Optimisation study of α-cyclotron production of At-211/Po-211g for high-LET metabolic radiotherapy purposes

The production of no-carrier-added (NCA) α-emitter 211At/211gPo radionuclides for high-LET targeted radiotherapy and immunoradiotherapy, through the 209Bi(α,2n) reaction, together with the required wet radiochemistry and radioanalytical quality controls carried out at LASA is described, through dedicated irradiation experiments at the MC-40 cyclotron of JRC-Ispra. The amount of both the γ-emitter 210At and its long half-lived α-emitting daughter 210Po is optimised and minimised by appropriate choice of energy and energy loss of α particle beam. The measured excitation functions for production of the main radioisotopic impurity 210At→210Po are compared with theoretical predictions from model calculations performed at ENEA.