title: Occult primary tumors of the head and neck: detection with 2-[F-18] fluoro-2-deoxy-D-glucose SPECT.
abstract: OBJECTIVE
  To evaluate 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) single photon emission computed tomography (SPECT) in the detection of clinically occult primary tumors of the upper aerodigestive tract.
  
  
  METHODS
  Eighteen patients with histologically proved cervical nodal metastasis from squamous cell carcinoma (SCC) underwent FDG SPECT; 17 also underwent computed tomography (CT) and one underwent magnetic resonance (MR) imaging. All 18 patients underwent direct panendoscopy and biopsy. Biopsy and imaging results were correlated.
  
  
  RESULTS
  Among 11 histologically proved primary tumors, FDG SPECT depicted nine tumors; CT depicted four lesions. Five patients had abnormal FDG uptake with negative biopsy results. Among five patients with normal SPECT findings, biopsy results were positive in two and negative in three. FDG SPECT at the initial reading had sensitivity of 81%, specificity of 38%, positive predictive value of 64%, and negative predictive value of 60% for detection of occult primary tumors.
  
  
  CONCLUSIONS
  FDG SPECT guidance of endoscopic biopsies in patients with occult primary SCCs of the head and neck has the potential to yield a higher rate of positive biopsy results than that traditionally expected from "blind" endoscopic procedures with "random" or "speculative" biopsy. FDG SPECT and CT are likely to remain complementary studies for the detection of occult primary tumors of the head and neck.
authors.affiliation: Department of Radiology, University of Florida College of Medicine, Gainesville 32610-0374, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Mukherji
authors.forename: W E
authors.initials: WE
authors.lastname: Drane
authors.forename: A A
authors.initials: AA
authors.lastname: Mancuso
authors.forename: J T
authors.initials: JT
authors.lastname: Parsons
authors.forename: W M
authors.initials: WM
authors.lastname: Mendenhall
authors.forename: S
authors.initials: S
authors.lastname: Stringer
mesh_terms: D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging* / Q000473:pathology; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose