Abstract:
A brachytherapy appliance and method utilizing a body portion or element removably positionable within a cavity of a living body, such as an oral cavity, the body portion having a shape at least generally conforming to a surface within the cavity in proximity to a cancer or diseased tissue so as to be retainable in intimate relation with the surface, and at least one conduit in connection with the body portion and extending to a predetermined location adjacent to the cancer when the body portion is retained in the cavity, the at least one conduit being adapted for cooperatively receiving a radiation emitting element or media for positioning the radiation emitting element or media at the predetermined location adjacent to the cancer for irradiating the cancer, and at least one radiation shield in association with the body portion adapted for shielding adjacent tissue and/or organs from radiation emitted by the radiation emitting element or media.

Description:
TECHNICAL FIELD 
     This invention relates generally to appliances positionable in a cavity of a living body, such as the body of a human or animal, for removably positioning a therapeutic device in a desired precise location in relation to a selected portion of the body in or adjacent to the cavity, and, more particularly, the invention relates to a brachytherapy appliance positionable and retainable in the oral cavity for holding one or more radiation therapy delivery elements in desired relation to a cancer, tumor, or other diseased tissue, for irradiating it, while shielding adjacent healthy tissue regions from the radiation, and a method of practicing the same. 
     BACKGROUND OF THE INVENTION 
     In the field of medicine, there are courses of treatment for diseases and injuries which are facilitated by placement of a therapeutic device within a body cavity, in a particular relation to a selected, or a predetermined, region thereof, or adjacent tissue, for delivering a therapeutic dosage. For instance, in oncology, particularly for the treatment of mouth and/or throat cancers, and more generally cancers of the head and/or throat, breast and prostate, and also non-cancerous diseases, such as non-malignant tumors and neuromas, therapeutic benefit has been achieved by brachytherapy, that is, the placement of radioactive elements, also referred to as radioactive seeds, in proximity to, or surgically directly in the cancer or cancerous or other diseased tissue, for directing radiation thereat. However, a side effect that has been observed is relatively uncontrolled irradiation of the surrounding tissue and/or organs. Specifically in this regard in relation to cancers and other diseases of the neck, head and mouth, is injury to and loss of teeth, and injury to salivary and other glands such as those relating to the sense of taste and smell, which is undesirable for many reasons. 
     It is thus sought to provide an appliance configured and/or adapted for placement within a body cavity, such as, but not limited to, the oral cavity, which allows removably or temporarily positioning of one or more radiation emitting elements, such as radioactive seeds, wires or the like, in precise relation to a cancer or other diseased tissue in or adjacent to the cavity, which provides shielding for other regions of healthy tissue, glands and/or organs, as well as teeth, from the radiation emitted by the radioactive element or elements. Further in this regard, it would be advantageous to provide an appliance custom configured, such as by molding, to conform to the shapes and contours of certain tissue regions defining a body cavity, so as to be positionable and automatically retained thereagainst in conforming relation thereto in a selected precise location and orientation in relation to the tissue which is to be irradiated, while providing radiation shielding for the other tissue and organs not intended to be irradiated. In such appliance, it would be advantageous to provide at least one receptacle or passage into which a therapeutic device, such as a seed or seeds, or a wire having a radioactive tip or other region, or other radioactive medium, is removably insertable, so as to be positioned for delivery of a radioactive dose in precise relation to a cancer to be irradiated for a specific time or specific therapeutic dosage. 
     SUMMARY OF THE INVENTION 
     According to the invention, a brachytherapy appliance and method of practicing the same, which overcomes one or more of the problems and/or shortcomings, and provides one or more of the advantages set forth above, is disclosed. 
