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Journal of Biomedicine and Biotechnology
Volume 2011, Article ID 276907, 7 pages
Research Article

Synthesis and Evaluation of Amino Acid-Based Radiotracer 99mTc-N4-AMT for Breast Cancer Imaging

Department of Experimental Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA

Received 30 December 2010; Accepted 14 February 2011

Academic Editor: Lie-Hang Shen

Copyright © 2011 Fan-Lin Kong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. This study was to develop an efficient synthesis of 99mTc-O-[3-(1,4,8,11-tetraazabicyclohexadecane)-propyl]- -methyl tyrosine (99mTc-N4-AMT) and evaluate its potential in cancer imaging. Methods. N4-AMT was synthesized by reacting N4-oxalate and 3-bromopropyl AMT (N-BOC, ethyl ester). In vitro cellular uptake kinetics of 99mTc-N4-AMT was assessed in rat mammary tumor cells. Tissue distribution of the radiotracer was determined in normal rats at 0.5–4 h, while planar imaging was performed in mammary tumor-bearing rats at 30–120 min. Results. The total synthesis yield of N4-AMT was 14%. Cellular uptake of 99mTc-N4-AMT was significantly higher than that of 99mTc-N4. Planar imaging revealed that 99mTc-N4-AMT rendered greater tumor/muscle ratios than 99mTc-N4. Conclusions. N4-AMT could be synthesized with a considerably high yield. Our in vitro and in vivo data suggest that 99mTc-N4-AMT, a novel amino acid-based radiotracer, efficiently enters breast cancer cells, effectively distinguishes mammary tumors from normal tissues, and thus holds the promise for breast cancer imaging.