PET / CT is a device that combines the features of diagnostic nuclear medicine (PET) and Radiology (CT) images superimposed metabolic (PET) and anatomical (CT). By combining the two technologies examinations, the PET/CT scan allows physicians to diagnose more accurately and identify cancer, heart disease and brain disorders. In Brazil, the prostate cancer is the second leading cause of cancer death among men, second only to lung cancer. The design of 18F-FAc (fluoroacetate) aims its production and its application in detection of primary tumors of prostate and breast, using PET-CT (positron emission computed tomography) techniques. Recent studies are showing the efficacy of the 18F-FAc in the detection of tumors that have low uptake of 18F-FDG (fluorodeoxyglucose). The fluoroacetate is a substrate for the enzyme acetyl-CoA synthase that metabolizes acid fluorcitrate that, not being metabolized, causes inhibition of aconitase and inhibition of tricarboxylic acid. The overexpression of FAZ (fatty acid synthase) is shown in many cancers, especially in prostate cancer where the degree of overexpression is related to tumor aggressiveness. The aim of this paper is to present the initial results of the project for the production of 18F-acetate at IPEN-CNEN/SP, an agreement with Hospital A.C.Camargo/ São Paulo. The 18F-fluoride ion was produced using the Cyclone 30 and 18 cyclotrons from IBA located at IPEN-CNEN/SP, by irradiating enriched 18O water with protons. The integrated dose was 30μAh. The labelling of 18F-FAc was performed in a synthesis module TRACERlab MXFDG (Ge), using kits purchased from ABX The radiochemical quality control of 18F-FAc was performed by Thin Layer Chromatography using TLC-SG 25 aluminium sheets strips (1.5 x 12 cm) and chloroform:methanol (1:1) as the solvent. For the radionuclidic quality control, samples of 18F-FAc and 18F-Fluoride were analysed by gama-ray spectroscopy. The evaluation of the residual solvents was performed by gas chromatography and the analysis of kryptofix was performed by TLC using TLC-SG strips, methanol:chloroform (9:1) as solvent and kryptofix 2.2.2 standards. Biodistribution studies were performed with 18F-FAc injected into healthy Swiss mice. This study will also be carried out in animals inoculated with tumor cells. A reliable procedure was developed for preparation of 18F-FAc with a labelling yield of 37% (uncorrected) and 52% (decay corrected) and stability of 19 hours. The quality control analysis showed that the product had the proper requirements for use. The biodistribution studies in healthy animals showed the expected uptake results in all the measured organs and they will be further compared with the results from the animals with tumor.

Instituição: IPEN-Instituto De Pesquisas EnergéTicas E Nucleares; Hospital AC-Camargo