Chemotherapy response monitoring of colorectal liver metastases by dynamic Gd-DTPA-enhanced MRI perfusion parameters and 18F-FDG PET metabolic rate.
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 (18)F-FDG PET, during cytotoxic treatment of patients with colorectal liver metastases.


METHODS
Twenty-three patients underwent DCE-MRI (using gadolinium dimeglumine) and dynamic (18)F-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 [k(ep)] and volume transfer constant [K(trans)]), extracellular space (v(e)), tumor size (the maximal axial diameter of each included lesion [MAD]), and metabolism (glucose metabolic rates [MR(glc)]) 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 MR(glc) and MAD were individually predictive for OS and PFS. During treatment, K(trans) increased significantly, but this increase could not be confirmed in a lesion-by-lesion analysis. MR(glc) decreased significantly (P < 0.001). No correlations were found for changes in DCE-MRI parameters and DeltaMR(glc). No relationship was found between changes in DCE-MRI parameters and OS or PFS. DeltaMR(glc) was able to predict OS (P = 0.008) after correction for confounders.


CONCLUSIONS
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.
Vriens
Dennis
D
Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. D.Vriens@nucmed.umcn.nl
van Laarhoven
Hanneke W M
HW
van Asten
Jack J A
JJ
Krabbe
Paul F M
PF
Visser
Eric P
EP
Heerschap
Arend
A
Punt
Cornelis J A
CJ
de Geus-Oei
Lioe-Fee
LF
Oyen
Wim J G
WJ
D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000098:blood supply* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D019786:Gadolinium DTPA / Q000493:pharmacokinetics; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism* / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D015996:Survival Rate; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D019788:Fluorodeoxyglucose F18; D019786:Gadolinium DTPA