Preoperative FDG-PET imaging to assess the malignant potential of follicular neoplasms of the thyroid.
OBJECTIVE
When a fine needle aspiration biopsy of a thyroid nodule suggests follicular neoplasm, surgery is required for diagnosis. Establishing the diagnosis preoperatively would allow the patient to undergo the appropriate initial thyroidectomy. Preoperative [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging may be able to determine malignancy in follicular neoplasms.


METHODS
Prospective cases series.


METHODS
Twenty-three patients with a diagnosis of follicular neoplasm underwent presurgical FDG-PET at 60, 90, and 120 minutes after injection of fluorodeoxyglucose (F18). Thyroidectomy was performed with comparison of the histopathologic results with the FDG-PET results.


RESULTS
There were 5 malignant conditions and 18 benign conditions identified with the standard uptake valve (SUV) ranging from 0.9 to 44.8. The follicular thyroid cancers that exhibited only capsular invasion had an average SUV of 3.1, whereas those with vascular invasion had an average SUV of 39.9. The SUV increased in 80% of the malignant cases but in only 50% of the benign cases.


CONCLUSIONS
Despite certain patterns being suggestive of malignancy, FDG-PET can not consistently predict the malignant potential of a follicular neoplasm.
Smith
Russell B
RB
Department of Otolaryngology-Head and Neck Surgery, University of Nebraska, Omaha, NE 68198, USA. rbsmith@unmc.edu
Robinson
Robert A
RA
Hoffman
Henry T
HT
Graham
Michael M
MM
D018263:Adenocarcinoma, Follicular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18