Risk stratification of gallbladder polyps (1-2 cm) for surgical intervention with 18F-FDG PET/CT.
We assessed the value of (18)F-FDG uptake in the gallbladder polyp (GP) in risk stratification for surgical intervention and the optimal cutoff level of the parameters derived from GP (18)F-FDG uptake for differentiating malignant from benign etiologies in a select, homogeneous group of patients with 1- to 2-cm GPs.


METHODS
Fifty patients with 1- to 2-cm GPs incidentally found on the CT portion of PET/CT were retrospectively analyzed. All patients had histologic diagnoses. GP (18)F-FDG activity was visually scored positive (≥liver) or negative (<liver). Maximal standardized uptake value of the GP (SUVgp) and ratio of SUVgp to mean SUV of the liver (GP/L ratio) were also measured. Univariate and multivariate logistic regression analyses were performed to determine the utility of patient and clinical variables--that is, sex, age, gallstone, polyp size, and three (18)F-FDG-related parameters in risk stratification.


RESULTS
Twenty GPs were classified as malignant and 30 as benign. Multivariate analyses showed that the age and all parameters (visual criteria, SUVgp, and GP/L) related to (18)F-FDG uptake were significant risk factors, with the GP/L being the most significant. The sex, size of GPs, and presence of concurrent gallstones were found to be insignificant.


CONCLUSIONS
(18)F-FDG uptake in a GP is a strong risk factor that can be used to determine the necessity of surgical intervention more effectively than other known risk factors. However, all criteria derived from (18)F-FDG uptake presented in this series may be applicable to the assessment of 1- to 2-cm GPs.
Division of Nuclear Medicine, Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, Korea.
Jaehoon
J
Lee
Mijin
M
Yun
Kyoung-Sik
KS
Kim
Jong-Doo
JD
Lee
Chun K
CK
Kim
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D000236:Adenoma / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D005706:Gallbladder Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D042882:Gallstones / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011127:Polyps / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D018570:Risk Assessment; D014055:Tomography, Emission-Computed / Q000379:methods*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18