title: Metastatic head and neck cancer: role and usefulness of FDG PET in locating occult primary tumors.
abstract: OBJECTIVE
  To assess the usefulness of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) of the head and neck in locating occult primary lesions in patients with metastatic cervical adenopathy.
  
  
  METHODS
  Seventeen patients with metastatic cervical adenopathy of unknown primary origin were referred for FDG PET of the head and neck. All patients had undergone correlative anatomic imaging within 1 month of FDG PET. Surgical, clinical, and histopathologic findings were used to assess the performance of FDG PET.
  
  
  RESULTS
  Increased apical lung uptake at FDG PET led to a biopsy-proved diagnosis of primary lung cancer in two patients. Of the remaining 15 patients, 10 had a focus of increased activity; directed biopsy of these sites led to confirmation of a primary carcinoma in seven patients. Correlative anatomic imaging failed to demonstrate the primary sites of disease in two of these seven patients. None of the five patients with negative FDG PET studies have manifested evidence of a primary site of disease during follow-up of 8-42 months (mean, 29 months).
  
  
  CONCLUSIONS
  FDG PET allows effective localization of the unknown primary site of origin in metastatic head and neck cancer and can contribute substantially to patient care.
authors.affiliation: Department of Radiology, University of California Medical Center, San Francisco 94143, USA.
authors.forename: O S
authors.initials: OS
authors.lastname: AAssar
authors.forename: N J
authors.initials: NJ
authors.lastname: Fischbein
authors.forename: G R
authors.initials: GR
authors.lastname: Caputo
authors.forename: M J
authors.initials: MJ
authors.lastname: Kaplan
authors.forename: D C
authors.initials: DC
authors.lastname: Price
authors.forename: M I
authors.initials: MI
authors.lastname: Singer
authors.forename: W P
authors.initials: WP
authors.lastname: Dillon
authors.forename: R A
authors.initials: RA
authors.lastname: Hawkins
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18