Glass microspheres
AssigneeThe Curators of the University of Missouri
InventorsDelbert E. Day, Gary J. Ehrhardt
Life of this patent
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Abstract
A radioactive microsphere for radiation therapy of a mammal comprising a biologically compatible glass material containing a beta or gamma emitting radioisotope distributed substantially uniformly throughout the glass. Advantageously, the radioisotope is produced by irradiation of the microsphere.
Claims8
A glass microsphere having a diameter of about 75 micrometers or less and adapted for radiation therapy of a mammal, said glass consisting essentially of an yttrium oxide-aluminosilicate glass composition lying substantially within a quadrilateral region of the ternary composition diagram of the yttria-alumina-silica system, the quadrilateral region being defined by its four corners having the following combination of weight proportions of the components:
- 20% silica, 10% alumina, 70% yttria;
- 70% silica, 10% alumina, 20% yttria;
- 70% silica, 20% alumina, 10% yttria;
- and 20% silica, 45% alumina, 35% yttria, the glass having a chemical durability such that subsequent to irradiation and administration of the microsphere to the mammal, the microsphere will not release a significant amount of yttrium-90 into the mammal's system.
Dependencies are inferred from the claim text.