CA1314456C - Hyperthermia applicator - Google Patents
Hyperthermia applicatorInfo
- Publication number
- CA1314456C CA1314456C CA000604424A CA604424A CA1314456C CA 1314456 C CA1314456 C CA 1314456C CA 000604424 A CA000604424 A CA 000604424A CA 604424 A CA604424 A CA 604424A CA 1314456 C CA1314456 C CA 1314456C
- Authority
- CA
- Canada
- Prior art keywords
- applicator
- distal end
- conductor
- outer conductor
- sleeve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
- A61B18/1815—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using microwaves
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
Abstract
ABSTRACT
An intracavitary hyperthermic applicator comprising outer and inner coaxial conductors, insulating means between the conductors, The outer conductor terminating in a distal end spaced proximally from the distal ends of the inner conductor, a junction defined by slot spaced from the distal end of the outer conductor, outer and inner tubular sleeves of conductive material disposed coaxially over a length of the outer conductor insulation means between the sleeves and between the inner sleeve and the outer conductor, conductive attachment means securing the proximal ends of the sleeves to the outer conductor, the outer sleeve terminating in a distal end spaced proximally from the distal end of such outer sleeve.
An intracavitary hyperthermic applicator comprising outer and inner coaxial conductors, insulating means between the conductors, The outer conductor terminating in a distal end spaced proximally from the distal ends of the inner conductor, a junction defined by slot spaced from the distal end of the outer conductor, outer and inner tubular sleeves of conductive material disposed coaxially over a length of the outer conductor insulation means between the sleeves and between the inner sleeve and the outer conductor, conductive attachment means securing the proximal ends of the sleeves to the outer conductor, the outer sleeve terminating in a distal end spaced proximally from the distal end of such outer sleeve.
Description
131/~)f~
~YP~RTH~RMIA APPLICATOR
FIELD OF THE INVENTION
This invention relates to intracavitar~ hyperthermia applicators for use in nearly closed-end cavities such as the nasopharynx and the cervix.
BACKGROUND OF THE INVENTION
Interstitial insertion of catheters to apply therapeutic radiation and hyperthermia is commonplace. Several miniature microwave antenna designs are known. Conventional antenna designs are typically 1 to 2 mm in diameter and 5 to 7 mm in length and are operated at frequencies of from about 300 MHz up to a~out 2450 MHz.
Locally induced microwave hyperthermia for cancer therapy permits flexibility in treatment procedures for tumors of 15 iirregular volume and for tumors located deep within the body.
¦Production of adequate thermal field distribution in superficial, accessible and deep-seated tumors is an important consideration. I,imited depth of energy penetration has restricted the use of prior art antennas primarily to the heating of well locali~ed tumors extending to depths of up to a ¦few centimeters. Tumors in hollow viscera or cavities such as ¦the oesophagus, cervix and prostate are amendable to treatment ¦with intracavitary hyperthermia techniques. Interstitial Ihyperthermia techniques are employed for accessible tumors of -25 ¦large volume. ~ major limitation of prior art interstitial , ¦devices is maximization of thermal energy along ~he sides rather than at the tip of the applicator. /
One prior art approach to enhancing the heating at the tipof the applicator is described in Lin, et alO, Int. J.
Hyperthermia, 3:37-47 (1987). The antenna described operates at 2450 M~z.
l ~ l 1 3 1 -9 ~ 1 A 915 MH~ applicator having a diameter in excess of 1 cm and hence too large for use in the treatment of nasopharyngeal cancer i5 described in ~bstract Ce-9, p. 43, "Abstracts of Papers fox the Thirty-Sixth ~nnual Meeting of the Radiation Research Society, Eighth Annual Meeting of the North ~merican Hyperthermia Group", Philadelphia, Psnnsylvania, April 16-21, 198B, and was shown at that meeting.
SUMMARY OF_THE INVENTIC)N
It is an object of an aspect of this invention to provide a hyperthermia applicator for treatin~ cancers and other abnormal tissues, in which thermal energy is concentrated near the applicator tip.
It is an object of an aspect of the invention to provide a hyperthermia applicator of a size appropriate for the treatment of nasopharyngeal cancer which provides a high concentration of energy at the tip.
An object of an aspect of the invention is to provide an intracavitary hyperthermia applicator which has low power req~lirements and may be operated from portable machines.
An object of an aspect of the invention is to provide an intracavitary hyperthermia applicator which has an improved heating pattern as compared with prior art devices.
.~ r~
,F ' 'f 5-, An aspect of the inven~ion is as follows:
An intracavitary hyperthermic applicator comprising:
outer and inner coaxial conductors, insulating means between said conductors, said outer conductor terminating in a distal end spaced proximally from the distal ends of said inner conductor; a junction defined by slot spaced from the distal end of said outer conductor; outer and inner tubular sleeves of conductive material disposed coaxially over a length of said outer conductor insulation means between said sleeves and between said inner ~leeve and said outer conductor, conductive attachment means securing the proximal ends of said sleeves to said outer conductor/ said outer sleeve terminating in a distal end spaced proximally from the distal end of such outer sleeve.
