Abstract: A radio frequency annular phased array hyperthermia system providing a relatively small heated focal zone in a relatively large tissue mass includes a plurality of radio frequency energy applicators in at least one ring adapted to surround the relatively large tissue mass. A bolus having a dielectric constant is positioned between the energy applicators and the tissue mass. The energy applicators operate at a frequency high enough to create the relatively small heated focal zone. The spacing between adjacent applicators in the at least one ring is less than a critical distance and spacing between adjacent rings when the at least one ring is a plurality of side by side rings is less than a critical distance with such critical distances being interdependent on the frequency of the energy radiated, the dielectric constant of the bolus, the size of the bolus, and the size of the relatively large tissue mass.

Abstract: The accuracy of tissue heating in a body when using a phased array hyperthermia system can be improved by using, in conjunction with the hyperthermia system, a program for predicting heating patterns within the tissue based upon a selected E-field value at each of the antenna energy feedpoints. The hyperthermia system includes circuitry necessary to provide information for calculating the complete EM field at each of the antenna feedpoints during treatment, and such calculated actual feedpoint EM fields are feed to the program to be used in place of the otherwise program generated e-fields in predicting the heating pattern produced by the hyperthermia system during treatment. Further initial operating parameters of the hyperthermia system can be set to produce calculated actual EM fields at the antenna feedpoints which approximate the E-field values used by the program in pretreatment optimizing of the heating pattern.

Abstract: Heat treatment is applied to tissue in need of such treatment which is surrounded by tissue not in need of such treatment, by positioning a deposit within the surrounding tissue adjacent the tissue in need of treatment. The dielectric constant and/or the conductivity of the deposit is greater than that of the surrounding tissue. A radio frequency antenna or antenna array directs a radio frequency signal at a selected frequency into the deposit. The deposit has a diameter within a range of about 0.5 times to about 0.16 times the wavelength of the radio frequency signal within the surrounding tissue. The deposit is heated, at least partially through resonant heating, to a temperature greater than the surrounding tissue to apply heat treatment to the tissue in need of treatment. The deposit may take the form of a balloon of a Mammosite® type device to provide hyperthermia treatment in conjunction with radiation treatment of a breast after a lumpectomy.

Abstract: A radio frequency annular phased array hyperthermia system providing a relatively small heated focal zone in a relatively large tissue mass includes a plurality of radio frequency energy applicators in at least one ring adapted to surround the relatively large tissue mass. A bolus having a dielectric constant is positioned between the energy applicators and the tissue mass. The energy applicators operate at a frequency high enough to create the relatively small heated focal zone. The spacing between adjacent applicators in the at least one ring is less than a critical distance and spacing between adjacent rings when the at least one ring is a plurality of side by side rings is less than a critical distance with such critical distances being interdependent on the frequency of the energy radiated, the dielectric constant of the bolus, the size of the bolus, and the size of the relatively large tissue mass.

Abstract: The accuracy of tissue heating in a body when using a phased array hyperthermia system can be improved by using, in conjunction with the hyperthermia system, a program for predicting heating patterns within the tissue based upon a selected E-field value at each of the antenna energy feedpoints. The hyperthermia system includes circuitry necessary to provide information for calculating the complete EM field at each of the antenna feedpoints during treatment, and such calculated actual feedpoint EM fields are feed to the program to be used in place of the otherwise program generated e-fields in predicting the heating pattern produced by the hyperthermia system during treatment. Further initial operating parameters of the hyperthermia system can be set to produce calculated actual EM fields at the antenna feedpoints which approximate the E-field values used by the program in pretreatment optimizing of the heating pattern.

Abstract: An apparatus and method for providing hyperthermia treatments to a protruding body portion having fatty tissue surrounding a deposit in the protruding body portion is disclosed. The apparatus includes a cavity for receiving the protruding body portion. A radio frequency antenna array is used to direct a radio frequency signal at a selected frequency into the protruding body portion such as a breast so that the radio frequency signal will have a selected wavelength in the breast to create a circularly polarized radio frequency electromagnetic field to selectively heat the deposit to a temperature greater than the surrounding fatty tissue through resonant heating within the deposit when a diameter of the deposit is within a range of about 0.5 times to 0.16 times the wavelength of the radio frequency signal within the fatty mammary tissue.

