Method and apparatus for the surgical treatment of tissues by thermal effect, and in particular the prostate, using a urethral microwave

Claims

We claim:

1. A method for the surgical treatment of the prostate by thermal effect, comprising

positioning a urethral emitting probe in the urethra, said probe having a front end, a rear end and an electromagnetic device for generating heat located in the vicinity of said front end and connected to an external means for generating electromagnetic energy;

inserting said urethral emitting probe into the urethra until said electromagnetic device reaches the level of the prostate;

cooling the urethra between the electromagnetic device and the prostate for protecting the urethra from the heat produced by said electromagnetic device, at least at the level of the prostate;

activating said electromagnetic energy generating means for generating electromagnetic energy through said electromagnetic device towards said prostate at a frequency and a power effective to heat said prostate to a predetermined temperature range for a period of time sufficient to treat said prostate by thermal effect while said cooling step minimizes damage to the urethral wall.

2. The method of claim 1, wherein said step of positioning a urethral emitting probe comprises positioning a urethral emitting probe having a front end, a rear end, and said electromagnetic device comprising a microwave antenna located in the vicinity of said front end and connected to an external microwave generating device; wherein said cooling step comprises cooling the urethra between the microwave antenna and the prostate; and wherein said activating step comprises activating said microwave generating device for generating microwaves through said microwave antenna.

3. The method of claim 2, wherein said activating step comprises activating said microwave generating device for generating microwaves at a frequency of about 1300 MHz.+-.50 MHz.

4. The method of claim 2, wherein said cooling step comprises circulating a cooling medium between the microwave antenna and the prostate.

5. The method of claim 2, further comprising the step of sensing the temperature adjacent the urethral probe at least during said activating step, and wherein said cooling step comprises adjusting said cooling of the urethra between said microwave antenna and the prostate in response to said sensed temperature.

6. The method of claim 5, further comprising the step of sensing the temperature of the rectum, and wherein said step of adjusting said cooling is carried out in response to the temperatures sensed adjacent the urethral probe and in the rectum.

7. The method of claim 2, wherein said external microwave generating device comprises power adjusting means for adjusting the power of the microwaves, and further comprising the steps of sensing the temperature adjacent the urethral probe at least during said activating step and adjusting one or both of said cooling and said power adjusting means in response to said sensed temperature.

8. The method of claim 7, further comprising the step of sensing the temperature of the rectum, and wherein said adjusting step is carried out in response to the temperatures sensed adjacent the urethral probe and in the rectum.

9. The method according to claim 2, further comprising the steps of:

(a) inserting into the rectum a rectal probe comprising control means for controlling the positioning of the urethral probe; and

(b) controlling the positioning of the urethral probe based on information received from said rectal probe.

10. The method of claim 9, wherein said activating step comprises activating said microwave generating device for generating microwaves at a frequency of about 1300 MHz.+-.50 MHz.

11. The method of claim 9, wherein said external microwave generating device comprises power adjusting means for adjusting the power of the microwaves, said urethral emitting probe comprises at least one urethral temperature sensor located in the vicinity of the microwave antenna for detecting urethral temperature, and said rectal probe comprises at least one rectal temperature sensor for detecting the rectal temperature at the level of the rectal wall facing the prostate, and further comprising the steps of:

(a) sensing the temperatures detected by said urethral and rectal temperature sensors at least during said activating step; and

(b) adjusting one or both of said cooling and said power adjusting means in response to said sensed temperatures.

12. The method of claim 11, wherein said urethral emitting probe has an inflatable balloon located between said microwave antenna and said front end, and further comprising the step of moving said urethral emitting probe with said balloon not inflated up to the level of the prostate, at which level said balloon reaches the bladder, and then inflating said balloon to lock the front end of the urethral probe in the bladder neck.

13. The method of claim 9, wherein the rectal probe has a front end having an inflatable balloon element, and further comprising the step of inflating said inflatable balloon element with a liquid medium when said rectal probe is inserted in the rectum.

