Patent Publication Number: US-2012029262-A1

Title: Treatment of a body cavity

Description:
RELATED APPLICATIONS 
     This application is a divisional of copending application Ser. No. 11/283,236, filed Nov. 18, 2005, which is incorporated herein in its entirety by reference and from which priority is claimed. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to the fields of medical treatment devices and methods. In particular, the invention relates to devices and methods for treating tissue surrounding a body cavity, such as a site from which cancerous, pre-cancerous, or other tissue has been removed. 
     BACKGROUND OF THE INVENTION 
     In diagnosing and treating certain medical conditions, it is often desirable to perform a biopsy, in which a specimen or sample of tissue is removed for pathological examination, tests and analysis. A biopsy typically results in a biopsy cavity occupying the space formerly occupied by the tissue that was removed. As is known, obtaining a tissue sample by biopsy and the subsequent examination are typically employed in the diagnosis of cancers and other malignant tumors, or to confirm that a suspected lesion or tumor is not malignant. Treatment of cancers identified by biopsy may include subsequent removal of tissue surrounding the biopsy site, leaving an enlarged cavity in the patient&#39;s body. Cancerous tissue is often treated by application of radiation, by chemotherapy, or by thermal treatment (e.g., local heating, cryogenic therapy, and other treatments to heat, cool, or freeze tissue). 
     Cancer treatment may be directed to a natural cavity, or to a cavity in a patient&#39;s body from which tissue has been removed, typically following removal of cancerous tissue during a biopsy or surgical procedure. For example, U.S. Pat. No. 6,923,754 to Lubock and U.S. patent application Ser. No. 10/849,410 to Lubock, the disclosures of which are all hereby incorporated by reference in their entireties, describe devices for implantation into a cavity resulting from the removal of cancerous tissue which can be used to deliver cancer treatments to surrounding tissue. One form of radiation treatment used to treat cancer near a body cavity remaining following removal of tissue is “brachytherapy” in which a source of radiation is placed near to the site to be treated. 
     Lubock above describes implantable devices for treating tissue surrounding a cavity left by surgical removal of cancerous or other tissue that includes an inflatable balloon constructed for placement in the cavity. Such devices may be used to apply one or more of radiation therapy, chemotherapy, and thermal therapy to the tissue surrounding the cavity from which the tissue was removed. The delivery lumen of the device may receive a solid or a liquid radiation source. Radiation treatment is applied to tissue adjacent the balloon of the device by placing radioactive material such as radioactive “seeds” in a delivery lumen. Such treatments may be repeated if desired. 
     For example, a “MammoSite® Radiation Therapy System” (MammoSite® RTS, Proxima Therapeutics, Inc., Alpharetta, Ga. 30005 USA) includes a balloon catheter with a radiation source that can be placed within a tumor resection cavity in a breast after a lumpectomy. It can deliver a prescribed dose of radiation from inside the tumor resection cavity to the tissue surrounding the original tumor. The radiation source is typically a solid radiation source; however, a liquid radiation source may also be used with a balloon catheter placed within a body cavity (e.g., Iotrex®, Proxima Therapeutics, Inc.). A radiation source such as a miniature or microminiature x-ray tube may also be used (e.g. U.S. Pat. No. 6,319,188). The x-ray tubes are small, flexible and are believed to be maneuverable enough to reach the desired treatment location within a patient&#39;s body. The radiation source is to be removed following each treatment session, or remains in place as long as the balloon remains within the body cavity. Inflatable treatment delivery devices and systems, such as the MammoSite® RTS and similar devices and systems (e.g., GliaSite® RTS (Proxima Therapeutics, Inc.)), are useful to treat cancer in tissue adjacent a body cavity. 
     However, radiation, chemotherapy, thermal treatment, and other cancer treatments often have deleterious effects on healthy tissue in addition to the desired effects on cancerous tissue. In such treatments, care must be taken to direct the maximum treatment effects to diseased tissue while minimizing its delivery or effects on healthy tissue. For example, radiation treatment may be most effective when only the portion of tissue requiring treatment receives the radiation and where surrounding healthy tissue is unaffected. Tissue cavities typically are not uniform or regular in their sizes and shapes, so that differences in dosages applied to different regions of surrounding tissue, including “hot spots” and regions of relatively low dosage, often result from radiation treatment. 
