Abstract:
An appliance for use in delivering x-ray radiation therapy internally at desired locations in a body is disclosed. The appliance may be inserted into the tissue to receive radiation and expanded to a desired shape, thereby providing a predetermined configuration to the tissue surrounding the appliance. The appliance can be configured to provide a spherical shape, for example, or an elliptical shape if desired.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present application claims priority from U.S. patent application Ser. No. 10/392,167 (Published Application No. 20030179854), entitled “X-Ray Apparatus With Field Emission Current Stabilization And Method Of Providing X-Ray Radiation Therapy” and filed on Mar. 19, 2003 and U.S. patent application Ser. No. 10/938,971 (Published Application No. 20050038488), also entitled “X-Ray Apparatus With Field Emission Current Stabilization And Method Of Providing X-Ray Radiation Therapy” and filed on Sep. 10, 2004. 
     
    
       [0002]     The present invention relates generally to an appliance useful in aiding apparatus and methods providing x-ray radiation therapy and specifically to such apparatus and methods for providing x-ray radiation therapy with real-time stabilization of the operating current, and thus the dosage rate. Without limitation to the foregoing referenced patent applications, those applications describe apparatus and method providing x-ray radiation therapy generated by a field effect x-ray emission device. The configuration and unique features of those inventions enable a therapist to provide radiation therapy at an internal location in a body.  
         [0003]     In using x-rays for medical therapy it is important that the proper dose rate be applied. The dose depends upon the energy of the x-rays and the intensity of the x-ray beam. In field emission devices, increasing the voltage of the electric field increases the energy of the x-rays while increasing the current increases the intensity of the beam. Higher energy x-rays penetrate to greater depths in body tissue, so voltage control is important in controlling the energy to avoid damaging healthy tissue needlessly due to an undesired depth of penetration of the x-rays. The beam flux is also dependent upon the gap between the anode and the cathode. Increasing the gap decreases the beam flux and vice versa.  
         [0004]     An undesirable feature of known field x-ray emitter devices is the inability to closely control the dose rate. One reason for this lack of control is that the generation of the electron beam from the cathode can be sporadic. That is, due to uncontrollable changes in the condition of the electron emitting surface of the cathode, field emitters are known for instability of their current, which can vary by a factor of 2. At the higher end of this range the emission current can overheat the emission site and create a vacuum discharge over the gap that can significantly change the electric properties of the gap or even make the device inoperable in the required settings. Because of the inconsistency in the current and thus the x-ray beam flux, the dose applied during any particular therapy session may not be well known, which leads to inconsistent treatment and results. The only sure way to know that a particular medical problem has been adequately addressed is to apply radiation at a presupposed rate that increases the likelihood of damage to healthy tissue.  
         [0005]     The inventions disclosed and claimed in the priority applications referenced above disclose apparatus that enables an operator of an x-ray apparatus to control the energy and intensity of an emitted x-ray beam by independently controlling the voltage and operating current, respectively. Generating x-rays with the inventions disclosed therein will enable to control the dose rate applied to tissues.  
         [0006]     Generally, when excising cancerous tissue, such as breast cancer, the surgeon will remove the tissue as well as a surround margin of tissue that may be healthy. To ensure that all of the cancer cells have been killed, radiation is provided. Due to the perhaps irregular configuration of the cancerous tissue and the removed margin tissue, providing a controlled dose of therapeutic radiation to the remaining, surrounding tissue can be problematic, resulting is some tissue receiving too much radiation and being injured and some tissue perhaps not receiving enough to kill any remaining cancer cells.  
         [0007]     Thus, it would be desirable to have an appliance that could be used with such field emission apparatus to provide a desired tissue cavity configuration into which the field emission apparatus could be deployed. This would ensure that the proper dose of radiation would be provided to the tissue surrounding the cavity and to the desired depth  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0008]     The present invention provides an appliance for use in delivering x-ray radiation therapy internally at desired locations in a body. Broadly speaking, the appliance may be inserted into the tissue to receive radiation and expanded to a desired shape, thereby providing a predetermined configuration to the tissue surrounding the appliance. The appliance can be configured to provide a spherical shape, for example, or an elliptical shape if desired.  