14. The method of claim 13, wherein said step of inflating said inflatable balloon element on said rectal probe with a liquid medium comprises inflating said balloon element with a radio reflecting liquid medium for providing heat protection of the rectal walls.

15. The method of claim 2, further comprising the steps of:

(a) inserting into the rectum a rectal probe comprising an echographic probe connected to a screen equipped echograph and to a central control device for receiving the information provided by said echographic probe;

(b) controlling the positioning of the urethral probe based on the information transmitted to said central control device from said echographic probe.

16. The method of claim 15, wherein said urethral probe comprises an inflatable balloon located between said microwave antenna and said front end, and wherein said position controlling step comprises repositioning said urethral probe by deflating and reinflating said balloon.

17. The method of claim 1, further comprising the step of maintaining the position of the urethral probe in the urethra following said inserting step.

18. The method of claim 17, wherein said probe further comprises an inflatable balloon located between said electromagnetic device and said front end and wherein said position maintaining step comprises inserting said urethral emitting probe with said balloon not inflated into the urethra up to the level of the prostate at which level said balloon reaches the bladder, and then inflating said balloon to lock the front end of the uerthral probe in the bladder neck.

19. A method for the surgical treatment of the prostate, comprising:

(a) positioning a urethral emitting probe in the urethra, said urethral emitting probe having a front end, a rear end, and a microwave antenna located in the vicinity of said front end and connected to an external microwave generating device;

(b) inserting said urethral emitting probe into the urethra until said microwave antenna reaches the level of the prostate; and

(c) activating said microwave generating device for generating microwaves at 1300 MHz.+-.50 MHz through said microwave antenna towards said prostate at a power effective to heat said prostate to a predetermined temperature range for a period of time sufficient to treat said prostate by thermal effect.

20. The method of claim 19, further comprising the step of maintaining the position of the urethral probe in the urethra following said inserting step.

21. The method of claim 20, wherein said probe further comprises an inflatable balloon located between said microwave antenna and said front end and wherein said position maintaining step comprises inserting said urethral emitting probe with said balloon not inflated into the urethra up to the level of the prostate at which level said balloon reaches the bladder, and then inflating said balloon to lock the front end of the urethral probe in the bladder neck.

22. The method of claim 19, further comprising the step of protecting the urethra from the heat produced by said microwave antenna, at least at the level of the prostate.

23. The method of claim 22, wherein said protecting step comprises cooling the urethra between the microwave antenna and the prostate.

24. The method of claim 23, further comprising the step of sensing the temperature adjacent the urethral probe at least during said activating step, and wherein said cooling step comprises adjusting said cooling of the urethra between said microwave antenna and the prostate in response to said sensed temperature.

25. The method of claim 23, wherein said external microwave generating device comprises power adjusting means for adjusting the power of the microwaves, and further comprising the steps of sensing the temperature adjacent the urethral probe at least during said activating step and adjusting one or both of said cooling and said power adjusting means in response to said sensed temperature.

26. The method of claim 25, further comprising the step of sensing the temperature of the rectum, and wherein said adjusting step is carried out in response to the temperatures sensed adjacent the urethral probe and in the rectum.

27. The method of claim 24, further comprising the step of sensing the temperature of the rectum, and wherein said step of adjusting said cooling is carried out in response to the temperatures sensed adjacent the urethral probe and in the rectum.

28. The method according to claim 19, further comprising the steps of:

(a) inserting into the rectum a rectal probe comprising control means for controlling the positioning of the urethral probe; and

(b) controlling the positioning of the urethral probe based on information received from said rectal probe.

29. The method of claim 28 further comprising the step of protecting the urethra from the heat produced by the microwave antenna, at least at the level of the prostate.

30. The method of claim 28, wherein said external microwave generating device comprises power adjusting means for adjusting the power of the microwaves, said urethral emitting probe comprises at least one urethral temperature sensor located in the vicinity of the microwave antenna for detecting urethral temperature, and said rectal probe comprises at least one rectal temperature sensor for detecting the rectal temperature at the level of the rectal wall facing the prostate, and further comprising the steps of,

(a) sensing the temperatures detected by said urethral an rectal temperature sensors at least during said activating step; and

(b) adjusting said power adjusting means for adjusting the power of the microwaves in response to said sensed temperatures.

