Patent Publication Number: US-2005124843-A1

Title: Method and apparatus for delivering targeted therapy to a patient

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates generally to delivering targeted therapy to a patient, and more specifically to delivering targeted therapy to tissue adjacent a cavity of the patient.  
      In radiation brachytherapy, catheters are placed in close proximity to the tissue targeted for radiation. Currently, such proximity is achieved by free-hand placement of brachytherapy catheters over a needle. However, such free-hand placement is challenging and can vary greatly between operators, making it difficult to consistently achieve accurate placement of the catheter. Moreover, a variety of organs are inaccessible for free-hand placement of brachytherapy catheters and therefore are not routinely treated with brachytherapy. Single balloon catheters have been used for brachytherapy to treat breast cancer using a radiation source positioned within the center of the balloon. However, controlling the distribution of radiation to the target tissue as well as achieving a quick fall-off of dose to the non-target tissue can be difficult because of the single dwell position of the radiation source and because of the distance between the source and the target tissue.  
     SUMMARY OF THE INVENTION  
      In one aspect, the present invention includes an applicator for delivering targeted radiation brachytherapy to tissue adjacent a cavity of a patient. The applicator includes a balloon adapted for introduction to the cavity of the patient, wherein the balloon has a deflated state in which the balloon is adapted for insertion into the cavity and an inflated state in which the balloon is enlarged for at least partially filling the cavity of the patient. The balloon moves from the deflated state to the inflated state upon introduction of pressurized fluid to an interior of the balloon. The applicator also includes a conduit in fluid communication with the interior of the balloon for introducing pressurized fluid to the interior of the balloon to move the balloon from the deflated state to the inflated state, and a catheter extending over at least a portion of the balloon for delivering radiation from a radiation source to the tissue adjacent the cavity.  
      In another aspect, the present invention includes an applicator system for delivering targeted thermal therapy to tissue adjacent a cavity of a patient. The applicator system includes a balloon adapted for introduction to the cavity of the patient, wherein the balloon has a deflated state in which the balloon is adapted for insertion into the cavity and an inflated state in which the balloon is enlarged for at least partially filling the cavity of the patient. The balloon moves from the deflated state to the inflated state upon introduction of pressurized fluid to an interior of the balloon. The applicator system also includes a conduit in fluid communication with the interior of the balloon for introducing pressurized fluid to the interior of the balloon to move the balloon from the deflated state to the inflated state, and a catheter extending over at least a portion of the balloon. The catheter has a heat source therein for delivering heat to the tissue adjacent the cavity.  
      In yet another aspect, a method is provided of delivering targeted radiation brachytherapy to tissue adjacent a cavity of a patient using an applicator including a balloon having a deflated state in which the balloon is adapted for insertion into the cavity of the patient and an inflated state in which the balloon is enlarged for at least partially filling the cavity. The method includes attaching a catheter to the balloon for movement with the balloon, inserting the balloon and the catheter into the cavity when the balloon is in the deflated state, inserting a radiation source into the catheter so the radiation source is generally adjacent the balloon, inflating the balloon within the cavity so the radiation source is a predetermined distance from the tissue adjacent the cavity, and controlling a dose distribution of radiation delivered into the tissue adjacent the cavity by the radiation source by controlling the predetermined distance of the radiation source from the tissue.  
      In even another aspect, a method is provided of delivering targeted thermal therapy to tissue adjacent a cavity of a patient using an applicator including a balloon having a deflated state in which the balloon is adapted for insertion into the cavity of the patient and an inflated state in which the balloon is enlarged for at least partially filling the cavity. The method includes attaching a catheter to the balloon for movement with the balloon, inserting the balloon and the catheter into the cavity when the balloon is in the deflated state, inserting a heat source into the catheter so the heat source is generally adjacent the balloon, inflating the balloon within the cavity so the heat source is a predetermined distance from the tissue adjacent the cavity, and controlling a temperature increase of the tissue adjacent the cavity by controlling the predetermined distance of the heat source from the tissue.  
