18F-FDG PET rarely provides additional information to 11C-methionine PET imaging in hyperparathyroidism.
OBJECTIVE
The aim of this study was to assess the utility of combined C-methionine and F-FDG PET/CT imaging in hyperparathyroidism.


METHODS
We reviewed all scans performed for hyperparathyroidism with both C-methionine and F-FDG PET/CT or PET in our institution since 1993. Forty-three patients (47 pairs of scans) were included (13 men and 30 women) with a mean age of 63 years. C-methionine and F-FDG PET/CT scans were classified as positive or negative for localization of abnormal parathyroid tissue, and the site of uptake was noted in the positive scans. Other concurrent imaging (Tc-MIBI scintigraphy, ultrasonography, CT, or MRI) findings were also noted when performed. Clinical follow-up information was available in 27 patients (30 episodes).


RESULTS
Of the 47 PET scan episodes, 23 (49%) were positive. Twenty-two C-methionine scans showed abnormal focal localization of which 10 also showed concordant abnormal F-FDG uptake. One patient was positive with F-FDG and negative with C-methionine.Of the 16 patients who underwent subsequent surgery, 6 had concordant C-methionine, F-FDG, and surgical findings; 6 had concordant C-methionine and surgical findings; 1 had concordant F-FDG and surgical findings; and 3 had both PET scans negative but had adenomas excised during surgery.Of the 3 with both PET scans negative and discordant surgical findings, 1 had mediastinal parathyroid lipoadenoma excised and 2 had normally sited parathyroid adenoma excised.


CONCLUSIONS
F-FDG PET/CT rarely provides additional information and could be saved for patients in whom C-methionine PET/CT is negative.
From the *Clinical PET Centre, Division of Imaging Sciences, King's College London; †Department of Endocrine Surgery, King's College Hospital; and ‡Department of Endocrine Surgery, Guy's & St Thomas' Hospital, London, United Kingdom.
Sugama
S
Chicklore
Klaus-Martin
KM
Schulte
Nadia
N
Talat
Johnathan G
JG
Hubbard
Michael
M
O'Doherty
Gary J R
GJ
Cook
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D006961:Hyperparathyroidism / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008715:Methionine; D008875:Middle Aged; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D011859:Radiography
D019788:Fluorodeoxyglucose F18; C086242:carbon-11 methionine; D008715:Methionine