31. The method of claim 30, wherein said urethral emitting probe has an inflatable balloon located between said microwave antenna and said front end, and further comprising the step of moving said urethral emitting probe with said balloon not inflated up to the level of the prostate, at which level said balloon reaches the bladder, and then inflating said balloon to lock the front end of the urethral probe in the bladder neck.

32. The method of claim 28, wherein the rectal probe has a front end having an inflatable balloon element, and further comprising the step of inflating said inflatable balloon element with a liquid medium when said rectal probe is inserted in the rectum.

33. The method of claim 32, wherein said step of inflating said inflatable balloon element on said rectal probe with a liquid medium comprises inflating said balloon element with a radio reflecting liquid medium for providing heat protection of the rectal walls.

34. The method of claim 19, further comprising the steps of:

(a) inserting into the rectum a rectal probe comprising an echographic probe connected to a screen equipped echograph and to a central control device for receiving the information provided by said echographic probe;

(b) controlling the positioning of the urethral probe based on the information transmitted to said central control device from said echographic probe.

35. The method of claim 34, wherein said urethral probe comprises an inflatable balloon located between said microwave antenna and said front end, and wherein said position controlling step comprises repositioning said urethral probe by deflating and reinflating said balloon.

36. An apparatus for the surgical treatment of the prostate by thermal effect, comprising

an external means for generating electromagnetic energy;

a urethral emitting probe dimensioned for insertion in the urethra, said probe having a front end, a rear end, and an electromagnetic device for generating heat located in the vicinity of said front end and connected to said external means for generating electromagnetic energy;

means extending substantially the full length of the electromagnetic device for cooling the urethra for protecting the urethra from the heat produced by said electromagnetic device, at least at the level of the prostate;

means for activating said electromagnetic energy generating means for generating electromagnetic energy through said electromagnetic device towards said prostate at a frequency and a power effective to heat said prostate to a predetermined temperature range for a period of time sufficient to treat said prostate by thermal effect while said cooling means minimizes damage to the urethral wall.

37. The apparatus of claim 36, wherein said electromagnetic device comprises a microwave antenna; wherein said means for generating electromagnetic energy comprises a microwave generating device; and wherein said means for cooling the urethra from the heat produced by said electromagnetic device comprises means for cooling the urethra between the microwave antenna and the prostate.

38. The apparatus of claim 37, wherein said activating means comprises means for activating said microwave generating device for generating microwaves at a frequency of about 1300 MHz.+-.50 MHz.

39. The apparatus of claim 37, wherein said cooling means comprises means for circulating a cooling medium between the microwave antenna and the prostate.

40. The apparatus of claim 37, further comprising means for sensing the temperature adjacent the urethral probe and means for adjusting said cooling means for adjusting cooling of the urethra between said microwave antenna and the prostate in response to said sensed temperature.

41. The apparatus of claim 40, further comprising means for sensing the temperature of the rectum, and wherein said means for adjusting said cooling means is responsive to the temperatures sensed adjacent the uerthral probe and in the rectum.

42. The apparatus of claim 37, wherein said external microwave generating device has a variable power output, means for sensing the temperature adjacent the urethral probe, and means for adjusting one or both of said cooling means and said power output in response to said sensed temperature.

43. The apparatus of claim 42, further comprising means for sensing the temperature of the rectum, and wherein said means for adjusting is responsive to the temperatures sensed adjacent the urethral probe and in the rectum.

44. The apparatus of claim 37, further comprising a rectal probe insertable in the rectum and comprising control means providing an output signal indicative of the position of the urethral probe, and means for controlling the positioning of the urethral probe based on the output signal from said rectal probe.

45. The apparatus of claim 44, wherein said means for activating comprises means for activating said microwave generating device for generating microwaves at a frequency of about 1300 MHz.+-.50 MHz.