By way of added explanation, the foregoing objects are achieved by a microwave antenna, for example, a coaxial cable, having an inner conductor and an outer conductor, and in which the outer conductor is terminated in spaced relation to the end of the inner conductor and may be ~lotted at a location spaced ~rom the end, defining a junction. A first sleeve of conductive material is shorted to the outer conductor at a predetermined spaced location rearwardly from the junction, and a second sleeve of conductive material is shorted to the outer conductor spaced rearwardly from the first ~- f ,~
LII1'I 5!'~ l sleeve. The sleeves extend forwardly in coaxial relationship with the cable end, but terminate at mutually spaced positions and all are spaced from the distal end of the inner conductor of the cable. A conductive body i8 affixed to the di~tal end of the inner conductor, and the entire active portion of the antenna is encapsulated in an insulating material such as epoxy. The dimensional relationships of the terminal ends of the sleeves and inner and outer conductors, their radial spacing from one another, the lengths of the sleeves, the location of the junction, and the geometry of the conductive body at the ~istal end of the inner conductor are all selected to achieve optimum results.
The outer diameter and the length of the applicators of the invention are selected to accommodate the bodily cavity in which a cancer may appear. Outer diameters may, for example, ¦Irange from about 0.5 centimeter~ for nasopharyngeal cancer ¦Itherapy to about 5 centimeters for cervical cancer treatment.
¦Applicator lengths may correspondingly range from about 4.5 to about 10 centimeters.
20For example, a first form of the invention is designed as a small applicator for use in nasopharyngeal cancer therapy.
. This applicator has an outer diameter of about 0.75 cm and a length of about 5.5 cm. The sleeves comprise copper foil or l screen, and the conductive ~ody comprises brass. ~he cable is 25 j preferably Micro coax, semi-rigid UT-250-A or RG-58A/U, and the sleeves are soldered to the outer conductor. When operated on a muscle phantom at 315 M~z, return losses of 10-15 dB are obtained, and maximum heatings of 1.3 and 0~85 degrees C/W-min.
1.15 cm apart are achieved at the tip and at the junction, respectively.
ll l Il ~31~-)v In a second form of the invention, the applicator is designed for the treatment of cervical cancer. This applicator comprises RG-9/U coaxial cable and has first and second coaxially arranged sleeves shorted at their rearward ends in spaced locations on the outer conductor of the cable, similarly to the nasopharyngeal form of the invention. How~ver, the second or outer sleeve is spaced a greater distance radially from the first sleeve, and the conductive body at ~he distal tip of the inner conductor is a spiral. This applicator has an outer diameter of about 3 cm and an overall length of about 6.5 cm. Further, this applicator has distinct heating at the tip when operated at 915 MHz on a muscle phantom, with a maximum rate of heating of 0.25 degrees C/W-min.
Applicatcrs of the invention described above can be effectively operated at 915 MHz with a 30 watt power generator, thus facilitating use with portable equipment at small rural hospitals or clinics~ Deeper penetration is obtained at 915 MHæ than at 2450 MHz, rendering the applicators more clinically useful than prior art designs.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, in which like reference characters designate like parts throughout the several views, and wherein:
Figure 1 is a longitudinal sectional view of a nasopharyngeal form of applicator according to the invention.
Figure 2 is a view depicting the terminal exterior of the distal end cap of the applicator.
Computer generated Figures 3A, 3B, 3D and 3E show a thermographic temperature elevation of the applicator as shown in Flgure 1 perated at 915 ~Hz on a muscle phartom.
1 31 ~,5~) 1 Figure 3D illustrates the relationship of the applicator tip to the maximum heating peak shown if Figure 3B.
Figure 4 is a longitudinal section of an intracavitary applicator for treatment of cervical cancer.
Computer generated Figures 5A, 5B, 5C and 5D show a thermographic temperature elevation of ~he applicator shown in Figure 4 operated at 915 MHz on a muscle phantom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more specifically to the drawings, a first form of intracavitary hyperthermia applicator in accordance with the invention is indicated generally at 10 in Figure 1. This form of the invention is relatively small in size and is suitable for use in the treatment of nasopharyngeal cancer. The ~evice is also useful in the treatment of other conditionsl such as sinusitis, for example.
The applicator 10 comprises a length of Micro coax semi-rigid cable, UT-250-A or RG-58A/U, having an inner conductor 1] and a tubular outer conductor 12 spaced from the inner conductor by a layer of non-conductive teflon material 13. The outer conductor is terminated short of the distal end 14 of the inner conductor, and is slotted at 15, spaced a dis~ance "C" from its distal end 16. The slot has a longitudinal axial dimension "B".
