Investigation of copper-PTSM as a PET tracer for tumor blood flow

C. J. Mathias, M. J. Welch, D. J. Perry, A. H. McGuire, X. Zhu, J. M. Connett, M. A. Green

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Abstract

Copper-PTSM has been shown in previous studies to act as a fluid microsphere and to be useful in quantitating blood flow in brain, myocardium, and kidneys. In this study we have evaluated this agent as a PET tumor blood flow agent. 64Cu- or 67Cu-labeled Cu-PTSM was administered (i.v.) to Golden Syrian hamsters with colorectal carcinoma cell implants (GW39). One minute prior to sacrifice (10-60 min after Cu-PTSM was administered) 125I-iodoantipyrine (125I-IAP), an agent known to measure tumor blood flow, was administered intravenously by a 3-stage, 1 min ramp infusion. Following sacrifice, samples of tumor and brain were removed (within 40 s) and the tumor and brain levels of Cu-PTSM and iodoantipyrine determined. Since the brain uptake of both Cu-PTSM and IAP is perfusion rate limited, the brain was used as a reference organ to normalize tumor levels of the two tracers. The plot of Cu-PTSM versus 125I-IAP tumor/brain ratios showed a good linear correlation (r value of 0.97), suggesting that Cu-PTSM could be used to quantify tumor blood flow. Since the mechanism of Cu-PTSM trapping is likely to be due to glutathione levels in the tissue, and because tumor tissue glutathione levels might vary, the temporal uptake of Cu-PTSM was investigated by PET imaging both the tumor-bearing hamsters and ~300 g Copenhagen rats bearing R3227 prostate tumors. The tumors were clearly visualized and the retained copper radioactivity in the tumor was constant over the 30 min imaging period.

Original languageEnglish (US)
Pages (from-to)807-811
Number of pages5
JournalInternational Journal of Radiation Applications and Instrumentation.
Volume18
Issue number7
DOIs
StatePublished - 1991

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ASJC Scopus subject areas

  • Medicine(all)

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