46. The apparatus of claim 44, wherein said external microwave generating device comprises power adjusting means for adjusting the power of the microwaves, said urethral emitting probe comprises at least one urethral temperature sensor located in the vicinity of the microwave antenna for detecting urethral temperature, and said rectal probe comprises at least one rectal temperature sensor for detecting the rectal temperature at the level of the rectal wall facing the prostate, and further comprising means for sensing the temperatures detected by said urethral and rectal temperature sensors, and means for adjusting one or both of said cooling means and said power adjusting means in response to said sensed temperatures.

47. The apparatus of claim 46, wherein said urethral emitting probe has an inflatable balloon located between said microwave antenna and said front end, and further comprising means for inflating said balloon to lock the front end of the urethral probe in the bladder neck.

48. The apparatus of claim 44, wherein the rectal probe has a front end having an inflatable balloon element, and further comprising means for inflating said inflatable balloon element with a liquid medium when said rectal probe is inserted in the rectum.

49. The apparatus of claim 48, wherein said liquid medium comprises a radio reflecting liquid medium for inflating said balloon element on said rectal probe for providing heat protection of the rectal walls.

50. The apparatus of claim 37, wherein said cooling means comprises said urethral emitting probe having an inlet duct and an outlet duct communicating at the front end of said probe for accommodating circulation of a fluid medium.

51. The apparatus of claim 50, wherein said inlet and outlet ducts occupy a longitudinally extending annular section of said probe.

52. The apparatus of claim 37, wherein said cooling means comprises said urethral emitting probe having plural inlet ducts and plural outlet ducts, each inlet duct communicating with a corresponding outlet duct at the front end of said probe, for accommodating circulation of a fluid medium.

53. The apparatus of claim 52, wherein said inlet ducts and outlet ducts occupy longitudinally extending annular sectors of said probe.

54. The apparatus of claim 36, further comprising position maintaining means for maintaining the position of the urethral probe in the urethra following insertion.

55. The apparatus of claim 54, wherein said position maintaining means comprises an inflatable balloon located between said electromagnetic device and the front end of said probe, and a duct for feeding an inflating medium to said balloon for locking the front end of the urethral probe in the bladder neck.

56. The apparatus of claim 36, further comprising a rectal probe insertable in the rectum and comprising an echographic probe connected to a screen equipped echograph and to a central control device for receiving the information provided by said echographic probe, and means for controlling the positioning of the urethral probe based on the information transmitted to said central control device from said echographic probe.

57. The apparatus of claim 56, wherein said urethral probe comprises an inflatable balloon located between said electromagnetic device and said front end, and wherein said means for controlling the positioning of the urethral probe comprises means for deflating and reinflating said balloon.

58. An apparatus for the surgical treatment of the prostate, comprising:

a urethral emitting probe dimensioned for insertion in the urethra, said urethral emitting probe having a front end, a rear end, and a microwave antenna located in the vicinity of said front end;

an external microwave generating device connected to said antenna; and

means for activating said microwave generating device for generating microwaves at 1300 MHz.+-.50 MHz through said microwave antenna towards said prostate at a power effective to heat said prostate to a predetermined temperature range for a period of time sufficient to treat said prostate by thermal effect.

59. The apparatus of claim 58, further comprising position maintaining means for maintaining the position of the urethral probe in the urethra following insertion.

60. The apparatus of claim 59, wherein said position maintaining means comprises an inflatable balloon located between said microwave antenna and said front end, and a duct for feeding an inflating medium to said balloon for locking the front end of the urethral probe in the bladder neck.

61. The apparatus of claim 58, further comprising means for protecting the urethra from the heat produced by said microwave antenna, at least at the level of the prostate.

62. The apparatus of claim 61, wherein said means for protecting the urethra from the heat produced by said microwave antenna comprises means for cooling the urethra between the microwave antenna and the prostate.

63. The apparatus of claim 66, further comprising means for sensing the temperature adjacent the urethral probe, and means for adjusting said cooling means for adjusting the cooling of the urethra between said microwave antenna and the prostate in response to said sensed temperature.

