Abstract: A system for delivering therapeutic radiation, such as x-rays, to a treatment region includes a plurality of individually controllable therapeutic radiation sources. The therapeutic radiation sources are selectively and moveably disposed along one or more axes, or upon a two-dimensional surface, or within a three-dimensional volume, so as to form a one-dimensional or a multi-dimensional array. Each therapeutic radiation source includes an electron source for emitting electrons, and an associated target element adapted to emit therapeutic radiation in response to incident electrons. In one embodiment, each therapeutic radiation source is coupled to a distal end of an associated optical delivery structure, which is adapted to direct a beam of optical radiation to impinge upon a surface of the electron source so as to cause emission of electrons therefrom.

Abstract: A therapeutic radiation source includes a spiral-shaped, laser-heated thermionic cathode. A fiber optic cable directs a beam of radiation, having a power level sufficient to heat at least a portion of the electron-emissive surface to an electron emitting temperature, from a laser source onto the cathode. The cathode generates an electron beam along a beam path by thermionic emission, and strikes a target positioned in its beam path. The target includes radiation emissive material that emits therapeutic radiation in response to incident accelerated electrons from the electron beam. The spiral-shaped conductive element has a plurality of spaced apart turns, and is disposed in a vacuum. An interstitial spacing is defined between adjacent turns, so that heat transfer across the spacing between each adjacent turn is essentially eliminated, thereby substantially reducing heat loss in the cathode caused by thermal conduction.

Abstract: A miniaturized, optically driven therapeutic radiation source operates at significantly reduced power levels. The apparatus includes a laser-driven thermionic cathode, a target element, a probe assembly, and a laser source. The probe assembly includes an optical delivery structure, such as a fiber optic cable, that directs a laser beam from the laser source to impinge upon a surface of the thermionic cathode, heating the surface to a temperature sufficient to cause thermionic emission of electrons. The emitted electrons form an electron beam along a beam path. The target element is positioned in the beam path, and includes means for emitting therapeutic radiation, such as x-rays, in response to incident accelerated electrons from the electron beam. Reflector elements may be included to reflect unabsorbed laser radiation back to the thermionic cathode.

Abstract: A therapeutic radiation source includes a optically heated thermionic cathode that is shaped so as to maximize the coupling efficiency of the incident optical radiation to the thermionic cathode. A fiber optic cable directs a beam of radiation, having a power level sufficient to heat at east a portion of the electron-emissive surface to an electron emitting temperature, from a laser source onto the cathode. An electron beam generated by said cathode strikes a target which is positioned in its beam path and which emits therapeutic radiation in response to incident accelerated electrons from the electron beam. The thermionic cathode has a non-planar configuration, such as a conical shape and a concave shape, adapted to allow an incident ray of optical radiation to impinge upon, and undergo absorption from, a plurality of regions within the surface of the cathode in succession.

Abstract: The invention is directed toward an X-ray treatment kit to be used in an X-ray treatment apparatus. The X-ray treatment kit includes at least one of an improved biocompatible sheath or an improved probe, wherein an airflow path is maintained between the sheath and probe to allow air present within a void region of the sheath to escape as the probe is inserted therein. In various embodiments, the sheath includes a securing assembly which removably secures the sheath to the probe and provides an airflow path, e.g. an internally disposed annular ring with air shunts. Such a sheath may be used with a typical smooth probe to form an X-ray treatment kit. In other embodiments, an improved probe includes an air channel formed substantially along its length. In such a case, the improved probe may be used with a typical sheath, i.e., a sheath having a solid annular ring at its open end, to form an X-ray treatment kit.

Abstract: A radiation applicator system is structured to be mounted to a radiation source for producing a predefined dose of radiation for treating a localized volume of tissue, such as the tissue surrounding the site of an excised tumor. The applicator system includes an applicator and, in some embodiments, an adapter. The adapter is formed for fixedly securing the applicator to a radiation source, such as the x-ray source of a radiosurgery system which produces a predefined radiation dose profile with respect to a predefined location along its radiation producing probe. The applicator includes a shank and an applicator head, wherein the head is located at a distal end of the applicator shank. A proximate end of the applicator shank couples to the adapter. A distal end of the shank includes the applicator head, which defines a concave treatment surface for engaging and, preferably, supporting the area to be treated with a predefined does of radiation.

Abstract: This invention is directed to a radiation source comprising a power supply, a flexible fiber optic cable assembly, a light source, and a target assembly. The power supply includes a first terminal and a second terminal, and elements for establishing an output voltage between the first terminal and the second terminal. The flexible fiber optical cable assembly has an originating end and a terminating end, and includes a fiber optical element extending from the originating end to the terminating end. The cable is adapted for transmitting light incident on the originating end to the terminating end. The light source includes elements for generating a beam of light at and directed to the originating end of the fiber optical cable assembly. The target assembly is affixed to the terminating end of the fiber optical cable assembly and is electrically coupled to the power supply by way of the first terminal and the second terminal.

