Abstract: A seed for implanting radioactive material within the living body of a recipient which contains radioactive material which emits therapeutic radiation to treat a specific localized area of the recipient's body. A capsule, which sealingly encloses the radioactive material, preventing contact with the recipient's body fluid and tissue, includes a generally cylindrical body portion having a pair of open ends. End members of a wall thickness substantially that of the cylindrical body close the open ends, and include an end wall and a generally tubular skirt portion extending therefrom. The skirt portion and the ends of the cylindrical body are deformably joined together by welding, crimping, peening or other cold flow metal treatment, to form a hermetic seal between the end cap and cylindrical body. Also disclosed is a cylindrical plug-like coupling member which joins the pair of seeds in end-to-end coaxial relationship.

Abstract: Particles or "seeds" are manufactured for implantation into tumors within a human body for emitting X-rays to destroy or reduce the tumors. The seeds contain palladium which is substantially enriched in palladium-102 and which is activated by exposure to neutron flux so as to contain a minor, but significant, fraction of X-ray-emitting palladium-103. The palladium is distributed on or throughout a base material so as to reduce self-shielding by the palladium. The seeds include an X-ray-opaque marker to facilitate external visualization of the seeds after their implantation, the marker preferably being formed of a material, such as lead or rhodium, which does not activate to contain undesirable isotopes under the radiation conditions in which palladium-102 is activated to palladium-103.