A first sleeve 17 extends coaxially with the outer conductor and is maintained in xadially outwardly spaced relationship thereto by a layer of non-conductive insulating material 18. The distal end 18 of the sleeve 17 extends beyond the end of the outer conductor by a distance "D", and is connected or shorted to the outer conductor at a location spaced a distance "A" rearwardly from the slot 15.
~31~,5) A second sleeve 19 extends coaxially with the first sleeve and is maintained in radially outwardly spac~d relationship thereto by an insulating layer 21. The second sleeve is connected or shorted to the outer conductor 12 at a location spaced a distance "Al" rearwardly of the point of connection of the first sleeve, and extends forwardly over the first sleeve a distance "F".
A cap 30 of conductive material, preferably brass, is affixed to the distal end 14 of the inner conductor 11 in transverse relationship to the axis of the applicator. The cap 30 has a diameter "G" approximately the same as the diameter of the second æleeve, and has a plurality of radial holes 31 extending from the center through the outer periphery at 90 degree intervals.
In a preferred construction, the dimensions of the various components of the applicator illustrated in Figures 1 and 2 are as follows: A=l cm; Al=l cm; ~=0.5 cm; C=1~5 cm; D=0.3 cm;
E-1.2 cm; F=3.8 cm, and G=0.75 cm. The first and second sleeves are soldered to the outer conductor and comprise copper foil or screen. A layer 40 of epoxy is used to encapsulate the entire active section of the applicator. With the stated dimensions and when operated at 915 MHz as covered with a rubber finger cot or the like, this applicator produces a computer generated thermograph heating pattern as shown in Figures 3A, 3B, 3D and 3E. Figure 3C shows the relationship of the applicator 10 to the tip of the maximum heating peak shown in Figure 3D.
Figure 3A depicts heating gradient lines. Maximum heating is shown at the point marked .~+u. In Figure 3B, the peak, reflecting a maximum heating of about 1.3 degrees C. per minute watt (C/W-min), corresponds to the point ~t" in Figure 3A.
~ r /-1- 5 (/~ ~
In Figure 3D, the peak again shown at a maximum heating of 1.3 degrees C. per watt minute, corresponds to the "+" on Figure 3A, as does the maximum peak in the three-dimen~ional Figure 3E.
The second form of the invention is indicated generally at 50 in Figure 4. This form of the invention comprises a length of RG=9/U coaxial cable having an inner conductor 51 and a tubular outer conductor 52 separated from the inner conductor by a layer of insulation 53. The outer or distal end 54 of the outer conductor is t~rminated short of the distal end 55 of th~
inner conductor by a distance "D" plus "E", and is slotted at 56 at a location spaced a distance "C" ~rom its distal end.
The slot has an axial dimension of "B".
A first sleeve 60 extends coaxially over the outer conductor and is maintained in radially outwardly spaced relationship thereto by a length of insulating Tygon tubing 61. The first sleeve extends at its distal end 62 a distance "D" beyond the distal end of the outer conductor, and is shorted or connected ~o the outer conductor at a location spaced a distance "A" rearwardly of the slot 56.
A second sleeve 70 is connected or shorted to the outer conductor at a location spaced a distance "Al" rearwardly from the point of attachment of the first sleeve, and extends coaxially forwardly over the first sleeve a distance "F". The second sleeve is maintained in radially outwardly spaced relationship to the first sleeve by a layer of insulation 71, such as Styrofoam or the like, for example.
¦ A body 80 of conductive ma~erial i5 secured to the forward or distal end of the inner conductor, and in the form of invention shown, comprises a spiral. The spiral has a diameter "G" approximately the same as the diameter of the second sleeve.
1 31 ~456 In a preferred construction of this form of the invention, the first and second sleeves are made of brass and the dimensional relationships are as follows: A-l cm; A1=2 cm;
B=O.S cm; C=105 cm; D=0.3 cm; E=1.2 cm; F=4 cm, and G-3 cm.
When operated at a frequency at 915 M~z on a muscle phantom and with the stated dimensions as covered with a rubber finger cot or the like, this applicator produces a computer generated thermograph heating patterns a~ shown in Figures 5A, 5B, 5C
and SD.
Figures SA, SB, 5C and SD are analogous to Figures 3A, 3B, 3D and 3E. The point of maximum heating appears at the place marked "+" in Figure 5A. As appears from Figures 5B and-~5C, a maximum heating of about 0.25 degrees C. per watt minute is l obtained.
15 1 The first form of the invention descxibed above is particularly suited to treatment of nasopharyngeal cancer, while the second form is best suited for treatment of cervical cancer. However, as noted, either form of the invention could be used in the treatment of other illnesses.
¦ Although the invention has been described with reference to a particular embodiment, it is to be understood that this embodiment is merely illustrative of the application of the princip7es of the invention. Numerous modifications may be made therein and other arrangements may be devised without departing from the spirit and scope of the invention.
