Title:
RADIOACTIVE SOURCE PROJECTOR
Document Type and Number:
United States Patent 3861380
Abstract:
A radioactive source projector for the treatment of cancerous lesions, said projector comprising, on the one hand, a projector unit containing a shield block and, on the other hand, ancillary means for displacing radioactive sources, said means being constituted by source-holders formed by a flexible metallic spring and each of which is intended to be applied at one end in the vicinity of the lesions, and to be joined to an actuating cable, each source holder being contained in a flexible tube secured to a flexible ejection sheath.
Inventors:
Chassagne, Daniel (Wissous, FR)
Delouche, Gilles (Paris, FR)
Fradin, Jean (Bois Comombes, FR)
Rocoplan, Jean-antoine (Sevres, FR)
Delouche, Gilles (Paris, FR)
Fradin, Jean (Bois Comombes, FR)
Rocoplan, Jean-antoine (Sevres, FR)
Plaque It!
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Application Number:
05/300222
Publication Date:
01/21/1975
Filing Date:
10/24/1972
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Export Citation:
Assignee:
Commissariat, L'energie Atomique A. (Paris, FR)
Primary Class:
Other Classes:
976/DIG.353
International Classes:
A61M36/04; A61N5/01
Field of Search:
128/1.1,1.2 250/363,366,369,327,303,393,497-507
US Patent References:
| 2750517 | Method of handling radio-active materials | June 1956 | Baum | |
| 2798164 | Portable chi-ray or gamma source | July 1957 | Untermeyer | |
| 2862108 | Device for containing and exposing a radioactive material | November 1958 | Meilink | |
| 2916628 | Radiographic device | December 1959 | Prest | |
| 3147383 | Apparatus for manipulating radioactive material to and from a storage chamber | September 1964 | Prest | |
| 3224432 | Device for irradiating a body cavity | December 1965 | Billingsley | |
| 3323511 | Radiation source applicator | June 1967 | Holter | |
| 3669093 | APPARATUS FOR GIVING MEDICAL TREATMENT BY IRRADIATION FROM RADIOACTIVE SUBSTANCES | June 1972 | Sauerwein et al. |
Other References:
Intern. Abstracts of Surgery, Vol. 96, No. 6, June, 1953, p. 595..
Primary Examiner:
Howell, Kyle L.
Attorney, Agent or Firm:
Craig & Antonelli
Parent Case Data:
CROSS REFERENCE TO RELATED APPLICATION:
This application is a continuation-in-part of applicants' co-pending application Ser. No. 11,226 filed on Feb. 13, 1970, now abandoned.
Claims:
What is claimed is
1. A radioactive-source projector which comprises:
2. a moveable casing including openings;
3. source-holder means in said casing and extendable through said openings, said source-holder means containing radioactive sources, and said source-holder means including a flexible tubular element that is closed at one end and adapted to be applied to the vicinity of a cancerous tissue to be treated in a living body, and that is opened at the other end for receiving said radioactive sources;
4. shield block means in said casing containing said source-holder means to afford protection against the radioactive sources positioned within said moveable casing;
5. flexible outer tube means receiving said one end of said source-holder means, said outer tube means having a small outer diameter and being adapted to be placed adjacent to the surface of a living body for treatment of cancerous tissue;
6. flexible ejection sheath means having one end connected to said shield block means and another end connected removably to said flexible outer tube for guiding said source-holder means from said shield block means to said flexible outer tube means;
7. actuating cable means removably coupled to said source-holder means for displacing said source-holder means through said flexible ejection sheath means; and
8. transfer means for transferring said actuating cable means and the associated source-holder means via said flexible ejection sheath means from said shield block means to said outer tube means and from said outer tube means to said shield block means.
9. The projector according to claim 1, further comprising another source-holder means in said casing containing dummy non-radioactive sources adapted to be connected to said actuating cable and to be used in place of said source-holder means containing radioactive sources.
10. The projector according to claim 1, wherein a plurality of said source-holder means containing radioactive sources are provided with an equal plurality of associated flexible outer tube means, actuating cable means, flexible ejection sheath means and transfer means, each of said associated means being associated, respectively, with each of said source-holder means and with said shield block means whereby a plurality of said cancerous tissues can be treated with said projector.