Abstract: A hyperthermia treatment system for heating a selected region within a target body that includes a power source and a plurality of electromagnetic applicators that are in electrical communication with the power source and arranged in a surrounding array around a focal region to concentrate their combined radiation output onto the focal region. The treatment system also includes a support mechanism that is adapted to support a target body within the surrounding array of applicators, and a positioning mechanism adapted to move the support mechanism and align the selected region within the target body with the focal region. Furthermore, the positioning mechanism is adapted to compensate for movement of the focal region in response to an interaction between the combined radiation output and the target body.

Abstract: A system and corresponding method for irradiating a target with electromagnetic radiation to produce a heated region. The system comprises a coupling device operable to couple electromagnetic radiation from a magnetic resonance imaging system. A plurality of energy radiator applicators are connected to the coupling device to receive electromagnetic radiation energy from the coupling device. Each of the radiator applicators is operable to emit a radio frequency heating signal using the electromagnetic radiation energy from the coupling device. A bolus filled with a dielectric fluid is positioned within the inner area of the MRI system. The bolus is operable to receive the radio frequency heating signals from the plurality of energy radiator applicators and direct the radio frequency heating signals into a section of the body to produce a heated region within the body.

Abstract: A hyperthermia treatment system for heating a selected region within a target body that includes a power source and a plurality of electromagnetic applicators that are in electrical communication with the power source and arranged in a surrounding array around a focal region to concentrate their combined radiation output onto the focal region. The treatment system also includes a support mechanism that is adapted to support a target body within the surrounding array of applicators, and a positioning mechanism adapted to move the support mechanism and align the selected region within the target body with the focal region. Furthermore, the positioning mechanism is adapted to compensate for movement of the focal region in response to an interaction between the combined radiation output and the target body.

Abstract: An electromagnetic energy supply system for supplying electromagnetic energy signals to an applicator for applying the electromagnetic energy signals to tissue for heating such tissue can supply electromagnetic energy signals of at least one selected frequency of a plurality of frequencies available for selection. The system includes a plurality of individual electromagnetic signal generators each adapted to generate signals of a particular frequency, such as two microwave energy signal generators with one operating at 915 MHz and one operating at 1450 MHz. A system controller coordinates operation of the generators. Each generator is connected to connectors for connecting an applicator or array of applicators for applying the selected frequency electromagnetic energy signals to the tissue to be heated. A power splitting circuit can provide multiple connectors tuned for one or for more than one applicator to be connected.

Abstract: An applicator and method for application of electromagnetic energy to an area of tissue is described. The applicator includes a visually-transparent, high-dielectric interfacing assembly which has a conformable tissue-engaging surface and an opposed antenna-engaging surface. At least one balanced, circularly-polarized antenna is disposed in a plane substantially parallel and adjacent to the antenna-engaging surface. The interfacing assembly and at least one antenna are substantially transparent to enable visual viewing of the area of tissue. This enables monitoring of the tissue for adverse treatment effects while electromagnetic energy is being applied to the at least one antenna and radiated into the tissue.

Abstract: Heat treatment is applied to tissue in need of such treatment which is surrounded by tissue not in need of such treatment, by positioning a deposit within the surrounding tissue adjacent the tissue in need of treatment. The dielectric constant and/or the conductivity of the deposit is greater than that of the surrounding tissue. A radio frequency antenna or antenna array directs a radio frequency signal at a selected frequency into the deposit. The deposit has a diameter within a range of about 0.5 times to about 0.16 times the wavelength of the radio frequency signal within the surrounding tissue. The deposit is heated, at least partially through resonant heating, to a temperature greater than the surrounding tissue to apply heat treatment to the tissue in need of treatment. The deposit may take the form of a balloon of a Mammosite® type device to provide hyperthermia treatment in conjunction with radiation treatment of a breast after a lumpectomy.

