Automated Production of No Carrier Added Holmium-166

Abstract

Holmium-166 (166Ho) is used in radiotherapeutic applications such as radioimmunospecificpharmaceuticals, bone marrow ablation and radiation synovectomy andcan be produced with moderate specific activity by the 165Ho[n,g]166Ho reaction. Higherspecific activity carrier-free 166Ho can be obtained from the decay of dysprosium-166(166Dy), produced by the double neutron capture reaction 164Dy[n,g]165Dy[n,g]166Dy. 166Hocan be separated from 166Dy by reverse phase ion exchange chromatography in highradionuclidic purity. An automated system has been developed to process the irradiateddysprosium oxide (Dy2O3) targets, carry out HPLC separation and deliver 166Ho in a formsuitable for radiolabelling proteins and pharmaceuticals.