Thyroid-stimulating hormone-stimulated fused positron emission tomography/computed tomography in the evaluation of recurrence in 131I-negative papillary thyroid carcinoma.
Fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) detects recurrence of papillary thyroid carcinoma (PTC) in thyroidectomized patients with elevated thyroglobulin (Tg) levels and negative (131)I-whole-body scans. This paper describes the utility of thyroid-stimulating hormone (TSH)-stimulated fused FDG-PET/computed tomography (CT) scanning on our first 15 patients of this population.


METHODS
Patients were prepared for PET/CT imaging with thyroid hormone withdrawal (n = 7) or recombinant human TSH (n = 8). All other imaging before the PET/CT did not demonstrate evidence of recurrence.


RESULTS
PET/CT scans revealed active foci in 9 patients, 4 prepared with hypothyroidism, and 5 with exogenous TSH. Positive results were demonstrated even in those with relatively low stimulated-TSH Tg values (13 and 14 microg/L). Six patients with positive PET/CT scans were treated surgically, yielding malignant tissue for 5 of those patients.


CONCLUSIONS
PET/CT scans performed under TSH stimulation are an effective method of detecting of recurrence of PTC and direct surgical interventions, even in those with persistently elevated but relatively low Tg levels.
Saab
George
G
Division of Diagnostic Radiology, Nuclear Medicine, and Endocrinology, University of Western Ontario, London, Ontario, Canada.
Driedger
Albert A
AA
Pavlosky
William
W
McDonald
Tom
T
Wong
Ching-Yee O
CY
Yoo
John
J
Urbain
Jean-Luc
JL
D000328:Adult; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging* / Q000473:pathology; D005188:False Negative Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D013972:Thyrotropin; D014055:Tomography, Emission-Computed
D007457:Iodine Radioisotopes; D019788:Fluorodeoxyglucose F18; D013972:Thyrotropin; D013954:Thyroglobulin