~YP~RTH~RMIA APPLICATOR
FIELD OF THE INVENTION
This invention relates to intracavitar~ hyperthermia applicators for use in nearly closed-end cavities such as the nasopharynx and the cervix.
BACKGROUND OF THE INVENTION
Interstitial insertion of catheters to apply therapeutic radiation and hyperthermia is commonplace. Several miniature microwave antenna designs are known. Conventional antenna designs are typically 1 to 2 mm in diameter and 5 to 7 mm in length and are operated at frequencies of from about 300 MHz up to a~out 2450 MHz.
Locally induced microwave hyperthermia for cancer therapy permits flexibility in treatment procedures for tumors of 15 iirregular volume and for tumors located deep within the body.
¦Production of adequate thermal field distribution in superficial, accessible and deep-seated tumors is an important consideration. I,imited depth of energy penetration has restricted the use of prior art antennas primarily to the heating of well locali~ed tumors extending to depths of up to a ¦few centimeters. Tumors in hollow viscera or cavities such as ¦the oesophagus, cervix and prostate are amendable to treatment ¦with intracavitary hyperthermia techniques. Interstitial Ihyperthermia techniques are employed for accessible tumors of -25 ¦large volume. ~ major limitation of prior art interstitial , ¦devices is maximization of thermal energy along ~he sides rather than at the tip of the applicator. /
One prior art approach to enhancing the heating at the tipof the applicator is described in Lin, et alO, Int. J.
Hyperthermia, 3:37-47 (1987). The antenna described operates at 2450 M~z.
l ~ l 1 3 1 -9 ~ 1 A 915 MH~ applicator having a diameter in excess of 1 cm and hence too large for use in the treatment of nasopharyngeal cancer i5 described in ~bstract Ce-9, p. 43, "Abstracts of Papers fox the Thirty-Sixth ~nnual Meeting of the Radiation Research Society, Eighth Annual Meeting of the North ~merican Hyperthermia Group", Philadelphia, Psnnsylvania, April 16-21, 198B, and was shown at that meeting.
SUMMARY OF_THE INVENTIC)N
It is an object of an aspect of this invention to provide a hyperthermia applicator for treatin~ cancers and other abnormal tissues, in which thermal energy is concentrated near the applicator tip.
It is an object of an aspect of the invention to provide a hyperthermia applicator of a size appropriate for the treatment of nasopharyngeal cancer which provides a high concentration of energy at the tip.
An object of an aspect of the invention is to provide an intracavitary hyperthermia applicator which has low power req~lirements and may be operated from portable machines.
An object of an aspect of the invention is to provide an intracavitary hyperthermia applicator which has an improved heating pattern as compared with prior art devices.
.~ r~
,F ' 'f 5-, An aspect of the inven~ion is as follows:
An intracavitary hyperthermic applicator comprising:
outer and inner coaxial conductors, insulating means between said conductors, said outer conductor terminating in a distal end spaced proximally from the distal ends of said inner conductor; a junction defined by slot spaced from the distal end of said outer conductor; outer and inner tubular sleeves of conductive material disposed coaxially over a length of said outer conductor insulation means between said sleeves and between said inner ~leeve and said outer conductor, conductive attachment means securing the proximal ends of said sleeves to said outer conductor/ said outer sleeve terminating in a distal end spaced proximally from the distal end of such outer sleeve.
By way of added explanation, the foregoing objects are achieved by a microwave antenna, for example, a coaxial cable, having an inner conductor and an outer conductor, and in which the outer conductor is terminated in spaced relation to the end of the inner conductor and may be ~lotted at a location spaced ~rom the end, defining a junction. A first sleeve of conductive material is shorted to the outer conductor at a predetermined spaced location rearwardly from the junction, and a second sleeve of conductive material is shorted to the outer conductor spaced rearwardly from the first ~- f ,~
LII1'I 5!'~ l sleeve. The sleeves extend forwardly in coaxial relationship with the cable end, but terminate at mutually spaced positions and all are spaced from the distal end of the inner conductor of the cable. A conductive body i8 affixed to the di~tal end of the inner conductor, and the entire active portion of the antenna is encapsulated in an insulating material such as epoxy. The dimensional relationships of the terminal ends of the sleeves and inner and outer conductors, their radial spacing from one another, the lengths of the sleeves, the location of the junction, and the geometry of the conductive body at the ~istal end of the inner conductor are all selected to achieve optimum results.
The outer diameter and the length of the applicators of the invention are selected to accommodate the bodily cavity in which a cancer may appear. Outer diameters may, for example, ¦Irange from about 0.5 centimeter~ for nasopharyngeal cancer ¦Itherapy to about 5 centimeters for cervical cancer treatment.
¦Applicator lengths may correspondingly range from about 4.5 to about 10 centimeters.
