title: Does volume perfusion computed tomography enable differentiation of metastatic and non-metastatic mediastinal lymph nodes in lung cancer patients? A feasibility study.
abstract: OBJECTIVE
  To compare the perfusion characteristics of mediastinal lymph node metastases with those of non-metastatic nodes in patients with newly diagnosed lung cancer using volume perfusion computed tomography (VPCT).
  
  
  METHODS
  Between January 2010 and October 2011, 101 patients with histologically confirmed, untreated lung cancer received a 40-s VPCT of the tumor bulk; 32/101 patients had evident hilar/mediastinal metastatic disease and 17/101 patients had proven non-metastasized lymph nodes within the VPCT scan range. Validation or exclusion of metastatic node involvement was proven by mediastinoscopy, biopsy, positron emission tomography imaging and/or unequivocal volume dynamics on follow-up computed tomography. A total of 45 metastases and 23 non-metastatic lymph nodes were found within the scan range and subsequently evaluated. Blood flow (BF), blood volume (BV) and K(trans) were determined. Tumor volume was recorded as whole tumor volume.
  
  
  RESULTS
  In a comparison between metastatic and non-metastatic lymph nodes, we controlled for age, lymph node volume, lung tumor volume, lung tumor location, and histologic type effects and found no significant differences with respect to BF, BV, K(trans) or heterogeneity in nodal perfusion (P > 0.05, respectively), even after adjusting lymph node perfusion values to the perfusion parameters of the primary tumor (P > 0.05, respectively). Metastatic lymph node volume had a significant increasing effect on perfusion heterogeneity (P < 0.05, respectively) and BV in the primary was a highly significant factor for BV in metastatic disease (P < 0.001).
  
  
  CONCLUSIONS
  Perfusion characteristics of mediastinal metastatic and non-metastatic lymph nodes in untreated lung cancer show considerable overlap, so that a reliable differentiation via VPCT is not possible.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany. daniel.spira@med.uni-tuebingen.de
authors.forename: Daniel
authors.initials: D
authors.lastname: Spira
authors.forename: Matthias
authors.initials: M
authors.lastname: Wecker
authors.forename: Sven Michael
authors.initials: SM
authors.lastname: Spira
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hetzel
authors.forename: Werner
authors.initials: W
authors.lastname: Spengler
authors.forename: Alexander
authors.initials: A
authors.lastname: Sauter
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008198:Lymph Nodes / Q000098:blood supply / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008482:Mediastinum / Q000473:pathology*; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D012044:Regression Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden