FDG-EGF-frag (¹⁸F): development, characterization and dosimetric evaluation

The Epidermal Growth Factor and its receptor have an important role in regulation of cell proliferation and differentiation, and a direct relationship with cancer development, being interesting the development of a radiotracer for this receptor. The present work presents the development of a new radiotracer, ¹⁸F-FDG-EGF-frag, and a female mouse dosimetric model to evaluate the developed radiotracer. A protocol for manual synthesis of peptide was developed, as well as analysis and purification methods for the synthesized peptide. Protocols were also developed for the modification of the ¹⁸F-Fludeoxyglucose molecule, aiming at the radiofluorination of the synthesized peptide, and for analysis of the synthesized prosthetic group. A protocol for radiolabel the peptide synthesized, using the keto-¹⁸F-FDG prosthetic group, was also developed, along with purification and analysis methods for radiochemical identification and purity and residual solvents. The biodistribution of the synthesized radiotracer was evaluated in healthy mice and the generated data were used for dosimetric evaluation performed in a homemade dosimetric model. The viability of the dosimetric model was evaluated using data from the biodistribution of the radiopharmaceutical ¹⁸F-Fluorestradiol and compared with data already existing in the literature. The synthesis protocols developed proved to be effective for the intended use, obtaining products with satisfactory yield and high purity. The analysis, purification and quality control methods created were efficient in the identification and quantification of the analyzed compounds, being able to identify process deviations when they occur. The radiotracer showed slow biodistribution and predominant enterohepatic excretion, with higher dose absorption in organs related to this type of excretion. The dosimetric model built was able to reproduce data from the literature for the radiopharmaceutical ¹⁸F-Fluorestradiol, crediting the results obtained in the dosimetric analysis performed for the developed radiotracer. (author)