Patent ID: 6099457
Filing Date: 2000-08-08
Classification: A61K,A61N,A61P,C23C,G21G,H01J,Y10T

Abstract:
A one-piece substantially spherical seamless multilayered radioactive seed, comprising:a microsphere including a central sphere and a layer section with no substantial voids between the central sphere and the layer section;said layer section including at least two layers concentric with the central sphere; said layer section being in intimate contact with the outer surface of the central sphere;said microsphere enclosing first material having a therapeutic amount of radioactivity and an outside diameter no greater than 1 millimeter;at least a first layer of said two layers enclosing said first material and containing a second material that reacts chemically with said first material; and at least a second layer containing a third material that forms a diffusion barrier to said first material.