Integration of quantitative DCE-MRI and ADC mapping to monitor treatment response in human breast cancer: initial results.
OBJECTIVE
The objective of this study was to assess changes in the water apparent diffusion coefficient (ADC) and in pharmacokinetic parameters obtained from the fast-exchange regime (FXR) modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) during neoadjuvant chemotherapy in breast cancer.


METHODS
Eleven patients with locally advanced breast cancer underwent MRI examination prior to and after chemotherapy but prior to surgery. A 1.5-T scanner was used to obtain T1, ADC and DCE-MRI data. DCE-MRI data were analyzed by the FXR model returning estimates of K(trans) (volume transfer constant), v(e) (extravascular extracellular volume fraction) and tau(i) (average intracellular water lifetime). Histogram and correlation analyses assessed parameter changes post-treatment.


RESULTS
Significant (P < .05) changes or trends towards significance (P < .10) were seen in all parameters except tau(i), although there was qualitative reduction in tau(i) values post-treatment. In particular, there was reduction (P < .035) in voxels with K(trans) values in the range 0.2-0.5 min(-1) and a decrease (P < .05) in voxels with ADC values in the range 0.99 x 10(-3) to 1.35 x 10(-3) mm2/s. ADC and v(e) were negatively correlated (r = -.60, P < .02). Parameters sensitive to water distribution and geometry (T(1), v(e), tau(i) and ADC) correlated with a multivariable linear regression model.


CONCLUSIONS
The analysis presented here is sensitive to longitudinal changes in breast tumor status; K(trans) and ADC are most sensitive to these changes. Relationships between parameters provide information on water distribution and geometry in the tumor environment.
Yankeelov
Thomas E
TE
Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232-2310, USA. thomas.yankeelov@vanderbilt.edu
Lepage
Martin
M
Chakravarthy
Anuradha
A
Broome
Elizabeth E
EE
Niermann
Kenneth J
KJ
Kelley
Mark C
MC
Meszoely
Ingrid
I
Mayer
Ingrid A
IA
Herman
Cheryl R
CR
McManus
Kevin
K
Price
Ronald R
RR
Gore
John C
JC
D000970:Antineoplastic Agents / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000473:pathology* / Q000628:therapy*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000628:therapy; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D020360:Neoadjuvant Therapy; D010865:Pilot Projects
D000970:Antineoplastic Agents; D003287:Contrast Media