      In yet another aspect, the present invention includes an applicator system for facilitating the delivery of at least one of external beam radiation and external thermal therapy to tissue adjacent a cavity of a patient. The applicator system includes a balloon adapted for introduction to the cavity of the patient, wherein the balloon has a deflated state in which the balloon is adapted for insertion into the cavity and an inflated state in which the balloon is enlarged for at least partially filling the cavity of the patient. The balloon moves from the deflated state to the inflated state upon introduction of pressurized fluid to an interior of the balloon. The applicator system also includes a conduit in fluid communication with the interior of the balloon for introducing pressurized fluid to the interior of the balloon to move the balloon from the deflated state to the inflated state, and a catheter extending over at least a portion of the balloon. The catheter has a radio opaque maker therein adjacent the balloon for marking a position of the balloon when the balloon is received within the cavity.  
      Other features of the present invention will be in part apparent and in part pointed out hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective of an applicator of the present invention including a balloon shown in a deflated state;  
       FIG. 2  is a partially cut-away perspective of the applicator of  FIG. 1  showing the balloon in an inflated state;  
       FIG. 3  is a partially cut-away perspective of a cavity of a patient and an applicator system of the present invention for delivering targeted radiation brachytherapy to tissue adjacent the cavity;  
       FIG. 4  is a partially cut-away perspective of a cavity of a patient and an applicator system of the present invention for delivering targeted thermal therapy to tissue adjacent the cavity;  
       FIG. 5  is a partially cut-away perspective of a cavity of a patient and an applicator system of the present invention for facilitating the delivery of external beam radiation to tissue adjacent the cavity; and  
       FIG. 6  is a perspective of an alternative embodiment of the applicator of the present invention. 
    
    
      Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.  
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring now to the drawings, and more specifically to  FIGS. 1 and 2 , an applicator is designated in its entirety by the reference numeral  20 . The applicator  20  includes a catheter  22  and a body (generally designated by  24 ) having a first end (generally designated by  26 ), a second end (generally designated by  28 ), a conduit  30  extending between the first end and the second end, and a balloon (generally designated by  32 ).  
      The balloon  32  is adapted for introduction to a cavity (designated by  62  in  FIG. 3 ) of a patient, such as a patient&#39;s bladder, esophagus, and/or rectum. More specifically, the balloon  32  has a deflated state ( FIG. 1 ) in which the balloon and the first end  26  of the body  24  are adapted for insertion into the cavity through an entrance to the cavity. Additionally, at least a portion of the conduit  30  may also be adapted for insertion through the entrance and into the cavity. The first end  26  of the body  24 , the balloon  32  in its deflated state, and where applicable all or a portion of the conduit  30 , are sized and shaped appropriately for insertion into the particular cavity (e.g., bladder) through its entrance (e.g., urethra). The balloon  32  also has an inflated state ( FIG. 2 ) in which the balloon is enlarged for at least partially filling the cavity. The conduit  30  is in fluid communication with an interior  34  of the balloon  32  for introducing pressurized fluid to the interior of the balloon to move (inflate) the balloon  32  from the deflated state to the inflated state. Pressurized fluid is introduced into the conduit  30  through an opening (generally designated by  36 ) within the body  24  in fluid communication with the conduit. Although any suitable fluid (e.g., saline) may be introduced into the conduit  30  and the interior  34  of the balloon to move the balloon from the deflated state to the inflated state without departing from the scope of the present invention, in one embodiment air is used to move the balloon from the deflated state to the inflated state.  
      As illustrated in  FIGS. 1 and 2 , the balloon  32  defines the first end  26  of the body  24 . However, the balloon  32  may be suitably positioned anywhere along the body  24  such that the balloon is adapted for insertion into the cavity and for movement (inflation) to the inflated state once received within the cavity. Additionally, in the inflated state the balloon  32  may be suitably shaped for the particular cavity. For example, the balloon  32  may be generally spherical in the inflated state when the balloon is intended to at least partially fill a patient&#39;s bladder, or may be generally cylindrical in the inflated state when the balloon is intended to at least partially fill a patient&#39;s rectum or esophagus. The particular size (e.g., radius) of the balloon  32  in the inflated state may also vary depending upon the particular cavity in which it is intended to be used. Additionally, the balloon  32  may be inflatable to a variety of sizes and/or shapes such that the inflated state of the balloon may comprise a plurality of states each having a different size and/or shape.  
      The body  24  may be formed from any suitable material(s), for example rubber and/or plastic. Although different sections of the body  24  may be formed from different materials, in one embodiment the entirety of the body is formed from one material. The portions of the body  24  adapted for introduction to the patient&#39;s cavity may be formed from any material suitable for use within the cavity, so that such portions do not damage tissue adjacent the cavity and/or injure/infect the patient. Additionally, in one embodiment at least a portion of the body  24  (e.g., at least a portion of the conduit  30  and/or the balloon  32 ) is formed from a transparent material to facilitate use of a viewing apparatus ( 70 ,  FIG. 3 ) with the applicator  20 , as is described in more detail below.  