Abstract: A support system for a radiation treatment system includes a rotatable extension arm extending from a vertical shaft and a rotatable counterbalance extending diametrically opposed to the extension arm from the vertical shaft. The vertical shaft is rotatably supported by a support base. The support base may include a damping mechanism to damp the rotational motion of the vertical shaft relative to the support base, wherein the damping force is preferably proportional to the velocity of the vertical shaft. The radiation treatment system is suspended from a cable extending from a distal end of the extension arm. The extension arm can be formed from a first arm extending from the vertical shaft and a second arm rotatably coupled to the first arm in order to permit the radiation treatment system to be moved in horizontal direction. The cable supporting the radiation treatment system can be coupled to a vertical counterbalance weight to allow the vertical position of the radiation treatment system to be adjusted.

Abstract: A radiation applicator system is structured to be mounted to a radiation source for producing a beam of radiation for treating a localized volume of tissue, such as growing blood vessels in the eye that can cause macular degeneration. The applicator system includes an applicator and, in some embodiments, an adapter. The adapter is formed for fixedly securing the applicator to a radiation source, such as a radiosurgery system which produces a predefined radiation dose profile with respect to a predefined location along the radiation producing probe. The applicator includes a shank and an applicator head. A proximate end of the applicator shank couples to the adapter. A distal end of the shank includes the applicator head, which is adapted to produce a beam of radiation. The applicator head includes a radiation shield and a beam collimator. The radiation shield selectively blocks the emitted radiation so that the applicator can be held by a surgeon during treatment.

Abstract: A radiation applicator system is structured to be mounted to a radiation source for providing a predefined dose of radiation for treating a localized volume of tissue, such as the tissue surrounding the site of an excised tumor. The applicator system includes an applicator and, in some embodiments, an adapter. The adapter is formed for fixedly securing the applicator to a radiation source, such as a radiosurgery system which produces a predefined radiation dose profile with respect to a predefined location along its radiation producing probe. The applicator includes a shank and an end cap, wherein the end cap includes a substantially flat or convex treatment surface and is located at a distal end of the applicator shank. A proximate end of the applicator shank couples to the adapter. A distal end of the shank includes the end cap, which is adapted for engaging and preferably supporting the area to be treated with a predefined does of radiation.

Abstract: The invention is directed toward an X-ray treatment kit to be used in an X-ray treatment apparatus. The X-ray treatment kit includes at least one of an improved biocompatible sheath or an improved probe, wherein an airflow path is maintained between the sheath and probe to allow air present within a void region of the sheath to escape as the probe is inserted therein. In various embodiments, the sheath includes a securing assembly which removably secures the sheath to the probe and provides an airflow path, e.g. an internally disposed annular ring with air shunts. Such a sheath may be used with a typical smooth probe to form an X-ray treatment kit. In other embodiments, an improved probe includes an air channel formed substantially along its length. In such a case, the improved probe may be used with a typical sheath, i.e., a sheath having a solid annular ring at its open end, to form an X-ray treatment kit.

Abstract: A modular multistage accelerator for use in an X-ray treatment system includes a first 10 kV acceleration stage which houses an electron beam gun supplied with −50 kV of voltage. The modular multi-stage accelerator includes four additional 10 kV stages placed in series with the first stage to achieve a 50 kV accelerator overall. Each stage is shielded to prevent stray electrons from being propagated along the length of the drift tube. The triple point within each modular stage is recessed to significantly reduce the emission of stray electrons within each stage. Additionally, the beam current at the X-ray emitting probe of the X-ray source is measured by isolating the beam current to a beam current measuring circuit in electrical connection with a nulling junction node, wherein other currents within the circuit are nulled at the nulling junction node and the beam current flows to the beam current measuring circuit.

Abstract: This invention is directed to a radiation source comprising a power supply, a flexible fiber optic cable assembly, a light source, and a target assembly. The power supply includes a first terminal and a second terminal, and elements for establishing an output voltage between the first terminal and the second terminal. The flexible fiber optical cable assembly has an originating end and a terminating end, and includes a fiber optical element extending from the originating end to the terminating end. The cable is adapted for transmitting light incident on the originating end to the terminating end. The light source includes elements for generating a beam of light at and directed to the originating end of the fiber optical cable assembly. The target assembly is affixed to the terminating end of the fiber optical cable assembly and is electrically coupled to the power supply by way of the first terminal and the second terminal.

