Abstract |
Early and reliable diagnosis of colorectal cancer continues to be demanding and challenging. Colorectal cancer cells express Vasoactive Intestinal Peptide ( VIP) receptors in high density. We have prepared a VIP analog ( TP3654), labeled it with (99m)Tc, and evaluated it in experimental animals as an agent for imaging colorectal cancer. The tissue distribution of (99m)Tc-TP3654 has been compared with that of (111)In-DTPA-Octreotide and (99m)Tc-anti-CEA scan in nude mice bearing human colorectal cancer LS174T. Finally, pharmacokinetic and tissue distribution studies of (99m)Tc-TP3654 have been performed in four normal human volunteers. Data suggest that (99m)Tc-TP3654 can be prepared efficiently without loss of its receptor specificity and biological activity. Although the 24 hr tumor uptake of (99m)Tc-TP3654 in the animal model used was modest (0.21 +/- 0.07% I.D./g), the tissue distribution profile was more favorable than that of (111)In-DTPA-Octreotide or (99m)Tc-anti-CEA scan. Human studies indicated that (99m)Tc-TP3654 had no adverse effect in any subject. Within 24 hours, approximately 70% of the injected dose cleared through the kidneys, and approximately 20% through the hepatobiliary system. In these non-fasting volunteers hepatobiliary clearance was slow and in cancer patients tumor uptake was rapid. Data suggest that (99m)Tc-TP3654 is a promising agent for imaging colorectal cancer.
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Authors | P S Rao, M L Thakur, V Pallela, R Patti, K Reddy, H Li, S Sharma, H L Pham, L Diggles, C Minami, C S Marcus |
Journal | Nuclear medicine and biology
(Nucl Med Biol)
Vol. 28
Issue 4
Pg. 445-50
(May 2001)
ISSN: 0969-8051 [Print] United States |
PMID | 11395318
(Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Indium Radioisotopes
- Oligopeptides
- Radiopharmaceuticals
- Receptors, Vasoactive Intestinal Peptide
- TP 3654
- Vasoactive Intestinal Peptide
- Technetium
- Octreotide
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Topics |
- Colorectal Neoplasms
(diagnostic imaging)
- Humans
- Indium Radioisotopes
- Kidney
(metabolism)
- Octreotide
(analogs & derivatives)
- Oligopeptides
(metabolism)
- Quality Control
- Radionuclide Imaging
- Radiopharmaceuticals
(metabolism)
- Receptors, Vasoactive Intestinal Peptide
(metabolism)
- Technetium
(chemistry)
- Tissue Distribution
- Vasoactive Intestinal Peptide
(metabolism)
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