| 主权项 |
1. A radioactive low density microparticle for radioimaging or radiation therapy of a mammal comprising a biologically compatible magnesium-alumina-silicate glass microparticle having a density of about 3.0 g/cc or less said microparticle containing at least one beta or gamma radiation emitting isotope distributed substantially throughout the magnesium-alumina-silicate glass which emits a therapeutic intensity and amount of beta or gamma radiation, and a balance of elements selected from the group consisting of elements that do not become radioactive upon neutron irradiation and elements that have a half-life that is sufficiently short so that the elements do not emit a significant amount of beta or gamma radiation at the time of administration, the microparticle having a chemical durability such that subsequent to administration of the microparticle to the mammal, the microparticle will not release a significant amount of the radiation emitting radioisotope into the mammal's system;
wherein the glass microparticle comprises 8-14 wt % MgO, 32-35 wt % Al2O3, and 47-52 wt % SiO2. |
