Abstract:
A treatment method and apparatus for debilitating or killing  Helicobacter pylori  or other microorganisms within the body of a patient is especially suited for treating stomach or duodenal ulcers. The present therapeutic method involves the use of ionizing radiation for eliminating pathogenic microorganisms within or supported upon the lining of a body cavity of a patient, e.g., the stomach. An elongated flexible shaft is provided for insertion into the body in any of various ways selected by the surgeon. It can be placed endoscopically, e.g., through the esophagus, placed surgically, placed laparoscopically or by CAT scan-guided percutaneous insertion. A radiant energy distribution head is provided at the end of the flexible shaft to transmit ionizing radiation for destroying microorganisms within the body. Radiant energy, e.g., x-ray, ultraviolet light, beta radiation, gamma radiation, radio waves, microwaves, or infrared energy, is then transferred from the head of the instrument to the epithelium around the head of the instrument in an amount sufficient to debilitate or kill the  Helicobacter pylori  or other microorganisms in the lining of the body cavity.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a method and apparatus for the destruction of microorganisms on or within a body cavity of a patient through the use of ionizing radiation.  
         BACKGROUND OF THE INVENTION  
         [0002]    Infections involving the human gastrointestinal tract are extremely common, involving many millions of people on an annual basis. These infections include bacteria, viruses, and fungi, and are responsible for significant illness, morbidity and, in many cases, death. While the invention has utility in destroying microorganisms in various parts of the body, e.g., the stomach, bowel, lungs, peritoneal cavity, urinary tract, etc., it is particularly useful in the treatment of gastrointestinal infections.  
           [0003]    It has recently been shown that the most common gastrointestinal infection in the world is due to  Helicobacter pylori , a bacterial pathogen that infects the stomach and duodenum. In the United States, for example,  Helicobacter pylori  is found in approximately 20% of the adult population. It is a chronic gut infection and, once acquired, is notoriously difficult to cure. Most infectious bacteria can be readily destroyed by the human immune system; however,  Helicobacter pylori  lives in the lumen of the stomach and on the surfaces of the stomach and duodenal cells, making it relatively resistant to a host immune response, even if vigorous. I have, however, taken advantage of its location in the treatment method and apparatus employed in the present invention.  
           [0004]    [0004] Helicobacter pylori  is typically a silent infection in humans, the majority of the time causing a relatively innocuous gastric inflammation or gastritis. In a significant minority of infected people, however,  Helicobacter pylori  can cause symptomatic gastritis, gastric ulcer, duodenal ulcer, gastric cancer, and gastric lymphoma. The organism is responsible for approximately 90% of all reported duodenal ulcers, 50% of gastric ulcers, 85% of gastric cancer, and virtually 100% of gastric lymphoma. Millions of Americans have symptomatic gastritis due to  Helicobacter pylori  or the much more serious entities noted above.  Helicobacter pylori  is responsible for thousands of deaths in this country due to complicated ulcer disease and cancer, and is considered to be a Class 3 carcinogen by the World Health Organization, in the same class as Benzene and DDT.  
           [0005]    The organism is found in all countries in the world, causing the same symptoms, diseases, and deaths, but it is most prevalent in undeveloped countries, presumably due to poor hygiene, contaminated water supplies and crowding. In Peru and other South American countries, for example, the prevalence rate of  Helicobacter pylori  infection approaches 90%.  
           [0006]    There is no vaccine available for  Helicobacter pylori  and none is anticipated in the foreseeable future, despite years of intensive effort. The only treatment currently available is prolonged and complicated antibiotic regimens involving three or four expensive antibiotics given over a two-week period. Even using a vigorous antibiotic regimen, however, up to 20% of those treated are not cured of their infection.  
           [0007]    The antibiotics used are powerful, sometimes not well tolerated, and can cause nausea, an altered taste sensation and diarrhea. Allergic reactions are not uncommon. In addition to the problems of efficacy and side effects, antibiotic resistance to this organism is growing rapidly. Up to 50% of the Helicobacter isolates are now resistant to one or more of the best antibiotics known to cure the infection. This problem of antibiotic resistance is only expected to grow in the future, leading to worsening disease outcomes and an ever-increasing health expense.  