         [0009]     In accordance with the invention, an appliance may have a bulb that is expandable and contractible between at least the extremes of expansion and contraction, though intermediate states therebetween can also be provided as desired. The bulb will preferably be formed from a predetermined number of spokes extending between a bulb base and a bulb collar such that movement of the bulb base and bulb collar relative to each other will cause the spokes to either flex outwardly to an expanded position or be pulled inwardly into a contracted position. The bulb may be configured such that the expanded bulb can assume a substantially spherical shape or a substantially elliptical shape as desired.  
         [0010]     The present invention may further include a bulb member having a bulb member base that is attachable, either removably or permanently, to the bulb base such that the bulb member extends through and out of the bulb. The bulb member may have a central passage for receiving an x-ray probe of the type described in the aforementioned incorporated patent applications. A latch may be provided that extends and operates between the bulb member and the bulb to latch the bulb into the desired position of expansion or contraction.  
         [0011]     In one embodiment of the invention, the bulb may include a collar extension having a central passage configured to receive the bulb member. A latch useful with such an embodiment may provide a knob that is attached to the bulb, in particular the bulb collar, that is inwardly extending, and that is received by one of a plurality of appropriately configured holes in the bulb member. To engage and disengage the knob from the holes, the collar extension may include a substantially saw-tooth shaped ramp surface that engages the inner surface of the collar. Relative motion of the collar and the collar extension will cause the collar to move inwardly and outwardly with respect to the collar extension and thus the bulb member, thereby causing the knob to engage and disengage the holes.  
         [0012]     In another embodiment of the present invention latch may be provided by a latch button that is attached to or integrally part of the bulb member.  
         [0013]     In another embodiment of the invention, the latch may be provided by a latch bar that is attached to the bulb member. The latch bar may have a finger rest such that pushing on the finger rest pushes the latch pin out of one of a plurality of appropriately configured latch bar grooves disposed on the collar extension, thus freeing the collar extension, and hence the collar, for relative motion relative to the bulb base for expanding and contracting the bulb.  
         [0014]     To aid in the utilization of the appliance, a pair of grips in the form of finger rings or finger rests may be provided that engage the bulb member at the end thereof.  
         [0015]     It will be understood that the various figures included and described herein are of various scales to enable the various features of the present invention to be shown more clearly.  
         [0016]     The present invention, as well as its various features and advantages, will become evident to those skilled in the art when the following description of the invention is read in conjunction with the accompanying drawings as briefly described below and the appended claims. Throughout the drawings, like numerals refer to similar or identical parts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0017]      FIG. 1  shows an embodiment of the present invention in a perspective view.  
         [0018]      FIG. 2  shows the bulb of  FIG. 1  in a perspective view.  
         [0019]      FIG. 3  illustrates the “top” portion of a bulb that is manufactured in two parts for later assembly together.  
         [0020]      FIG. 4  depicts the “bottom” portion of a bulb that is manufactured in two parts for later assembly together.  
         [0021]      FIG. 5  shows the bulb member used with the appliance shown in  FIG. 1 .  
         [0022]      FIG. 6  shows a perspective view of the bulb member of  FIG. 5  and illustrates in particular the central passage therein for receiving an x-ray radiation therapy device.  
         [0023]      FIG. 7  depicts in a perspective view the collar extension of the appliance shown in  FIG. 1 .  
         [0024]      FIG. 8  illustrates bulb member and the collar extension in the manner in which they interact.  
         [0025]      FIG. 9  illustrates the bulb member of  FIG. 1  and its association with the finger rings shown in the appliance of  FIG. 1 .  
         [0026]      FIG. 10  illustrates one of the two finger rings shown in  FIG. 1 .  
         [0027]      FIG. 11  illustrates the other of the two finger rings shown in  FIG. 1 .  
         [0028]      FIG. 12  depicts a top plan view of the bulb with the bulb member shown in phantom cross-section.  