     According to a preferred aspect of the invention, a brachytherapy appliance is provided including a body portion fabricated to conform to interior surface contours of a body cavity, particularly the oral cavity, so as to be insertable into the cavity and positioned in close proximity to or against the interior surface soon as to be retained in the cavity, the body portion including at least one receptacle or passage disposed in or extending through a portion thereof adapted for receiving and holding a therapeutic element in precise relation to a cancer or cancerous tissue in the cavity or in nearby tissue, and shielding for protecting other tissue and body portions from the therapeutic element or effects thereof, particularly radiation therefrom. The invention additionally includes a therapeutic element, which can be for instance, but is not limited to, a radiation delivery element such as a wire including a radiation emitting or irradiated portion, such as a tip or other segment, or one or more radiation emitting seeds, or other radioactive media, which is removably insertable in the body portion receptacle or passage in a predetermined position and/or orientation for emitting radiation toward the cancer or cancerous tissue. By providing the radioactive media separately of the body portion, the number and radioactivity of the radioactive media can be varied, for instance, to allow changing the radiation dose or time of dosage over the course of therapy, or otherwise. This also allows use of the same radioactive media with more than one appliance, and also facilitates handling and storage of the radioactive media, and safe disposal of the non-radioactive body portion. 
     According to another preferred aspect of the invention, the body portion is configured or custom fit to fit securely on the upper teeth in the oral cavity, if any, or to the upper edentulous arch, such as by molding, so as to be positioned in the superior region of the oral cavity. The body portion is fabricated from a suitable polymeric material, such as, but not limited to, a suitable well known, commercially available moldable dental acrylic, such as, but not limited to, a methyl methacrylate. The at least one receptacle or passage will be molded into the body portion, and will comprise a tube or catheter adapted for receiving the radiation emitting media, such as a wire, therein, the tube or catheter being routed so as to have a portion or opening positioned to be disposed in desired relation to the cancer when the body portion is properly positioned in the body cavity, for delivery of the desired therapy, i.e., irradiation and destruction of the cancerous or diseased tissue or cells. The body portion additionally includes one or more layers of shielding material embedded therein, such as a lead shielding material, positioned for shielding adjacent healthy tissue, organs, teeth, or other vulnerable body parts, from radiation emitted by a radioactive region or portion of a wire or other radiation emitting media inserted into the tube or catheter. The lead shielding material, in turn, is incorporated into the body portion such that when the body portion is positioned in the oral cavity, the lead material will not contact the adjacent tissue, nor will the lead material be exposed to saliva or other fluids present in the cavity, which could carry contaminants to the surrounding tissue. It is also contemplated that an appliance of the invention can be configured for fitting in other regions of the oral cavity, such as on the lower teeth and/or edentulous arch, for treatment of cancers or diseases in the vicinity thereof. 
     According to still another preferred aspect of the invention, the radiation emitting media comprises a wire removably insertable into the tube or catheter, and can be, for instance, a stainless steel wire, and can be, for instance, tipped with iridium  192 , or another suitable radioactive substance. The wire is of a suitable length so as to extend through the tube or catheter so as to position the irradiated portion in the desired location in relation to the cancer or other diseased tissue, hereinafter sometimes referred to as “the cancer”, with the opposite end of the wire protruding from the appliance, and more preferably, also from the body cavity so as to be graspable for insertion and removal from the appliance. The wire can also include indicia along the length thereof for indicating proper placement of the tip or other irradiated portion at the desired location within the appliance, and thus in relation to the cancer to be irradiated. 
     According to a further preferred aspect of the invention, the body portion of the appliance will include multiple ones of the tubes or catheters, as required for holding the media necessary for irradiating the cancer to the desired extent. As an example, a plurality of the tubes or catheters will be arranged in a required array, such as, a linear, side-by-side array, for providing a desired pattern and/or dose of radiation to the cancer. The required location of the tubes or catheters within the body portion of the appliance will be determined by the location of the cancer or diseased tissue, as found using common techniques, such as CT scanning or the like. The duration and/or dosage of treatment will be determined by an oncology professional or physicist. 
