An exploratory pilot study into the association between microcirculatory parameters derived by MRI-based pharmacokinetic analysis and glucose utilization estimated by PET-CT imaging in head and neck cancer

Objectives: To examine the feasibility of deriving quantitative microcirculatory parameters and to investigate the relationship between vascular and metabolic characteristics of head and neck tumours in vivo, using dynamic contrast-enhanced (DCE) MRI and fluorodeoxyglucose (FDG) PET imaging. Methods: Twenty-seven patients with primary squamous cell carcinoma (SCCA) underwent DCE-MRI and combined PET/CT imaging. DCE-MRI data were post-processed by using commercially available software. Transfer constant ( K trans ), extravascular extracellular blood volume ( v e ), transfer constant from the extracellular extravascular space to plasma ( k ep ) and iAUC (initial area under the signal intensity–time curve) were calculated. 3D static PET data were acquired and standardised uptake values (SUV) calculated. Results: All microcirculatory parameters in tumours were higher than in normal muscle tissue ( P ≤ 0.0019). Significant correlations were shown between k ep and K trans ( ρ = 0.77), v e and k ep ( ρ = −0.7), and iAUC and v e ( ρ = 0.53). Significant correlations were observed for SUV mean and v e as well as iAUC ( ρ = 0.42 and ρ = 0.66, respectively). SUV max was significantly correlated with iAUC ( ρ = 0.69). Conclusions: The demonstrated relationships between vascular and metabolic characteristics of primary SCCA imply a complex interaction between vascular delivery characteristics and tumour metabolism. The lack of correlation between SUV and K trans / k ep suggests that both diagnostic techniques may provide complementary information.