Lactate MRSI and DCE MRI as surrogate markers of prostate tumor aggressiveness
Abstract
Longitudinal studies of lactate MRSI and dynamic contrast‐enhanced MRI were performed at 4.7 T in two prostate tumor models grown in rats, Dunning R3327‐AT (AT) and Dunning R3327‐H (H), to determine the potential of lactate and the perfusion/permeability parameter Akep as markers of tumor aggressiveness. Subcutaneous AT (n = 12) and H (n = 6) tumors were studied at different volumes between 100 and 2900 mm3 (Groups 1–5). Lactate concentration was determined using selective multiple quantum coherence MRSI with the phantom substitution method. Tumor enhancement after the administration of gadolinium diethylenetriaminepenta‐acetic acid was analyzed using the Brix–Hoffmann model and the Akep parameter was used as a measure of tumor perfusion/permeability. Lactate was not detected in the smallest AT tumors (Group 1; 100–270 mm3). In larger AT tumors, the lactate concentration increased from 2.8 ± 1.0 mm (Group 2; 290–700 mm3) to 8.4 ± 2.9 mm (Group 3; 1000–1340 mm3) and 8.2 ± 2.2 mm (Group 4; 1380–1750 mm3), and then decreased to 5.0 ± 1.7 mm (Group 5; 1900–2500 mm3), and was consistently higher in the tumor core than in the rim. Lactate was not detected in any of the H tumors. The mean tumor Akep values decreased with increasing volume in both tumor types, but were significantly higher in H tumors. In AT tumors, the Akep values were significantly higher in the rim than in the core. Histological hypoxic and necrotic fractions in AT tumors increased with volume from 0% in Group 1 to about 20% and 30%, respectively, in Group 5. Minimal amounts of hypoxia and necrosis were found in H tumors of all sizes. Thus, the presence of lactate and heterogeneous perfusion/permeability are signatures of aggressive, metabolically deprived tumors. Copyright © 2011 John Wiley & Sons, Ltd.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 25, 2011
- Source ID
- 10.1002/nbm.1723
Entities
People
- A. Rizwan
- C. C. Matei
- H. T. Thaler
- J. A. Koutcher
- J. Yaligar
- K. L. Zakian
- L. Bokacheva
- M. E. Lupu
- S. B. Thakur
- S. Carlin
- Yaonan Wang
Organizations
- Memorial Sloan Kettering Cancer Center
- National Cancer Institute
- United States Department of Defense