title: Lymphangiography causes false-positive findings on 18F-FDG PET imaging.
abstract: BACKGROUND
  18F-FDG positron emission tomography (PET) may alter therapeutic management of patients with cervical cancer because 18F-FDG-positive pelvic and para-aortic lymph nodes are associated with lower progression-free survival and vice versa. However, the accuracy of 18F-FDG PET might be impaired by a preceding lymphangiography (LAG).
  
  
  METHODS
  LAG, magnetic resonance (MR)-imaging and 18F-FDG PET were performed in 6 patients with cervical cancer stage FIGO IB and II. All patients were scheduled for radical hysterectomy and pelvic and para-aortic lymphadenectomy. The results of LAG, MR-imaging and 18F-FDG PET were compared with histological findings.
  
  
  RESULTS
  18F-FDG PET showed false-positive foci in both patients who had LAG before PET-study but not in 4 patients who had LAG thereafter. Histology confirmed false-positive 18F-FDG accumulation in lymphnodes to be consistent with granulomateous changes as induced by foregoing LAG.
  
  
  CONCLUSIONS
  Whenever 18F-FDG PET and LAG are performed in the same patient to assess the extent of lymph-node metastases, LAG should always be done after the 18F-FDG PET study to obviate false-positive results.
authors.affiliation: Department of Nuclear Medicine, University Hospital Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. michael.reinhardt@ukb.uni-bonn.de
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Reinhardt
authors.forename: Katja
authors.initials: K
authors.lastname: Technau-Ihling
authors.forename: Carsten
authors.initials: C
authors.lastname: Altehoefer
authors.forename: Dagmar
authors.initials: D
authors.lastname: Vogelgesang
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Krause
mesh_terms: D000328:Adult; D000368:Aged; D005189:False Positive Reactions; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008220:Lymphography / Q000009:adverse effects*; D008875:Middle Aged; D009367:Neoplasm Staging; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging*
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18