Imaging medullary thyroid carcinoma with persistent elevated calcitonin levels.
OBJECTIVE
Because calcitonin level remains elevated after initial treatment in many medullary thyroid carcinoma (MTC) patients without evidence of disease in the usual imaging work-up, there is a need to define optimal imaging procedures.


METHODS
Fifty-five consecutive elevated calcitonin level MTC patients were enrolled to undergo neck and abdomen ultrasonography (US); neck, chest, and abdomen spiral computed tomography (CT); liver and whole-body magnetic resonance imaging (MRI); bone scintigraphy; and 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/CT scan (PET).


RESULTS
Fifty patients underwent neck US, CT, and PET, and neck recurrence was demonstrated in 56, 42, and 32%, respectively. Lung and mediastinum lymph node metastases in the 55 patients were demonstrated in 35 and 31% by CT and in 15 and 20% by PET. Liver imaging with MRI, CT, US, and PET in 41 patients showed liver in 49, 44, 41, and 27% patients, respectively. Bone metastases in 55 patients were demonstrated in 35% by PET, 40% by bone scintigraphy, and 40% by MRI; bone scintigraphy was complementary with MRI for axial lesions but superior for the detection of peripheral lesions. Ten patients had no imaged tumor site despite elevated calcitonin level (median 196 pg/ml; range 39-816). FDG uptake in neoplastic foci was higher in progressive patients but with a considerable overlap with stable ones.


CONCLUSIONS
The most efficient imaging work-up for depicting MTC tumor sites would consist of a neck US, chest CT, liver MRI, bone scintigraphy, and axial skeleton MRI. FDG PET scan appeared to be less sensitive and of low prognostic value.
Giraudet
Anne Laure
AL
Nuclear Medicine and Endocrine Oncology, Institut Gustave Roussy, 94805 Villejuif Cédex, France.
Vanel
Daniel
D
Leboulleux
Sophie
S
Aupérin
Anne
A
Dromain
Clarisse
C
Chami
Linda
L
Ny Tovo
Noël
N
Lumbroso
Jean
J
Lassau
Nathalie
N
Bonniaud
Guillaume
G
Hartl
Dana
D
Travagli
Jean-Paul
JP
Baudin
Eric
E
Schlumberger
Martin
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000175:diagnosis / Q000556:secondary; D001842:Bone and Bones / Q000000981:diagnostic imaging; D002116:Calcitonin / Q000097:blood*; D018276:Carcinoma, Medullary / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary; D008175:Lung Neoplasms / Q000175:diagnosis / Q000556:secondary; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D014915:Whole-Body Counting
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002116:Calcitonin