S-11C-methyl-L-cysteine: a new amino acid PET tracer for cancer imaging
| Autor: | Xiaolan Tang, Huaifu Deng, Chang Yi, Fuhua Wen, Xinchong Shi, Ganghua Tang, Quanfei Meng, Hongliang Wang, Kening Wu |
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| Rok vydání: | 2011 |
| Předmět: |
Male
Quality Control Biodistribution Biological Transport Active Mice Nude Pharmacology Mice Non-competitive inhibition In vivo Glioma Cell Line Tumor Neoplasms medicine Animals Radiology Nuclear Medicine and imaging Tissue Distribution Whole Body Imaging Cysteine Radioactive Tracers Chromatography High Pressure Liquid chemistry.chemical_classification medicine.diagnostic_test Radiosynthesis Proteins medicine.disease In vitro Amino acid Mice Inbred C57BL chemistry Positron emission tomography Isotope Labeling Positron-Emission Tomography Female Radiopharmaceuticals Neoplasm Transplantation |
| Zdroj: | Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 52(2) |
| ISSN: | 1535-5667 |
| Popis: | S-(11)C-methyl-L-cysteine ((11)C-MCYS), an analog of S-(11)C-methyl-L-methionine ((11)C-MET), can potentially serve as an amino acid PET tracer for tumor imaging. The aim of this study was to investigate the radiosynthesis and perform a biologic evaluation of (11)C-MCYS as a tumor imaging tracer. The results of the first human PET study are reported.(11)C-MCYS was prepared by (11)C-methylation of the precursor L-cysteine with (11)CH(3)I and purification on commercial C18 cartridges. In vitro competitive inhibition experiments were performed with Hepa1-6 hepatoma cell lines, and biodistribution of (11)C-MCYS was determined in normal mice. The incorporation of (11)C-MCYS into tissue proteins was investigated. In vivo (11)C-MCYS uptake studies were performed on hepatocellular carcinoma-bearing nude mice and inflammation models and compared with (11)C-MET PET and (18)F-FDG PET. In a human PET study, a patient with a recurrence of glioma after surgery was examined with (11)C-MCYS PET and (18)F-FDG PET.The uncorrected radiochemical yield of (11)C-MCYS from (11)CH(3)I was more than 50% with a synthesis time of 2 min, the radiochemical purity of (11)C-MCYS was more than 99%, and the enantiomeric purity was more than 90%. In vitro studies showed that (11)C-MCYS transport was mediated through transport system L. Biodistribution studies demonstrated high uptake of (11)C-MCYS in the liver, stomach wall, and heart and low uptake of (11)C-MCYS in the brain. There was higher accumulation of (11)C-MCYS in the tumor than in the muscles. The tumor-to-muscle and inflammatory lesion-to-muscle ratios were 7.27 and 1.62, respectively, for (11)C-MCYS, 5.08 and 3.88, respectively, for (18)F-FDG, and 4.26 and 2.28, respectively, for (11)C-MET at 60 min after injection. Almost no (11)C-MCYS was incorporated into proteins. For the patient PET study, high uptake of (11)C-MCYS with true-positive results, but low uptake of (18)F-FDG with false-negative results, was found in the recurrent glioma.Automated synthesis of (11)C-MCYS is easy to perform. (11)C-MCYS is superior to (11)C-MET and (18)F-FDG in the differentiation of tumor from inflammation and seems to have potential as an oncologic PET tracer for the diagnosis of solid tumors. |
| Databáze: | OpenAIRE |
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