64. The apparatus of claim 63, further comprising means for sensing the temperature of the rectum, and wherein said means for adjusting said cooling means is responsive to the temperatures sensed adjacent the urethral probe and in the rectum.

65. The apparatus of claim 66, wherein said external microwave generating device having a variable power output, means for sensing the temperature adjacent the urethral probe, and means for adjusting one or both of said cooling means and said power output in response to said sensed temperature.

66. The apparatus of claim 65, further comprising means for sensing the temperature of the rectum, and wherein said means for adjusting is responsive to the temperatures sensed adjacent the urethral probe and in the rectum.

67. The apparatus of claim 66, wherein said cooling means comprises said urethral emitting probe having an inlet duct and an outlet duct communicating at the front end of said probe for accommodating circulation of a fluid medium.

68. The apparatus of claim 67, wherein said inlet and outlet ducts occupy a longitudinally extending annular section of said probe.

69. The apparatus of claim 66, wherein said cooling means comprises said urethral emitting probe having plural inlet ducts and plural outlet ducts, each inlet duct communicating with a corresponding outlet duct at the front end of said probe, for accommodating circulation of a fluid medium.

70. The apparatus of claim 69, wherein said inlet ducts and outlet ducts occupy longitudinally extending annular sectors of said probe.

71. The apparatus of claim 58, further comprising a rectal probe insertable in the rectum and providing an output signal indicative of the position of the urethral probe, and means for controlling the positioning of the urethral probe based on the output signal from said rectal probe.

72. The apparatus of claim 71, further comprising means for protecting the urethra from the heat produced by said microwave antenna, at least at the level of the prostate.

73. The apparatus of claim 71, wherein said external microwave generating device comprises power adjusting means for adjusting the power of the microwaves, said urethral emitting probe comprises at least one urethral temperature sensor located in the vicinity of the microwave antenna for detecting urethral temperature, and said rectal probe comprises at least one rectal temperature sensor for detecting the rectal temperature at the level of the rectal wall facing the prostate, and further comprising means for sensing the temperatures detected by said urethral and rectal temperature sensors, and means for adjusting said power adjusting means for adjusting the power of the microwaves in response to said sensed temperatures.

74. The apparatus of claim 73, wherein said urethral emitting probe has an inflatable balloon located between said microwave antenna and said front end, and further comprising means for inflating said balloon to lock the front end of the urethral probe in the bladder neck.

75. The apparatus of claim 71, wherein the rectal probe has a front end having an inflatable balloon element, and further comprising means for inflating said inflatable balloon element with a liquid medium when said rectal probe is inserted in the rectum.

76. The apparatus of claim 75, wherein said liquid medium comprises a radio reflecting liquid medium for inflating said balloon element on said rectal probe for providing heat protection of the rectal walls.

77. The apparatus of claim 58, further comprising a rectal probe insertable in the rectum and comprising an echographic probe connected to a screen equipped echograph and to a central control device for receiving information provided by said echographic probe, and means for controlling the positioning of the urethral probe based on the information transmitted to said central control device from said echographic probe.

78. The apparatus of claim 77, wherein said urethral probe comprises an inflatable balloon located between said microwave antenna and said front end, and wherein said means for controlling the positioning of the urethral probe comprises means for deflating and reinflating said balloon.

FIELD OF THE INVENTION

The present invention relates to a method and apparatus for the surgical treatment of tissues by thermal effect, and in particular, the prostate, using a urethral microwave-emitting probe means.

BACKGROUND OF THE INVENTION

European patent 0,248,758 describes a microwave applicator which is inserted in the rectum for treating the prostate by hyperthermia. The microwave applicator is kept in position inside the rectum by a laterally projecting balloon, meaning that special protection of the rectum is required. Preferably, for heating the prostate, means are provided for reflecting the emitted microwaves which are then concentrated at the side of the body opening opposite to the balloon. Ducts are provided in the microwave emitting rectal applicator for circulating a cooling liquid (see page 5, lines 1 to 5).