     A treatment delivery device for treating tissue adjacent a body cavity has been disclosed in U.S. Pat. No. 6,923,754. This device applies a partial-vacuum or suction to bring tissue towards a radiation source and allows for uniform application of radiation to tissue surrounding a body cavity. An advantage of the present invention is that it allows for the protection of healthy tissue within that body cavity and provides a seal in the passageway leading to the body cavity while treating the desired tissue. 
     SUMMARY OF THE INVENTION 
     This invention is generally directed to treating a patient&#39;s body cavity, such as by irradiation, and devices and methods for such treatments. The invention is particularly suitable for treating tissue adjacent a patient&#39;s body cavity formed by removal of tissue for a biopsy. 
     More specifically, a device embodying features of the invention includes an elongate shaft with a treatment location at a distal portion of the shaft which is configured to receive or which includes a source for a treatment agent, such as a radiation source. In this embodiment the device has one or more radiation shielding components that control at least in part the radiation emitted from the radiation source. 
     The radiation shielding component is designed to reduce or minimize damaging irradiation of healthy tissue surrounding the body cavity while treating nearby areas having diseased tissue with radiation emitted from the radiation source. The radiation shielding components include one or more radiation shields disposed about a delivery shaft containing the radiation source. Preferably, the radiation shielding component has a pair of radiation shields one that is deployed proximal and one that is deployed distal to the treatment location to control axial and near axial radiation emissions of the radiation source. The location of the pair of radiation shields is configured to be adjustable to accommodate anatomical structural variations or to adjust treatment parameters. A central radiation shield preferably has or defines at least in part a window to control the dispersal of radiation from a radiation source. The window defined at least in part by the central radiation shield has a length between about 2 millimeters and 5 centimeters. The shielded area of the central radiation shield is arcuate with an angular range from about 20° to about 240°. While the central radiation shield may be utilized by itself, preferably, the central radiation shield is configured to be deployed between the proximal and distal shields such as discussed above. 
     A device embodying features of another aspect of the invention includes an elongate shaft with a sealing member located on the elongate shaft proximal to the treatment location to seal the intracorporeal passageway through which the device is advanced. The sealing member is expanded or expandable and configured to minimize the loss of vacuum within the body cavity when a vacuum is developed therein. Preferably the sealing member is also configured to seal the passageway when aspirating fluid from the body cavity or delivering fluid, e.g. treatment fluid, to the body cavity. 
     A device embodying features of the invention preferably has an enlarged or enlargeable cavity filling member at the treatment location which at least in part fills the body cavity. Preferably the cavity filling member is inflatable such as a balloon. The device also includes an inner lumen configured to be in fluid communication with a proximal vacuum source and one or more vacuum ports preferably proximal and or distal to the cavity filling member such as described in U.S. Pat. No. 6,923,754 and co-pending application Ser. No. 10/849,410 filed on May 19, 2004, both of which are assigned to the present assignee. Application of a vacuum within the inner lumen aspirates fluid in the cavity through one or more vacuum ports and the vacuum within the body cavity pulls tissue defining the cavity onto the exterior of the cavity filling member deployed within the cavity. 
     Methods for treating a body cavity of a patient include methods for delivering a source for a treatment agent such as a radiation source to a body cavity to treat the desired tissue while minimizing damaging irradiation of healthy tissues. More specifically, a method for treating a body cavity includes providing a device having an elongate shaft with a proximal end, a distal end, and a treatment location in a distal portion of the shaft. The method further includes providing a radiation source configured to be deposited in the treatment location and a radiation shielding component configured to control at least in part the emission of radiation emitted from the treatment location. The device is inserted into a body cavity and the radiation source is positioned within the treatment location. The radiation shielding component is positioned to shield portions of the body cavity from radiation emitted from the radiation source. 
     Enhanced control over the emission of radiation from a radiation source and an improved seal in the passageway leading to the body cavity are provided by the present invention. These and other advantages of the present invention are described in more detail in the following written description and the accompanying exemplary drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic view of a device embodying features of the invention including a cavity filling member. 
         FIG. 1B  is a longitudinal cross sectional view of the device along lines  1 B- 1 B in  FIG. 1A . 
         FIG. 1C  is a transverse cross sectional view of the device taken along lines  1 C- 1 C in  FIG. 1A . 