      The catheter  22  extends over at least a portion of the balloon  32  and is adapted for movement with the balloon as the balloon is moved from the deflated state to the inflated state. Although the applicator  20  is described herein and illustrated in  FIGS. 1, 2 , and  6  as including only one catheter  22 , it should be understood that the applicator  20  may include a plurality of catheters as is illustrated in  FIGS. 3-5 . The size of the entrance to the cavity may influence the maximum number of catheters included with the applicator  20 . As Illustrated in  FIGS. 1 and 2 , in one embodiment the catheter  22  extends through the conduit  30  and along an interior surface  37  of the balloon  32 , and is attached to the interior surface for movement with the interior surface when the balloon is moved from the deflated state to the inflated state. The catheter  22  may also be attached to an interior surface  38  of the conduit  30 . In an alternative embodiment, the catheter  22  extends along an exterior surface  40  of the conduit  30  and/or an exterior surface  42  of the balloon. In yet another alternative embodiment, the catheter extends within the body  24 , and more specifically within a wall  44  of the body defining at least one of the conduit  30  and the balloon  32 . As will be described in more detail below, the catheter  22  is adapted to receive a device (not shown in  FIGS. 1 and 2 ) facilitating treatment of the tissue adjacent the patient&#39;s cavity.  
      As illustrated in  FIG. 3 , the applicator  20  described above may be used to deliver targeted radiation brachytherapy to tissue (generally designated by  60 ) adjacent a patient&#39;s cavity (generally designated by  62 ). More specifically, an applicator system (generally designated by  64 ) includes the applicator  20  and a radiation source (generally designated by  66 ) in the catheter  22 . Each catheter  22  may include any number of radiation sources  66 . Although other radiation sources may be used without departing from the scope of the present invention (e.g., radioactive ribbons, radioactive pellets), in the exemplary embodiment illustrated in  FIG. 3  the radiation source  66  is a radioactive seed  66  attached to a wire  68 . The seed may be formed from any suitable radioactive isotope, such as Iridium 192, Cesium 137, Iodine 125, and/or Palladium 103. The wire  68  is positioned in the catheter  22  so the seed  66  is generally adjacent the balloon  32 . The applicator system  64  may also include a viewing apparatus  70  positioned generally adjacent the balloon  32  for viewing the catheter  22  and the tissue  60  adjacent the cavity  62 , as is described below. Although other viewing apparatus may be used without departing from the scope of the present invention, in one embodiment the viewing apparatus  70  is a fiber optic scope (e.g., a 3.4 mm Flexible Fiber Optic Nasopharyngoscope, commercially available from Kelleher Medical, Inc. of Richmond, Va.).  
      To deliver targeted radiation brachytherapy to the tissue  60 , when the balloon  32  is in the deflated state a portion of the applicator  20  is inserted into the patient&#39;s cavity  62  through its entrance  74 , such that the balloon and a portion of the catheter  22  are inserted into the cavity. The radiation source  66  is inserted into the catheter  22  so the radiation source is generally adjacent the balloon. For example, in the exemplary embodiment illustrated in  FIG. 3 , the wire  68  is inserted into the catheter  22  so the radioactive seed  66  is generally adjacent the balloon  32 . In one embodiment, the radiation source  66  is inserted into the catheter  22  prior to insertion of the applicator  20  into the cavity  62 . In another embodiment, the radiation source  66  is inserted into the catheter  22  after insertion of the applicator  20  into the cavity  62 . In yet another embodiment, the radiation source  66  is inserted into the catheter  22  generally simultaneously with insertion of the applicator  20  into the cavity  62 . Once the balloon  32  is received within the cavity  62  and the radiation source  66  is positioned in the catheter  22  adjacent the balloon, pressurized fluid is introduced to the conduit  30  and into the interior  34  of the balloon to inflate the balloon and move it from the deflated state to the inflated state. The balloon  32  is inflated (moved) to an inflated state wherein the radiation source  66  is at a predetermined dwell position, and more specifically a predetermined distance from areas  76  of the tissue  60  targeted for brachytherapy and from areas  78  of the tissue not targeted for brachytherapy. By controlling the predetermined dwell position, a dose distribution of radiation delivered into the tissue  60  can be controlled. More specifically, the amount of radiation delivered to the targeted tissue  76  can be more accurately controlled while facilitating a generally quick fall off dose in the non-targeted tissue  78 .  
