title: Thyroid nodules with indeterminate cytology: prospective comparison between 18F-FDG-PET/CT, multiparametric neck ultrasonography, 99mTc-MIBI scintigraphy and histology.
abstract: OBJECTIVE
  To evaluate the role of (18)F-flurodeoxiglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) in predicting malignancy of thyroid nodules with indeterminate cytology.
  
  
  METHODS
  We analysed 87 patients who have been scheduled to undergo surgery for thyroid nodule with indeterminate cytology. All patients underwent (18)F-FDG-PET/CT, multiparametric neck ultrasonography (MPUS), and (99m)Tc-methoxyisobutylisonitrile scintigraphy ((99m)Tc-MIBI-scan). Histopathology was the standard of reference. We compared the sensitivity (SE), specificity (SP), accuracy (AC), positive (PPV) and negative predictive (NPV) values of (18)F-FDG-PET/CT with those of (99m)Tc-MIBI-scan and MPUS in detecting cancer. Univariate and multivariate analyses evaluated the association between each diagnostic tool and histopathology.
  
  
  RESULTS
  On histopathology, 69 out of 87 nodules were found to be benign and 18 to be malignant. The SE, SP, AC, PPV and NPV of (18)F-FDG-PET/CT were 94, 58, 66, 37 and 98% respectively. The SE, AC and NPV of (18)F-FDG-PET/CT were significantly higher than those of MPUS and (99m)Tc-MIBI-scan. The association of both positive (18)F-FDG-PET/CT and MPUS (FDG+/MPUS+) showed significantly lower SE (61% vs 94%) and NPV (88% vs 98%) than (18)F-FDG-PET/CT alone, but significantly higher SP (77% vs 58%). On univariate analysis, (18)F-FDG-PET/CT and the combination of FDG+/MPUS+ and of FDG+/MIBI- were all significantly associated with histopathology. On multivariate analysis, only FDG+/MIBI- was significantly associated with histopathology.
  
  
  CONCLUSIONS
  The AC of (18)F-FDG-PET /CT in detecting thyroid malignancy is higher than that of (99m)Tc-MIBI-scan and MPUS. A negative (18)F-FDG-PET/CT correctly predicts benign findings on histopathology. The association of FDG+/MPS+ is significantly more specific than (18)F-FDG-PET/CT alone in identifying differentiated thyroid cancer. A positive (18)F-FDG-PET/CT is significantly associated with malignancy when qualitative (99m)Tc-MIBI-scan is rated as negative.
authors.affiliation: Nuclear Medicine UnitOffice of the Scientific Director, Galliera Hospital, Genoa, Italy arnoldo.piccardo@galliera.it.
authors.forename: A
authors.initials: A
authors.lastname: Piccardo
authors.affiliation: Clinical Trial UnitOffice of the Scientific Director, Galliera Hospital, Genoa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Puntoni
authors.affiliation: Department of Nuclear Medicine and PET/CT CentreOncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Treglia
authors.affiliation: Internal MedicineGalliera Hospital, Genoa, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Foppiani
authors.affiliation: Department of Nuclear MedicineUniversity of Brescia and Spedali Civili di Brescia, Brescia, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Bertagna
authors.affiliation: Department of RadiologyGalliera Hospital, Genoa, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Paparo
authors.affiliation: Nuclear Medicine UnitOffice of the Scientific Director, Galliera Hospital, Genoa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Massollo
authors.affiliation: Nuclear Medicine UnitOffice of the Scientific Director, Galliera Hospital, Genoa, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Dib
authors.affiliation: Department of Nuclear Medicine and PET/CT CentreOncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Paone
authors.affiliation: Department of SurgeryThyroid Centre, Galliera Hospital, Genoa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Arlandini
authors.affiliation: Department of SurgeryThyroid Centre, Galliera Hospital, Genoa, Italy.
authors.forename: U
authors.initials: U
authors.lastname: Catrambone
authors.affiliation: Department of PathologyGalliera Hospital, Genoa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Casazza
authors.affiliation: Department of PathologyGalliera Hospital, Genoa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Pastorino
authors.affiliation: Nuclear Medicine UnitOffice of the Scientific Director, Galliera Hospital, Genoa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Cabria
authors.affiliation: Department of Nuclear Medicine and PET/CT CentreOncology Institute of Southern Switzerland, Bellinzona, Switzerland arnoldo.piccardo@galliera.it.
authors.forename: L
authors.initials: L
authors.lastname: Giovanella
mesh_terms: D000368:Aged; D003581:Cytodiagnosis / Q000592:standards*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000592:standards*; D009333:Neck / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000592:standards*; D011877:Radionuclide Imaging / Q000592:standards*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D016606:Thyroid Nodule / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000592:standards*; D014463:Ultrasonography
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D017256:Technetium Tc 99m Sestamibi