           [0008]    Thus, a great need exists for a new, effective, rapid and well-tolerated cure of  Helicobacter pylori , a luminal infection of the gut. There also exists a need for a well-tolerated and effective treatment for debilitating or killing microorganisms with as little intrusion as possible in other body cavities, such as the bowel, lungs, peritoneal cavity or urinary tract.  
         SUMMARY OF THE INVENTION  
         [0009]    This invention provides a treatment method and apparatus for debilitating or killing  Helicobacter pylori  or other microorganisms within the body of a patient and is especially suited for treating stomach or duodenal ulcers. The present therapeutic method involves the use of ionizing radiation for eliminating pathogenic microorganisms within or supported upon the lining of a body cavity of a patient, e.g., the stomach. An elongated flexible shaft is provided for insertion into the body in any of various ways selected by the surgeon. It can be placed endoscopically, e.g., through the esophagus, placed surgically, placed laparoscopically or by CAT scan-guided percutaneous insertion. A radiant energy distribution head is provided at the end of the flexible shaft to provide ionizing radiation for destroying microorganisms within the body. Radiant energy, e.g., x-ray, ultraviolet light, beta radiation, gamma radiation, radio waves, microwaves, or infrared energy is then transferred from the head of the instrument to the epithelium around the head of the instrument in an amount sufficient to debilitate or kill the  Helicobacter pylori  or other microorganisms in the lining of the body cavity.  
           [0010]    In one preferred form of instrument, the flexible shaft comprises a coaxial cable surrounded by an electrical insulation layer and has the radiant energy distribution head located at its distal end. In a preferred optional form of the invention, a positioning and distending device around the head of the instrument is of sufficient size to contact and expand the walls of the body cavity in which it is placed both in the front of the distribution head as well as on the sides of the distribution head. For example, the head of the instrument can be supported a controlled distance from the wall of the body cavity by an expandable balloon so as to regulate the amount of energy transferred to the microorganisms. The balloon is preferably bonded to a portion of the flexible shaft at a point spaced from the head. The ionizing radiation can be x-ray energy, infrared, ultraviolet, radio waves, microwave, beta radiation or gamma radiation. Other forms of ionizing radiant energy that can be used for killing or debilitating surface microorganisms will be apparent to those skilled in the art.  
           [0011]    These and other more detailed and specific objects of the present invention will be better understood by reference to the following figures and detailed description which illustrate by way of example of but a few of the various forms of the invention within the scope of the appended claims. 
       
    
    
     THE FIGURES  
       [0012]    [0012]FIG. 1 is a vertical cross-sectional view showing the use of the invention in the stomach.  
         [0013]    [0013]FIG. 2 is a view similar to FIG. 1 showing an elliptical balloon in use for positioning an ionizing radiation source in the stomach.  
         [0014]    [0014]FIG. 3 is a diagrammatic, longitudinal, cross-sectional view of an instrument and supporting equipment in accordance with one form of the invention.  
         [0015]    [0015]FIG. 4 is an enlarged longitudinal cross-sectional view of the distal end of an instrument in accordance with one form of the invention.  
         [0016]    [0016]FIG. 5 is a vertical cross-sectional view taken on line  5 - 5  of FIG. 4.  
         [0017]    [0017]FIG. 6 is a vertical cross-sectional view of another form of the invention shown as it appears during use in the stomach.  
         [0018]    [0018]FIG. 7 is a transverse cross-sectional view taken on line  7 - 7  of FIG. 6 but on a larger scale, and  
         [0019]    [0019]FIG. 8 is a cross-sectional view of the invention in use with a radioactive isotope employed for providing ionizing radiation. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    The therapeutic method in accordance with the present invention is suited for use in various body cavities including, but not limited to, the stomach, the bowel, the lungs, the peritoneal cavity, the urinary tract, and can also be used with various devices, fabrication methods, arrangements, systems and methods of employment which irradiate the walls of various body cavities or interior sites within the body of a patient by means of ionizing radiation in sufficient amount to debilitate or kill microorganisms lining the body cavity in which the invention is used.  