         FIG. 1D  is a transverse cross sectional view of the device taken along lines  1 D- 1 D. 
         FIGS. 2A and 2B  are diagramatic views of a radiation shielding component which includes a proximal radiation shield and a distal radiation shield. 
         FIG. 3A  is a diagramatic view of a central radiation shield disposed about a radiation source. 
         FIG. 3B  is a perspective view and  FIG. 3C  is an elevational view of a central radiation shield including a window. 
         FIG. 3D  is a transverse cross sectional view of the central radiation shield taken along lines  3 D- 3 D in  FIG. 3C . 
         FIG. 3E  is a perspective view and  FIG. 3F  is an elevational view of a central radiation shield including a window. 
         FIG. 3G  is a transverse cross sectional view of the central radiation shield taken along lines  3 G- 3 G in  FIG. 3F . 
         FIGS. 4A and 4B  are transverse cross sectional views of an embodiment of the invention including three chambers, some of which contain radiation shields. 
         FIG. 5A  is perspective view of a device embodying features of the invention including a sealing member which is formed of an adhesive material. 
         FIG. 5B  is a perspective view of a device embodying features of the invention including an sealing member which is inflatable. 
         FIG. 6  is a cross sectional view of the device taken along line  6 - 6  in  FIG. 5B . 
         FIGS. 7A and 7B  show the steps of a preferred method for treating a body cavity. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides devices and methods for treatment of a patient&#39;s body cavity. For example, devices and methods having features of the invention are used to deliver radiation or other treatment into a biopsy site or into a cavity left after removal of cancerous tissue from the patient&#39;s body. 
     As shown in  FIGS. 1A-1D  a device  10  embodying features of the invention includes an elongated shaft  12  with a treatment location  14  in a distal portion  16  of the elongate shaft  12 . The treatment location  14  includes a source for a treatment agent such as a radiation source  18 . The elongate shaft  12  contains a delivery shaft  20  having a delivery lumen  22 . The delivery shaft  20  also includes a delivery port  24  through which the radiation source  18  is advanced. The device  10  has one or more radiation shielding components  26  disposed about the delivery shaft  20  that control in part the radiation emitted from the radiation source  18 . The radiation shielding component  26  is designed to reduce or minimize damaging irradiation of healthy tissue surrounding a body cavity while treating nearby areas having diseased tissue with radiation emitted from the radiation source  18 . 
     The radiation shielding component  26  includes at least one radiation shield  28  which is configured to be deployed proximal to, distal to, or within the treatment location  14 . Preferably, the radiation shielding component  26  has a pair of radiation shields including a proximal radiation shield  30  and a distal radiation shield  32  ( FIGS. 2A-2B ). The proximal shield  30  is deployed proximal to the treatment location  14  and the distal shield  32  is deployed distal to the treatment location  14 . The shields allow for control, at least in part, of the axial and near axial emissions from the proximal and distal end portions of the elongate shaft  12 . When the proximal end of distal radiation shield  32  is adjacent the radiation source  18  and the distal end of the proximal radiation shield  30  is adjacent the radiation source  18  the radiation dispersal pattern  34  would be a small cone emanating from the radiation source  18 . As the proximal end of the distal radiation shield  32  and the distal end of the proximal radiation shield  30  move further away from the radiation source  18  the radiation dispersal pattern  34  increases to a near spherical shape having an axial cone of shielding  36  expanding from the radiation source  18  along the longitudinal axis in both directions. The pair of radiation shields  30  and  32  are preferably configured to be adjustable to accommodate anatomical structural variations or to adjust treatment parameters. 
     The radiation shielding component  26  includes one or more radiation shields  28 . The radiation shields  28  are formed of a suitably radiopaque metal or polymer containing at least in part a radiation absorbing material and are preferably tubular. The shields are preferably slidably disposed about the delivery lumen  22  of the device  10 . Suitable radiation absorbing materials include tantalum, bismuth subcarbonate, barium sulfate, platinum, gold and tungsten. 
