental / Q000473:pathology / Q000556:secondary; D051379:Mice; D008810:Mice, Inbred C57BL; D049268:Positron-Emission Tomography; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed
D019788:Fluorodeoxyglucose F18