11. The projector according to claim 1, wherein said transfer means is an electromechanical transfer device which is electrically controlled to effect displacement of said actuating cable means and its associated source-holder means.
12. The projector according to claim 1, wherein said source-holder means is connected to said actuating cable means by a rapid coupling means.
13. The projector according to claim 1, wherein said flexible outer tube means is connected to said flexible ejection sheath means by a screw coupling.
14. The projector according to claim 1, wherein said source-holder means is a thin elongated metallic element having an external diameter on the order of 2 mm.
15. The projector according to claim 1, wherein the radioactive sources contained in said source-holder means are cesium-137 sources.
16. The projector according to claim 1, wherein a train of sources is housed in said source-holder means said train being formed by a plurality of unit sources having a diameter of 1.5 mm to provide a total activity of 650 mc.
17. The projector according to claim 1, wherein said outer flexible tube means has an external diameter on the order of 5 mm and a length on the order of 30 cm.
18. The projector according to claim 1, wherein said shield block means is formed of tungsten and lead.
19. The projector according to claim 1, wherein said shield block means is formed of depleted uranium.
20. The projector according to claim 1, wherein said source-holder means includes an abutment member which contacts an open end of said flexible outer tube means to prevent the source-holder means from passing beyond a correct irradiation position at the front of said open end of said flexible outer tube means.
1. A radioactive-source projector which comprises:
2. a moveable casing including openings;
3. source-holder means in said casing and extendable through said openings, said source-holder means containing radioactive sources, and said source-holder means including a flexible tubular element that is closed at one end and adapted to be applied to the vicinity of a cancerous tissue to be treated in a living body, and that is opened at the other end for receiving said radioactive sources;
4. shield block means in said casing containing said source-holder means to afford protection against the radioactive sources positioned within said moveable casing;
5. flexible outer tube means receiving said one end of said source-holder means, said outer tube means having a small outer diameter and being adapted to be placed adjacent to the surface of a living body for treatment of cancerous tissue;
6. flexible ejection sheath means having one end connected to said shield block means and another end connected removably to said flexible outer tube for guiding said source-holder means from said shield block means to said flexible outer tube means;
7. actuating cable means removably coupled to said source-holder means for displacing said source-holder means through said flexible ejection sheath means; and
8. transfer means for transferring said actuating cable means and the associated source-holder means via said flexible ejection sheath means from said shield block means to said outer tube means and from said outer tube means to said shield block means.
9. The projector according to claim 1, further comprising another source-holder means in said casing containing dummy non-radioactive sources adapted to be connected to said actuating cable and to be used in place of said source-holder means containing radioactive sources.
10. The projector according to claim 1, wherein a plurality of said source-holder means containing radioactive sources are provided with an equal plurality of associated flexible outer tube means, actuating cable means, flexible ejection sheath means and transfer means, each of said associated means being associated, respectively, with each of said source-holder means and with said shield block means whereby a plurality of said cancerous tissues can be treated with said projector.
11. The projector according to claim 1, wherein said transfer means is an electromechanical transfer device which is electrically controlled to effect displacement of said actuating cable means and its associated source-holder means.
12. The projector according to claim 1, wherein said source-holder means is connected to said actuating cable means by a rapid coupling means.
13. The projector according to claim 1, wherein said flexible outer tube means is connected to said flexible ejection sheath means by a screw coupling.
14. The projector according to claim 1, wherein said source-holder means is a thin elongated metallic element having an external diameter on the order of 2 mm.
15. The projector according to claim 1, wherein the radioactive sources contained in said source-holder means are cesium-137 sources.
16. The projector according to claim 1, wherein a train of sources is housed in said source-holder means said train being formed by a plurality of unit sources having a diameter of 1.5 mm to provide a total activity of 650 mc.
17. The projector according to claim 1, wherein said outer flexible tube means has an external diameter on the order of 5 mm and a length on the order of 30 cm.
18. The projector according to claim 1, wherein said shield block means is formed of tungsten and lead.
19. The projector according to claim 1, wherein said shield block means is formed of depleted uranium.
20. The projector according to claim 1, wherein said source-holder means includes an abutment member which contacts an open end of said flexible outer tube means to prevent the source-holder means from passing beyond a correct irradiation position at the front of said open end of said flexible outer tube means.