         [0029]      FIG. 13  illustrates an alternative embodiment of the present invention.  
         [0030]      FIG. 14  illustrates a bulb member useful with the embodiment shown in  FIG. 13 .  
         [0031]      FIG. 15  depicts another embodiment  102  of an appliance in accord with the present invention.  
         [0032]      FIG. 16  shows the appliance of  FIG. 15  in another view.  
         [0033]      FIG. 17  illustrates a top bulb half in a perspective view.  
         [0034]      FIG. 18  shows a collar extension useful with the embodiment shown in  FIG. 15 .  
         [0035]      FIGS. 19A and 19B  illustrate a cantilevered latch member useful with the embodiment shown in  FIG. 15 .  
         [0036]      FIG. 20  shows a cross-sectional view of the embodiment shown in  FIG. 15 .  
         [0037]      FIG. 21  shows a flexible sleeve that may be used with the present invention. 
     
    
       [0038]      FIG. 13  illustrates the embodiments of  FIGS. 11 and 12  in use with the present invention intra-operatively in a body cavity.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0039]     Referring now to  FIGS. 1-10 , an embodiment of the present invention will now be described. Thus, as shown in the Figures, an appliance  10  may include an expandable/contractible bulb  12  including a bulb base  14  and a collar  16 . Bulb  12  may include a plurality of spokes  18  extending between the bulb base  14  and collar  16 . The particular embodiment shown in  FIGS. 1-10  includes 8 such spokes, though other numbers of spokes may be used as desired and appropriate for the tissue in which the appliance  10  may be used.  
         [0040]     The bulb  12  may be manufactured as a single integral item, or it may be manufactured in parts and assembled. For example, as best seen in  FIGS. 3 and 4 , the bulb  12  may comprise a top bulb half  20  including collar  16  and a bottom bulb half  22 . Following manufacture the two halves  20  and  22  may be attached to each other in any known manner appropriate for its intended use. For example, in the embodiment shown in the Figures, each partial spoke  18  in the bottom bulb half  20  includes a crush pin  24  that is configured to be received by the appropriately configured pin receiving hole  26  in the corresponding partial spoke in the top bulb half  20 . The attachment of the two halves  20  and  22  can be made secure by heat staking or sonic welding or any other desirable form of attachment.  
         [0041]      FIGS. 1, 5  and  6  show a bulb member  30  including a bulb member base  32  that is attached to the bulb base  14 . The bulb member base  32  includes a circumferentially extending groove  34  configured to receive the inner mating edge  36  of the bulb base  24 , best seen in  FIG. 2 . Preferably the diameter of the edge  36  will be slightly less than that of the groove  34  such that the bulb member base  32  “snaps” into position in the bulb base  14  and is held there tightly. If desired, the bulb member  32  may be permanently attached to the bulb base  14  in any known manner or may be manufactured as an integral unit therewith.  
         [0042]     The bulb member  30  further includes an elongate tubular portion  36  that extends upwardly from the bulb  12 . Tubular portion  36  includes at least a pair of positioning holes  38 ,  40  that is used to position the bulb  12  in the desired position of expansion or contraction as will be described in greater detail later. As stated, a pair of such positioning holes are shown, though more could be provided if desired. The tubular portion  36  further includes a pair of ribs  42  extending outwardly on opposite sides therefrom. Ribs  42  bear against the inside surface  43  ( FIG. 2 ) of the collar  16  and aid in maintaining the position of the bulb member  30  along the central longitudinal axis of the bulb  12 . Stated otherwise, the bulb member  30  defines the longitudinal axis of the appliance  10 .  
         [0043]     Bulb member  30  may also comprise a fixture  44  at the end thereof. Fixture  44  as shown includes a pair of opposed substantially annularly configured ear members  46 . Annular ear members  46  may be used to secure appropriate finger/hand grips to appliance  10  as will be described below.  
         [0044]     Bulb member  30  also includes a centrally disposed passage  48  ( FIG. 6 ) that is appropriately sized to receive an x-ray radiation therapy device. As noted earlier, the positioning ribs  42  function to align the bulb member along a precise longitudinal axis. Thus, disposing the therapy device within passage  48  enables the therapist to know the precise location of the therapy device for radiation therapy.  
