Therapeutic endo-rectal probe, and apparatus constituting an application thereof for destroying cancer tissue, in particular of the prostate, and preferably in combination with an imaging endo-cavitary-probe

• US 5,666,954 A
• Filed: 06/07/1995
• Issued: 09/16/1997
• Est. Priority Date: 03/05/1991
• Status: Expired due to Term

• Current Assignee: Technomed Medical Systems
• Original Assignee: Parc D'Activites La Poudrette Lamartine, Technomed Medical Systems Inserm-Institut National de La Sante et de La Recherche Medicale
• Inventors: Gelet, Albert, Chapelon, Jean-Yves, Cathignol, Dominique, Blanc, Emmanuel
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): Casler, Brian L.
• Application Number:
  US08/486,738
• Time in Patent Office: 832 Days
• Field of Search: 128/660.03, 128/653.1, 128/660.01, 128/660.02, 128/662.03, 128/662.06, 604/22, 606/128, 601/2, 601/4, 601/3
• US Class Current: 600/439
• CPC Class Codes: A61B 17/22004 using mechanical vibrations, e.g. ultrasonic shock waves A61B17/225 takes precedence
• CPC Class Codes: A61B 17/22012 in direct contact with, or very close to, the obstruction or concrement for removing obstructions in blood vessels by laser A61B18/245
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 2017/00274 Prostate operation, e.g. prostatectomy, turp, bhp treatment
• CPC Class Codes: A61B 2017/22021 electric leads passing through the catheter
• CPC Class Codes: A61B 2017/22025 applying a shock wave A61B2017/22091 takes precedence
• CPC Class Codes: A61B 2017/22028 arrays, e.g. phased arrays
• CPC Class Codes: A61B 2018/00547 Prostate
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: A61N 7/022 intracavitary
• CPC Class Codes: B06B 1/06 operating with piezoelectric effect or with electrostriction piezoelectric or electrostrictive devices per se H10N30/00

Abstract

A therapeutic endo-rectal probe comprises at least a piezoelectric transducer element mounted in a support member itself connected to a rigid guide means enabling endo-rectal insertion of said probe, the outside shape of said support member preferably being that of a disk having an outline that is for the most part substantially circular or substantially elliptical, thereby facilitating endo-rectal insertion.

Claims

1. A probe for insertion in a body cavity having a maximum predetermined perimeter, comprising:

a probe support member having a proximal end and a distal end and defining a longitudinal axis; and

a piezoelectric transducer element mounted on said probe support member at the distal end thereof and operative to emit ultrasonic waves at a focus effective for therapeutic treatment of body tissue, said piezoelectric transducer element being substantially disk-shaped and having a substantially disk-shaped front face defining an emitting surface substantially parallel to said longitudinal axis for emitting said ultrasonic waves for effecting said therapeutic treatment at said focus;

said piezoelectric transducer element having a cross-section in a plane perpendicular to said longitudinal axis, said cross-section having a dimension parallel to said front face which is substantially greater than a dimension perpendicular to said front face for defining a substantially flat piezoelectric transducer element;

said distal end of said probe support member having a cross-section conforming closely to said cross-section of said piezoelectric transducer element and a maximum cross-sectional perimeter no greater than said maximum predetermined perimeter of said body cavity, whereby said distal end of said probe support member may be inserted into said body cavity and the area of said emitting surface of said front face of said piezoelectric transducer element is maximized.

2. The probe according to claim 1, wherein said substantially disk-shaped front face of said piezoelectric transducer element is smaller in a direction substantially parallel to said front face and perpendicular to said longitudinal axis than in a direction parallel to said longitudinal axis, thereby maximizing the ultrasound wave emitting surface of said piezoelectric transducer element while minimizing the maximum cross-sectional perimeter of said distal end of said probe support member.

3. The probe according to claim 2, wherein the front face of said disk-shaped piezoelectric transducer element is selected from the group consisting of substantially circular with truncated longitudinally extending side portions and substantially elliptical.

4. The probe according to claim 1, wherein said front face of said transducer element is concave for focusing the ultrasound waves generated thereby.

5. The probe according to claim 1, wherein said maximum cross-sectional perimeter of said probe support member is about 16 cm, thereby being adapted for an endorectal insertion.

6. The probe according to claim 1, further comprising a backing layer disposed between said rear face of said transducer element and said probe support member for improving the performance of said transducer element.

7. The probe according to claim 1, further comprising electrical conducting means extending from the proximal end of said probe support member to the distal end thereof and connected at said distal end to the rear face of said transducer element.

