40 results about "Brachytherapy source" patented technology

A microwave hyperthermia apparatus that can be inserted into the body which includes a hollow central tube for the insertion of radioactive therapy sources. The use of a coaxial transmission line impedance transformation along the insertable portion of the coaxial cable enables a reduction in the characteristic impedance by increasing the outer diameter of the inner coaxial conductor so that the center conductor can be a metal tube. If the ratio of the outer coaxial conductor diameter vs. the inner coaxial conductor is decreased, the characteristic impedance of the transmission line is lowered. This enables the inner conductor diameter to increase sufficiently to make the central hollow opening large enough to receive standard radioactive sources therein. This provides for a good impedance match that improves microwave energy efficiency while at the same time permitting a large hollow center opening. The combination of the microwave antenna device and brachytherapy sources provides for enhanced effectiveness when the two treatments are delivered simultaneously or in close time proximity to each other.

Radioactive sources, preferably radioactive seeds, for use in brachytherapy comprising a radioisotope within a sealed biocompatible container, wherein at least one part of the outer surface of the container is grooved, preferably with a curved groove. The grooved outer surface is preferably substantially free from angularities. Such grooves enhance the echogenicity of the source using medical ultrasound at a greater range of angles to the ultrasound probe, thus enhancing the ultrasound visibility of the source. Preferred radioisotopes are palladium-103 and iodine-125.

Methods and devices for minimally-invasive delivery of radiation to the posterior portion of the eye including a cannula comprising a distal portion connected to a proximal portion and a means for advancing a radionuclide brachytherapy source (RBS) toward the tip of the distal portion; a method of introducing radiation to the human eye comprising inserting a cannula between the Tenon's capsule and the sclera of the human eye and emitting the radiation from the cannula on an outer surface of said sclera.

Methods and devices for delivering radiation to a target at a posterior portion of an eye using a brachytherapy-administering device adapted to be inserted into a suprachoroidal space of the eye including a brachytherapy source and a means of advancing the brachytherapy source from a storage position to a radiation position corresponding to a position in a distal portion of the device, positioning the device appropriately such that the distal portion of the device is in close proximity to the target, exposing the target to the brachytherapy source for a predetermined length of time then removing the device and closing incisions made during a surgical procedures to reach the suprachoroidal space of the eye.

Brachytherapy dose attributable to a brachytherapy source is computed for portions of a patient treatment volume corresponding to a pathological target volume and critical structures. Patient image data is accessed to derive a material voxel array. Multiple computation grids are derived. Primary particle fluence is computed for each first grid element using a ray tracing process from which a primary dose and a first scattered particle source are derived. Scattered particle fluence of the first scattered particle source is derived for each second grid element from which a secondary dose is derived. Each first grid element corresponds to a plurality of second grid elements. Primary dose and scattered dose combine to provide total dose at specific volumes. Brachytherapy source models and non-anatomical body surface models may be applied as applicable.

The present invention also features a brachytherapy system comprising a spiral cut tube having a first end and a second end; a radioactive brachytherapy source (RBS) disposed on the first end of the spiral cut tube; and a handle and a generally hollow cannula disposed on the handle, wherein a channel is disposed in the handle aligned with the hollow cannula, and the spiral cut tube and RBS are adapted to slide within the channel and the hollow cannula.

Therapeutic sources for use in the practice of brachytherapy comprise a radioactive composite that includes (a) a polymeric matrix and (b) a radioactive powder, e.g. Pd-103 or I-125, consisting essentially of very fine radioactive particles that are randomly and essentially uniformly dispersed within the polymeric matrix. The composite may be in the shape of one or more solid cylindrical rods surrounded by a non-radioactive sleeve. Alternatively it may be a hollow rod, suture, film, sheet, or microspheroidal particles. The composite may be shaped by molding, extrusion or other methods, may be made with a flexibility suitable to its intended use or may be encapsulated in a metallic capsule.

A radiation protection system for shielding medical personnel from a gamma ray source being used to provide brachytherapy to a patient is provided by disposing shielding material between the source of radiation and locations outside the radiation protection system in such a manner as to provide shielding for the primary radiation in directions from which radiation from the source may emerge, while providing the patient an open viewing area with a large field of view for the patient to view the locations outside the radiation protection system. The described system reduces the radiation exposure of staff in the treatment room, thereby permitting physicians and therapists to observe the patient without being exposed to excessive amounts of radiation. The opening in the radiation protection system around the head of the patient provides the ability for the patient to see his surroundings and to eliminate the anxiety resulting from the feeling of being closed in.

