title: Dual-phase dual-energy CT in patients with lung cancer: assessment of the additional value of iodine quantification in lymph node therapy response.
abstract: OBJECTIVE
  To investigate the potential contribution of iodine uptake calculation from dual-phase dual-energy CT (DE-CT) for lymph node staging and therapy response monitoring in lung cancer patients.
  
  
  METHODS
  Retrospective analysis of 27 patients with non-small cell lung carcinoma (NSCLC), who underwent dual-phase DE-CT before and after chemotherapy, was performed. Iodine uptake (mg/mL) and total iodine uptake (mg) were calculated using prototype software in the early (arterial) and late (venous) post-contrast circulatory phase in 110 mediastinal lymph nodes. The arterial enhancement fraction (AEF) was calculated and compared with lymph node size and response to chemotherapy.
  
  
  RESULTS
  A significant difference of AEF was observed between enlarged (90.4%; 32.3-238.5%) and non-enlarged (72.7%; -37.5-237.5%) lymph nodes (p = 0.044) before treatment onset. A significantly different change of AEF in responding (decrease of 26.3%; p = 0.022) and non-responding (increase of 43.0%; p = 0.031) lymph nodes was demonstrated. A higher value of AEF before treatment was observed in lymph nodes with subsequent favourable response (88.6% vs. 77.7%; p = 0.122), but this difference did not reach statistical significance.
  
  
  CONCLUSIONS
  The dual-phase DE-CT examination with quantification of ratio of early and late post-contrast iodine uptake is a feasible and promising method for the functional evaluation of mediastinal lymph nodes including therapy response assessment.
  
  
  CONCLUSIONS
  • Dual-phase DE-CT is beneficial for mediastinal lymph node assessment in NSCLC. • Arterial to venous iodine uptake ratio was higher in enlarged lymph nodes. • Change of arterial enhancement fraction correlated to therapy response.
authors.affiliation: Department of Imaging Methods, Charles University Teaching Hospital Plzen, alej Svobody 80, 306 40, Plzen, Czech Republic, baxaj@fnplzen.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Baxa
authors.forename: Alena
authors.initials: A
authors.lastname: Vondráková
authors.forename: Táňa
authors.initials: T
authors.lastname: Matoušková
authors.forename: Olga
authors.initials: O
authors.lastname: Růžičková
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmidt
authors.forename: Thomas
authors.initials: T
authors.lastname: Flohr
authors.forename: Martin
authors.initials: M
authors.lastname: Sedlmair
authors.forename: Jiří
authors.initials: J
authors.lastname: Ferda
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000556:secondary; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007455:Iodine / Q000493:pharmacokinetics*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D009367:Neoplasm Staging / Q000379:methods*; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D007455:Iodine