Description:
The present invention relates to a radioactive source projector which is intended to be employed in plesiocurietherapy according to the method known as non-radioactive preparation for the treatment of cancerous lesions at the surface of the human body or in either artificial or natural cavities (endocurietherapy), in particular in gynecology.
It is known that, in gynecology, there are essentially two types of methods for the treatment of cancerous lesions, namely transcutaneous teleradiotherapy, whether associated with surgical methods or not, and plesiocurietherapy which has the object of sterilizing the cancerous tumor at the level of the uterine cervix and of its immediately adjacent extensions.
This second method makes use of radioactive sources which are inserted into the vagina and the uterus and which are maintained in contact with the cancerous lesions.
The majority of methods for the treatment of lesions of this type by plesiocurietherapy require the introduction of a probe in the uterus and of a colpostat in the vagina.
In the oldest methods of treatment, these two devices which are known as applicators are loaded with radioactive sources before being brought into the operating room and placed in position on the patient, and it is often difficult to protect personnel against the radioactivity of the sources all the more as the treatment which is carried out calls for the use of sources having higher activity and that a greater number of persons may come close to the patient while the sources are being placed in position and throughout the period of application.
During the last few years, plesiocurietherapy has made substantial strides in the field of radiation protection by virtue of the application of the so-called non-radioactive preparation technique which consists in dissociating the positioning of applicators (colpostat and probe) from the positioning of radioactive sources in these applicators.
In other words, the applicators are first placed in position and it is only during a second stage that the radioactive sources are inserted in the applicators by means of outer tubes.
The present invention relates to a plesiocurietherapy apparatus or applicator which serves to apply the non-radioactive preparation technique. In particular, this apparatus permits accurate remote handling of radioactive sources under conditions of absolute safety; tubes in which the radioactive sources travel are light in weight, flexible, sterilizable, disposable after use and readily disconnectable after the sources have been employed on the patient.
More precisely, the present invention relates to a polyvalent radioactive source projector for plesiocurietherapy according to the method of non-radioactive preparation for the treatment of cancerous lesions at the surface of the body or in either artificial or natural cavities (endocurietherapy) and in particular in gynecology. On the one hand, said projector essentially comprises a projector proper as constituted by a body adapted to rest on a wheeled trolley frame and to contain a shield block which affords protection against radioactive sources and which is formed of a metal or sandwich of heavy metals having a density and an atomic number at least equal to those of lead as well as an electro-mechanical device for transferring said sources which is provided externally with a control panel attached to said body. On the other hand, said projector essentially comprises ancillary means for displacing the sources, said ancillary means being constituted by at least four source-holders each formed of a flexible metallic spring which has contiguous turns fastened together if necessary and which is closed at one end, each source-holder being intended to be applied at one end in the vicinity of or within a cancerous tissue to be treated and being joined by means of a rapid coupling device to an actuating cable which is in turn displaced by said electromechanical transfer device and, in the case of each source-holder, a flexible outer tube which contains said source-holder and permits substantial degrees of curvature is secured by means of a screw-coupling to a flexible ejection sheath which can be joined to the projector proper; and an ancillary unit or control means operatively associated with the electromechanical transfer device for the electric and remote control of displacemnts carried out by the source-holders from said shield block to their irradiation positions at the ends of the outer tubes and conversely for return from said outer tubes to said shield block.
Further properties and advantages of the present invention will be brought out by the following description in which one embodiment of the device according to the invention is given by way of explanation but not in any sense by way of limitation.
Reference is made to the accompanying drawings, in which:
FIG. 1 shows in perspective the complete projector unit together with four flexible sheaths, one of which is completed by the corresponding assembly of source-displacement ancillaries;
FIG. 2 is an axial longitudinal sectional view showing a complete set of source-actuating ancillaries;
FIG. 3 is a view in perspective showing the projector unit, a portion of which has been broken away in order to show the block which serves as a shield for the sources and the electromechanical device for transferring said sources;
FIG. 4 illustrates the control panel of said projector unit;
FIG. 5 is a diagram which shows the mode of utilization of the apparatus according to the invention.