Abstract: An apparatus and method for providing hyperthermia treatments in a deposit surrounded by tissue in a body is disclosed. A radio frequency antenna array is used to direct a radio frequency signal at a selected frequency into the deposit so that the radio frequency signal will have a selected wavelength in the deposit to selectively heat the deposit to a temperature greater than the surrounding tissue through resonant heating within the deposit. An injectable medium is injected in the deposit to increase a dielectric value and/or conductivity value of the deposit. The injectable medium is selected to increase a specific absorption rate of the radio frequency signal within the deposit relative to the surrounding tissue.

Abstract: A system and corresponding method for creating hyperthermia in a selected position in target tissue using the application of electromagnetic radiation (EMR) in the HF, VHF and UHF microwave region and phased array steering includes an array of applicators and a single channel EMR radiation energy source coupled to at least one of the applicators of the array. A variable reflective termination device is coupled to at least one of the applicators so that a user can vary the energy radiated from the coupled applicator to steer the heating region in the target to a desired position in the target. Several different applicator arrays are suitable for use with the system, and comprise generally cylindrical annuli which emit radiation toward a central axis. Parasitic applicators with variable reflective termination devices can be used in the applicator array along with at least one applicator directly coupled to the energy source.

Abstract: An apparatus and method for providing hyperthermia treatments to a protruding body portion having fatty tissue surrounding a deposit in the protruding body portion is disclosed. The apparatus includes a cavity for receiving the protruding body portion. A radio frequency antenna array is used to direct a radio frequency signal at a selected frequency into the protruding body portion such as a breast so that the radio frequency signal will have a selected wavelength in the breast to create a circularly polarized radio frequency electromagnetic field to selectively heat the deposit to a temperature greater than the surrounding fatty tissue through resonant heating within the deposit when a diameter of the deposit is within a range of about 0.5 times to 0.16 times the wavelength of the radio frequency signal within the fatty mammary tissue.

Abstract: A system and corresponding method for irradiating a target with electromagnetic radiation to produce a heated region. The system comprises a coupling device operable to couple electromagnetic radiation from a magnetic resonance imaging system. A plurality of energy radiator applicators are connected to the coupling device to receive electromagnetic radiation energy from the coupling device. Each of the radiator applicators is operable to emit a radio frequency heating signal using the electromagnetic radiation energy from the coupling device. A bolus filled with a dielectric fluid is positioned within the inner area of the MRI system. The bolus is operable to receive the radio frequency heating signals from the plurality of energy radiator applicators and direct the radio frequency heating signals into a section of the body to produce a heated region within the body.

Abstract: An applicator and method for application of electromagnetic energy to an area of tissue is described. The applicator includes a visually-transparent, high-dielectric interfacing assembly which has a conformable tissue-engaging surface and an opposed antenna-engaging surface. At least one balanced, circularly-polarized antenna is disposed in a plane substantially parallel and adjacent to the antenna-engaging surface. The interfacing assembly and at least one antenna are substantially transparent to enable visual viewing of the area of tissue. This enables monitoring of the tissue for adverse treatment effects while electromagnetic energy is being applied to the at least one antenna and radiated into the tissue.

Abstract: A system and corresponding method for creating hyperthermia in a selected position in target tissue using the application of electromagnetic radiation (EMR) in the HF, VHF and UHF microwave region and phased array steering includes an array of applicators and a single channel EMR radiation energy source coupled to at least one of the applicators of the array. A variable reflective termination device is coupled to at least one of the applicators so that a user can vary the energy radiated from the coupled applicator to steer the heating region in the target to a desired position in the target. Several different applicator arrays are suitable for use with the system, and comprise generally cylindrical annuli which emit radiation toward a central axis. Parasitic applicators with variable reflective termination devices can be used in the applicator array along with at least one applicator directly coupled to the energy source.

Abstract: 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.

Abstract: 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.