The cooling liquid protects the rectal walls in contact with the microwave antenna from damage. Moreover, the presence of the reflecting means is absolutely necessary to prevent the antenna from emitting in all directions, when the radiation is only required to be directed onto the prostate tissues.

European patent 0,246,176 describes a catheter having an antenna equipped with a temperature sensor which is inserted into the urethra through to the bladder, for controlling the temperature reached in the urethra through use of the microwave applicator described in the above-cited European patent 0,248,558.

From a practical point of view, the design of the microwave applicator described in European patent 0,248,758 for introduction in the rectum, is not satisfactory in that the application lacks accuracy since the prostate is remotely-irradiated.

It is furthermore essential with this method to prevent the emission of microwaves in all directions, this implying an emitting antenna of very special design equipped with reflecting means for directing the radiated microwaves in only one direction, namely towards the prostate.

Also, and unquestionably, with such a device, it is quite difficult, if not impossible, to protect the sphincter, and more generally to protect the surrounding tissues. This being especially so in the case of bladder treatment.

Finally, no working frequency is disclosed.

European patent 0,105,677 describes such a microwave antenna device for hyperthermia therapy designed to be introduced in the tract or the lumen, in which device the antenna assembly is placed inside a thin supple polymer film, without any means of protecting the sensitive tissues from the heat. The working frequency is broadly disclosed as ranging between 300 and 3,000 MHz, for instance 915 MHz (page 4, lines 7 and 24).

Patent document WO-A-81/03616 to Bicher describes yet again a microwave antenna system for hyperthermia therapy, which is inserted into a body cavity and used for the treatment of cancer and similar. Typical examples of inserting apertures are the mouth and upper throat.

The introductory part of said patent document cites the document J. Microwave Power 14(2): 167-171 (1979) relative to an applicator working at a frequency of 400 or 915 MHz, introduced through the rectum for irradiation of the prostate. It is specified that said irradiation treatment involves a burning of the tissues which are close to the electrode.

According to said document, the characteristic of this irradiation treatment is that it is carried out at a lower frequency and at a higher wavelength to improve penetration into the tissues to depths of 5 to 6 cm. Such deep penetration permits extensive irradiation of large tumors in the bowels or similar.

The revue "Proceedings of the 13th Annual Northeast Bioengineering Conference, Philadelphia, Mar. 12-13, 1987, pages 390-393, Ryan" describes the pretreating by microwave-induced hyperthermia of patients suffering from biliary obstruction due to cancer, by inserting a catheter into the choledoch to allow drainage in an invasive way. The catheter works at 915 MHz.

Tests have been carried out with the same antenna in various media, as reported in FIG. 5. In the case of tests B and D, the medium was a saline solution, and it is underlined in the "Discussion" part that when the medium is changed from air to a conductive medium such as a saline or bile medium, the performances decrease dramatically, which rather discourages the specialist from using a saline solution in microwave-induced hyperthermia.

Also, it is known from Proceedings of the IEEE, 72 (1984), February, No. 2, 224-225, the advantage of using focused microwave hyperthermia applicators. It is also disclosed obtention of an optimal frequency for a fixed aperture size and a given penetration depth. FIG. 2 discloses optimal frequencies for given penetration depth of 2, 4 and 6 cm at 3,000; 1,500 and 915 MHz.

SUMMARY OF THE INVENTION

It is now a main object of the present invention to solve the new technical problem consisting in providing a solution permitting a more accurate surgical treatment of tissues by thermal effect, in particular of the prostate.

It is a further main object of the present invention to solve the above new technical problem, particularly in the thermal effect treatment of the prostate, without the need to use special probe means emitting in only one direction.

It is a further main object of the present invention to solve the new technical problem, consisting in providing a solution permitting to precisely generate the microwaves in a relatively narrow penetration field, thereby avoiding to damage the tissues surrounding the tissues to be treated by thermal effect, these surrounding tissues necessitating not to be reached by the microwaves used to perform the thermal effect treatment.