20For example, a first form of the invention is designed as a small applicator for use in nasopharyngeal cancer therapy.
. This applicator has an outer diameter of about 0.75 cm and a length of about 5.5 cm. The sleeves comprise copper foil or l screen, and the conductive ~ody comprises brass. ~he cable is 25 j preferably Micro coax, semi-rigid UT-250-A or RG-58A/U, and the sleeves are soldered to the outer conductor. When operated on a muscle phantom at 315 M~z, return losses of 10-15 dB are obtained, and maximum heatings of 1.3 and 0~85 degrees C/W-min.
1.15 cm apart are achieved at the tip and at the junction, respectively.
ll l Il ~31~-)v In a second form of the invention, the applicator is designed for the treatment of cervical cancer. This applicator comprises RG-9/U coaxial cable and has first and second coaxially arranged sleeves shorted at their rearward ends in spaced locations on the outer conductor of the cable, similarly to the nasopharyngeal form of the invention. How~ver, the second or outer sleeve is spaced a greater distance radially from the first sleeve, and the conductive body at ~he distal tip of the inner conductor is a spiral. This applicator has an outer diameter of about 3 cm and an overall length of about 6.5 cm. Further, this applicator has distinct heating at the tip when operated at 915 MHz on a muscle phantom, with a maximum rate of heating of 0.25 degrees C/W-min.
Applicatcrs of the invention described above can be effectively operated at 915 MHz with a 30 watt power generator, thus facilitating use with portable equipment at small rural hospitals or clinics~ Deeper penetration is obtained at 915 MHæ than at 2450 MHz, rendering the applicators more clinically useful than prior art designs.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, in which like reference characters designate like parts throughout the several views, and wherein:
Figure 1 is a longitudinal sectional view of a nasopharyngeal form of applicator according to the invention.
Figure 2 is a view depicting the terminal exterior of the distal end cap of the applicator.
Computer generated Figures 3A, 3B, 3D and 3E show a thermographic temperature elevation of the applicator as shown in Flgure 1 perated at 915 ~Hz on a muscle phartom.
1 31 ~,5~) 1 Figure 3D illustrates the relationship of the applicator tip to the maximum heating peak shown if Figure 3B.
Figure 4 is a longitudinal section of an intracavitary applicator for treatment of cervical cancer.
Computer generated Figures 5A, 5B, 5C and 5D show a thermographic temperature elevation of ~he applicator shown in Figure 4 operated at 915 MHz on a muscle phantom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more specifically to the drawings, a first form of intracavitary hyperthermia applicator in accordance with the invention is indicated generally at 10 in Figure 1. This form of the invention is relatively small in size and is suitable for use in the treatment of nasopharyngeal cancer. The ~evice is also useful in the treatment of other conditionsl such as sinusitis, for example.
The applicator 10 comprises a length of Micro coax semi-rigid cable, UT-250-A or RG-58A/U, having an inner conductor 1] and a tubular outer conductor 12 spaced from the inner conductor by a layer of non-conductive teflon material 13. The outer conductor is terminated short of the distal end 14 of the inner conductor, and is slotted at 15, spaced a dis~ance "C" from its distal end 16. The slot has a longitudinal axial dimension "B".
A first sleeve 17 extends coaxially with the outer conductor and is maintained in xadially outwardly spaced relationship thereto by a layer of non-conductive insulating material 18. The distal end 18 of the sleeve 17 extends beyond the end of the outer conductor by a distance "D", and is connected or shorted to the outer conductor at a location spaced a distance "A" rearwardly from the slot 15.
~31~,5) A second sleeve 19 extends coaxially with the first sleeve and is maintained in radially outwardly spac~d relationship thereto by an insulating layer 21. The second sleeve is connected or shorted to the outer conductor 12 at a location spaced a distance "Al" rearwardly of the point of connection of the first sleeve, and extends forwardly over the first sleeve a distance "F".
A cap 30 of conductive material, preferably brass, is affixed to the distal end 14 of the inner conductor 11 in transverse relationship to the axis of the applicator. The cap 30 has a diameter "G" approximately the same as the diameter of the second æleeve, and has a plurality of radial holes 31 extending from the center through the outer periphery at 90 degree intervals.
In a preferred construction, the dimensions of the various components of the applicator illustrated in Figures 1 and 2 are as follows: A=l cm; Al=l cm; ~=0.5 cm; C=1~5 cm; D=0.3 cm;
E-1.2 cm; F=3.8 cm, and G=0.75 cm. The first and second sleeves are soldered to the outer conductor and comprise copper foil or screen. A layer 40 of epoxy is used to encapsulate the entire active section of the applicator. With the stated dimensions and when operated at 915 MHz as covered with a rubber finger cot or the like, this applicator produces a computer generated thermograph heating pattern as shown in Figures 3A, 3B, 3D and 3E. Figure 3C shows the relationship of the applicator 10 to the tip of the maximum heating peak shown in Figure 3D.
