RT Journal Article SR Electronic T1 Chemotherapy Response Monitoring of Colorectal Liver Metastases by Dynamic Gd-DTPA–Enhanced MRI Perfusion Parameters and 18F-FDG PET Metabolic Rate JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1777 OP 1784 DO 10.2967/jnumed.109.064790 VO 50 IS 11 A1 Dennis Vriens A1 Hanneke W.M. van Laarhoven A1 Jack J.A. van Asten A1 Paul F.M. Krabbe A1 Eric P. Visser A1 Arend Heerschap A1 Cornelis J.A. Punt A1 Lioe-Fee de Geus-Oei A1 Wim J.G. Oyen YR 2009 UL http://jnm.snmjournals.org/content/50/11/1777.abstract AB In this study, we examined the in vivo relationship between functional tumor vasculature, determined by dynamic contrast-enhanced (DCE-) MRI, and tumor metabolism, determined by dynamic 18F-FDG PET, during cytotoxic treatment of patients with colorectal liver metastases. Methods: Twenty-three patients underwent DCE-MRI (using gadolinium dimeglumine) and dynamic 18F-FDG PET at baseline and after 3 treatment cycles, unless treatment was terminated because of toxicity. Parameters for vasculature (rate constant between extravascular extracellular space and blood plasma [kep] and volume transfer constant [Ktrans]), extracellular space (ve), tumor size (the maximal axial diameter of each included lesion [MAD]), and metabolism (glucose metabolic rates [MRglc]) were derived, and changes during treatment were correlated. Overall survival (OS) and progression-free survival (PFS) served as outcome measures for the predictive abilities of pretreatment parameters and of treatment-related parameter changes. Results: Pretreatment MRglc and MAD were individually predictive for OS and PFS. During treatment, Ktrans increased significantly, but this increase could not be confirmed in a lesion-by-lesion analysis. MRglc decreased significantly (P < 0.001). No correlations were found for changes in DCE-MRI parameters and ΔMRglc. No relationship was found between changes in DCE-MRI parameters and OS or PFS. ΔMRglc was able to predict OS (P = 0.008) after correction for confounders. Conclusion: The efficacy of cytotoxic chemotherapy assessed by reduction in tumor metabolism does not depend on pretreatment properties of the tumor vasculature determined by DCE-MRI. Cytotoxic chemotherapy does not alter DCE-MRI–derived properties of tumor vasculature but decreases glucose consumption of tumor cells.