, Volume 43, Issue 3, pp 678–685 | Cite as

F18-FDG-PET/CT thyroid incidentalomas: a wide retrospective analysis in three Italian centres on the significance of focal uptake and SUV value

  • Francesco BertagnaEmail author
  • Giorgio Treglia
  • Arnoldo Piccardo
  • Elisabetta Giovannini
  • Giovanni Bosio
  • Giorgio Biasiotto
  • El Khayat Bahij
  • Roberto Maroldi
  • Raffaele Giubbini
Original Article


Thyroid incidental uptake is defined as a thyroid uptake incidentally and newly detected by imaging techniques performed for an unrelated purpose and especially for non-thyroid diseases. Aim of the study was to establish the prevalence and pathological nature of focal thyroid incidentalomas detected at F18-FDG-PET/CT in patients studied for oncological purposes and not for thyroid disease. Secondary end point was to establish a possible maximum standardised uptake value cut-off over which a malignant lesion should be suspected. We have retrospectively evaluated 49519 patients who underwent F18-FDG-PET/CT for oncologic purposes in three Nuclear Medicine Centres (N.1 = 11278, N.2 = 31076, N.3 = 7165). A focal incidental thyroid uptake was diagnosed in 729 (1.5 %) patients (287–39.4 % male and 442–60.6 % female; average age: 65.26). Of 729 thyroid incidentalomas 211 (28.9 %) underwent further investigation to determine the nature of the nodule; 124/211 (58.8 %) incidentalomas were benign, 72/211 (34.1 %) malignant, 4/211 (1.9 %) non-diagnostic at cytological examination in the absence of surgery and histological evaluation and 11/211 (5.2 %) were indeterminate at cytological examination. A centre-based receiver operating curve (ROC) analysis of the patients with a definitive diagnosis was performed to identify a SUVmax cut-off useful in differentiating benign from malignant incidentalomas. In the centre N.1 it was 4.8 (sensitivity = 95.7 %, specificity = 46.4 %, area under the curve = 0.758); 5.3 in the centre N.2 (sensitivity = 76.3 %, specificity = 72.5 %, area under the curve = 0.815); 7 in the centre N.3 (sensitivity = 57.1 %, specificity = 79.3 %, area under the curve = 0.627). F18-FDG-PET/CT thyroid incidentalomas are a relevant diagnostic reality which requires further investigations and clinical management especially considering that, despite mainly benign, approximately one third of focal thyroid uptakes are malignant.


PET/CT F18-FDG Thyroid Incidentaloma 


Conflict of interest

The authors declare that they have no conflict of interest.

Ethical standard

The authors declare that the experiments comply with the current laws of the country in which they were performed.


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Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • Francesco Bertagna
    • 1
    Email author
  • Giorgio Treglia
    • 2
  • Arnoldo Piccardo
    • 3
  • Elisabetta Giovannini
    • 2
  • Giovanni Bosio
    • 1
  • Giorgio Biasiotto
    • 4
  • El Khayat Bahij
    • 5
  • Roberto Maroldi
    • 5
  • Raffaele Giubbini
    • 1
  1. 1.Nuclear MedicineUniversity of Brescia and Spedali Civili di BresciaBresciaItaly
  2. 2.Nuclear MedicineCatholic University of Sacred HeartRomeItaly
  3. 3.Department of Nuclear MedicineOspedali GallieraGenoaItaly
  4. 4.Biomedical Technology DepartmentUniversity of BresciaBresciaItaly
  5. 5.Department of RadiologyUniversity of Brescia and Spedali Civili di BresciaBresciaItaly

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