8. The probe according to claim 1, further comprising a flexible membrane mounted to said probe support member and surrounding said distal end of said probe support member and said transducer element for providing a fluid seal thereabout, and means extending from the proximal end of said probe support member to said membrane for communicating fluid from said proximal end of said probe support member to said membrane for expanding same.

9. The probe according to claim 8, further comprising means for sealing said transducer element to said probe support member for preventing fluid at said front face of said transducer element from reaching said rear face thereof.

10. The probe according to claim 8, wherein said membrane comprises radial deformation means for enhancing radial expansion of said membrane.

11. The probe according to claim 8, wherein said membrane is mounted to said probe support member for longitudinal movement of said probe support member relative to said membrane.

12. The probe according to claim 1, wherein said piezoelectric transducer element is constructed from material selected from the group consisting of piezoelectric ceramics and composite piezoelectric ceramics.

13. The probe according to claim 1, wherein said piezoelectric transducer element is a mosaic design comprising a plurality of transducer elements, and further comprising electronic means connected to said transducer elements for focusing at said focus the ultrasound waves emitted thereby.

14. The probe according to claim 1, wherein the ratio of a diameter d of said front face of said transducer element to the focal length F of said transducer element is about 0.5 to about 1.5.

15. The probe according to claim 14, wherein said ratio is about 0.8 to about 1.2.

16. The probe according to claim 15, wherein said ratio is about 1.0.

17. The probe according to claim 1, wherein the shape of said front face of said transducer element is substantially circular with truncated longitudinally extending side portions, and wherein the ratio of the diameter of said front face of said transducer element in the longitudinal direction divided by the diameter in a direction perpendicular thereto is in the range of 1 to 2.

18. The probe according to claim 1, further comprising an imaging endocavitary probe for generating an image of said focus for monitoring said therapeutic treatment.

19. The probe according to claim 18, wherein said imaging endocavitary probe is secured to said probe support member.

20. The probe according to claim 18, wherein the proximal end of said probe support member comprises a rigid guide member, and wherein said imaging endocavitary probe is secured to said rigid guide member for axial movement relative thereto.

21. The probe according to claim 18, wherein said piezoelectric transducer element has an acoustic window therein, and wherein said imaging endocavitary probe is positioned beneath said acoustic window.

22. The probe according to claim 1, wherein said probe support member has a front face defining an opening for receiving said transducer element, said front face of said transducer element confronting said front face of said probe support member when said transducer element is received in said opening.

23. The probe according to claim 1, wherein said substantially disk-shaped front face of said piezoelectric transducer element is concave for defining a concave emitting surface.

24. A method for treating a body zone located inside the body of a patient, comprising the steps of:

(a) providing a probe for insertion in a body cavity near said body zone of said patient, said body cavity having a maximum predetermined perimeter, said probe including;

a probe support member having a proximal end and a distal end and defining a longitudinal axis; and

a piezoelectric transducer element mounted on said probe support member at the distal end thereof and operative to emit ultrasonic waves at a focus effective for therapeutic treatment of body tissue, said piezoelectric transducer element being substantially disk-shaped and having a substantially disk-shaped front face defining an emitting surface substantially parallel to said longitudinal axis for emitting said ultrasonic waves for effecting said therapeutic treatment at said focus;

said piezoelectric transducer element having a cross-section in a plane perpendicular to said longitudinal axis, said cross-section having a dimension parallel to said front face which is substantially greater than a dimension perpendicular, to said front face for defining a substantially flat piezoelectric transducer element;

said distal end of said probe support member having a cross-section conforming closely to said cross-section of said piezoelectric transducer element and a maximum cross-sectional perimeter no greater than said maximum predetermined perimeter of said body cavity, whereby said distal end of said probe support member may be inserted into said body cavity and the area of said emitting surface of said front face of said piezoelectric transducer element is maximized;

(b) inserting said probe into said body cavity near said body zone to be treated with said front face of said piezoelectric transducer element in front of said body zone to be treated, said focus being located in said body zone; and

(c) causing said piezoelectric transducer element to emit ultrasound waves effective for said therapeutic treatment at said focus in said body zone.

25. The method of claim 24, wherein said step of inserting said probe into said body cavity comprises inserting said probe into said body cavity near a tumor.

26. The method of claim 24, wherein said step of inserting said probe into said body cavity comprises inserting said probe into said body cavity near a prostate tumor.

27. The method of claim 26, including:

providing said probe, comprising said at least one piezoelectric transducer element and said probe support member, as an endorectal therapeutic probe having a longitudinal axis;

inserting said endorectal probe into the rectum until said front face confronts the prostate tumor to be treated;

causing said piezoelectric transducer element to emit ultrasound waves effective for said therapeutic treatment at said focus; and

displacing said endorectal probe for treating the entire volume of the tumor.

