title: An exploratory study into the role of dynamic contrast-enhanced magnetic resonance imaging or perfusion computed tomography for detection of intratumoral hypoxia in head-and-neck cancer.
abstract: OBJECTIVE
  Hypoxia in patients with head-and-neck cancer (HNC) is well established and known to cause radiation resistance and treatment failure in the management of HNC. This study examines the role of parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perfusion computed tomography (CT) as surrogate markers of intratumoral hypoxia, defined by using the exogenous marker of hypoxia pimonidazole and the endogenous marker carbonic anhydrase 9 (CA9).
  
  
  METHODS
  Patients with HNC underwent preoperative DCE-MRI, perfusion CT, and pimonidazole infusion. Imaging parameters were correlated with pimonidazole and CA9 staining. The strength of correlations was tested by using a two-tailed Spearman's rank correlation coefficient.
  
  
  RESULTS
  Twenty-three regions of interest were analyzed from the 7 patients who completed the DCE-MRI studies. A number of statistically significant correlations were seen between DCE-MRI parameters (volume transfer between blood plasma and extracellular extravascular space [EES], volume of EES, rate constant between EES and blood plasma, time at arrival of contrast inflow, time to peak, average gradient, and time to onset) and areas with a pimonidazole score of 4. In the case of CA9 staining, only a weak correlation was shown with wash-in rate. There were no significant correlations between perfusion CT parameters and pimonidazole staining or CA9 expression.
  
  
  CONCLUSIONS
  Intratumoral hypoxia in patients with HNC may be predicted by using DCE-MRI; however, perfusion CT requires further investigation.
authors.affiliation: The Royal Marsden Hospital, Sutton, United Kingdom.
authors.forename: Kate
authors.initials: K
authors.lastname: Newbold
authors.forename: Isabel
authors.initials: I
authors.lastname: Castellano
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Charles-Edwards
authors.forename: Dorothy
authors.initials: D
authors.lastname: Mears
authors.forename: Aslam
authors.initials: A
authors.lastname: Sohaib
authors.forename: Martin
authors.initials: M
authors.lastname: Leach
authors.forename: Peter
authors.initials: P
authors.lastname: Rhys-Evans
authors.forename: Peter
authors.initials: P
authors.lastname: Clarke
authors.forename: Cyril
authors.initials: C
authors.lastname: Fisher
authors.forename: Kevin
authors.initials: K
authors.lastname: Harrington
authors.forename: Christopher
authors.initials: C
authors.lastname: Nutting
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000032:analysis / Q000378:metabolism; D015687:Cell Hypoxia; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D006258:Head and Neck Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000601:surgery; D006801:Humans; D007472:Iohexol / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009593:Nitroimidazoles / Q000493:pharmacokinetics; D011836:Radiation Tolerance; D011838:Radiation-Sensitizing Agents / Q000493:pharmacokinetics; D018709:Statistics, Nonparametric; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D009593:Nitroimidazoles; D011838:Radiation-Sensitizing Agents; D007472:Iohexol; C033815:pimonidazole; D002256:Carbonic Anhydrases