Figure 3A depicts heating gradient lines. Maximum heating is shown at the point marked .~+u. In Figure 3B, the peak, reflecting a maximum heating of about 1.3 degrees C. per minute watt (C/W-min), corresponds to the point ~t" in Figure 3A.
~ r /-1- 5 (/~ ~
In Figure 3D, the peak again shown at a maximum heating of 1.3 degrees C. per watt minute, corresponds to the "+" on Figure 3A, as does the maximum peak in the three-dimen~ional Figure 3E.
The second form of the invention is indicated generally at 50 in Figure 4. This form of the invention comprises a length of RG=9/U coaxial cable having an inner conductor 51 and a tubular outer conductor 52 separated from the inner conductor by a layer of insulation 53. The outer or distal end 54 of the outer conductor is t~rminated short of the distal end 55 of th~
inner conductor by a distance "D" plus "E", and is slotted at 56 at a location spaced a distance "C" ~rom its distal end.
The slot has an axial dimension of "B".
A first sleeve 60 extends coaxially over the outer conductor and is maintained in radially outwardly spaced relationship thereto by a length of insulating Tygon tubing 61. The first sleeve extends at its distal end 62 a distance "D" beyond the distal end of the outer conductor, and is shorted or connected ~o the outer conductor at a location spaced a distance "A" rearwardly of the slot 56.
A second sleeve 70 is connected or shorted to the outer conductor at a location spaced a distance "Al" rearwardly from the point of attachment of the first sleeve, and extends coaxially forwardly over the first sleeve a distance "F". The second sleeve is maintained in radially outwardly spaced relationship to the first sleeve by a layer of insulation 71, such as Styrofoam or the like, for example.
¦ A body 80 of conductive ma~erial i5 secured to the forward or distal end of the inner conductor, and in the form of invention shown, comprises a spiral. The spiral has a diameter "G" approximately the same as the diameter of the second sleeve.
1 31 ~456 In a preferred construction of this form of the invention, the first and second sleeves are made of brass and the dimensional relationships are as follows: A-l cm; A1=2 cm;
B=O.S cm; C=105 cm; D=0.3 cm; E=1.2 cm; F=4 cm, and G-3 cm.
When operated at a frequency at 915 M~z on a muscle phantom and with the stated dimensions as covered with a rubber finger cot or the like, this applicator produces a computer generated thermograph heating patterns a~ shown in Figures 5A, 5B, 5C
and SD.
Figures SA, SB, 5C and SD are analogous to Figures 3A, 3B, 3D and 3E. The point of maximum heating appears at the place marked "+" in Figure 5A. As appears from Figures 5B and-~5C, a maximum heating of about 0.25 degrees C. per watt minute is l obtained.
15 1 The first form of the invention descxibed above is particularly suited to treatment of nasopharyngeal cancer, while the second form is best suited for treatment of cervical cancer. However, as noted, either form of the invention could be used in the treatment of other illnesses.
¦ Although the invention has been described with reference to a particular embodiment, it is to be understood that this embodiment is merely illustrative of the application of the princip7es of the invention. Numerous modifications may be made therein and other arrangements may be devised without departing from the spirit and scope of the invention.
Claims (9)
1. An intracavitary hyperthermic applicator comprising' outer and inner coaxial conductors;
insulating means between said conductors, said outer conductor terminating in a distal end spaced proximally from the distal ends of said inner conductor;
a junction defined by slot spaced from the distal end of said outer conductor;
outer and inner tubular sleeves of conductive material disposed coaxially over a length of said outer conductor insulation means between said sleeves and between said inner sleeve and said outer conductor;
conductive attachment means securing the proximal ends of said sleeves to said outer conductor, said outer sleeve terminating in a distal end spaced proximally from the distal end of such outer sleeve.
insulating means between said conductors, said outer conductor terminating in a distal end spaced proximally from the distal ends of said inner conductor;
a junction defined by slot spaced from the distal end of said outer conductor;
outer and inner tubular sleeves of conductive material disposed coaxially over a length of said outer conductor insulation means between said sleeves and between said inner sleeve and said outer conductor;
conductive attachment means securing the proximal ends of said sleeves to said outer conductor, said outer sleeve terminating in a distal end spaced proximally from the distal end of such outer sleeve.
2. An intracavitary hyperthermic applicator as defined by claim 1 in which said outer and inner coaxial conductors are a length of coaxial cable.
3. An intracavitary hyperthermic applicator as defined by claim 1 in which said outer coaxial conductor is circumferentially slotted.