     According to a still further preferred aspect of the invention, a method of use of the appliance will include steps of molding the body portion to a region of a body cavity, such as the oral cavity, including installing the shielding and the at least one tube or catheter in the respective locations for holding the radioactive media for providing the radiation dosing to the cancer. The finished appliance can then be inserted into the oral cavity and secured in place. The radioactive wire or wires or other media are then inserted into the one or more catheters or tubes, respectively, to position the radioactive element or elements in the desired relation to the cancer or diseased tissue. The appliance will then be left in place for the period of time necessary for delivery of the determined radiation dose to the cancer or diseased tissue. The radioactive wire or wires are then removed from the appliance, and the appliance removed from the oral cavity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of aspects of a brachytherapy appliance according to the present invention, including a plurality of catheters for receiving radioactive tipped wires, respectively, for dosing a cancer with radiation; 
         FIG. 2  is another top view of the brachytherapy appliance, illustrating alternative locations for the catheters; 
         FIG. 3  is a side view of the brachytherapy appliance; 
         FIG. 4  is a sectional view of the brachytherapy appliance, taken along line  4 - 4  of  FIG. 3 ; 
         FIG. 4   a  is a sectional view of the appliance illustrating alternative shielding of the invention; 
         FIG. 4   b  is a top view of the appliance, illustrating another alternative shielding; 
         FIG. 4   c  is another top view of the appliance, illustrating another alternative shielding; 
         FIG. 4   d  is a fragmentary top view of the appliance, illustrating still further alternative shielding; 
         FIG. 5  is a side view of a human head including a brachytherapy appliance of the invention installed in an oral cavity of the head; 
         FIG. 5   a  is an enlarged fragmentary side view of the human head of  FIG. 5 , showing the appliance in relation to a cancer, and radiation being emitted toward the cancer; 
         FIG. 6  is a side view of aspects of another brachytherapy appliance according to the present invention, including a plurality of catheters for receiving radioactive tipped wires, respectively, for dosing a cancer with radiation; 
         FIG. 7  is a bottom view of the brachytherapy appliance of  FIG. 6 ; 
         FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 7 ; and 
         FIG. 9  is another sectional view of the appliance of  FIGS. 6 and 7 , illustrated in association with teeth and a jaw in an oral cavity of a human head. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to  FIGS. 1 ,  2 ,  3  and  4 , wherein like numerals refer to like parts, a brachytherapy appliance  10  constructed and operable according to the teachings of the present invention, is shown. Brachytherapy appliance  10  is configured for use in an oral cavity of a living body, which, as depicted hereinafter, is a human body. Appliance  10  generally includes a body portion  12  which will be at least generally and preferably custom molded to the contours of a region of an oral cavity of a living body. More particularly, body portion  12  is molded to conform to the upper regions or palate of a human oral cavity, including a center region  14  molded to selected regions of the hard and/or the soft palate of the oral cavity, and a peripheral region  16  molded to the upper teeth, if any, and/or the endentulous ridge or arch, thereby forming a recess  18  extending partially around the center region  14 , and contoured for cooperatively receiving and releasably attaching to the upper teeth, if any, or to the edentulous ridge or arch. Body portion  12  can be molded using common dental molding techniques and commercially available polymeric materials commonly used in the same, such as a well-known, commercially available dental acrylic material such as a methyl methacrylate. Importantly, at least one therapy delivery element is incorporated into appliance  10 , which here preferably comprises at least one catheter  20  incorporated in or on body portion  12 . Each catheter  20  is preferably adapted for cooperatively receiving and positioning radioactive media in desired relation to a cancer, which media here comprises an elongate wire  22  including a radiation emitting portion, which is preferably a radioactive tip  24  of iridium  192 . Each catheter  20  is essentially a hollow tube defining a passage  26  ( FIG. 4 ) having at least a terminal end portion  28  ( FIG. 1 ) which is precisely positioned in relation to body portion  12 , such that when a wire  12  is received in passage  26  with radioactive tip  24  located in the terminal end portion  28 , tip  24  will be precisely positioned for irradiating a cancer or diseased tissue when appliance  10  is installed in the oral cavity. 