The projector unit is constituted by an outer casing or body 14 which rests on a trolley frame 1 having four wheels and contains an electromechanical transfer device 15 (See FIG. 3), devices for stopping sources in the irradiation position or storage position, and a source shield block 16 which dispenses with the need for any permanent shielding means located outside the projector unit. This shield block is formed, for example, of tungsten and lead or of depleted uranium.
A control panel 2 which is rigidly fixed to the projector body comprises control knobs and visual indicators which are intended to carry out, respectively, the general switching-on (reference 17), checking the application of power (reference 18), checking the selection of sources (reference 19), indicating the positions of each source-holder (reference 20) as well as reading irradiation times (reference 21); an access 22 is also provided for the insertion of a resetting key.
Since the projector is shown in FIG. 1 as comprising four source-holders, four flexible sheaths 3 can therefore pass through the side wall 4. Four flaps 5 are pivotally displaceable by means of a key so that, when the apparatus is not in use, the openings 6 formed in the projector body 14 for the penetration of the sheathed cables may accordingly be closed and any displacement of the corresponding source-holders outside the shield block 16 is thereby prevented.
The projector unit also has four openings (not shown in the drawings) which permit the insertion of a crank-handle for the manual return of each source-holder. In addition, a mechanical counter (not shown) which permits the totalization of the number of ejections is located within the projector body 14.
The ancillaries for the displacement of radioactive sources comprise in the case of each of the four sheaths 3:
1. A flexible source-holder 7 which can be of very small size (for example having an external diameter of 2 mm) which permits of its insertion in the uterus without preliminary anesthesia; the length of said source-holder is constant. There is housed within said source-holder 7 a train of radioactive sources 8 obtained by juxtaposition of unit sources such as, for example, sources of cesium-137 having a diameter of 1.5 mm and a total permissible activity of 650 mc.
An abutment member 23 has the intended function of preventing the source-holder 7 from passing beyond its correct irradiation position at the front end. This is effected by contact between member 23 and end 12' of outer tube 12. The source-holder 7 may be provided if necessary with identical non-radioactive metallic balls 9.
2. An actuating cable 10 which is connected to the source-holder 7 by means of a rapid coupling device 11 and carries out the displacement of the source-holder 7 by means of the electromechanical transfer device 15 which is housed within the projector unit. (The cable is stored in the lower portion of the projector body, for example, on a reel or in the form of a coil.)
3. A flexible outer tube 12 which permits substantial degrees of curvature (for example a radius of curvature of 15 mm). This tube may be formed of a material such as "nylon" and may have, for example, an external diameter of 5 mm and a length of 30 cm.
4. A flexible sheath 3 which is connected to said outer tube 12 by means of a screw-coupling 13 and has a length of 2 meters.
Finally, the electric remote-control means 15' comprises, for example, a light signal system with one color corresponding to each position of storage, irradiation and transfer of radioactive sources from the shield block 16 (located within the interior of the projector proper) to the end of the outer tubes 12 and conversely.
The mode of utilization of the projector in accordance with the invention is as follows:
1. Opening of one, two or more lateral flaps 5 (carried out by the doctor by means of a control-panel key of which he is the sole possessor) results in final selection of the channels which will be utilized.
2. The projector unit is wheeled to the storage room 24 and dummy source-holders (such as non-radioactive balls, for example) are coupled to the actuating cable 10
3. Said projector unit is then wheeled to the radiographic inspection room 25 in order to check the correct operation of the apparatus before proceeding to irradiation of the patient. The operations involved are identical with those which are subsequently to be carried out for the positioning of radioactive source-holders in the patient and are as follows: when the outer tube 12 has been inserted into the vagina the extremity of said outer tube is secured to the sheath 3 by means of the screw-coupling 13. By use of the remote operation control means 15', the electromechanical transfer device 15 is then actuated and causes the source-holder 7 (which contains neutral or non-radioactive sources) to pass first out of the projector unit under the thrust exerted by the cable 10 and then into the sheath 3, then into the outer tube 12. It will be appreciated that the sheath 3 has been previously extended from storage in the bottom of the projector unit via rollers 30 which direct the sheath 3 into tube 31 and then out of the casing 14 via the opening covered by flap 5. The source-holder 7 containing neutral sources is returned into the projector unit, again by means of the remote operation and control device and the outer tube 12, which remains in the vagina, is released from the sheath 3 by means of the screw-coupling 13.