         [0045]      FIG. 7  illustrates a collar extension  50  useful with appliance  10 . Collar extension  50  includes a cap  52  and a pair of opposed downwardly extending arms  54  and  56 . The arms are spaced apart to define a channel  58  configured to slidably receive the bulb member  30  as seen in  FIG. 8 . As seen in  FIG. 1 , the collar extension  50  includes a collar extension passage  60  passing centrally therethrough. In the fully assembled apparatus shown in  FIG. 1 , the passage  60  and the bulb member passage  48  are aligned so as to permit the insertion of an x-ray radiation therapy device therein.  
         [0046]     Referring to  FIG. 7  again, collar extension arm  56  includes a pair of spaced apart ribs  62  each having a substantially saw-tooth shaped ramp  64  on the surface thereof. The ramp  64  includes a plurality of hills/valleys arranged sequentially that bear against the collar  16 . Disposed therebetween on the arm  56  is an elongate slot  66  that extends through the arm  56 . As will be discussed below, the ramps  64  and slot  66  aid in the positioning of the bulb  12  in the desired position of expansion or contraction.  
         [0047]     Referring now to  FIGS. 1 and 9 - 11 , the appliance  10  may include finger rings  68  and  70  to aid in the operator&#39;s use of the apparatus. Finger rings  68  and  70  may be formed by a pair of finger ring portions  72  and  74  shown in  FIGS. 10 and 11 . As seen there, each portion  72  and  74  includes a substantially half-cylindrically configured fixture capture portion  76  with attached finger ring members  78  and  80 . When portions  72  and  74  are attached to each other, the finger ring member  76  of one portion will cooperate with the finger ring member  78  of the other portion to form one of the finger rings  68  or  70  as seen in  FIG. 1 . The finger ring portions  72  and  74  may be joined together through the use of pegs  82  and corresponding appropriately configured peg-receiving holes  84 .  
         [0048]     Fixture capture portions  76  of finger ring portions  72  and  74  cooperate to form a fixture receiving chamber having substantially cylindrically shaped configuration. As best seen in  FIGS. 1 and 9 , the fixture  44  is received within the chamber formed when finger ring portions  72  and  74  are joined together. Each fixture capture portion  76  includes a substantially cylindrical half-wall  86 . Extending inwardly from the half-walls  86  are top wall segments  88  that define therebetween a “cut-out” portion  90  that receives an arm  54  or  56  of the collar extension  50  as best seen in  FIG. 1 .  
         [0049]      FIG. 12  illustrates the bulb  12  in a top plan view and its interaction with the bulb member  30 , shown in phantom cross-section. It will be observed that the collar  16  of the bulb  12  includes a positioning pin  92  that is received within one of the positioning holes  38  or  40 . The positioning pin  92  holds the bulb  12  in the desired position of expansion or contraction.  
         [0050]     Having described the appliance  10 , its operation will be described. To expand and contract the bulb  12 , the operator/therapist will grasp the appliance  10  with one hand using the finger rings  68   79  and with the other hand will grasp the cap  60  of collar extension  50  and move it upwardly or downwardly as indicated by double-headed arrow  94  in  FIG. 1 . As the collar extension  50  moves, the ramp  64  will bear against a ramp-bearing surface  96  ( FIG. 12 ). As the ramp  64  moves against the surface  96 , the various hills and valleys of the ramp  64  will travel against the surface  96 . As a “hill” is encountered by the ramp-bearing surface  96 , the collar  16  in the vicinity of the positioning pin  92  will be forced outwardly, thus pulling the positioning pin  92  out of a positioning hole, such as hole  38  or  40 . Encountering a “valley” will allow the collar  16  to relax inwardly and setting the pin in the desired positioning hole.  