28. The method of claim 24, wherein said causing step includes causing said piezoelectric transducer element to emit ultrasound waves pulsed at a frequency in the range from 1 MHz to 4 MHz with pulses of short duration ranging between 50 milliseconds and 5 seconds.

29. The method of claim 28, wherein said step of causing said piezoelectric transducer element to emit ultrasound waves comprises delivering an intensity at the focus in the range from 1,000 W/cm² to 10,000 W/cm².

30. The method of claim 28, wherein said step of causing said piezoelectric transducer element to emit ultrasound waves comprises emitting pulses have a short duration ranging between 200 milliseconds and 2 seconds.

31. The method of claim 24, wherein said step of providing a probe includes selecting the shape of the front face of said transducer element from the group consisting of substantially circular, substantially circular with truncated longitudinally extending side portions, and substantially elliptical.

32. The method of claim 24, wherein said step of providing a probe includes providing a probe support member having a front face defining an opening for receiving said transducer element, with said front face of said transducer element confronting said front face of said probe support member when said transducer element is received in said opening.

33. The method of claim 24, wherein said step of providing a probe comprises providing a probe with a maximum cross-sectional perimeter of said probe support member of about 16 cm.

34. The method of claim 24, further comprising providing a flexible membrane mounted to said probe support member and surrounding said distal end of said probe support member and said transducer element for providing a fluid seal thereabout and defining a chamber between said membrane and said probe support member;

providing means extending from the proximal end of said probe support member to said membrane for communicating fluid from said proximal end of said probe support member to said membrane for expanding same; and

after inserting said probe into said body cavity near said body zone to be treated, inflating said membrane for moving said membrane into close contact with the inside wall of the body cavity.

35. The method of claim 34, further comprising the step of providing said membrane with radial deformation means for enhancing radial expansion of said membrane relative to longitudinal deformation.

36. The method of claim 24, wherein said step of providing a probe comprises providing a piezoelectric transducer element wherein the ratio of a diameter d of said front face of said transducer element to the focal length F of said transducer element is between about 0.5 and about 1.5.

37. The method of claim 36 wherein said step of providing a piezoelectric transducer element comprises providing a piezoelectric transducer element wherein said ratio is between about 0.8 and 1.2.

38. The method of claim 24, further comprising providing said front face of said transducer element with a substantially circular shape with truncated longitudinally extending side portions, wherein the ratio of the diameter of said front face of said transducer element in the longitudinal direction divided by the diameter in a direction perpendicular thereto is in the range of 1 to 2.

39. The method claim 24, further comprising providing an imaging endocavitary probe for generating an image of said focus for monitoring said therapeutic treatment.

40. The method of claim 39, further comprising securing said imaging endocavitary probe to said probe support member.

41. The method of claim 40, further comprising providing said piezoelectric, transducer element with an acoustic window therein and positioning said imaging endocavitary probe beneath said acoustic window.

42. A probe for insertion in a body cavity having a maximum predetermined perimeter, comprising:

a probe support member having a proximal end and a distal end and defining a longitudinal axis; and

a piezoelectric transducer element mounted on said probe support member at the distal end thereof and operative to emit ultrasonic waves at a focus effective for therapeutic treatment of body tissue, said piezoelectric transducer element being substantially disk-shaped and having a substantially disk-shaped front face defining an emitting surface substantially parallel to said longitudinal axis for emitting said ultrasonic waves for effecting said therapeutic treatment at said focus;

said piezoelectric transducer element having a cross-section in a plane perpendicular to said longitudinal axis defining a predetermined cross-sectional perimeter, said front face of said transducer element having a maximum diameter d and a focal length F, the ratio of the diameter d of said front face of said transducer element to the focal length F of said transducer element ranging between 0.5 and 1.5;

said distal end of said probe support member having a cross-section conforming closely to said cross-section of said piezoelectric transducer element and a maximum cross-sectional perimeter no greater than said maximum predetermined perimeter of said body cavity, whereby said distal end of said probe support member may be inserted into said body cavity and the area of said emitting surface of said front face of said piezoelectric transducer element is maximized.