         [0021]    In one preferred form of the invention, an x-ray device is provided which includes components for producing localized x-ray radiation within a vacuum housing or tube and, optionally, including an inflatable balloon surrounding the vacuum housing and preferably connected near the distal end of the device for positioning the source of ionizing radiation as well as for expanding the walls of the body cavity. While the invention can be employed for killing or debilitating various pathogenic microorganisms, it can be used to advantage in treating  Helicobacter pylori  infections of the gastrointestinal system and other ailments in which ionizing radiation is to be delivered to portions of the body that are not easily accessible. In order to provide a better understanding, the present invention will be described by way of example in the treatment of  Helicobacter pylori  infections within the stomach. It should be understood, however, that the invention is not limited to specific apparatus or methods described.  
         [0022]    [0022] Helicobacter pylori  is an infection of the stomach and duodenum and the major cause of stomach ulcers. Various forms of ionizing radiation, including x-rays, radiation from isotopes, radio waves, microwaves, or light radiation, e.g., ultraviolet light in accordance with the invention provide an advantageous method of treating such infections. The x-ray device, for example, produces ionizing radiation that penetrates the lining of the body cavity, in this case the columnar epithelial lining of the walls of the stomach, or the epithelium of any other passage or lumen that is being treated. During this treatment, the ionizing radiation produces apoptosis or programmed cell death in which the DNA of the microorganism is rendered unable to divide. The apoptosis that occurs in the microorganisms is different from necrosis, another type of cell death. In apoptosis produced by the ionizing radiation, a disruption of the gene structure of the microorganism prevents it from further replication. Consequently, the microorganisms die by mutation and, in some cases, by the disruption of metabolic processes at the cellular level. Some fraction of the microorganisms may also be killed immediately by the radiation. An important advantage of the invention lies in the fact that many organisms, such as bacteria, are exquisitely sensitive to ionizing radiation, sensitive to a much greater degree than the surrounding human cells. Accordingly, the bacteria can be killed or debilitated by apoptosis without serious destruction of the host cells.  
         [0023]    In one aspect of the present invention, a source of ionizing radiation such as an x-ray device is positioned in a body cavity, e.g., the stomach, for treating  H. pylori  infections by inducing apoptosis in the bacterial cells carried on or within in the epithelium lining the stomach. The x-ray or other ionizing radiation of the present invention can therefore be used to prevent the escalation of the infection to stomach ulcers and cancer.  
         [0024]    Refer now to the figures wherein the same numbers refer to corresponding parts in the several views. FIGS.  1 - 4  illustrate by way of example one method of use in accordance with the present invention; the treatment of  Helicobacter pylori  infections of the stomach designated by the numeral  5 . Numeral  5   a  indicates the esophagus and numeral  5   b  indicates the pyloric sphincter. In this case, an instrument  6  is provided which includes a flexible supporting cable or shaft  7  and a distal ionizing radiation distribution head  8  from which radiation emanates as shown by rays  9  that strike the adjacent lining of the stomach where the  H. pylori  infection thrives in the epithelium and mucous lining the stomach  5 . In this case, the source of ionizing radiation is an x-ray device  10  that includes a cathode  16 , an anode  18 , and a getter  24 , all disposed within a vacuum chamber or tube wall  28  (see especially FIGS. 3 and 4). The cable or shaft  7  permits a physician to maneuver the x-ray device  10  to the treatment site in the body. It is contemplated that different types of maneuvering devices could be employed to position the head  8  containing the x-ray device  10  which provides the ionizing radiation, depending upon the particular site to be treated. In the embodiments showing the use of the instrument  6  in the stomach and gastrointestinal system, it is helpful for the shaft  7  to be flexible, to have a reduced diameter and rounded forward end such that it can be easily introduced into the esophagus and stomach, either by itself or, if desired, through an appropriate flexible endoscope (not shown). In one particular embodiment, the shaft  7  will have an outer diameter of less than or equal to approximately 3 mm, allowing it to fit easily within a standard endoscope that typically has a working lumen diameter of about 3 mm. In other applications, the properties and dimensions of the shaft  7  may vary to meet the requirements of the task.  
