Incidental pituitary uptake on whole-body 18F-FDG PET/CT: a multicentre study.
OBJECTIVE
The purpose of this study was to determine the incidence of incidental pituitary uptake on whole-body 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and to investigate its clinical significance.


METHODS
The files of 40,967 patients who underwent whole-body FDG PET/CT were retrospectively reviewed. Quantification of pituitary metabolic activity was obtained by using the maximum standardized uptake value (SUVmax). Hormone assays and pituitary MRIs were performed to assess pituitary lesions.


RESULTS
Focally increased pituitary FDG uptake on PET/CT was found in 30 of 40,967 patients, accounting for an incidence of 0.073%. The mean SUVmax of 30 patients was 8.9±6.6 (range: 3.2-32.6). Histological diagnosis was obtained in three patients and included two growth hormone-secreting adenomas and one non-functioning adenoma. Hormone assays were performed on serum samples from 11 patients, 2 of whom were shown to have hypersecretion of pituitary hormone. MRI was performed on 19 patients. Abnormal MRI findings suggesting a pituitary mass were found in 18 of 19 cases (94.7%). The mean SUV(max) calculated without correction for partial volume effect for macroadenomas was significantly higher than the SUVmax for microadenomas (11.5±8.4 vs 4.8±1.3; p<0.05). There were no cases diagnosed with metastasis to the pituitary gland during clinical follow-up.


CONCLUSIONS
Incidental pituitary FDG uptake was a very rare finding. Cases with incidental pituitary FDG uptake were diagnosed primarily with clinically non-functioning adenomas, and there were also a few functioning adenomas. Further evaluations, including hormone assays and pituitary MRI, are warranted when pituitary uptake is found on FDG PET/CT.
Jeong
Shin Young
SY
Department of Nuclear Medicine, Kyungpook National University Hospital, Samduk 2-ga 50, Daegu, 700-721, Korea.
Lee
Sang-Woo
SW
Lee
Hui Joong
HJ
Kang
Sungmin
S
Seo
Ji-Hyoung
JH
Chun
Kyung Ah
KA
Cho
Ihn Ho
IH
Won
Kyung Sook
KS
Zeon
Seok Kil
SK
Ahn
Byeong-Cheol
BC
Lee
Jaetae
J
D000236:Adenoma / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D015994:Incidence; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000378:metabolism*; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D051598:Whole Body Imaging / Q000706:statistics & numerical data*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18