PT  - JOURNAL ARTICLE
AU  - Jeffrey Tseng
AU  - Lisa K. Dunnwald
AU  - Erin K. Schubert
AU  - Jeanne M. Link
AU  - Satoshi Minoshima
AU  - Mark Muzi
AU  - David A. Mankoff
TI  - <sup>18</sup>F-FDG Kinetics in Locally Advanced Breast Cancer: Correlation with Tumor Blood Flow and Changes in Response to Neoadjuvant Chemotherapy
DP  - 2004 Nov 01
TA  - Journal of Nuclear Medicine
PG  - 1829--1837
VI  - 45
IP  - 11
4099  - http://jnm.snmjournals.org/content/45/11/1829.short
4100  - http://jnm.snmjournals.org/content/45/11/1829.full
SO  - J Nucl Med2004 Nov 01; 45
AB  - The aim of this study was to characterize the biologic response of locally advanced breast cancer (LABC) to chemotherapy using 15O-water–derived blood flow measurements and 18F-FDG–derived glucose metabolism rate parameters. Methods: Thirty-five LABC patients underwent PET with 15O-water and 18F-FDG before neoadjuvant chemotherapy and 2 mo after the initiation of treatment. Kinetic analysis for 15O-water was performed using a single tissue compartment model to calculate blood flow; a 2-tissue compartment model was used to estimate 18F-FDG rate parameters K1, k2, k3, and the flux constant, Ki. Correlations and ratios between blood flow and 18F-FDG rate parameters were calculated and compared with pathologic tumor response. Results: Although blood flow and 18F-FDG transport (K1) were correlated before chemotherapy, there was relatively poor correlation between blood flow and the phosphorylation constant (k3) or the overall 18F-FDG flux (Ki). Blood flow and 18F-FDG flux were more closely matched after chemotherapy, with changes in k3 accounting for the increased correlation. These findings were consistent with a decline in both the Ki/flow and k3/flow ratios with therapy. The ratio of 18F-FDG flux to transport (Ki/K1) after 2 mo of chemotherapy was predictive of ultimate response. Conclusion: The pattern of tumor glucose metabolism in LABC, as reflected by analysis of 18F-FDG rate parameters, changes after therapy, even in patients with modest clinical responses. This may indicate a change in tumor “metabolic phenotype” in response to treatment. A low ratio of glucose metabolism (reflected by Ki) to glucose delivery (reflected by K1 and blood flow) after therapy is associated with a favorable response. Further work is needed to understand the tumor biology underlying these findings.