title: The value of preoperative PET-CT in papillary thyroid cancer.
abstract: OBJECTIVE
  To evaluate the clinical usefulness of preoperative positron emission tomography-computed tomography (PET-CT) in primary papillary thyroid cancer (PTC).
  
  
  METHODS
  Preoperative PET-CT scans of patients with biopsy-confirmed PTC who were undergoing thyroidectomy were examined and the maximum standardized uptake value (SUV max) of 2-deoxy-2-((18)F)fluoro-D-glucose ((18)F-FDG) was calculated. Demographic and clinical data were obtained from medical records. Tumour tissue was pathologically classified according to World Health Organization guidelines. Univariate and multivariate analyses were performed to determined the demographic, clinical and pathological factors affecting PET positivity and SUV max.
  
  
  RESULTS
  The study included 194 patients. Multivariate analysis indicated that patients were significantly more likely to be PET positive if they were female, had larger tumours (>1 cm), coexisting pathology (nodular hyperplasia or Hashimoto's thyroiditis) or nonfollicular variant PTC. SUV max <2.0 indicated possible follicular variant PTC.
  
  
  CONCLUSIONS
  PET-positive results were unrelated to extrathyroidal extension and lymph node metastasis. PET positivity was related to larger tumour size and implied coexisting pathology. PET negativity or low SUV max suggested possible follicular variant PTC.
authors.affiliation: Department of Surgery, Chung-Ang University Hospital, Seoul, Republic of Korea.
authors.forename: Byung Seup
authors.initials: BS
authors.lastname: Kim
authors.forename: Han Suk
authors.initials: HS
authors.lastname: Ryu
authors.forename: Kyung Ho
authors.initials: KH
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D002291:Carcinoma, Papillary; D003710:Demography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000473:pathology / Q000601:surgery; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Papillary thyroid cancer; positron emission tomography–computed tomography (PET–CT)