4. An intracavitary hyperthermia applicator as claimed in claim 3, wherein:
the distal end of the outer coaxial conductor terminates short of the distal end of the inner conductor, the distal end of the inner sleeve is spaced axially between the distal ends of the inner and outer conductors, and the distal end of the outer sleeve terminates short of the distal ends of both the first sleeve and the outer conductor.
the distal end of the outer coaxial conductor terminates short of the distal end of the inner conductor, the distal end of the inner sleeve is spaced axially between the distal ends of the inner and outer conductors, and the distal end of the outer sleeve terminates short of the distal ends of both the first sleeve and the outer conductor.
5. An intracavitary hyperthermia applicator as claimed in claim 4, wherein:
the length of the slot in the outer conductor is equal to substantially one-half the spacing between the points of attachment of the first and second sleeves to the outer conductor.
the length of the slot in the outer conductor is equal to substantially one-half the spacing between the points of attachment of the first and second sleeves to the outer conductor.
6. An intracavitary hyperthermia applicator as claimed in claim 5, wherein:
the spacing between the points of attachment of the first and second sleeves to the outer conductor is substantially equal to the spacing between the slot in the outer conductor and the point of attachment of the first sleeve to the outer conductor.
the spacing between the points of attachment of the first and second sleeves to the outer conductor is substantially equal to the spacing between the slot in the outer conductor and the point of attachment of the first sleeve to the outer conductor.
7. An intracavitary applicator as defined by claim 1 having a maximum outer diameter of from about 0.5 to about 5.0 centimeters and a length of from about 4.5 to about 10 centimeters.
8. An intracavitary applicator as defined by claim 1 in which the dimensions of the parts substantially correspond to the dimensions set forth on Figure 1.
9. An intracavitary applicator as defined by claim 1 in which the dimensions of the parts substantially correspond to the dimensions set forth on Figure 4.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US213,921 | 1988-06-30 | ||
| US07/213,921 US4865047A (en) | 1988-06-30 | 1988-06-30 | Hyperthermia applicator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1314456C true CA1314456C (en) | 1993-03-16 |
Family
ID=22797037
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000604424A Expired - Fee Related CA1314456C (en) | 1988-06-30 | 1989-06-29 | Hyperthermia applicator |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4865047A (en) |
| CN (1) | CN1024256C (en) |
| CA (1) | CA1314456C (en) |
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| US5542915A (en) * | 1992-08-12 | 1996-08-06 | Vidamed, Inc. | Thermal mapping catheter with ultrasound probe |
| US5385544A (en) * | 1992-08-12 | 1995-01-31 | Vidamed, Inc. | BPH ablation method and apparatus |
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| US5421819A (en) | 1992-08-12 | 1995-06-06 | Vidamed, Inc. | Medical probe device |
| US5370675A (en) * | 1992-08-12 | 1994-12-06 | Vidamed, Inc. | Medical probe device and method |
| EP0407057B1 (en) * | 1989-06-20 | 1995-08-23 | Rocket of London Limited | Apparatus for applying electromagnetic energy to a portion of the body of a patient |
| DE3926934A1 (en) * | 1989-08-16 | 1991-02-21 | Deutsches Krebsforsch | HYPERTHERMIC MICROWAVE APPLICATOR FOR WARMING A LIMITED ENVIRONMENT IN A DISSIPATIVE MEDIUM |
| US5549559A (en) | 1990-03-22 | 1996-08-27 | Argomed Ltd. | Thermal treatment apparatus |
| US5409453A (en) * | 1992-08-12 | 1995-04-25 | Vidamed, Inc. | Steerable medical probe with stylets |
| US5190037A (en) * | 1991-10-21 | 1993-03-02 | Adm Tronics Unlimited, Inc. | High-power corona discharge beam thermotherapy system |
| US5330518A (en) * | 1992-03-06 | 1994-07-19 | Urologix, Inc. | Method for treating interstitial tissue associated with microwave thermal therapy |
| US5413588A (en) * | 1992-03-06 | 1995-05-09 | Urologix, Inc. | Device and method for asymmetrical thermal therapy with helical dipole microwave antenna |
| US5370677A (en) * | 1992-03-06 | 1994-12-06 | Urologix, Inc. | Gamma matched, helical dipole microwave antenna with tubular-shaped capacitor |
| WO1993020768A1 (en) * | 1992-04-13 | 1993-10-28 | Ep Technologies, Inc. | Steerable microwave antenna systems for cardiac ablation |
| US5562720A (en) * | 1992-05-01 | 1996-10-08 | Vesta Medical, Inc. | Bipolar/monopolar endometrial ablation device and method |
