title: How often do we see incidental 68Ga-DOTATATE thyroid uptake in PET/CT in patients with neuroendocrine tumours?
abstract: BACKGROUND
  Thyroid diseases, which may occur as focal or diffuse changes in thyroid parenchyma, are most often observed in women.
  
  
  OBJECTIVE
  Our aim was to assess the prevalence of incidental thyroid uptake of 68Ga-DOTATATE PET/CT in patients referred to the Nuclear Medicine Department for evaluation of neuroendocrine neoplasia (NEN).
  
  
  METHODS
  We retrospectively evaluated 1150 68Ga-DOTATATE PET/CT images. Clinical history, serum TSH and thyroid antibody (TAb) concentrations, ultrasonography, and cytological assessment of the material from fine-needle aspiration biopsy (FNA) of the thyroid lesion were investigated.
  
  
  RESULTS
  We found incidental abnormalities in 46/1150 (4.1%) patients (12 men, 34 women). 34/46 patients (8 men, 26 women) showed diffuse 68Ga-DOTATATE thyroid uptake, with mean SUVmax 4.6 ± 1.6. Based on laboratory tests and ultrasound, we found: 38% of patients with an active autoimmune thyroiditis, 27% with benign goitre, and 6% with multinodular goitre with autoimmune thyroiditis. The remaining 29% of patients did not show any pathology. In 12/47 patients (4 men, 8 women) focal uptake in the thyroid with SUVmax 7.3 ± 3.3 was found. During one-year follow-up, category II and category III lesions (according to Bethesda classification) were revealed in 9/12 (75%) patients and in one patient, respectively. Histopathological examination after surgery revealed papillary thyroid carcinoma in one patient and benign multinodular goitre in another patient.
  
  
  CONCLUSIONS
  Patients with focal 68Ga-DOTATATE uptake should undergo further examination (FNA) due to potential risk of malignancy. Diffuse 68Ga-DOTATATE uptake was predominantly associated with active autoimmune thyroiditis or benign goitre. The focal lesions and diffuse pathology diseases were frequently seen in women.
authors.affiliation: Department of Nuclear Medicine, Medical University of Warsaw, Poland. jolanta.kunikowska@wum.edu.pl.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kunikowska
authors.forename: Renata
authors.initials: R
authors.lastname: Matyskiel
authors.forename: Anna
authors.initials: A
authors.lastname: Zemczak
authors.forename: Janusz
authors.initials: J
authors.lastname: Strzelczyk
authors.forename: Dariusz
authors.initials: D
authors.lastname: Pawlak
authors.forename: Leszek
authors.initials: L
authors.lastname: Królicki
authors.forename: Beata
authors.initials: B
authors.lastname: Kos-Kudła
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000473:pathology*; D002291:Carcinoma, Papillary; D005260:Female; D006044:Goiter, Nodular / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D000072078:Positron Emission Tomography Computed Tomography; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000276:immunology; D013963:Thyroid Hormones / Q000097:blood; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D013967:Thyroiditis, Autoimmune / Q000000981:diagnostic imaging / Q000473:pathology*
chemical_list: D001323:Autoantibodies; D009942:Organometallic Compounds; D013963:Thyroid Hormones; C513399:gallium Ga 68 dotatate