title: Functional imaging of lung cancer using dual energy CT: how does iodine related attenuation correlate with standardized uptake value of 18FDG-PET-CT?
abstract: OBJECTIVE
  To investigate the correlation between maximum standardized uptake value (SUV(max)) of (18)FDG PET-CT and iodine-related attenuation (IRA) of dual energy CT (DECT) of primary tumours and (18)FDG PET-CT positive thoracic lymph nodes (LN) in patients with lung cancer.
  
  
  METHODS
  37 patients with lung cancer (27 NSCLC, 10 SCLC, 86 (18)FDG PET-CT positive thoracic LN) who underwent both (18)FDG PET-CT and DECT were analyzed. The mean study interval between (18)FDG PET-CT and DECT was ≤21 days in 17 patients. The mean and maximum IRA of DECT as well as of virtual unenhanced and virtual 120 kV images of DECT was analyzed and correlated to the SUV(max) of (18)FDG PET-CT in all tumours and (18)FDG PET-CT positive thoracic lymph nodes. Further subgroup analysis was performed for histological subtypes in all groups.
  
  
  RESULTS
  A moderate correlation was found between SUV(max) and maximum IRA in all tumours (n = 37;r = 0.507;p = 0.025) whereas only weak or no correlation were found between SUV(max) and all other DECT measurements. A strong correlation was found in patients with study intervals ≤21 days (n = 17; r = 0.768;p = 0.017). Analysis of histological subtypes of lung cancer showed a strong correlation between SUV(max) and maximum IRA in the analysis of all patients with NSCLC (r = 0.785;p = 0.001) and in patients with NSCLC and study intervals ≤21 days (r = 0.876;p = 0.024). Thoracic LN showed moderate correlation between SUV(max) and maximum IRA in patients with study intervals ≤21 days (r = 0.654; p = 0.010) whereas a weak correlation was found between SUV(max) and maximum IRA in patients with study intervals >21 days (r = 0.299; p = 0.035).
  
  
  CONCLUSIONS
  DECT could serve as a valuable functional imaging test for patients with NSCLC as the IRA of DECT correlates with SUV(max) of (18)FDG PET-CT.
authors.affiliation: Interdisciplinary Thoracic Oncology, Department of Surgery, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167, Mannheim, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Schmid-Bindert
authors.forename: Thomas
authors.initials: T
authors.lastname: Henzler
authors.forename: T Q
authors.initials: TQ
authors.lastname: Chu
authors.forename: M
authors.initials: M
authors.lastname: Meyer
authors.forename: J W
authors.initials: JW
authors.lastname: Nance
authors.forename: U J
authors.initials: UJ
authors.lastname: Schoepf
authors.forename: D J
authors.initials: DJ
authors.lastname: Dinter
authors.forename: P
authors.initials: P
authors.lastname: Apfaltrer
authors.forename: R
authors.initials: R
authors.lastname: Krissak
authors.forename: C
authors.initials: C
authors.lastname: Manegold
authors.forename: S O
authors.initials: SO
authors.lastname: Schoenberg
authors.forename: C
authors.initials: C
authors.lastname: Fink
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D007455:Iodine / Q000378:metabolism*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000378:metabolism*; D055752:Small Cell Lung Carcinoma / Q000000981:diagnostic imaging / Q000378:metabolism*; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D007455:Iodine