         [0051]     The pin  92  and the positioning holes such as holes  38  and  40  thus act as a latch to latch the bulb in the desired state of expansion or contraction. In use, the bulb  12  will be contracted for insertion into the desired position in the body and then expanded. A therapeutic x-ray apparatus as shown in the applications referenced above may be inserted into the passages  48  and  60  of the bulb member  30  and collar extension  50 , respectively, and x-ray therapy may be provided at the desired location.  
         [0052]     Referring to  FIG. 13  another embodiment  100  of an appliance in accord with the present invention is shown. Appliance  100  includes a bulb  12 , collar extension  50  and finger rings as previously described.  FIG. 14  shows a bulb member  102  useful with the appliance  100 . As shown there, the bulb member  100  includes a bulb member base  32 , a tubular portion  36 , positioning holes  38  and  40  and a passage  48 , fixture  44  with opposed substantially annularly configured members  46 , and a rib  42 , all as previously described with respect to bulb member  30 . Bulb member  102  further includes a rib  104  on the opposite side of portion  36  from rib  42 . Rib  102  as best seen in  FIG. 14  includes compressible latch button  106  formed in part by removing a portion of the rib  104  to create a gap  108  between the button  106  and the tubular portion  36 . Gap  108  allows button  106  to be pressed backwards toward the tubular portion  36 . The latch button  106  includes an outwardly projecting hook  110 .  
         [0053]     Referring to  FIG. 13 , it will be observed that the latch button  106  is depressed backwardly such that the hook  110  is hidden within the collar  16 . By moving the collar  16  downwardly relative to the bulb base  14 , the bulb will expand, the hook  110  will be exposed, and the latch button will move outwardly to its natural position. The hook  110  will catch on the upper edge  112  of the collar  16  and hold the bulb in position. That is, the hook will prevent the bulb  12  from contracting by retaining the collar  16  in position.  
         [0054]     Another embodiment  200  of the present invention is shown in  FIGS. 15-20 . Appliance  200  may include a bulb  202  similar to that previously described, a bulb member  30  as previously described, a collar extension  204 , as well as other features described hereafter.  
         [0055]     Referring to  FIG. 17 , a top half  206  of bulb  202  is shown in a perspective view looking down the collar  16  into the bulb. Extending inwardly from the inner surface of the collar  16  is an attachment stud  208 , which will be used to attach the collar extension  204  to the collar  16  as described further below.  
         [0056]     The collar extension  204  is shown in  FIG. 18 . As with the previously described collar extension  50 , collar extension  204  includes a cap  210  and a pair of opposed downwardly extending arms  212  and  214 . The arms  212  and  214  are spaced apart to define a channel  216  configured to slidably receive the bulb member  30  as seen in  FIGS. 15-16  and  20  As seen in  FIG. 18 , the collar extension  204  includes a collar extension passage  218  passing centrally therethrough. In the fully assembled apparatus shown in  FIG. 15 , the passage  218  and the bulb member passage  48  are aligned so as to permit the insertion of an x-ray radiation therapy device therein.  
         [0057]     Referring to  FIG. 18  again, collar extension arm  212  includes an aperture  219  therethrough configured to receive stud  208  and hold the collar extension  204  in position relative to the collar  16 .  
         [0058]     Also seen in the Figure are a pair of spaced apart ribs  220  each having a plurality of grooves  222  therein that aid in the positioning of the bulb  12  in the desired position of expansion or contraction. Spaced apart from the plurality of grooves  222  further down the ribs  220  is a solitary groove  224  that marks the greatest contraction of the bulb  202  whereas the grooves  222  mark a plurality of degrees of expansion of the bulb.  
         [0059]     Appliance  200  is assembled substantially identically to the previous embodiments, with the bulb member  30  being attached to the bulb base and extending upwardly and outwardly therefrom. The passage  216  of collar extension  204  receives the bulb member  30 .  
         [0060]     Also shown in the Figures an particularly in  FIGS. 19A and 19B  are grip and latch bar  230  comprising finger rest portion  232  and latch bar portion  234 . Portions  232  and  234  are attached to each other using complimentary pegs and holes  236  and  238 , respectively, similar to the pegs and holes  82  and  84 , respectively, as previously described. When attached, portions  232  and  234  define a chamber that receives the fixture  44  of bulb member  30 .  
