Magnetic Resonance and Nuclear Imaging Combined with Therapy of Tumours Using ~166Ho-loaded Particles

摘要

Introduction: Cancer treatment with holmium-166 (~166Ho) has obvious advantages over other radionuclides for therapeutic purposes. Namely, holmium is the only element which can be neutron-activated to both a beta- and gamma-emitter with a logistically favourable half-life, and can also be visualized by MRI (see Table 1) [1-3]. Holmium is an element from the group of lanthanides. The chemical characteristics of the lanthanides are dominated by their +3 oxidation state and their bonding is predominantly ionic in character. Therefore, it will be relatively easy to adapt holmium-loaded systems for specific treatment/diagnostic demands, when required. For treatment of unresectable liver tumours internal radiation therapy is thought to be a promising alternative [4]. During this therapy ~166Ho containing poly(L-lactic acid) microspheres (~166Ho-PLLA-MS) are administered into the hepatic artery. These microspheres should lodge in and around the tumour and irradiate the surrounding tissue. Promising results have been obtained with ~166Ho-PLLA-MS in rats [5].