     The location, size and extent of the cancer will be determined by an oncology professional, and the radiological dosing will be determined by the oncology professional and/or physicist. From that information, the number and position of catheters  20  required will be determined by the professionals. Appliance  10  will be fabricated to include the required number of catheters  20 , in the required position or positions, such that the therapy delivering region or regions of the wire or wires inserted into the catheter or catheters will be properly disposed for delivering the contemplated radiation dose to the cancer or diseased tissue. In this embodiment, this will entail the positioning of terminal end portions  28  of the catheters  20  in, or in connection with, molded body portion  12 , such that the radioactive tips  24  of the wires when located in the catheters will be positioned for delivery of the required radiation dose to the cancer. Preferably, this will entail the fixed molding in place of catheters  20  within body portion  12 , such that terminal end portions  28  will be fixed in location with respect to the cancer or diseased tissue when appliance  10  is installed in the oral cavity. Also preferably, this will entail allowing the extension of opposite ends  30  of catheters  20  from body portion  12 , and thus also from the mouth  32  of a person  34  when appliance  10  is installed, as shown in  FIG. 5 . This will allow a healthcare professional to safely and conveniently insert wires  22  into catheters  20  with body portion  12  installed in the mouth, to position radioactive tips  24  at terminal end portions  28  within catheters  20 , for delivering the required radiation dose to a cancer or diseased tissue, such as representative cancer  36 , also illustrated in  FIG. 5 . At the end of the radiation therapy, wires  22  are removed from body portion  12 , and body portion  12  removed from the mouth. 
     As noted hereinabove, radiation emitted by a therapeutic device, such as any of radioactive tips  24  of wires  22 , can potentially unintentionally injure or damage noncancerous body parts, tissue, glands and/or organs, such as the teeth, salivary glands, olfactory nerves, taste buds, and the like. To avoid such injury or damage, appliance  10  includes one or more shields, such as a radiation shield  38  as variously illustrated in  FIGS. 4 ,  4   a ,  4   b ,  4   c  and  4   d , in association with body portion  12 , positioned or disposed for providing shielding of desired tissue regions, glands, organs, and/or other body parts, from radiation emitted by tips  24 . A shield, such as radiation shield  38 , can comprise a suitable radiation absorbing or containing material, such as lead. To protect non-diseased body portions, such as the tissue of the superior region of the oral cavity, such as the endentulous arch, the tongue, teeth, and the like, located in the vicinity of a shield, such as shield  38 , from unhealthy effects from exposure to the material of the shield, the shield is preferably encapsulated by a layer of protective material, for instance, by one or more layers of the polymeric material constituting body portion  12 , such as an acrylic or the like. A shield can be encapsulated within body portion  12  when molded, or can be installed on a surface thereof, then coated with the protective layer. Here, for instance, terminal and portions  28  of catheters  20  are disposed in the posterior region of body portion  12 , for irradiating a cancer in the posterior region of the oral cavity, or the upper throat region, as generally illustrated by cancer  36  in  FIGS. 5 and 5   a . Shield  38  for this location, can cover the inferior or lower or lateral surface of body portion  12  which will face the oral cavity, generally denoted as region  40  in  FIG. 3 , to protect the healthy tissue, as well as those portions of the upper teeth and gums that face and therefore could be injured by subjection to radiation emitted by tips  24  when installed in catheters  20  ( FIG. 5   a ), as generally denoted by regions  42  and  44  in  FIG. 4 . 
     Here, it should be noted that it is contemplated that the shielding to be used in association with a brachytherapy appliance of the invention, such as appliance  10 , can take any of a variety of forms, as desired or required for providing protection to tissue and other body parts from radiation emitted by the radioactive elements of the appliance. For instance, the shielding can take the form of an envelope ( FIGS. 4   a ,  4   b ,  4   c  and  4   d ) covering both the superior and/or inferior surfaces of catheters  20 , as well as, anterior and/or posterior shielding and lateral shielding. More particularly in this regard, it is contemplated that an appliance according to the invention could include catheters  20  which are substantially completely ensconced within radiation shielding, with the exception of one or more precisely placed and oriented windows, such as a window or windows  48  ( FIGS. 4   b ,  4   c  and  4   d ) for the emission of radiation toward a cancer or diseased tissue. 