     The radiation source  18  of the device  10  can include a radiation source which is solid or liquid. Suitable liquid radiation sources include, for example, a liquid containing a radioactive iodine isotope (e.g., I 125  or I 131 ), a slurry of a solid isotope, for example,  198 AU or  169 Yb, or a gel containing a radioactive isotope. Liquid radiation sources are commercially avaliable (e.g., Iotrex®, Proxima Therapeutics, Inc., Alpharetta, Ga.). The radiation source  18  preferably includes brachytherapy seeds or other solid radiation sources used in radiation therapy, for example, a radioactive microsphere available from 3M company of St. Paul, Minn. The radiation source  18  is either preloaded into the device  10  at the time of manufacture or is loaded into the device  10  after placement into a body cavity of a patient. Solid radionuclides suitable for use with a device  10  embodying features of the present invention are currently generally available as brachytherapy radiation sources (e.g., I-Plant™, Med-Tec, Orange City, Iowa.). Radiation may also be delivered by a device such as the x-ray tube of U.S. Pat. No. 6,319,188. The x-ray tubes are small, flexible and are believed to be capable of being maneuverable enough to reach the desired location within a patient&#39;s body. 
     One embodiment of the device  10  also includes a vacuum lumen  38 . The vacuum lumen  38  is configured to be in fluid communication with a vacuum source and one or more vacuum ports  42  in the exterior of the elongated shaft  12 . The vacuum ports  42  are in fluid communication with the vacuum lumen  38  to provide a vacuum within a body cavity. 
     In one embodiment the device  10  includes a cavity filling member  44  which at least in part fills the body cavity located on the distal portion  16  of the elongated shaft  12 . The cavity filling member  44  can be inflatable or expandable and configured to contact tissue surfaces defining the body cavity. The cavity filling member  44  is in fluid communication with a first inflation lumen  46  which has a first inflation port  48 . The vacuum ports  42  for the vacuum lumen  38  preferably are located proximal and or distal to the cavity filling member  44  which at least partially fills the body cavity. 
     A central radiation shield  50 , shown in  FIG. 3A , can be deployed between the proximal  30  and distal  32  radiation shields. The central radiation shield  50  preferably defines at least in part a window  52  to allow for dispersal of radiation from a radiation source  18 . Preferably the central radiation shield  50  defines a window  52  which may have a variable length as shown in  FIGS. 3B-G . Preferably the length of the window  52  is between about 2 millimeters to 5 centimeters and the central radiation shield is tubular in shape. Preferably the shielded area is arcuate with an angular range from about 20° to about 240°. Alternatively the central radiation shield  50  comprises a pair of separately rotatable members to allow for adjusting the window dimensions. The central radiation shield  50  is rotated or advanced to position the window  52  near the target tissue. 
     Another embodiment of the invention shown in  FIGS. 4A and 4B  includes a partitioned shaft  54  disposed about the delivery shaft  20 . The partitioned shaft  54  has a lumen  56  which is divided into at least two chambers  58  by spacing elements  60 . Radiation shields  28  are configured to be inserted into one or more chambers  58  through the proximal end of the elongate shaft  12  to surround at least a portion of the treatment location  14 . The radiation shields  28  reduce or minimize irradiation of healthy portions of the body cavity while treating nearby areas with the radiation source  18 . 
     In one possible embodiment the radiation shield  28  has varying densities acting as a filter to allow for some controlled amount of radiation to pass through yielding a non-symmetric radiation dosing. In another embodiment the radiation shields  28  are constructed of sintered metal to block radiation and still allow for a fluid pathway for suction or vacuum of the body cavity. 
     In another embodiment of the invention depicted in  FIGS. 5A ,  5 B and  6  the device includes an elongate shaft  12  with a sealing member  62  located on the elongate shaft  12  to seal the passageway  64  through which the device  10  is advanced. The sealing member can be inflated via a second inflation lumen  66  ( FIGS. 5B and 6A ) which is in fluid communication with a second inflation port  68  on the proximal end of the elongate shaft  12 . The sealing member  62  allows for closer contact with the walls of the passageway  64 . Preferably, the device  10  also includes a cavity filling member  44  which at least in part fills the body cavity and which is inflatable or expandable. The sealing member  62  is located on the elongate shaft  12  proximal to the distal end of the elongate shaft. 
     Alternatively, as shown in  FIG. 5A , the device  10  can include a sealing member  62  formed of a flange or cuff having an adhesive distal face and located toward the proximal end of the elongate shaft  12 . The sealing member  62  preferably is configured to form a seal in the passageway  64  leading to the body cavity by adhering to a patient&#39;s skin. 
