TY - JOUR T1 - Chemotherapy Response Monitoring of Colorectal Liver Metastases by Dynamic Gd-DTPA–Enhanced MRI Perfusion Parameters and <sup>18</sup>F-FDG PET Metabolic Rate JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1777 LP - 1784 DO - 10.2967/jnumed.109.064790 VL - 50 IS - 11 AU - Dennis Vriens AU - Hanneke W.M. van Laarhoven AU - Jack J.A. van Asten AU - Paul F.M. Krabbe AU - Eric P. Visser AU - Arend Heerschap AU - Cornelis J.A. Punt AU - Lioe-Fee de Geus-Oei AU - Wim J.G. Oyen Y1 - 2009/11/01 UR - http://jnm.snmjournals.org/content/50/11/1777.abstract N2 - 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 &lt; 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. ER -