     Referring more particularly to  FIG. 2 , as noted above, it is also contemplated that catheters  20 , and more particularly, the terminal end portions  28  or other portions thereof which are to hold the radiation emitting elements, can be positioned at any location on or in connection with an appliance of the invention, such as appliance  10 , for facilitating delivery of the radiation dose required for treatment of a cancer. This is denoted by numerals  28 A,  28 B,  28 C and  28 D, which illustrate alternative locations for terminal and portions  28 , both in the anterior/posterior and lateral directions. 
     Still further, it is contemplated according to the invention that catheters  20  can be of the same or a different length, for positioning radiation emitting portions of wires, such as tips  24  of wires  22 , in desired relation to a cancer for dosing the cancer with radiation, as illustrated in  FIGS. 4   b ,  4   c  and  4   d . For instance, terminal end portions  28  or other radiation positioning portions of a plurality of catheters  20  could be arranged in a generally circular, oval, offset, or other shaped array deemed most effective for dosing a cancer with radiation, as illustrated in  FIGS. 4   c  and  4   d . A plurality of catheters  20  can also be arranged in a three-dimensional array, again, such as deemed most effective for dosing a cancer with radiation. 
     As another feature of the invention, wires  22  and/or catheters  20  can include indicia for indicating when wires  22  are fully received within catheters  20 , respectively, for positioning the radiation emitting portions of the wires, such as radioactive tips  24 , at the desired position in relation to a cancer. For instance, such indicia can include a mark or markings along the length of a wire  22 , such as a dyed or etched spot, notch, or the like, as generally denoted by numerals  46  in  FIG. 1 , which will match up with an end  30  of a catheter  20  ( FIG. 5 ), such that when the mark or marking is coincident with, or in other predetermined relation with, end  30 , a healthcare professional inserting the wire  22  into a catheter  20  will know that the wire is properly and fully positioned within the catheter. The properly positioned wire or wires  22  will then be left in the catheter or catheters  20  for the prescribed time, and then removed when the radiation dose has been delivered. Alternatively, or additionally, a wire or wires  22  could include a hard stop, such as a sharp bend or crease at the location therealong to be coincident with the end  30  of conduit  20 , to provide the desired indication of proper positioning. 
     Referring also to  FIGS. 6 ,  7 ,  8  and  9 , another brachytherapy appliance  50  constructed and operable according to the teachings of the present invention, is shown, like parts of appliance  50  and appliance  10  being identified by like numerals. Brachytherapy appliance  50  is configured for use in an oral cavity of a living body, which, as depicted in  FIG. 9 , is a human body. Appliance  50  generally includes a body portion  52  which will be at least generally and preferably custom molded to the contours of a region of an oral cavity of a living body. More particularly, body portion  52  is molded to conform to the lower teeth  54 , if any, and/or the lower endentulous ridge or arch, thereby forming a recess  56  contoured for cooperatively receiving and releasably attaching to the lower teeth  54 , if any, or to the lower edentulous ridge or arch. Body portion  52 , like body portion  12 , can be molded using common dental molding techniques and commercially available polymeric materials commonly used in the same, such as a well-known, commercially available dental acrylic material such as a methyl methacrylate. Importantly, at least one therapy delivery element is incorporated into appliance  50 , which here preferably comprises at least one catheter  20  incorporated in or on body portion  52 . Each catheter  20  is preferably adapted for cooperatively receiving and positioning radioactive media in desired relation to a cancer, which media here comprises an elongate wire  22  (illustrated in other Figures) including a radiation emitting portion, which is preferably a radioactive tip of iridium  192 , as explained above. Each catheter  20  is essentially a hollow tube defining a passage having at least a terminal end portion  28  which is precisely positioned in relation to body portion  52 , such that when a wire  12  is receivable in the passage with radioactive tip  24  located in the terminal end portion  28 , tip  24  will be precisely positioned for irradiating a cancer or diseased tissue when appliance  50  is installed in the oral cavity. 
