title: Mediastinal lymph node uptake in patients with prostate carcinoma on F18-choline PET/CT.
abstract: CONCLUSIONS
  Fluorine-18-methyl-choline (F18-choline) PET/computed tomography (CT) is routinely performed in our hospital for patients with significantly increased or rapidly increasing prostate-specific antigen (PSA) levels to detect and localize recurrent prostate carcinoma. We observed uptake of this PET tracer in mediastinal lymph nodes in a significant number of patients. The aim of this study was to assess the frequency of this finding and to determine whether it is correlated with tumour and nontumour-related aspects.
  
  
  METHODS
  A total of 48 consecutive men (mean age: 65.6 years; range: 50-79 years, standard deviation: 7.1) with histopathologically proven prostate cancer were referred for F18-choline PET/CT imaging for restaging from March 2009 to October 2010. All patients had a suspicion of tumour recurrence because of an increased PSA or a rapidly increasing PSA. All studies were reviewed, and the results were correlated with general data such as age; smoking; chronic obstructive pulmonary disease; tumor, lymph nodes and distant metastases stage; Gleason Score and PSA level; with a maximum interval of 3 months between serum PSA and the PET/CT scan.
  
  
  RESULTS
  In 27 patients (56.3%), F18-choline PET/CT showed positive lymph nodes in the mediastinum (mean standardized uptake values: 3.75; range: 1.7-13.8, standard deviation: 2.4). No histological biopsy was carried out in F18-choline-positive lymph nodes, but in none of the patients was mediastinal recurrence or pulmonary infection observed during a 6-month follow-up. Only one patient had histologically proven pulmonary metastasis. No significant relationship was observed between mediastinal F18-choline lymph node uptake and serum PSA level (P=0.785), initial T stage (P=0.555), N stage (P=0.548), M stage (P=0.426), smoking (P=0.537), chronic obstructive pulmonary disease (P=0.115) or the presence of tumour recurrence on F18-choline PET/CT.
  
  
  CONCLUSIONS
  Mediastinal lymph node uptake of F18 choline is frequently observed, without any significant relationship with tumour characteristics. Therefore, interpretation of positive mediastinal lymph node uptake should be done carefully.
authors: Department of Nuclear Medicine, the Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.
authors: Daphne D D
authors: DD
authors: Rietbergen
authors: Bernies
authors: B
authors: van der Hiel
authors: Wouter
authors: W
authors: Vogel
authors: Marcel P M
authors: MP
authors: Stokkel
mesh_terms: D000368:Aged; D002794:Choline / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D005462:Fluorine Radioisotopes; D006801:Humans; D008198:Lymph Nodes / Q000737:chemistry / Q000000981:diagnostic imaging*; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D009367:Neoplasm Staging / Q000379:methods; D049268:Positron-Emission Tomography; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014057:Tomography, X-Ray Computed
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; C448902:fluoroethylcholine; D017430:Prostate-Specific Antigen; D002794:Choline