4. The projector unit is returned to the storage room 24 and loaded with radioactive sources (i.e., the source-holder containing the neutral sources is disconnected from cable 13 and replaced by a new source-holder containing radioactive sources).
5. The projector unit is then wheeled to the treatment room 26 to which the patient has been brought after radiographic examination.
6. The sheath 3, which has been extended out of the casing 14, is again attached to the outer tube 12 which has remained in the patient and the same operations as those performed at the time of radiographic inspection in the room 25 are again carried out.
It should be noted that the projector in accordance with the invention can be put to a number of uses outside the field of gynecology and that radioactive sources other than cesium-137 can be employed. This projector permits very different periods of treatments ranging, for example, from one-quarter of an hour to eight days. A further advantage is that the projector can be adapted to the majority of applicators at present in existence (for example probes and colpostats).
An important feature of the apparatus lies in the fact that the control panel 2 can operate only by means of a key which serves both to swing open the lateral flaps 5 and to switch-on the apparatus as a whole.
The projector according to the invention is so designed as to have a small overall size, with the result that it can readily be employed in very small rooms, as well as a light weight (less than 100 kgs), so that the apparatus can readily be moved by one person.
Moreover, the projector has a low exposure rate at the outer surface of its body 14, with the result that it does not require to be completed by any shielding for the purpose of maintaining the exposure rate at legally and medically permissible values.
All the control circuits of the electromechanical devices are supplied with direct current at low voltage (for example 24 V) in order to remove any danger of accidental electrocution.
On the general control panel 2, the reference numeral 27 designates circuit breakers which are intended to initiate shut-down of the apparatus in the event of accidental overvoltage and the reference numeral 28 designates the control knobs of each visual signal circuit.
Reference numeral 30 refers to a pair of rollers for directing sheath 3 through tube 31.
While the novel principles of the invention have been described, it will be understood that various omissions, modifications and changes in these principles may be made by one skilled in the art without departing from the spirit and scope of the invention.
It is known that, in gynecology, there are essentially two types of methods for the treatment of cancerous lesions, namely transcutaneous teleradiotherapy, whether associated with surgical methods or not, and plesiocurietherapy which has the object of sterilizing the cancerous tumor at the level of the uterine cervix and of its immediately adjacent extensions.
This second method makes use of radioactive sources which are inserted into the vagina and the uterus and which are maintained in contact with the cancerous lesions.
The majority of methods for the treatment of lesions of this type by plesiocurietherapy require the introduction of a probe in the uterus and of a colpostat in the vagina.
In the oldest methods of treatment, these two devices which are known as applicators are loaded with radioactive sources before being brought into the operating room and placed in position on the patient, and it is often difficult to protect personnel against the radioactivity of the sources all the more as the treatment which is carried out calls for the use of sources having higher activity and that a greater number of persons may come close to the patient while the sources are being placed in position and throughout the period of application.
During the last few years, plesiocurietherapy has made substantial strides in the field of radiation protection by virtue of the application of the so-called non-radioactive preparation technique which consists in dissociating the positioning of applicators (colpostat and probe) from the positioning of radioactive sources in these applicators.
In other words, the applicators are first placed in position and it is only during a second stage that the radioactive sources are inserted in the applicators by means of outer tubes.
The present invention relates to a plesiocurietherapy apparatus or applicator which serves to apply the non-radioactive preparation technique. In particular, this apparatus permits accurate remote handling of radioactive sources under conditions of absolute safety; tubes in which the radioactive sources travel are light in weight, flexible, sterilizable, disposable after use and readily disconnectable after the sources have been employed on the patient.