A system, method, and computer program product of clinical treatment planning implements complex Monte Carlo (MC) based brachytherapy dose distributions using conventional brachytherapy treatment planning systems (TPS). Dose distributions from complex brachytherapy source configurations determined with MC methods are used as inputs. Radial dose functions and 2D anisotropy functions are obtained by positioning the coordinate system origin along the dose distribution cylindrical axis of symmetry. Origin to tissue distance and active length are chosen to minimize TPS interpolation errors. A 2D anisotropy function is determined, and a brachytherapy dose rate constant is selected. A virtual brachytherapy source dose distribution is calculated based upon the complex treatment configuration. Additional dosimetry parameters may be considered as well, and dose distributions may be calculated and compared to the original MC-derived dose distributions. The present techniques may calculate dose to a specific tissue type instead of dose to water as used in the TG-43 formalism

In cancer brachytherapy treatment, a small californium-252 neutron source capsule is attached to a guide cable using a modified crimping technique. The guide cable has a solid cylindrical end, and the attachment employs circumferential grooves micromachined in the solid cable end. The attachment was designed and tested, and hardware fabricated for use inside a radioactive hot cell. A welding step typically required in other cable attachments is avoided.

The present invention provides a method of preparing Cesium-131 (Cs-131) as a dispersed radioisotope. Uses of the dispersed Cs-131 prepared by the method include cancer research and treatment, such as for the use in brachytherapy. Cs-131 is particularly useful in the treatment of faster growing tumors.

The invention relates to a method for producing a radioactive brachytherapy source material comprising indium-114m in radioactive equilibrium with indium-114 as main radioactive isotopes. A new radioactive brachytherapy source material comprises indium-114m in radioactive equilibrium with indium-114 as main radioactive isotopes. A new encapsulated radioactive brachytherapy source comprises the new radioactive brachytherapy source material.

The radial dose function of an electronic x-ray brachytherapy source is flattened by filtering with transition metals in the fourth row of the periodic table, i.e. titanium through nickel. Titanium-walled applicator devices of small diameter, under 10 mm, and with wall thicknesses of about 0.2 mm to 0.6 mm, are disclosed. The walls can be of titanium or alloys thereof, providing adequate strength and flattening the radial dose function curve particularly for x-rays in an energy range of about 45 kV to 55 kV.

Radioactive sources are manufactured for treating a tumor or cancerous area occurring around a conduit or duct in the body by emitting X-rays to destroy or reduce the tumors. The sources contain ytterbium which is substantially enriched in ¹⁶⁸Ytterbium and which is activated by exposure to neutron flux so as to contain a minor, but significant, fraction of X-ray and gamma-emitting ¹⁶⁹Ytterbium. The radioactive ¹⁶⁹Ytterbium source is inserted through a catheter or applicator or needle to the site of the cancer where it is maintained in position for a period of time to reduce the occurrence of cancer. The ytterbium also acts as an X-ray-opaque marker to facilitate external visualization of the sources during their delivery to the treatment site. The sources are encased in a shell to prevent direct contact of the radioactive material with human tissue. This encapsulation may be formed by welding a pair of end caps to a tubular member.

The present invention discloses a methodology for the characterization and determination of mixed-field dosimetry for ²⁵²Cf Applicator Tube (AT)-type medical sources, utilizing ionization chambers, GM counters, and Monte Carlo methods. Unlike the previous methodologies, the present invention discloses a specification of dose to muscle, rather than dose to water, for clinical dosimetry of ²⁵²Cf medical sources. A dosimetry protocol, similar to that utilized for ICRU-45, with parameters determined specifically for ²⁵²Cf brachytherapy is disclosed. Neutron isodose distributions and data necessary for clinical implementation of ²⁵²Cf AT sources are also disclosed herein. Additionally, novel methods for the encapsulation, storage, and delivery/implantation of ²⁵²Cf radionuclide sources are disclosed.

Methods and devices for minimally-invasive delivery of radiation to the posterior portion of the eye including a cannula comprising a distal portion connected to a proximal portion and a means for advancing a radionuclide brachytherapy source (RBS) toward the tip of the distal portion; a method of introducing radiation to the human eye comprising inserting a cannula between the Tenon's capsule and the sclera of the human eye and emitting the radiation from the cannula.

A brachytherapy source delivery device includes a first tissue-piercing leg having proximal and distal ends, a second tissue-piercing leg having proximal and distal ends, wherein the proximal ends of the first and second tissue-piercing legs are joined at a span section in a first angular orientation with respect to each other, and a carrier element formed at, or attached to, the span section, the carrier element configured to support a radioactive brachytherapy source. The distal ends of the first and second legs can be curved inward toward each other to pierce a tissue when engaged toward each other into a closed position. The first and second tissue-piercing legs can be formed of a wire having a circular cross-sectional or non-circular cross-sectional shape. The carrier element can be tangentially attached to the span section. Each of the legs have a length that is greater than the length of the span section.