      Depending on the type and size of the cavity  62  and/or the desired predetermined dwell position(s) of the radiation source(s), the balloon  32  in the inflated state may completely fill the cavity  62  so the exterior surface  42  of the balloon contacts some or all of the tissue  60 , or may only partially fill the cavity as illustrated in  FIG. 3 . Additionally, depending on the type and size of the cavity  62  and/or the desired predetermined dwell position(s), some or all of the tissue  60  may deform to the shape of the balloon  32  in its inflated state, or portions or all of the balloon in its inflated state may deform to the shape of the cavity. The number of catheters  22  included with the applicator  20  may also depend on the type and size of the cavity  62 , the desired predetermined dwell position(s), and/or the size of the entrance  74  to the cavity. For example, when a large area of the tissue  60  is targeted for brachytherapy it may be desirable to include the maximum number of catheters  22  the entrance  74  to the cavity allows to obtain as many different dwell positions for the radiation source(s)  66  as possible.  
      Additionally, it may be desirable to rotate the balloon  32  to increase the number of dwell positions for the radiation source(s)  66  and thereby further control the dose distribution of radiation delivered into the tissue  60 . For example, for large cavities with small entrances, the applicator  20  may include only one catheter  22  so the applicator  20  is more easily and comfortably inserted into the cavity  62 , yet the balloon  32  can be rotated to obtain multiple dwell positions for the radiation source(s) in the catheter  22 . The viewing apparatus  70  may be used to monitor rotation of the balloon  32  to ensure the radiation source(s)  66  is accurately located at the desired predetermined dwell position(s). Additionally, the viewing apparatus  70  may be used to generally view/monitor/document the tissue  60 , including the targeted and non-targeted areas  76 ,  78 , the applicator  20  and its various components, and the brachytherapy procedure being performed on the patient. The viewing apparatus  70  may be positioned anywhere on/in the applicator  20  facilitating its purpose(s). For example, the viewing apparatus  70  may be inserted into a catheter  22  before or after insertion of the applicator  20  and such that the apparatus is positioned in the catheter generally adjacent the balloon  32  for viewing the catheter and the tissue  60 .  
      As illustrated in  FIG. 4 , the applicator  20  described above may be used to deliver targeted thermal therapy to tissue (generally designated by  80 ) adjacent a patient&#39;s cavity (generally designated by  82 ). More specifically, an applicator system  84  includes the applicator  20  and a heat source (generally designated by  86 ) in the catheter  22 . Each catheter  22  may include any number of heat sources  86 . Although other heat sources may be used without departing from the scope of the present invention (e.g., radiofrequency antennas, ultrasound applicators), in the exemplary embodiment illustrated in  FIG. 4  the heat source  86  is an antenna  86  configured to emit microwaves into the tissue  80  to heat the tissue. Although other types of antennas may be used without departing from the scope of the present invention (e.g., line dipole or multisection antennas), in one embodiment the antenna  86  is a helical antenna. The antenna  86  is positioned in the catheter  22  such that the antenna emits microwaves generally adjacent the balloon  32 . Similar to the applicator system described above and illustrated in  FIG. 3 , the applicator system  84  may also include a viewing apparatus (not shown) positioned generally adjacent the balloon  32  for viewing the catheter  22  and the tissue  80  adjacent the cavity  82 .  
      To deliver targeted thermal therapy to the tissue  80 , when the balloon  32  is in the deflated state a portion of the applicator  20  is inserted into the patient&#39;s cavity  82  through its entrance  94 , such that the balloon and a portion of the catheter  22  are inserted into the cavity. The heat source  86  is inserted into the catheter  22  so the heat source is generally adjacent the balloon. For example, in the exemplary embodiment illustrated in  FIG. 4 , the antenna  86  is inserted into the catheter  22  so the antenna emits microwaves generally adjacent the balloon  32 . In one embodiment, the heat source  86  is inserted into the catheter  22  prior to insertion of the applicator  20  into the cavity  82 . In another embodiment, the heat source  86  is inserted into the catheter  22  after insertion of the applicator  20  into the cavity  82 . In yet another embodiment, the heat source  86  is inserted into the catheter  22  generally simultaneous with insertion of the applicator  20  into the cavity  82 . Once the balloon  32  is received within the cavity  82  and the heat source  86  is positioned in the catheter  22  adjacent the balloon, pressurized fluid is introduced to the conduit  30  and into the interior  34  of the balloon to inflate the balloon and move it from the deflated state to the inflated state. The balloon  32  is inflated to an inflated state wherein the heat source  86  is at a predetermined dwell position, and more specifically a predetermined distance from areas  96  of the tissue  80  targeted for thermal therapy and from areas  98  of the tissue not targeted for thermal therapy. By controlling the predetermined dwell position, a temperature increase of the targeted tissue  96  and the non-targeted tissue  98  can be controlled.  
