Role of gastric distention with additional water in differentiating locally advanced gastric carcinomas from physiological uptake in the stomach on 18F-fluoro-2-deoxy-D-glucose PET.
OBJECTIVE
In this study, we investigated the role of gastric distention with additional water to determine whether it is beneficial for the differentiation of locally advanced gastric carcinomas from physiological 18F-fluoro-2-deoxy-D-glucose (FDG) uptake in the stomach and to characterize the FDG uptake of gastric carcinomas by relating it to the histopathological properties of the tumours.


METHODS
Sixteen patients with locally advanced gastric carcinomas and 20 control patients were studied by FDG-PET. After whole-body PET imaging, the patients drank 400 ml of water and then spot imaging with additional water of the stomach was performed. The final diagnosis was determined from the results of surgery. The gastric areas were divided into the upper, middle, and lower parts. The degree of FDG uptake in the stomach was qualitatively evaluated by visual grading into three degrees. For quantitative analysis, the regional tumour uptake was measured by mean standardized uptake values using a region of interest technique.


RESULTS
In visual analysis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET without additional water ingestion were 100, 50, 62, 100 and 72%, respectively, and those of PET with additional water ingestion were 88, 100, 100, 91 and 94%, respectively. Using spot imaging under the condition with additional water ingestion, four gastric carcinomas were depicted more clearly.


CONCLUSIONS
Gastric distention as a result of patients drinking a glass of water is a simple and noninvasive method for improving the diagnostic accuracy of FDG-PET in patients with locally advanced gastric carcinoma.
Kamimura
Kiyohisa
K
Department of Radiology, Fujimoto Hayasuzu Hospital, Miyazaki, Japan. kiyohisa@mp.0038.net
Nagamachi
Shigeki
S
Wakamatsu
Hideyuki
H
Fujita
Seigo
S
Nishii
Ryuichi
R
Umemura
Yoshiro
Y
Ogita
Mikio
M
Komada
Naoto
N
Sakurai
Toshinori
T
Inoue
Teruhiko
T
Fujimoto
Toshiro
T
Nakajo
Masayuki
M
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004326:Drinking; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D012680:Sensitivity and Specificity; D013270:Stomach / Q000187:drug effects* / Q000473:pathology; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology; D014867:Water / Q000494:pharmacology*
D014867:Water; D019788:Fluorodeoxyglucose F18