A solid support generator of the Auger electron emitter rhodium-103m from [103Pd]palladium

Auger electron therapy is an attractive modality for targeting microscopic tumors. Rhodium-103 m (Rh-103m, T-1/2 = 56.1 min) is a promising Auger electron emitter that can be obtained as the decay product of palladium-103 (Pd-103, T-1/2 = 16.99 days). Pd-103 was chelated in a lipophilic derivative of the 16aneS4 macrocycle and the complex was trapped on a C18 cartridge. Elution with dilute hydrochloric acid gave radiochemically pure Rh-103m. We hypothesize this to be through a combination of the Szilard-Chalmers effect and transient ionization.