      Depending on the type and size of the cavity  82  and/or the desired predetermined dwell position(s) of the heat source(s), the balloon  32  in the inflated state may completely fill the cavity  82  such that the exterior surface  42  of the balloon contacts some or all of the tissue  80 , or may only partially fill the cavity as illustrated in  FIG. 4 . Additionally, depending on the type and size of the cavity  82  and/or the desired predetermined dwell position(s), some or all of the tissue  80  may deform to the shape of the balloon  32  in its inflated state, or portions or all of the balloon in its inflated state may deform to the shape of the cavity. The number of catheters  22  included with the applicator  20  may also depend on the type and size of the cavity  82 , the desired predetermined dwell position(s), and/or the size of the entrance  94  to the cavity. For example, when a large area of the tissue  80  is targeted for thermal therapy it may be desirable to include the maximum number of catheters  22  the entrance  94  to the cavity allows to obtain as many different dwell positions for the heat source(s)  86  as possible.  
      Similar to the applicator system described above and illustrated in  FIG. 3 , it may be desirable to rotate the balloon  32  to increase the number of dwell positions for the heat source(s)  86 . As described above with regard to  FIG. 3 , a viewing apparatus may be used to monitor rotation of the balloon  32  as well as to generally view/monitor the tissue  80 , including the targeted and non-targeted areas  96 ,  98 , as well as applicator  20  and its various components.  
      As illustrated in  FIG. 5 , the applicator  20  described above may be used to facilitate the delivery of external beam radiation and/or external thermal therapy to tissue (generally designated by  100 ) adjacent the patient&#39;s cavity (generally designated by  102 ). More specifically, an applicator system  104  includes the applicator  20  and a radio opaque marker (generally designated by  106 ) in the catheter  22 . Each catheter  22  may include any number of radio opaque markers  106 . Although other radio opaque markers  106  may be used without departing from the scope of the present invention (e.g., cerrobend, steel), in the exemplary embodiment illustrated in  FIG. 5  the radio opaque marker  106  is formed from lead. The marker  106  is positioned in the catheter  22  so that the marker is generally adjacent the balloon  32 . When an x-ray is taken of the patient&#39;s cavity  102 , the marker  106  can then be used to mark the location of the balloon  32  to facilitate the delivery of external beam radiation and/or external thermal therapy to a predetermined area of the tissue  100 .  
      As illustrated in  FIG. 6 , in an alternative embodiment the applicator  20  includes a body (generally designated by  124 ) in addition to the body  24 . The body  124  has a first end (generally designated by  126 ), a second end (generally designated by  128 ), a conduit  130  extending between the first end and the second end, and a balloon (generally designated by  132 ). Either of the conduit  30  and the conduit  130  may be referred to herein as a first conduit or a second conduit. Additionally, either of the balloon  32  and the balloon  132  may be referred to herein as a first balloon or a second balloon. As with the body  24 , the balloon  132  is adapted for introduction to a patient&#39;s cavity. More specifically, the balloon  132  has a deflated state (not shown) in which the balloon  132  and the first end  126  of the body  124  are adapted for insertion into the cavity through its entrance. Additionally, at least a portion of the conduit  130  may also be adapted for insertion through the entrance and into the cavity. The first end  126  of the body  124 , the balloon  132  in its deflated state, and where applicable all or a portion of the conduit  130 , are sized and shaped appropriately for insertion into the particular cavity (e.g., bladder) through its entrance (e.g., urethra). The body  124  is positioned relative to the body  24  so the balloon  132  is adjacent the balloon  32 , such that the balloon  132  is adapted for introduction to the patient&#39;s cavity generally simultaneous with the balloon  32 . In one embodiment, as illustrated in  FIG. 6 , the body  124  surrounds the body  24  such that the balloon  132  surrounds the balloon  32 .  