More precisely, the present invention relates to a polyvalent radioactive source projector for plesiocurietherapy according to the method of non-radioactive preparation for the treatment of cancerous lesions at the surface of the body or in either artificial or natural cavities (endocurietherapy) and in particular in gynecology. On the one hand, said projector essentially comprises a projector proper as constituted by a body adapted to rest on a wheeled trolley frame and to contain a shield block which affords protection against radioactive sources and which is formed of a metal or sandwich of heavy metals having a density and an atomic number at least equal to those of lead as well as an electro-mechanical device for transferring said sources which is provided externally with a control panel attached to said body. On the other hand, said projector essentially comprises ancillary means for displacing the sources, said ancillary means being constituted by at least four source-holders each formed of a flexible metallic spring which has contiguous turns fastened together if necessary and which is closed at one end, each source-holder being intended to be applied at one end in the vicinity of or within a cancerous tissue to be treated and being joined by means of a rapid coupling device to an actuating cable which is in turn displaced by said electromechanical transfer device and, in the case of each source-holder, a flexible outer tube which contains said source-holder and permits substantial degrees of curvature is secured by means of a screw-coupling to a flexible ejection sheath which can be joined to the projector proper; and an ancillary unit or control means operatively associated with the electromechanical transfer device for the electric and remote control of displacemnts carried out by the source-holders from said shield block to their irradiation positions at the ends of the outer tubes and conversely for return from said outer tubes to said shield block.
Further properties and advantages of the present invention will be brought out by the following description in which one embodiment of the device according to the invention is given by way of explanation but not in any sense by way of limitation.
Reference is made to the accompanying drawings, in which:
FIG. 1 shows in perspective the complete projector unit together with four flexible sheaths, one of which is completed by the corresponding assembly of source-displacement ancillaries;
FIG. 2 is an axial longitudinal sectional view showing a complete set of source-actuating ancillaries;
FIG. 3 is a view in perspective showing the projector unit, a portion of which has been broken away in order to show the block which serves as a shield for the sources and the electromechanical device for transferring said sources;
FIG. 4 illustrates the control panel of said projector unit;
FIG. 5 is a diagram which shows the mode of utilization of the apparatus according to the invention.
The projector unit is constituted by an outer casing or body 14 which rests on a trolley frame 1 having four wheels and contains an electromechanical transfer device 15 (See FIG. 3), devices for stopping sources in the irradiation position or storage position, and a source shield block 16 which dispenses with the need for any permanent shielding means located outside the projector unit. This shield block is formed, for example, of tungsten and lead or of depleted uranium.
A control panel 2 which is rigidly fixed to the projector body comprises control knobs and visual indicators which are intended to carry out, respectively, the general switching-on (reference 17), checking the application of power (reference 18), checking the selection of sources (reference 19), indicating the positions of each source-holder (reference 20) as well as reading irradiation times (reference 21); an access 22 is also provided for the insertion of a resetting key.
Since the projector is shown in FIG. 1 as comprising four source-holders, four flexible sheaths 3 can therefore pass through the side wall 4. Four flaps 5 are pivotally displaceable by means of a key so that, when the apparatus is not in use, the openings 6 formed in the projector body 14 for the penetration of the sheathed cables may accordingly be closed and any displacement of the corresponding source-holders outside the shield block 16 is thereby prevented.
The projector unit also has four openings (not shown in the drawings) which permit the insertion of a crank-handle for the manual return of each source-holder. In addition, a mechanical counter (not shown) which permits the totalization of the number of ejections is located within the projector body 14.
The ancillaries for the displacement of radioactive sources comprise in the case of each of the four sheaths 3:
1. A flexible source-holder 7 which can be of very small size (for example having an external diameter of 2 mm) which permits of its insertion in the uterus without preliminary anesthesia; the length of said source-holder is constant. There is housed within said source-holder 7 a train of radioactive sources 8 obtained by juxtaposition of unit sources such as, for example, sources of cesium-137 having a diameter of 1.5 mm and a total permissible activity of 650 mc.
An abutment member 23 has the intended function of preventing the source-holder 7 from passing beyond its correct irradiation position at the front end. This is effected by contact between member 23 and end 12' of outer tube 12. The source-holder 7 may be provided if necessary with identical non-radioactive metallic balls 9.
