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
Received 27 March 2008; received in revised form 21 July 2008; accepted 22 July 2008. published online 25 November 2008.
Purpose
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 and Materials
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.
Conclusion
Intratumoral hypoxia in patients with HNC may be predicted by using DCE-MRI; however, perfusion CT requires further investigation.
∗The Royal Marsden Hospital, Sutton, United Kingdom
†Institute of Cancer Research, London, United Kingdom
‡Institute of Cancer Research, Sutton, Surrey, United Kingdom
§The Royal Marsden Hospital, London, United Kingdom
Reprint requests to: Kate Newbold, M.D., The Royal Marsden Hospital, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom. Tel: (00) 44-208-661-3638; Fax: (00) 44-208-915-6719
Dr. Newbold was funded by a Royal College of Radiologists/BUPA Research Fellowship and The Royal Marsden Hospital General Clinical Research Fund.
ABSTRACT