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Incidental 18F-FDG uptake in the thyroid in patients diagnosed with PET/CT for other malignancies
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Abstract
MATERIAL AND METHODS: 2478 PET/CT scans using 18F-FDG were performed in 1925 subjects for evaluation of different, non-thyroid malignancies. For PET/CT examination, a Discovery ST (General Electric) PET/CT scanner was used. Patients with focal 18F-FDG activity were further evaluated by means of fine needle aspiration biopsy (FNAB). If cytological examination disclosed malignancy or suspicion of malignancy, thyroidectomy was performed. Both cytological and histopathological results were then analyzed.
RESULTS: Focal increased 18F-FDG uptake was found in 71 patients (3.7%), and cytological or histopathological results were evaluable in 20 of them. In general, 8 cases of thyroid cancer were found, which accounts for 40% probability of malignancy. The predominant histopathological diagnosis was papillary thyroid carcinoma (5 out of 8 cases). Additionally, in one case (5%) thyroid metastasis of lung cancer was detected. Diffused 18F-FDG activity in both thyroid lobes was observed in 120 subjects (6.2%) — in most cases chronic thyroiditis was confirmed.
CONCLUSIONS: The probability of malignancy of focal thyroid incidentalomas in 18F-FDG PET/CT scans is rather high. Therefore, thorough evaluation of such lesions is highly recommended in each case. Most thyroid malignancies incidentally detected in PET/CT are papillary carcinomas.
Nuclear Med Rev 2011; 14, 2: 68–72
Abstract
MATERIAL AND METHODS: 2478 PET/CT scans using 18F-FDG were performed in 1925 subjects for evaluation of different, non-thyroid malignancies. For PET/CT examination, a Discovery ST (General Electric) PET/CT scanner was used. Patients with focal 18F-FDG activity were further evaluated by means of fine needle aspiration biopsy (FNAB). If cytological examination disclosed malignancy or suspicion of malignancy, thyroidectomy was performed. Both cytological and histopathological results were then analyzed.
RESULTS: Focal increased 18F-FDG uptake was found in 71 patients (3.7%), and cytological or histopathological results were evaluable in 20 of them. In general, 8 cases of thyroid cancer were found, which accounts for 40% probability of malignancy. The predominant histopathological diagnosis was papillary thyroid carcinoma (5 out of 8 cases). Additionally, in one case (5%) thyroid metastasis of lung cancer was detected. Diffused 18F-FDG activity in both thyroid lobes was observed in 120 subjects (6.2%) — in most cases chronic thyroiditis was confirmed.
CONCLUSIONS: The probability of malignancy of focal thyroid incidentalomas in 18F-FDG PET/CT scans is rather high. Therefore, thorough evaluation of such lesions is highly recommended in each case. Most thyroid malignancies incidentally detected in PET/CT are papillary carcinomas.
Nuclear Med Rev 2011; 14, 2: 68–72
Keywords
thyroid nodule; PET; 18F-fluorine-deoxyglucose; thyroid carcinoma
Title
Incidental 18F-FDG uptake in the thyroid in patients diagnosed with PET/CT for other malignancies
Journal
Issue
Article type
Research paper
Pages
68-72
Published online
2012-01-04
Page views
1248
Article views/downloads
3710
Bibliographic record
Nucl. Med. Rev 2011;14(2):68-72.
Keywords
thyroid nodule
PET
18F-fluorine-deoxyglucose
thyroid carcinoma
Authors
Rafał Czepczyński
Adam Stangierski
Robert Oleksa
Małgorzata Janicka-Jedyńska
Agata Czarnywojtek
Marek Ruchała
Jerzy Sowiński