ABSTRACT
The PET tracer 5-([11C]methyloxy)-L-tryptophan (5-(11)CMTP) was prepared by nucleophilic fluorination and alkylation reaction via a two-step procedure in order to develop specific tumor probe. The biodistribution and microPET imaging of 5-(11)CMTP were executed. The results unveiled that the overall radiochemical yield with no decay correction was (14.6 ±7.2) %, the radiochemical purity was more than 95% and high uptake and long retention time of 5-(11)CMTP in liver, kidney and blood were observed but low uptake in brain and muscle were found, furthermore, high uptake of 5-(11)CMTP in tumor tissue was observed. It seems that 5-(11)CMTP will be a potential amino acid tracer for tumors imaging with PET.
Subject(s)
Animals , Amino Acids , Neoplasms , Diagnostic Imaging , Positron-Emission Tomography , Radioactive Tracers , Tissue Distribution , TryptophanABSTRACT
OBJECTIVE: To develop 5-(3-fluoropropyloxy)-L-tryptophan(5-18FPTP)as a new amino acid positron emission tomography (PET) tracer for the differentiation of tumor and inflammation. METHODS: 5-18FPTP was prepared by nucleophilic fluorination and alkylation reaction via a two-step procedure. Twenty mice were divided into five groups randomly and the biodistribution of 5-18FPTP in normal mice was determined at different time after injecting the tracer by tail vein. Also, two mice bearing tumor and inflammation received PET imaging at 60 min after injecting the tracer to detect the uptake of the tracer in tumor and inflammatory tissue. RESULTS: The overall synthesis time of 5-18FPTP was about 60 min, the overall radiochemical yield with no decay correction was (21±4.6)%, and the radiochemical purity was more than 95%. High uptake and long retention time of 5-18FPTP in liver, kidney and blood were observed. But low uptake in brain and muscle were found. Furthermore, high uptake of 5-18FPTP in tumor but almost no uptake of 5-18FPTP in inflammatory tissue were observed. CONCLUSION: 5-18FPTP is easy to prepare and can be used to differentiate tumors and inflammatory tissues. It seems to be a potential amino acid tracer for tumor imaging with PET.
ABSTRACT
<p><b>OBJECTIVE</b>To study the biodistribution of L-[S-methyl-(11)C]-methioine ((11)C-MET) and explore its clinical application in positron emission tomography (PET) for brain tumor detection.</p><p><b>METHODS</b>Twenty-four Wistar rats and divided into 6 equal groups and injected with (11)C-MET through the tail vein and killed by decollation at 5, 10, 20, 30 and 40 min after injection, respectively. The liver, brain, blood, heart, lung, kidney, and spleen were harvested to measure the radioactivity and calculate the biodistribution of (11)C-MET. PET imaging with (11)C-MET was performed in 6 normal volunteers and 30 patients with pathologically confirmed brain gliomas.</p><p><b>RESULTS AND CONCLUSION</b>(11)C-MET showed high blood uptake and a long retention in the tumor mass, therefore can be a valuable tracer for PET imaging of brain tumor and the hypophysis.</p>