Abstract: An X-ray source interlock kit includes a probe-based portion integral with an X-ray source in communication with a peripheral-based portion, the interlock kit serving as an interface between an X-ray treatment system and a given class of peripheral devices. Peripheral devices are classified based on their shielding characteristics and whether or not radiation is permitted with the device, and include, for example, a stereotactic frame, a probe adjuster, and a photodiode array. The probe-based portion includes a probe side bushing having two optical source-detector pairs housed therein and interlock electronics, which accomplish signal processing as required. The peripheral-based portion is the form of a peripheral side bushing which is coded with the shielding and radiation information for a given class of peripheral devices.

Abstract: A modular multistage accelerator (102) for use in an X-ray treatment system includes a first 10 kV acceleration stage (120) which houses an electron beam gun supplied with -50 kV of voltage. The modular multi-stage accelerator includes four additional 10 kV stages (112,114,116,118) placed in series with the first stage to achieve a 50 kV accelerator overall. Each stage is shielded (190) to prevent stray electrons from being propagated along the length of the drift tube. The triple point within each modular stage is recessed to significantly reduce the emission of stray electrons within each stage. Additionally, the beam current at the X-ray emitting probe of the X-ray source is measured by isolating the beam current to a beam current measuring circuit (220) in electrical connection with a nulling junction node, wherein other currents within the circuit are nulled at the nulling junction node and the beam current flows to the beam current measuring circuit.

Abstract: A phantom apparatus for measuring the radiation dose distribution produced by a brachytherapy device used to treat a localized area with radiation. The brachytherapy device includes an insertable probe capable of producing predefined radiation dose geometries about a predefined point. The phantom apparatus includes a tank containing a medium having a radiological equivalent characteristic of the localized area to be treated. The phantom apparatus also includes a radiation sensor for measuring the radiation dose and a positioning system for moving the probe with respect to the radiation sensor. The radiation sensor is also coupled to a positioning system to orient the sensor for optimal dose measurements. The phantom apparatus includes a control system that coordinates the movements of the probe and the radiation sensor to avoid a collision. The control system moves the probe along a predefined path around radiation sensor and records the dose at predefined points along the path.

Abstract: A system is disclosed for producing images representing radiation dose distributions in order to verify the radiation dose applied to a target area. The system uses a phantom assembly constructed of material that is the radiological equivalent of live tissue. The phantom assembly has slits where radiation sensitive film can be inserted and can include a channel for an insertable radiation generating device. The treatment dose is then applied to the phantom and the radiation sensitive film records the dose. A CCD camera microdensitometer is then used to read the exposed radiation sensitive film. The CCD camera microdensitometer includes a computer system which processes the image to remove artifacts and generates isodose contours for the radiation treatment applied. In addition, several pieces of radiation sensitive film in different planes can be exposed and processed in order to produce images representing the radiation dose distribution in three dimensions.

Abstract: The present invention is directed to an x-ray source for irradiating a surface defining a body cavity in accordance with a predetermined dose distribution. The source comprises a housing, an elongated tubular probe, a target assembly, and an inflatable balloon. The housing encloses an electron beam source and includes elements for generating an electron beam along a beam path. The tubular probe extends along a central axis from the housing about the beam path. The target assembly extends along the central axis and is coupled to the end of the probe distal from the housing. The target assembly includes a target element is positioned in the beam path. The target element is adapted to emit x-rays in response to electrons incident thereon from the beam. The probe tip assembly and associated control electronics include elements for positioning the target element in the beam path, and is substantially x-ray transparent.

Abstract: The present invention is directed to a kit for delivering x-rays to the interior surface of a body cavity. The kit includes an x-ray source and an x-ray source guidance tube. The guidance tube includes an inflatable inelastic balloon disposed about and affixed at its distal end such that when inflated, the central axis of the balloon is coaxial with and is disposed about the central axis of the tubular element. Inflation and deflation of the balloon is controllable from the proximal end of the tubular element. The x-ray source may include an electron activated target for generating x-rays in response to electrons incident on the target. The x-ray source may also includes means for generating an electron beam and steering the beam so that it is incident on the target. The target end is slidably positionable within an interior channel of the source guidance tube.

Abstract: A method of treating brain tumors in a patient, comprising the steps of: identifying and locating a brain tumor in vivo; implanting at least a portion of an adjustable x-ray source in the patient proximate to the tumor, where the x-ray source generates an electron beam along a path on or slightly offset from a central axis to an x-ray emitting target element; and controlling the x-ray source to generate an x-ray pattern to selectively irradiate the tumor. Also disclosed is a method and apparatus for detecting certain x-ray photons generated by the x-ray source and propagating back on a path which is along or slightly off-set from the central axis of the implanted radiation source.