title: Iodine concentration as a perfusion surrogate marker in oncology: Further elucidation of the underlying mechanisms using Volume Perfusion CT with 80 kVp.
abstract: OBJECTIVE
  To assess the value of iodine concentration (IC) in computed tomography data acquired with 80 kVp, as a surrogate for perfusion imaging in hepatocellular carcinoma (HCC) and lymphoma by comparing iodine related attenuation (IRA) with quantitative Volume Perfusion CT (VPCT)-parameters.
  
  
  METHODS
  VPCT-parameters were compared with intra-tumoral IC at 5 time points after the aortic peak enhancement (APE) with a temporal resolution of 3.5 sec in untreated 30 HCC and 30 lymphoma patients.
  
  
  RESULTS
  Intra-tumoral perfusion parameters for HCC showed a blood flow (BF) of 52.7 ± 17.0 mL/100 mL/min, blood volume (BV) 12.6 ± 4.3 mL/100 mL, arterial liver perfusion (ALP) 44.4 ± 12.8 mL/100 mL/min. Lesion IC 7 sec after APE was 133.4 ± 57.3 mg/100 mL. Lymphoma showed a BF of 36.8 ± 13.4 mL/100 mL/min, BV of 8.8 ± 2.8 mL/100 mL and IC of 118.2 ± 64.5 mg/100 mL 3.5 sec after APE. Strongest correlations exist for VPCT-derived BF and ALP with IC in HCC 7 sec after APE (r = 0.71 and r = 0.84) and 3.5 sec after APE in lymphoma lesions (r = 0.77). Significant correlations are also present for BV (r = 0.60 and r = 0.65 for HCC and lymphoma, respectively).
  
  
  CONCLUSIONS
  We identified a good, time-dependent agreement between VPCT-derived flow values and IC in HCC and lymphoma. Thus, CT-derived ICs 7 sec after APE in HCC and 3.5 sec in lymphoma may be used as surrogate imaging biomarkers for tumor perfusion with 80 kVp.
  
  
  CONCLUSIONS
  • Iodine concentration derived from low kVp CT is regarded as perfusion surrogate • Correlation with Perfusion CT was performed to elucidate timing and histology dependencies • Highest correlation was present 7 sec after aortic peak enhancement in hepatocellular carcinoma • In lymphoma, highest correlation was calculated 3.5 sec after aortic peak enhancement • With these results, further optimization of Dual energy CT protocols is possible.
authors.affiliation: Department of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany.
authors.forename: Wolfgang M
authors.initials: WM
authors.lastname: Thaiss
authors.affiliation: Siemens AG, Healthcare Sector, Computed Tomography, H IM CR R&D PA SC, Siemensstr. 1, D-91301, Forchheim, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Haberland
authors.affiliation: Department of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Kaufmann
authors.affiliation: Department of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany.|Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Im Neuenheimer Feld 110, D-69120, Heidelberg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Spira
authors.affiliation: Department of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany.|Institute for Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstr. 5, D-40225, Düsseldorf, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Thomas
authors.affiliation: Department of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.affiliation: Department of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
authors.affiliation: Department of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany. alexander.sauter@usb.ch.|Department of Radiology and Nuclear Medicine, Division of Nuclear Medicine, University Hospital Basel, Petersgraben 4, CH-4031, Basel, Switzerland. alexander.sauter@usb.ch.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Sauter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001810:Blood Volume; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D007455:Iodine / Q000493:pharmacokinetics*; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008223:Lymphoma / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D007455:Iodine
keywords: Contrast media; Hepatocellular carcinoma; Lymphoma; Multislice computed tomography; Perfusion imaging