title: Comparison of dynamic contrast-enhanced MRI and dynamic contrast-enhanced CT biomarkers in bladder cancer.
abstract: Dynamic contrast-enhanced MRI (DCE-MRI) is frequently used to provide response biomarkers in clinical trials of novel cancer therapeutics but assessment of their physiological accuracy is difficult. DCE-CT provides an independent probe of similar pharmacokinetic processes and may be modeled in the same way as DCE-MRI to provide purportedly equivalent physiological parameters. In this study, DCE-MRI and DCE-CT were directly compared in subjects with primary bladder cancer to assess the degree to which the model parameters report modeled physiology rather than artefacts of the measurement technique and to determine the interchangeability of the techniques in a clinical trial setting. The biomarker K(trans) obtained by fitting an extended version of the Kety model voxelwise to both DCE-MRI and DCE-CT data was in excellent agreement (mean across subjects was 0.085 ± 0.030 min(-1) for DCE-MRI and 0.087 ± 0.033 min(-1) for DCE-CT, intermodality coefficient of variation 9%). The parameter v(p) derived from DCE-CT was significantly greater than that derived from DCE-MRI (0.018 ± 0.006 compared to 0.009 ± 0.008, P = 0.0007) and v(e) was in reasonable agreement only for low values. The study provides evidence that the biomarker K(trans) is a robust parameter indicative of the underlying physiology and relatively independent of the method of measurement.
authors: Imaging Science and Biomedical Engineering, School of Cancer and Enabling Sciences, University of Manchester, Manchester, United Kingdom. josephine.naish@manchester.ac.uk
authors: J H
authors: JH
authors: Naish
authors: D M
authors: DM
authors: McGrath
authors: L J
authors: LJ
authors: Bains
authors: K
authors: K
authors: Passera
authors: C
authors: C
authors: Roberts
authors: Y
authors: Y
authors: Watson
authors: S
authors: S
authors: Cheung
authors: M B
authors: MB
authors: Taylor
authors: J P
authors: JP
authors: Logue
authors: D L
authors: DL
authors: Buckley
authors: J
authors: J
authors: Tessier
authors: H
authors: H
authors: Young
authors: J C
authors: JC
authors: Waterton
authors: G J M
authors: GJ
authors: Parker
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*
chemical_list: D015415:Biomarkers