o-(2-fluoroethyl)tyrosine and Sarcoma-180

To develop S-(2-18F-fluoroethyl)-L-methionine (18FEMET) as an amino acid positron emission tomography (PET) tracer for tumors, and to evaluate the value of 18FEMET in the differentiation of experimental tumor and experimental inflammation.. 18FEMET was prepared by nucleophilic fluorination reaction via a two-step procedure. Biodistribution of 18FEMET in normal mice, carcinoma-bearing mice and inflammatory mice, and 18FEMET PET imaging for carcinoma-bearing mice and inflammatory mice were performed compared with 2-[18F] fluoro-2-deoxy-D-glucose (FDG) and O-(2-[18F] fluoroethyl)-L-tyrosine (FET).. The overall radiochemical yield with no decay correction was 15%-25%, the whole synthesis time was about 70 min by manual operation, and the radiochemical purity was above 95%. High uptake and long retention of 18FEMET in pancreas, kidney, colon, liver and heart were observed. But low uptakes in brain and blood were found. Furthermore, high uptake of 18FEMET, FDG and FET in tumor, high uptake of FDG in inflammatory tissue, and almost no uptake of 18FEMET and FET in inflammatory tissue were also observed.. 18FEMET is easy to prepare and can be used to differentiate between tumor and inflammatory tissue. It seems to be a potential amino acid tracer for tumors with PET imaging.

Topics: Animals; Fluorodeoxyglucose F18; Inflammation; Methionine; Mice; Neoplasm Transplantation; Radiopharmaceuticals; Sarcoma 180; Tissue Distribution; Tomography, Emission-Computed; Tumor Cells, Cultured; Tyrosine

To develop a 18F-labeled amino acid, O-(2-[18F]fluoroethyl) - L-tyrosine(18F-FET), as a positron emission tomography (PET) tracer for imaging cerebral tumors.. 18F-FET was synthesized. Preclinical studies including sterility, endotoxin, and toxicity tests were performed. Two brain tumor cases were studied using 18F-FET and compared with 18F-FDG.. Radiochemical purity of 18F-FET was over 95% which remained stable for 6 hours. The 18F-FET injection was sterile and its endotoxin content accorded with the standards of Chinese Pharmacopoeia. The uptake of 18F-FET in the normal brain tissues was significantly lower than that of the tumor, and the images of the brain tumor were clearer than those of 18F-FDG.. 18F-FET can accumulate in the tumor tissues to give high quality images. It suggests that 18F-FET may be a safe and effective tracer for brain tumor imaging.

Topics: Adult; Animals; Brain Neoplasms; Female; Fluorine Radioisotopes; Fluorodeoxyglucose F18; Glioblastoma; Humans; Male; Mice; Middle Aged; Sarcoma 180; Tomography, Emission-Computed; Tyrosine