It is another main object of the present invention to solve the new technical problem consisting in providing a solution permitting to perform the treatment of tissues by thermal effect in a localized manner, while providing a possibility of adapting the thermal effect treatment to the shape and the size of the tissues to be treated.

It is another object of the present invention to solve the aforesaid new technical problems in a semi-invasive way, namely by using the natural body cavities or body lumens.

All these technical problems are solved for the first time by the present invention, extremely simply, inexpensively, with greater accuracy and reliability a manner exploitable on an industrial scale.

According to a first aspect, the present invention provides a method for the surgical treatment of tissues by thermal effect, in particular prostate, comprising using an emitting probe having a front end and a rear end, capable of being inserted in a bodylumen, said emitting probe comprising a microwave antenna means located intermediate or in the vicinity of said front end, said microwave antenna means being connected to an external microwave generating device and generating microwaves through said microwave antenna means towards said tissues to be treated with said microwave generating device, at a frequency of about 1300 MHz.+-.50 MHz and a power effective to heat said tissues to a predetermined temperature for a period of time sufficient to treat said tissues by thermal effect.

According to the present invention, the thermal effect is preferably a "thermotherapy", that means that the tissues are treated by heat energy at a temperature higher than 45.degree. C. and perferably ranging between about 45.degree. C. and not more than about 85.degree. C., during a period of time sufficient to reach necrosis of the tissues submitted to the thermal effect.

Thermal effect treatment according to the preferred invention embodiment is fully different from the hyperthermia treatment of the prior art, since hyperthermia is limited to a temperature range lower than 45.degree. C. and generally of 40.degree. C.-43.degree. C. The invention is based on the discovery of unexpected positive therapeutical effects provided by a heating of tissues at a temperature higher than 45.degree. C. versus a heating of said tissues at a temperature lower than 45.degree. C. But, the invention can also be used to perform a hyperthermia treatment.

According to a preferred embodiment, said emitting probe is a urethral probe capable of being inserted in the urethra, and comprises positioning means to position and maintain the positioning of the urethral probe in the urethra. Preferably, the positioning means comprise an inflatable urethral balloon means located between said microwave antenna means and said front end, said method further comprising inserting said urethral emitting probe with said balloon means not inflated into the urethra up to the level of the tissues to be treated by thermal effect, at which level and urethral balloon means reaches the bladder, inflating said urethral balloon means to lock the front end of the urethral probe in the bladder neck.

According to a particular embodiment, the invention provides a method for the surgical treatment of tissues by thermal effect, in particular prostate, comprising using a urethral emitting probe having a front end and a rear end, capable of being inserted in the urethra, said urethral emitting probe comprising a microwave antenna means located intermediate or in the vicinity of said front end, said microwave antenna means being connected to an external microwave generating device, said urethral probe means comprising cooling means fed with a cooling medium, said cooling means extending up to the full length of the microwave antenna means, generating microwaves through said microwave antenna means towards said tissues to be treated with said microwave generating device, at a frequency and a power effective to heat said tissues to a predetermined temperature for a period of time sufficient to treat said tissues by thermal effect, and feeding a cooling medium to said cooling means during generation of said microwaves, to prevent burns on the walls of the urethra in contact with the probe means.

Preferably, microwaves are generated at a frequency of about 1300 MHz.+-.50 MHz.

According to a specific feature, the emitting probe is a urethral probe and comprises positioning means to position and maintain the positioning of the urethral probe in the urethra.

According to another specific feature, the positioning means comprise an inflatable balloon means located between said microwave antenna means and said front end, said method comprising inserting said urethral emitting probe with said balloon means not inflated into the urethra up to the level of the tissues to be treated by thermal effect, at which level said balloon means reaches the bladder, inflating said balloon means to lock the front end of the urethral probe in the bladder neck.

