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Yaligar J, Thakur SB, Bokacheva L, Carlin S, Thaler HT, Rizwan A, Lupu ME, Wang Y, Matei CC, Zakian KL, Koutcher JA. Lactate MRSI and DCE MRI as surrogate markers of prostate tumor aggressiveness. NMR Biomed 2012; 25:113-122. [PMID: 21618306 PMCID: PMC3985132 DOI: 10.1002/nbm.1723] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 03/09/2011] [Accepted: 03/10/2011] [Indexed: 05/12/2023]
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 Ak(ep) as markers of tumor aggressiveness. Subcutaneous AT (n = 12) and H (n = 6) tumors were studied at different volumes between 100 and 2900 mm(3) (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 Ak(ep) parameter was used as a measure of tumor perfusion/permeability. Lactate was not detected in the smallest AT tumors (Group 1; 100-270 mm(3) ). In larger AT tumors, the lactate concentration increased from 2.8 ± 1.0 mm (Group 2; 290-700 mm(3)) to 8.4 ± 2.9 mm (Group 3; 1000-1340 mm(3)) and 8.2 ± 2.2 mm (Group 4; 1380-1750 mm(3) ), and then decreased to 5.0 ± 1.7 mm (Group 5; 1900-2500 mm(3)), 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 Ak(ep) values decreased with increasing volume in both tumor types, but were significantly higher in H tumors. In AT tumors, the Ak(ep) 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.
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Affiliation(s)
- J Yaligar
- Department of Medical Physics, New York, NY, United States
| | - S B Thakur
- Department of Medical Physics, New York, NY, United States
- Department of Radiology, New York, NY, United States
| | - L Bokacheva
- Department of Medical Physics, New York, NY, United States
| | - S Carlin
- Department of Medical Physics, New York, NY, United States
| | - H T Thaler
- Department of Epidemiology and Biostatistics, New York, NY, United States
| | - A Rizwan
- Department of Medical Physics, New York, NY, United States
| | - M E Lupu
- Department of Medical Physics, New York, NY, United States
| | - Y Wang
- Department of Medical Physics, New York, NY, United States
| | - C C Matei
- Department of Radiology, New York, NY, United States
| | - K L Zakian
- Department of Medical Physics, New York, NY, United States
- Department of Radiology, New York, NY, United States
| | - J A Koutcher
- Department of Medical Physics, New York, NY, United States
- Department of Radiology, New York, NY, United States
- Department of Medicine Memorial Sloan-Kettering Cancer Center, New York, NY, United States
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