     The location, size and extent of the cancer will be determined by an oncology professional, and the radiological dosing will be determined by the oncology professional and/or physicist. From that information, the number and position of catheters  20  required will be determined by the professionals. Appliance  50  will be fabricated to include the required number of catheters  20 , in the required position or positions, such that the therapy delivering region or regions of the wire or wires inserted into the catheter or catheters will be properly disposed for delivering the contemplated radiation dose to the cancer or diseased tissue. In this embodiment, this will entail the positioning of terminal end portions  28  of the catheters  20  in, or in connection with, molded body portion  52 , such that the radioactive tips  24  of the wires when located in the catheters will be positioned for delivery of the required radiation dose to the cancer. Preferably, this will entail the fixed molding in place of catheters  20  within body portion  52 , such that terminal end portions  28  will be fixed in location with respect to the cancer or diseased tissue when appliance  50  is installed in the oral cavity. Also preferably, this will entail allowing the extension of opposite ends  30  of catheters  20  from body portion  52 , and thus also from the mouth  32  of a person  34  when appliance  50  is installed, as shown in  FIG. 9 . This will allow a healthcare professional to safely and conveniently insert wires  22  into catheters  20  with body portion  52  installed in the mouth, to position radioactive tips  24  at terminal end portions  28  within catheters  20 , for delivering the required radiation dose to a cancer or diseased tissue, such as representative cancer  58 , also illustrated in  FIG. 9 . At the end of the radiation therapy, wires  22  are removed from body portion  52 , and body portion  52  removed from the mouth. 
     As noted hereinabove in relation to appliance  10 , radiation emitted by a therapeutic device, such as any of radioactive tips  24  of wires  22 , can potentially unintentionally injure or damage noncancerous body parts, tissue, glands and/or organs, such as the teeth, salivary glands, olfactory nerves, taste buds, and the like. To avoid such injury or damage, appliance  50  includes one or more shields, such as a radiation shield  38  as illustrated in  FIGS. 8 and 9 , in association with body portion  52 , positioned or disposed for providing shielding of desired tissue regions, glands, organs, and/or other body parts, from radiation emitted by tips  24 . A shield, such as radiation shield  38 , can comprise a suitable radiation absorbing or containing material, such as lead. To protect non-diseased body portions, such as the tissue of the inferior and superior regions of the oral cavity, such as the endentulous arch, the tongue, teeth, and the like, located in the vicinity of a shield, such as shield  38 , from unhealthy effects from exposure to the material of the shield, the shield is preferably encapsulated by a layer of protective material, for instance, by one or more layers of the polymeric material constituting body portion  52 , such as an acrylic or the like. A shield can be encapsulated within body portion  52  when molded, or can be installed on a surface thereof, then coated with the protective layer. Here, for instance, terminal and portions  28  of catheters  20  are disposed in the lateral region of body portion  52 , for irradiating a cancer in the cheek region of the oral cavity, as generally illustrated by cancer  58  in  FIG. 9 . Shield  38  for this location, can cover the region of body portion  52  which will face the healthy tissue to be shielded, generally denoted as region  60  in  FIG. 9 , to protect the healthy tissue, as well as those portions of the teeth and gums that face and therefore could be injured by subjection to radiation emitted by tips  24  when installed in catheters  20 . 
     Thus, there has been shown and described a novel brachytherapy appliance and method, which overcomes many of the problems and shortcomings set forth above. It will be apparent, however, to those familiar in the art, that many changes, variations, modifications, and other uses and applications for the subject device are possible. All such changes, variations, modifications, and other uses and applications that do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.