     The device  10  preferably includes a vacuum lumen  38  configured to be in fluid communication with a proximal vacuum source and one or more vacuum ports  42  preferably proximal and or distal to the cavity filling member  44 . Application of a vacuum within the vacuum lumen  38  aspirates fluid in the cavity through one or more vacuum ports  42  and pulls tissue defining the cavity onto the exterior of the cavity filling member  44  deployed within the cavity. As shown in  FIG. 5B  the sealing member  62  preferably is expanded or expandable, such as a balloon, and configured to minimize the loss of vacuum within the body cavity when a vacuum is developed. 
     A device  10  having features of the invention can include contoured pads for use on the elongate shaft  12  of the device  10 . The contoured pads are provided on the proximal portion of the elongated shaft  12  of the device  10  and are configured to cover a portion of the shaft. The contoured pads preferably are comprised of material having soft tapered edges to minimize irritation to the skin caused by movement or dressing and undressing. The pads are taped externally to the patient or alternatively are attached to the patient with a double sided tape or adhesive material. 
     A device  10  having features of the invention can be provided, at least in part, with a lubricious coating, such as a hydrophilic material. The lubricious coating preferably is applied to the elongate shaft  12  or to the cavity filling member  44 , if one is present, to reduce sticking and friction during insertion of a device  10 . Hydrophilic coatings such as those provided by AST, Surmodics, TUA Systems, Hydromer, or STS Biopolymers are suitable. 
     A device  10  having features of the invention may also include an antimicrobial coating that covers all or a portion of the device  10  to minimize the risk of introducing of an infection during extended treatments. The antimicrobial coating preferably is comprised of silver ions impregnated into a hydrophilic carrier. Alternatively the silver ions are implanted onto the surface of the device  10  by ion beam deposition. The antimicrobial coating preferably is be comprised of an antiseptic or disinfectant such as chlorhexadiene, benzyl chloride or other suitable biocompatible antimicrobial materials impregnated into hydrophilic coatings. Antimicrobial coatings such as those provided by Spire, AST, Algon, Surfacine, Ion Fusion, or Bacterin International would be suitable. Alternatively a cuff member covered with the antimicrobial coating is provided on the elongated shaft of the delivery device  10  at the point where the device  10  enters the skin. 
     Methods for treating a body cavity  70  of a patient, shown in  FIGS. 7A and 7B , include delivering a radiation source  18  to a body cavity  70  to treat the desired tissue adjacent a device  10  embodying features of the invention while minimizing damaging irradiation of healthy tissue. For example, a method of treating tissue adjacent a body cavity  70  includes inserting a device  10  embodying features of the invention into the body cavity  70 , positioning a radiation shielding component  26  to shield healthy tissue in the body cavity  70  and positioning a source for a treatment agent, such as radiation source  18  within the treatment location  14  in a distal portion  16  of the shaft  12 . 
     Methods for treating tissue adjacent a body cavity  70  include methods for sealing a passageway  64  leading to a body cavity  70 . For example, a method of treating tissue adjacent a body cavity  70  includes inserting a device  10  embodying features of the invention into the body cavity  70  and sealing the passageway  64  leading to the body cavity  70  ( FIG. 7A ) and then at least in part contacting the passageway  64  with a sealing member  62  on the elongate shaft  12  ( FIG. 7B ). 
     While particular forms of the invention have been illustrated and described herein, it will be apparent that various modifications and improvements can be made to the invention. Moreover, individual features of embodiments of the invention may be shown in some drawings and not in others, but those skilled in the art will recognize that individual features of one embodiment of the invention can be combined with any or all the features of another embodiment. Accordingly, it is not intended that the invention be limited to the specific embodiments illustrated. It is therefore intended that this invention be defined by the scope of the appended claims as broadly as the prior art will permit. 
     Terms such as “element”, “member”, “component”, “device”, “means”, “portion”, “section”, “steps” and words of similar import when used herein shall not be construed as invoking the provisions of 35 U.S.C §112(6) unless the following claims expressly use the terms “means” or “step” followed by a particular function without reference to a specific structure or action. All patents and all patent applications referred to above are hereby incorporated by reference in their entirety.