47Sc production: comparison of the natV(p,x) and 48Ti(p,x) routes from the dosimetric point of view

The radionuclide 47Sc is a promising candidate for the development of theranostic radiopharmaceuticals,although its availability is currently low. .Yields of 47Sc produced through proton irradiation of both natV and 48Ti targets at energies EP ≤ 40 MeV were compared in this work. The co-production of other Sc radioisotopes and their contribution to the dose increment (DI) to the patient, by considering a DOTA-folate conjugate (47Sc-cm10)2 as an example of radiopharmaceutical, were also evaluated. About natV target, both 48Sc and 46Sc are co-produced, causing a decrease of the Radio Nuclidic Purity (RNP) over time and an increase of the dose to the patient. For EP ≤ 35 MeV and 24 h irradiation, the RNP is >99% and the DI is <10% up to tmax=60 h after the End of Bombardment (EOB). Increasing the irradiation time to 80 h, the 47Sc yield becomes almost a factor 3 higher, however tmax reduces to 30 h. About 48Ti target, 46Sc, 44mSc, 44gSc and 43Sc contaminants are produced and, in all the considered scenarios, the RNP is initially very low. For EP ≤30 MeV, the RNP increases, up to achieving 99% about 1500 h (almost 20 half-time of 47Sc) after the EOB. In conclusion, despite the 47Sc yield obtained by irradiation of 48Ti is larger when compared to the use of natV targets, its RNP is not suitable for medical applications.