The innovative ${}^{52g}$Mn for PET imaging: production cross section modeling and dosimetric evaluation

Abstract

Background: Recently, the reaction ${}^{nat}$V($\hat{I}\pm$,x)${}^{52g}$Mn has been proposed as a possible alternative to the standard ${}^{nat}$Cr($p$,x)${}^{52g}$Mn one, but improvements in the modeling were needed to better compare the two production routes. Purpose: This work focuses on the development of precise simulations and models to compare the ${}^{52g}$Mn production from both reactions in terms of amount of activity and radionuclidic purity (RNP), as well as in terms of dose increase (DI) due to the co-produced radioactive contaminants, with respect to a pure ${}^{52g}$MnCl${}_2$ injection. Methods: The nuclear code Talys has been employed to optimize the ${}^{nat}$V($\hat{I}\pm$,x)${}^{52g}$Mn cross section by tuning the parameters of the microscopic level densities. Dosimetric assessments of [${}^{xx}$Mn]Cl${}_2$ have been accomplished with OLINDA software 2.2.0 using female and male phantoms. At the end, the yield of ${}^{xx}$Mn radioisotopes estimated for the two production routes have been combined with the dosimetric results, to assess the DI at different times after the end of the irradiation. Results: Good agreement was obtained between cross sections calculations and measurements. The comparison of the two reaction channels suggests that ${}^{nat}$V($\hat{I}\pm$,x)${}^{52g}$Mn leads to higher yield and higher purity, resulting in a less harmful impact on patients' health in terms of DI. Conclusions: Both ${}^{nat}$V($\hat{I}\pm$,x) and ${}^{nat}$Cr($p$,x) production routes provide clinically acceptable ${}^{52g}$MnCl${}_2$ for PET imaging. However, the ${}^{nat}$V($\hat{I}\pm$,x)${}^{52g}$Mn reaction provides a DI systematically lower than the one obtainable with ${}^{nat}$Cr($p$,x)${}^{52g}$Mn and a longer time window in which it can be used clinically (RNP $\ge$ 99\%).

19 pages, 5 figures, 6 tables