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 (103mRh, T½ = 56.1 min) is a promising Auger electron emitter that can be obtained as the decay product of palladium-103 (103Pd, T½ = 16.99 days). 103Pd 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 103mRh. We hypothesize this to be through a combination of the Szilard-Chalmers effect and transient ionization. •[103Pd]PdCl2 was obtained by dissolving neutron irradiated 102Pd-enriched targets.•[103Pd]Pd was chelated by a 16aneS4-octyl derivative and trapped on a C18 support.•Elution of this generator provided 103mRh in excellent radiochemical purity.•The demonstrated generator will allow investigating 103mRh for Auger radiotherapy.