| US5277201A (en) * | 1992-05-01 | 1994-01-11 | Vesta Medical, Inc. | Endometrial ablation apparatus and method |
| US5443470A (en) * | 1992-05-01 | 1995-08-22 | Vesta Medical, Inc. | Method and apparatus for endometrial ablation |
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| US5630794A (en) * | 1992-08-12 | 1997-05-20 | Vidamed, Inc. | Catheter tip and method of manufacturing |
| US5514131A (en) * | 1992-08-12 | 1996-05-07 | Stuart D. Edwards | Method for the ablation treatment of the uvula |
| US5456662A (en) * | 1993-02-02 | 1995-10-10 | Edwards; Stuart D. | Method for reducing snoring by RF ablation of the uvula |
| US5720718A (en) * | 1992-08-12 | 1998-02-24 | Vidamed, Inc. | Medical probe apparatus with enhanced RF, resistance heating, and microwave ablation capabilities |
| US5672153A (en) * | 1992-08-12 | 1997-09-30 | Vidamed, Inc. | Medical probe device and method |
| US5470308A (en) * | 1992-08-12 | 1995-11-28 | Vidamed, Inc. | Medical probe with biopsy stylet |
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| DE69408826T2 (en) * | 1994-03-18 | 1998-07-23 | Schneider Europ Ag | Magnetic resonance imaging system for tracking a medical device |
| USRE40587E1 (en) | 1994-03-18 | 2008-11-25 | Schneider (Europe) A.G. | Antenna for magnetic resonance imaging and method of use |
| US5681308A (en) * | 1994-06-24 | 1997-10-28 | Stuart D. Edwards | Ablation apparatus for cardiac chambers |
| US5575788A (en) * | 1994-06-24 | 1996-11-19 | Stuart D. Edwards | Thin layer ablation apparatus |
| US5505730A (en) * | 1994-06-24 | 1996-04-09 | Stuart D. Edwards | Thin layer ablation apparatus |
| US5843144A (en) * | 1995-06-26 | 1998-12-01 | Urologix, Inc. | Method for treating benign prostatic hyperplasia with thermal therapy |
| US5938692A (en) * | 1996-03-26 | 1999-08-17 | Urologix, Inc. | Voltage controlled variable tuning antenna |
| US5769880A (en) * | 1996-04-12 | 1998-06-23 | Novacept | Moisture transport system for contact electrocoagulation |
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| US6813520B2 (en) | 1996-04-12 | 2004-11-02 | Novacept | Method for ablating and/or coagulating tissue using moisture transport |
| US5861021A (en) * | 1996-06-17 | 1999-01-19 | Urologix Inc | Microwave thermal therapy of cardiac tissue |
| US5827268A (en) * | 1996-10-30 | 1998-10-27 | Hearten Medical, Inc. | Device for the treatment of patent ductus arteriosus and method of using the device |
| US5989284A (en) * | 1997-02-18 | 1999-11-23 | Hearten Medical, Inc. | Method and device for soft tissue modification |
| US8551082B2 (en) | 1998-05-08 | 2013-10-08 | Cytyc Surgical Products | Radio-frequency generator for powering an ablation device |
| US6188930B1 (en) * | 1998-09-11 | 2001-02-13 | Medivance Incorporated | Method and apparatus for providing localized heating of the preoptic anterior hypothalamus |
| GB9904373D0 (en) * | 1999-02-25 | 1999-04-21 | Microsulis Plc | Radiation applicator |
| US7044960B2 (en) * | 2003-09-17 | 2006-05-16 | Medivance Incorporated | Method and apparatus for providing non-invasive ultrasound heating of the preoptic anterior hypothalamus |
| US7731712B2 (en) | 2004-12-20 | 2010-06-08 | Cytyc Corporation | Method and system for transcervical tubal occlusion |
| US7674260B2 (en) | 2005-04-28 | 2010-03-09 | Cytyc Corporation | Emergency hemostasis device utilizing energy |
| US8486060B2 (en) | 2006-09-18 | 2013-07-16 | Cytyc Corporation | Power ramping during RF ablation |
| US7846160B2 (en) | 2006-12-21 | 2010-12-07 | Cytyc Corporation | Method and apparatus for sterilization |
| CN107789052B (en) * | 2017-10-26 | 2024-03-01 | 咸阳张森医疗仪器有限公司 | Electronic therapeutic apparatus for cervical disease hot cutting |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0105677B1 (en) * | 1982-09-27 | 1986-12-10 | Kureha Kagaku Kogyo Kabushiki Kaisha | Endotract antenna device for hyperthermia |
| US4612940A (en) * | 1984-05-09 | 1986-09-23 | Scd Incorporated | Microwave dipole probe for in vivo localized hyperthermia |
| US4658836A (en) * | 1985-06-28 | 1987-04-21 | Bsd Medical Corporation | Body passage insertable applicator apparatus for electromagnetic |
-
1988
- 1988-06-30 US US07/213,921 patent/US4865047A/en not_active Expired - Lifetime
-
1989
- 1989-06-29 CA CA000604424A patent/CA1314456C/en not_active Expired - Fee Related
- 1989-06-29 CN CN89104373.XA patent/CN1024256C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1038939A (en) | 1990-01-24 |
| US4865047A (en) | 1989-09-12 |
| CN1024256C (en) | 1994-04-20 |
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