title: Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT.
abstract: OBJECTIVE
  The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting.
  
  
  METHODS
  A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV).
  
  
  RESULTS
  The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF.
  
  
  CONCLUSIONS
  DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT.
  
  
  CONCLUSIONS
  • Regorafenib treatment response was evaluated by CT in a rat tumour model. • Dual-energy contrast-enhanced CT allows early treatment monitoring of targeted anti-tumour therapies. • Dual-energy CT showed higher diagnostic potential than conventional contrast enhanced single-energy CT. • Dual-energy CT showed diagnostic potential comparable to dynamic contrast-enhanced CT. • Dual-energy CT is a promising method for efficient clinical treatment response evaluation.
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Charité Campus Virchow, Augustenburger Platz 1, 13353, Berlin, Germany, gesine.knobloch@charite.de.
authors.forename: Gesine
authors.initials: G
authors.lastname: Knobloch
authors.forename: Gregor
authors.initials: G
authors.lastname: Jost
authors.forename: Alexander
authors.initials: A
authors.lastname: Huppertz
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.forename: Hubertus
authors.initials: H
authors.lastname: Pietsch
mesh_terms: D000818:Animals; D003287:Contrast Media; D008297:Male; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000188:drug therapy; D010671:Phenylurea Compounds / Q000627:therapeutic use*; D011725:Pyridines / Q000627:therapeutic use*; D051381:Rats; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D013997:Time Factors; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D010671:Phenylurea Compounds; D011725:Pyridines; C559147:regorafenib