         [0061]     Finger rest portion  232  includes a finger rest  240 , which as shown is downwardly depending, and a fixture capture portion  241 .  
         [0062]     Latch bar portion  234  includes a lever portion  250  depending downwardly. As depicted, the lever portion  250  includes a first somewhat U-shaped portion  252  and a second somewhat U-shaped portion  254 . As best seen in  FIGS. 15-16  and  20 , first portion  252  is attached to the fixture capture portion  255  of latch bar portion  234  and defines a passage  256  through which the bulb member  30  and collar extension  204  pass. Second portion  254  is attached to the first portion  252  and also defines a passage  258  through which the bulb member  30  and collar extension  204  pass. Where the first and second portions  252  and  254  are attached to each other, a latch bar  260  is created that will engage the grooves  222 ,  224 . The latch bar portion  234  may also include a finger rest  262 . When assembled, the fixture capture portions  251  and  255  will form a substantially cylindrical chamber that will capture the fixture  44  of the bulb member  30 .  
         [0063]     Referring to  FIGS. 15, 16  and  20  in particular, the operation of the embodiment  200  will be explained. As seen in those figures, pressing on the finger rest  262  will cause the latch bar  260  to pivot out of engagement with one of the grooves  222 ,  224  (whichever groove it is in at that point in time). Once disengaged, the bulb member  30  can be moved reciprocally within the channel  216  in the collar extension  204  to the desired position of expansion or contraction of the bulb. When correctly positioned, the pressure on the finger rest  262  can be released to engage the latch bar  260  in a groove  222 ,  224  as desired.  
         [0064]      FIG. 20  is a cross-sectional illustration of the embodiment shown in  FIG. 15 . It will be observed that this illustration shows that the collar  16  can be manufactured as a separate part apart from the top portion  270  of the bulb  202 . When so manufactured the collar  16  and top portion  270  can be attached by any known means, including the slot and groove attachment shown in the Figure.  
         [0065]      FIG. 21  shows a compliant or flexible skin  280  that may be secured over the bulb  12  of either of the embodiments shown herein. If desired, the skin  280  may be hermetically sealed to the bulb  12 , thereby providing a solid surface to the tissue receiving therapy.  
         [0066]      FIG. 22  provides a highly schematic illustration of an example of the use of an appliance  300  of the type shown in  FIGS. 1-20  in combination with an x-ray apparatus  302  as described in the referenced and incorporated patent applications for an irradiation treatment following surgical excision of a breast tumor. Thus the Figure shows a breast  304  having a cavity  306  created by the excision of a tumor. The cavity  306  has been expanded by the use of the appliance  300  as previously described. A target zone for depth of irradiation of the margin tissue surrounding the tumor is indicated by the dotted line  308 . As indicated by double headed arrow  310 , the apparatus  302  is movable back and forth relative to the cavity  306 , facilitating irradiation of the target zone. As noted earlier, the appliance  300  would be inserted into the cavity  306  and would then be placed into the expanded or tissue stretching configuration shown in  FIG. 22 . If desired, the appliance can be inserted alone and then the apparatus  302  may be inserted therein, or the apparatus  302  may first be placed with the appliance and the appliance then inserted. The use in the Figure contemplates the use of the appliance disclosed herein.  
         [0067]     At least the spokes and bulb member of the present invention should be relatively transparent to x-ray radiation. Stated otherwise, they should be manufactured of a material have a low x-ray absorption or at least equal to and preferably less than that of soft tissue. Such materials include, among many others known to those skilled in the art, low density polyethylene, foamed plastic, polycarbonate impregnated plastics. Any material that provides low radiation absorption and that provides the functions specified herein, such as plastics and metals, may be used.  
         [0068]     The present invention has been described in language more or less specific as to the apparatus and method features illustrated in the Figures. It is to be understood, however, that the present invention is not limited to the specific features described, since the apparatus and method herein disclosed comprise exemplary forms of putting the present invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalency and other applicable judicial doctrines.