According to a further embodiment, the invention provides a method for the surgical treatment of tissues by thermal effect, in particular prostate, comprising:

providing

a) an urethral emitting probe having a front end and a rear end, capable of being inserted in the urethra, said urethral emitting probe comprising a microwave antenna means located intermediate or in the vicinity of said front end, said microwave antenna means being connected to an external microwave generating device;

b) a rectal probe means comprising control means for controlling the positioning of the urethral probe means; and

c) a central control device receiving the information provided by the control means for controlling the positioning of the urethral probe means,

inserting said urethral emitting probe into the urethra up to the level of the tissues to be treated by thermal effect,

controlling the positioning of the urethral probe means with said control device from information received by said control means, optionally correcting the positioning of the urethral probe means; and

generating microwaves through said microwave antenna means towards said tissues to be treated with said microwave generating device, at a frequency and a power effective to heat said tissues to a predetermined temperature for a period of time sufficient to treat said tissues by thermal effect.

According to a further embodiment, the invention provides a method for the surgical treatment of tissues by thermal effect, in particular prostate, comprising:

a) providing a urethral emitting probe having a front end and a rear end, capable of being inserted in the urethra, said urethral emitting probe comprising a microwave antenna means located intermediate or in the vicinity of said front end, said microwave antenna means being connected to an external microwave generating device, and an inflatable balloon means located between said microwave antenna means and said front end,

a rectal probe means comprising an echographic probe connected to a screen equipped echograph and to a central control device for receiving the information provided by said echographic probe and controlling the positioning of the urethral probe means,

b) inserting said urethral emitting probe with said balloon means not inflated into the urethra up to the level of the tissues to be treated by thermal effect, at which level said balloon reaches the bladder, inflating said balloon means to lock the front end of the urethral probe in the bladder neck,

c) controlling the positioning of the urethral probe means with the information transmitted to said central control device from said echographic probe, optionally correcting the positioning of the urethral probe means by way of deflating and inflating again said balloon means,

d) generating microwaves through said microwave antenna means towards said tissues to be treated with said microwave generating device, at a frequency and a power effective to heat said tissues to a predetermined temperature for a period of time sufficient to treat said tissues by thermal effect.

According to another further embodiment, the invention provides a method for the surgical treatment of tissues by thermal effect, in particular prostate, comprising:

a) providing

a urethral emitting probe having a front end and a rear end, capable of being inserted in the urethra, said urethral emitting probe comprising a microwave antenna means located intermediate or in the vicinity of said front end, said microwave antenna means being connected to an external microwave generating device, comprising power adjusting means for adjusting the power of the microwaves, an inflatable balloon means located between said microwave antenna means and said front end, and at least one urethral temperature sensor located in the vicinity of the microwave antenna means for detecting urethral temperature,

a rectal probe means comprising control means for controlling the positioning of the urethral probe means, and a central control device receiving the information provided by the control means for controlling the positioning of the urethral probe means, said rectal probe comprising at least one rectal temperature sensor for detecting the rectal temperature at the level of the rectal wall facing the tissues to be treated, and transmission means to transmit said temperature data recorded by said urethral and rectal temperature sensors to a thermometry device and to said central control device,

b) inserting said urethral emitting probe with said balloon means not inflated into the urethra up to the level of the tissues to be treated by thermal effect, at which level said balloon reaches the bladder, inflating said balloon means to lock the front end of the urethral probe in the bladder neck,

c) generating microwaves through said microwave antenna means towards said tissues to be treated with said microwave generating device, at a frequency and a power effective to heat said tissues to a predetermined temperature for a period of time sufficient to treat said tissues by thermal effect,

d) detecting the respective urethral and rectal temperatures provided by the urethral and rectal temperature sensors, during said microwaves generating step c), and

e) adjusting at least the power of the microwaves, when the temperature detected selected from the urethral temperature and the rectal temperature is not conform to said predetermined temperature range.

According to still another invention embodiment, the invention provides a method for the surgical treatment of tissues by thermal effect, in particular prostate, comprising:

a) providing

a urethral emitting probe having a front end and a rear end, capable of being inserted in the urethra, said urethral emitting probe comprising a microwave antenna means located intermediate or in the vicinity of said front end, said micro