      As illustrated in  FIG. 6 , the balloon  132  also has an inflated state in which the balloon is enlarged for at least partially filling the cavity. The conduit  130  is in fluid communication with an interior  134  of the balloon  132  for introducing pressurized fluid to the interior of the balloon to move the balloon  132  from the deflated state to the inflated state. Pressurized fluid is introduced into the conduit  130  through an opening (generally designated by  136 ) within the body  124  in fluid communication with the conduit. Although any suitable fluid (e.g., saline) may be introduced into the conduit  130  and the interior  134  of the balloon to move the balloon from the deflated state to the inflated state without departing from the scope of the present invention, in one embodiment air is used to move the balloon from the deflated state to the inflated state. As illustrated in  FIG. 6 , the balloon  132  defines the first end  126  of the body  124 . However, the balloon  132  may be suitably positioned anywhere along the body  124  such that the balloon  132  is adjacent the balloon  32  and is adapted for insertion into the cavity and movement to the inflated state once received within the cavity. Additionally, as with the balloon  32 , in the inflated state the balloon  132  may be suitably shaped for the particular cavity. The particular size (e.g., radius) of the balloon  132  in the inflated state may also vary for the particular cavity. Additionally, the balloon  132  may be inflatable to a variety of sizes and/or shapes such that the inflated state of the balloon may comprise a plurality of states each having a different size and/or shape.  
      Similar to the body  24 , the body  124  may be formed from any suitable material(s), for example rubber and/or plastic. Although different portions of the body  124  may be formed from different materials, in one embodiment the entirety of the body is formed from one material. The portions of the body  124  adapted for introduction to the patient&#39;s cavity may be formed from any material suitable for use within the cavity, so that such portions do not damage tissue adjacent the cavity and/or injure/infect the patient. Additionally, in one embodiment at least a portion of the body  124  (e.g., at least a portion of the conduit  130  and/or the balloon  132 ) is formed from a transparent material to facilitate use of a viewing apparatus (not shown in  FIG. 6 ) with the applicator  20 , as is described in more detail above.  
      This alternative embodiment of the applicator  20  facilitates even more control over an accurate predetermined dwell position of the radiation source(s)  66  ( FIG. 3 ) and/or the heat source(s)  86  by using two separate balloons  32 ,  132  to control the position of catheter  22 , and therefore the radiation source(s) and/or the heat source(s), and the position of the tissue adjacent the cavity, respectively.  
      Although each of the applicator systems described and illustrated herein are described and illustrated separately, it should be understood that the systems may be used in combination to perform a combination of targeted radiation brachytherapy and/or targeted thermal therapy, and/or to facilitate external beam radiation. For example, an applicator of the present invention may include a catheter having a radiation source therein, a catheter having a heat source therein, and/or a catheter having a radio opaque marker therein. Additionally, an applicator of the present invention may include a catheter having one or more of a radiation source, a heat source, and a radio opaque marker therein. Accordingly, a single applicator of the present invention may be used to simultaneously perform a combination of targeted radiation brachytherapy and/or targeted thermal therapy, and/or to facilitate external beam radiation and/or external thermal therapy.  
      As used herein, the term “cavity” includes any cavity of any animal where it is desired to deliver targeted radiation brachytherapy to tissue adjacent the cavity.  
      The above-described applicator and applicator systems are cost-effective and reliable for performing targeted radiation brachytherapy and targeted thermal therapy, and for facilitating external beam radiation. More specifically, the applicator and applicator systems of the present invention may facilitate access to previously inaccessible organs and cavities for targeted radiation brachytherapy and targeted thermal therapy such as, for example, the bladder, the rectum, the esophagus, the stomach, the bronchus, nasopharynx, and the nasal cavity. Additionally, the present invention can be rotated to allow an almost unlimited number of potential dwell positions for radiation and/or heat sources, and a viewing apparatus may be used along with the applicator to ensure accurate positioning of the radiation and/or heat sources, as well as generally monitoring the procedure being performed. Furthermore, access to most cavities is no more invasive than placement of a Foley catheter, which may allow for outpatient treatment with minimum or no analgesia.  
      Exemplary embodiments of applicator systems are described above in detail. The systems are not limited to the specific embodiments described herein, but rather, components of each system may be utilized independently and separately from other components described herein. Each applicator system component can also be used in combination with other applicator system components.  
      When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.  
      As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.