2. An actuating cable 10 which is connected to the source-holder 7 by means of a rapid coupling device 11 and carries out the displacement of the source-holder 7 by means of the electromechanical transfer device 15 which is housed within the projector unit. (The cable is stored in the lower portion of the projector body, for example, on a reel or in the form of a coil.)
3. A flexible outer tube 12 which permits substantial degrees of curvature (for example a radius of curvature of 15 mm). This tube may be formed of a material such as "nylon" and may have, for example, an external diameter of 5 mm and a length of 30 cm.
4. A flexible sheath 3 which is connected to said outer tube 12 by means of a screw-coupling 13 and has a length of 2 meters.
Finally, the electric remote-control means 15' comprises, for example, a light signal system with one color corresponding to each position of storage, irradiation and transfer of radioactive sources from the shield block 16 (located within the interior of the projector proper) to the end of the outer tubes 12 and conversely.
The mode of utilization of the projector in accordance with the invention is as follows:
1. Opening of one, two or more lateral flaps 5 (carried out by the doctor by means of a control-panel key of which he is the sole possessor) results in final selection of the channels which will be utilized.
2. The projector unit is wheeled to the storage room 24 and dummy source-holders (such as non-radioactive balls, for example) are coupled to the actuating cable 10
3. Said projector unit is then wheeled to the radiographic inspection room 25 in order to check the correct operation of the apparatus before proceeding to irradiation of the patient. The operations involved are identical with those which are subsequently to be carried out for the positioning of radioactive source-holders in the patient and are as follows: when the outer tube 12 has been inserted into the vagina the extremity of said outer tube is secured to the sheath 3 by means of the screw-coupling 13. By use of the remote operation control means 15', the electromechanical transfer device 15 is then actuated and causes the source-holder 7 (which contains neutral or non-radioactive sources) to pass first out of the projector unit under the thrust exerted by the cable 10 and then into the sheath 3, then into the outer tube 12. It will be appreciated that the sheath 3 has been previously extended from storage in the bottom of the projector unit via rollers 30 which direct the sheath 3 into tube 31 and then out of the casing 14 via the opening covered by flap 5. The source-holder 7 containing neutral sources is returned into the projector unit, again by means of the remote operation and control device and the outer tube 12, which remains in the vagina, is released from the sheath 3 by means of the screw-coupling 13.
4. The projector unit is returned to the storage room 24 and loaded with radioactive sources (i.e., the source-holder containing the neutral sources is disconnected from cable 13 and replaced by a new source-holder containing radioactive sources).
5. The projector unit is then wheeled to the treatment room 26 to which the patient has been brought after radiographic examination.
6. The sheath 3, which has been extended out of the casing 14, is again attached to the outer tube 12 which has remained in the patient and the same operations as those performed at the time of radiographic inspection in the room 25 are again carried out.
It should be noted that the projector in accordance with the invention can be put to a number of uses outside the field of gynecology and that radioactive sources other than cesium-137 can be employed. This projector permits very different periods of treatments ranging, for example, from one-quarter of an hour to eight days. A further advantage is that the projector can be adapted to the majority of applicators at present in existence (for example probes and colpostats).
An important feature of the apparatus lies in the fact that the control panel 2 can operate only by means of a key which serves both to swing open the lateral flaps 5 and to switch-on the apparatus as a whole.
The projector according to the invention is so designed as to have a small overall size, with the result that it can readily be employed in very small rooms, as well as a light weight (less than 100 kgs), so that the apparatus can readily be moved by one person.
Moreover, the projector has a low exposure rate at the outer surface of its body 14, with the result that it does not require to be completed by any shielding for the purpose of maintaining the exposure rate at legally and medically permissible values.
All the control circuits of the electromechanical devices are supplied with direct current at low voltage (for example 24 V) in order to remove any danger of accidental electrocution.
On the general control panel 2, the reference numeral 27 designates circuit breakers which are intended to initiate shut-down of the apparatus in the event of accidental overvoltage and the reference numeral 28 designates the control knobs of each visual signal circuit.
Reference numeral 30 refers to a pair of rollers for directing sheath 3 through tube 31.
While the novel principles of the invention have been described, it will be understood that various omissions, modifications and changes in these principles may be made by one skilled in the art without departing from the spirit and scope of the invention.