Semiquantitative analysis of dynamic contrast enhanced MRI in cancer patients: Variability and changes in tumor tissue over time.
OBJECTIVE
To evaluate variability of a simplified method for measuring semiquantitative DCE-MRI parameters in patients with cancer and to explore effects of treatment with a putative anti-angiogenic compound.


METHODS
A total of 19 patients enrolled on treatment trials with the putative anti-angiogenic agent SU5416 underwent contrast enhanced examinations, and 11 had a second examination eight weeks post therapy. Contrast media concentration as a function of time was calculated using changes in signal and literature baseline T(1) values in normal muscle or liver reference tissue. Semiquantitative DCE-MRI parameters, including the area under the contrast concentration vs. time curve (AUC), were calculated for regions-of-interest in normal liver and muscle, and in tumors.


RESULTS
The coefficients of variation for pretherapy parameters in normal tissue were 11% to 37%. No significant changes were detected in normal liver over two months of therapy. In tumors and muscle, a significant decrease in the AUC and maximum contrast concentration was observed.


CONCLUSIONS
Variability of semiquantitative DCE-MRI parameters utilizing a method based on known T(1) values in a reference tissue is low enough to detect changes in tumors during therapy. Use of this method as a pharmacodynamic marker should be further investigated.
Medved
Milica
M
Department of Radiology, The University of Chicago, Chicago, Illinois, USA.
Karczmar
Greg
G
Yang
Cheng
C
Dignam
James
J
Gajewski
Thomas F
TF
Kindler
Hedy
H
Vokes
Everett
E
MacEneany
Peter
P
Mitchell
Myrosia T
MT
Stadler
Walter M
WM
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000188:drug therapy; D003287:Contrast Media; D019786:Gadolinium DTPA; D006801:Humans; D007211:Indoles / Q000627:therapeutic use; D008099:Liver / Q000033:anatomy & histology; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008545:Melanoma / Q000175:diagnosis / Q000188:drug therapy / Q000556:secondary; D008654:Mesothelioma / Q000175:diagnosis / Q000188:drug therapy; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011758:Pyrroles / Q000627:therapeutic use
D020533:Angiogenesis Inhibitors; D003287:Contrast Media; D007211:Indoles; D011758:Pyrroles; C116890:Semaxinib; C064925:gadodiamide; D011505:Protein-Tyrosine Kinases; D019786:Gadolinium DTPA