43. The probe according to claim 42, wherein said ratio ranges between 0.8 and 1.2.

44. A probe for insertion in a body cavity having a maximum predetermined perimeter, comprising:

a probe support member having a proximal end and a distal end and defining a longitudinal axis; and

a piezoelectric transducer element mounted on said probe support member at the distal end thereof and operative to emit ultrasonic waves at a focus effective for therapeutic treatment of body tissue, said piezoelectric transducer element being substantially disk-shaped and having a substantially disk-shaped front face defining an emitting surface substantially parallel to said longitudinal axis for emitting said ultrasonic waves for effecting said therapeutic treatment at said focus;

said piezoelectric transducer element having a cross-section in a plane perpendicular to said longitudinal axis defining a predetermined cross-sectional perimeter, the shape of said front face of said transducer element being substantially circular with truncated longitudinally extending side portions, and wherein the ratio of the diameter of said front face of said transducer element in the longitudinal direction divided by the diameter in a direction perpendicular thereto is in the range of 1 to 2;

said distal end of said probe support member having a cross-section conforming closely to said cross-section of said piezoelectric transducer element and a maximum cross-sectional perimeter no greater than said maximum predetermined perimeter of said body cavity, whereby said distal end of said probe support member may be inserted into said body cavity and the area of said emitting surface of said front face of said piezoelectric transducer element is maximized.

45. The probe of claim 44, further comprising an imaging endocavitary probe for generating an image of said focus for monitoring said therapeutic treatment.

46. The probe of claim 45, wherein the proximal end of said probe support member comprises a rigid guide member, and wherein said imaging endocavitary probe is secured to said rigid guide member for movement relative thereto.

47. The probe of claim 46, wherein said piezoelectric transducer element has an acoustic window therein, and wherein said imaging endocavitary probe is positioned beneath said acoustic window.

48. The probe of claim 47, wherein said probe support member has a front face defining an opening for receiving said transducer element, said front face of said transducer element confronting said front face of said probe support member when said transducer element is received in said opening.

49. A probe for insertion in the rectum comprising:

a probe support member having a proximal end and a distal end and defining a longitudinal axis; and

a piezoelectric transducer element mounted on said probe support member at the distal end thereof and operative to emit ultrasonic waves at a focus effective for therapeutic treatment of body tissue, said piezoelectric transducer element being substantially disk-shaped and having a substantially disk-shaped front face defining an emitting surface substantially parallel to said longitudinal axis for emitting said ultrasonic waves for effecting said therapeutic treatment at said focus, said piezoelectric transducer element also having a rear face;

said piezoelectric transducer element having a cross-section in a plane perpendicular to said longitudinal axis defining a cross-sectional perimeter;

said distal end of said probe support member having a cross-section conforming closely to said cross-section of said piezoelectric transducer element and a maximum cross-sectional perimeter of about 16 cm, thereby being adapted for an endorectal insertion while the area of said emitting surface of said front face of said piezoelectric transducer element is maximized.

50. A method for treating a prostate tumor located inside the body of a patient, comprising the steps of:

(a) providing an endorectal probe having a longitudinal axis for insertion in the patient'"'"'s rectum near said prostate tumor, said rectum having a maximum predetermined perimeter, said endorectal probe including;

a probe support member having a proximal end and a distal end and defining said longitudinal axis; and

a piezoelectric transducer element mounted on said probe support member at the distal end thereof and operative to emit ultrasonic waves at a focus effective for therapeutic treatment of body tissue, said piezoelectric transducer element being substantially disk-shaped and having a substantially disk-shaped front face defining an emitting surface substantially parallel to said longitudinal axis for emitting said ultrasonic waves for effecting said therapeutic treatment at said focus;

said piezoelectric transducer element having a cross-section in a plane perpendicular to said longitudinal axis, said cross-section defining a cross-sectional perimeter;

said distal end of said probe support member having a cross-section conforming closely to said cross-section of said piezoelectric transducer element and a maximum cross-sectional perimeter in said plane perpendicular to said longitudinal axis no greater than said maximum predetermined perimeter of said rectum, whereby said distal end of said probe support member may be inserted into said rectum and the area of said emitting surface of said front face of said piezoelectric transducer element is maximized;

(b) inserting said endorectal probe into the rectum until said front face confronts the prostate tumor to be treated;

(c) causing said piezoelectric transducer element to emit ultrasound waves effective for said therapeutic treatment at said focus in said prostate tumor; and

(d) displacing said endorectal probe for treating the entire volume of the tumor.

51. The method claim 50, further comprising providing an imaging endocavitary probe for generating an image of said focus for monitoring said therapeutic treatment.

52. The method of claim 51, further comprising securing said imaging endocavitary probe to said probe support member.

53. The method of claim 52, further comprising providing said piezoelectric transducer element with an acoustic window therein and positioning said imaging endocavitary probe beneath said acoustic window.