title: Prospective study of 18FDG-PET in the detection and management of patients with lymph node metastases to the neck from an unknown primary tumor. Results from the DAHANCA-13 study.
abstract: BACKGROUND
  The benefit of a complementary fluorodeoxyglucose-positron emission tomography (FDG-PET) scan to standard workup for carcinoma of unknown primary (CUP) and metastatic neck lesions was prospectively studied.
  
  
  METHODS
  Sixty-seven patients underwent standardized diagnostic workup according to national guidelines including panendoscopies, multiple mucosal biopsies, and diagnostic CT/MRI scans. Median follow-up was 40 months (range, 2-65 months).
  
  
  RESULTS
  In 60 eligible patients, FDG-PET indicated a primary tumor or metastatic disease in 30 patients (50%). Additional investigations confirmed a primary tumor in 18 patients: hypopharynx in 5, oropharynx in 5, nasopharynx in 2, lung in 1, axilla in 1, bone in 1, rectum in 1, as well as multiple metastatic lesions from CUP in 2 patients. In retrospect, MRI was able to detect 1 of the PET-detected primaries, leading to an overall detection rate of PET of 29% in CUP. A therapeutic change of treatment was made in 25% as a consequence of FDG-PET. PET before panendoscopy demonstrated fewer false-positive pathological foci.
  
  
  CONCLUSIONS
  FDG-PET is a valuable tool in addition to conventional extensive workup in CUP and neck metastases. Consequently, FDG-PET is now recommended as an early diagnostic modality in the workup of these patients.
authors.affiliation: Department of Oncology, Odense University Hospital, Odense, Denmark. j.johansen@dadlnet.dk
authors.forename: Jørgen
authors.initials: J
authors.lastname: Johansen
authors.forename: Simon
authors.initials: S
authors.lastname: Buus
authors.forename: Annika
authors.initials: A
authors.lastname: Loft
authors.forename: Susanne
authors.initials: S
authors.lastname: Keiding
authors.forename: Marie
authors.initials: M
authors.lastname: Overgaard
authors.forename: Hanne Sand
authors.initials: HS
authors.lastname: Hansen
authors.forename: Cai
authors.initials: C
authors.lastname: Grau
authors.forename: Troels
authors.initials: T
authors.lastname: Bundgaard
authors.forename: Jørgen
authors.initials: J
authors.lastname: Kirkegaard
authors.forename: Jens
authors.initials: J
authors.lastname: Overgaard
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000628:therapy; D004724:Endoscopy; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy; D009382:Neoplasms, Unknown Primary; D049268:Positron-Emission Tomography; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D018714:Radiotherapy, Adjuvant; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18