Update on Cyclotron Production Studies on NCA Radionuclides: Copper-64, Astatine-211, Rhenium-186g

Radionuclide production for biomedical applications has been studied in recent years at INFN-LASA Laboratory, in co-operation with the Cyclotron Laboratory of the Joint Research Centre (JRC Ispra, Italy), taking advantage of extensive experience in the experimental nuclear physics and nuclear chemistry fields. Several research aspects concerning radiation detection and the relevant instruments, the measurements of excitation functions of the involved nuclear reactions and the required radiochemistry methods have been investigated. The latest studies on high specific activity, accelerator-produced radionuclides in no-carrier-added (NCA) form, for use in therapeutic applications and in related SPET/PET diagnoses investigated, are: 1. NCA 64Cu, produced by natZn(d,alphaxn), natZn(d,2pxn) and 64Zn(d,2p) reactions for simultaneous beta+/beta- metabolic radiotherapy, with intrinsic PET imaging, including the short-lived radionuclide 61Cu; 2. 186gRe, produced by 186W(p,n) and 186W(d,2n) reactions, for bone metastases pain palliation by beta (1.1 MeV) metabolic radiotherapy, including SPECT imaging; 3. NCA 211At/211gPo, produced by the 209Bi(alpha,2n) reaction, with internal spike of the alpha emitter 210At from the 209Bi(alpha,3n) reaction (leading to very small amount of 210Po as radiotoxic long-lived impurity), for high-LET metabolic radio- and immuno-radiotherapy; Targets are irradiated at the Scanditronix MC-40 Cyclotron (K=40) of the JRC with proton or alpha beams up to 39 MeV, 3He2+ particle beam up to 53 MeV or deuteron beams up to 19.5 MeV. Activity measurements are performed either at JRC Ispra or at LASA Laboratory: gamma, X spectra are measured with HPGe detectors, alpha spectra with PIPS detectors with a resolution of 17 keV (FWHM), and beta spectra with a conventional liquid scintillation counting LSC and spectrometry system with Horrocks number capability for quenching correction, and a higher-resolution liquid scintillation portable spectrometer with alpha/beta pulse shape analysis (PSA) discriminator. In order to produce NCA radionuclides suitable radiochemical separation processes for the radionuclides of interest, together with quality control checks must be developed. The radiochemical separations adopted are presented for each radionuclide produced. In order to evaluate production feasibility or to confirm the cross sections experimentally obtained, calculations for the involved nuclear reactions are carried out with the EMPIRE-II code, taking into accounting the major nuclear reaction channels.JRC.I.4-Nanotechnology and Molecular Imagin