Abstract: An implantable source (40) of therapeutic radiation for brachytherapy is provided as a sealed, biocompatible capsule (410) of plastic (e.g. polyethylene or PEEK) transparent to the radiation. The capsule contains a radiation source (400) comprising particles of a radioactive isotope (e.g. Pd103, I125, Cs131) in a fluid carrier that is resistant to radiation polymerization but solidifies at elevated temperature. It also has a marker (420), and desirably has a socket (430) which accommodates attaching spacers (660) and makes possible linear strands and planar arrays of the capsules. The spacers may be functional, e.g. heat-generating or medication-releasing.

Abstract: Therapeutic sources for use in the practice of brachytherapy are fabricated from radioactive composites of a radioactive powder of palladium-103, yttrium-90, phosphorus-32 or gold-198 and a biocompatible polymeric matrix. The particles of radioactive powder are dispersed within the polymer essentially randomly throughout a particular volume. The polymeric matrix is desirably manufactured with preselected flexibility suitable to its intended use, e.g. in the form of a rod, hollow rod, suture, film, sheet, or microspheroidal particles. The radioactive composites produce therapeutic sources which generate a radiation field that is substantially uniform in all directions. The therapeutic source may assembled from the radioactive composite during a medical procedure to emit the desired amount of therapeutic radiation. Optionally, the polymer is selected to dissolve or degrade in the body at a predetermined rate, the rate chosen depending upon the half life of the radioisotope used in the therapeutic source.

Abstract: A method and apparatus for precisely applying radioactive material to a substrate such as a brachytherapy device is disclosed. A radioactive fluid adapted to cure rapidly is deposited as discrete dots onto a surface with a fluid-jet printhead. The apparatus comprises a fluid-jet printhead in communication with a chamber containing radioactive fluid to be applied by the printhead. The printhead is microprocessor driven, and the microprocessor may be provided with feedback from a station where the radioactivity deposited on a preceding substrate in a batch is measured, permitting the system to be recalibrated on an ongoing basis as the batch of printed devices is produced. Compensation for attenuation of radiation by a casing may also be made part of the feedback technique. Also disclosed is a brachytherapy device having printed on a surface dots of radiation-emitting material, in a pattern comprising various bands, dots or areas.

Abstract: A method and apparatus for precisely applying radioactive material to a substrate such as a brachytherapy device is disclosed. A radioactive fluid adapted to cure rapidly is deposited as discrete dots onto a surface with a fluid-jet printhead. The apparatus comprises a fluid-jet printhead in communication with a chamber containing radioactive fluid to be applied by the printhead. The printhead is microprocessor driven, and the microprocessor may be provided with feedback from a station where the radioactivity deposited on a preceding substrate in a batch is measured, permitting the system to be recalibrated on an ongoing basis as the batch of printed devices is produced. Compensation for attenuation of radiation by a casing may also be made part of the feedback technique. Also disclosed is a brachytherapy device having printed on a surface dots of radiation-emitting material, in a pattern comprising various bands, dots or areas.

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.

Abstract: A tumorous patient is injected with a compound including an element that accumulates in tumors and that has an isotope which emits an alpha particle in a neutron capture reaction. The patient is positioned in front of a radiation beam that has been filtered to remove most neutrons having energies above 30 KeV and most thermal neutrons, leaving predominantly epithermal neutrons which are moderated to a thermal level by outer layers of tissue and are captured by the incorporated isotope.A radiation beam having neutrons with a wide distribution of energies is filtered with aluminum, sulfur and argon filters, whose cross sections complement each other in providing a beam with energies predominantly in the epithermal range. The filter mass attenuates the gamma radiation. Beams with lower ratios of undesirable gamma radiation to epithermal beam intensity can be attained with filter combinations which include liquid argon. A poor geometry filter of bismuth or lead can also improve the gamma to neutron ratio.

Abstract: A tumorous patient is injected with a compound including an element that accumulates in tumors and that has an isotope which emits an alpha particle in a neutron capture reaction. The patient is positioned in front of a radiation beam that has been filtered to remove most neutrons having energies above 30 KeV and most thermal neutrons, leaving predominantly epithermal neutrons which are moderated to a thermal level by outer layers of tissue and are captured by the incorporated isotope.A radiation beam having neutrons with a wide distribution of energies is filtered with aluminum and sulfur filters, whose cross sections complement each other in providing a beam with energies predominantly in the epithermal range. The filter mass attenuates the gamma radiation. Beams with lower ratios of undesirable gamma radiation to epithermal beam intensity can be attained with filter combinations which include liquid argon. A poor geometry filter of bismuth or lead can also improve the gamma to neutron ratio.

Abstract: Hydrogen is thermochemically produced from water in a cycle wherein a first reaction produces hydrogen iodide and H.sub.2 SO.sub.4 by the reaction of iodine, sulfur dioxide and water under conditions which cause two distinct aqueous phases to be formed, i.e., a lighter sulfuric acid-bearing phase and a heavier hydrogen iodide-bearing phase. After separation of the two phases, the heavier phase containing most of the hydrogen iodide is treated, e.g., at a high temperature, to decompose the hydrogen iodide and recover hydrogen and iodine. The H.sub.2 SO.sub.4 is pyrolyzed to recover sulfur dioxide and produce oxygen.

Abstract: Hydrogen is produced from water by reacting I.sub.2 SO.sub.2 and H.sub.2 O to make hydrogen iodide and sulfuric acid. SO.sub.2 is present in a substantial molar excess with respect to the available H.sub.2 O and I.sub.2 is also present in excess to cause the formation of a lighter sulfuric acid-bearing phase and a heavier hydrogen iodide-bearing phase. The heavier phase is separated from the lighter phase, degassed to remove SO.sub.2 and then treated with additional HI and I.sub.2 to cause the formation of a light immiscible fraction containing sulfuric acid and water which is removed to substantially reduce the sulfur content of the degassed phase. Finally, the hydrogen iodide product is separated and decomposed to produce hydrogen.

Abstract: A system for supporting a plurality of reflective surfaces in an arrangement for reflecting the rays emitted from a source of energy and converging the reflected rays to concentrate the heating effect thereof at a receptor, whereby a plurality of pairs of long tension members extend under tension between firmly anchored support members. Reflecting elements are supported by the pairs of tension members and each of the pairs is disposed to reflect the radiation from substantially all of the reflecting elements to the receptor.