         [0025]    For many disorders, an annular or donut-shaped radiation pattern  9  is ideally suited for treatment. In order to achieve this pattern, many passages and other interior portions of the body need to be dilated while treatment is carried out with ionizing radiation from the x-ray device  10 . The stomach is very soft and, except after a meal, is in a collapsed state. Rugae or folds  5   c  are present on its inner walls. Stomach ulcers resulting from an  H. pylori  infection are shown at  5   d . In one preferred embodiment of the present invention an optional dilating balloon  20  can be provided, if desired, to dilate the passage of the body, such as the stomach, and thereby distend the stomach wall and hence spread the rugae  5   c  apart and thus flatten the stomach wall so that a uniform annular radiation pattern can be created. The balloon  20  can also be important in positioning and holding the distribution head  8  in the desired location, especially in a central position that is equidistant from all parts of the surrounding stomach wall so as to provide the same dose of radiation to all portions of the stomach  5  surrounding the distribution head  8 .  
         [0026]    When using a small x-ray emitter, a problem is sometimes encountered when too much heat is produced at the anode during operation. If water circulates through the balloon interior, it further serves to cool the x-ray emitter and dissipate the potentially damaging heat. If desired, the balloon  20  can be in fluid communication with a fluid loop  22  that is disposed within the shaft  7  to carry fluid from outside the body to the interior of the balloon  20 , and provide a return path for the fluid. If desired, the fluid in loop  22  can circulate in the interior of the balloon  20 , inflating the balloon  20 , and can then be returned to the proximal portion of the shaft  7  through the fluid loop  22 . A circulating pump  34  can be used to circulate the fluid and maintain the pressure required to achieve the desired balloon size. The pump  34  can be coupled to the fluid loop  22  via fluid ports  35 . Other methods and devices known in the art may also be used to circulate the fluid and inflate the balloon  20 .  
         [0027]    Since it is generally desirable to provide independent control of the balloon size and cooling rate, a separate inflation lumen  40  and port  42  are shown in FIGS. 3 and 4 in fluid communication with the balloon  20 . The fluid loop  22  is positioned to circulate cooling fluid in heat conducting relationship with the anode  18 . In the embodiment shown in FIG. 3, the fluid loop  22  extends to surround a portion of the anode  18 . The circulating action of the fluid loop  22  can thus provide a constant cooling rate, regardless of the extent of balloon dilation. The separate inflation lumen  40  can be coupled to a fluid source of adjustable pressure for the balloon  20  via the inflation port  42 . In one embodiment, the fluid loop  22  and the inflation lumen  40  are created using plastic extrusion techniques. This arrangement has the advantage of allowing a liquid, e.g., water, to be used in fluid loop  22  for cooling and a gas, e.g., air, to be used for balloon inflation via lumen  40  so that the radiation from head  8  is not absorbed before reaching the stomach wall. Different cooling mechanisms could also be used.  
         [0028]    Thus, during use, an inflation fluid is provided to expand the balloon  20  via lumen  40 , inflation port  42  and a line  33  which is connected to the pump  34 . If a liquid is used instead of a gas such as air, the liquid, e.g., water or saline, can be supplied from tank  35  which is connected to the inlet of pump  34 . A gas is, however, preferred for filling the balloon  20 , since it will have a negligible tendency to attenuate the radiation  9  emitted from the energy supply head  8 . The coolant is circulated separately through the fluid loop  22  via lines  37  and  39  by means of circulating pump  34 ′. The pumps  34  and  34 ′ are controlled by the power supply  36  which also supplies the high voltage current through the coaxial cable via coupling  38  to a cathode  16  and an anode  18  that are contained within a vacuum tube or chamber  28 . The power supply  36  also includes an x-ray detector of suitable known construction that is used to calibrate the output of the device and control dosimetry, as well as an electronic display, if desired, for monitoring the therapy.  
         [0029]    In order to apply an electrical field across the anode  18  and cathode  16 , the anode  18  and cathode  16  are coupled to the power supply or high voltage source  36 . In this embodiment, a coaxial cable is disposed within the flexible shaft  7  and coupled to the high voltage source  36  at the proximal end of the shaft  7 . An internal conductor  30  of the coaxial cable is coupled to the anode  18  at the appropriate voltage and is enclosed in an insulating layer  31 . An external conductive layer  32  of the coaxial cable is held at ground and coupled to cathode  16 . A conductive solder on the outside of the vacuum chamber wall  28  may be used to couple the cathode  16  to the external conductive layer  32 . Other known methods may also be used to apply an electric potential across the anode and cathode.  
         [0030]    The vacuum tube  28  containing the cathode  16  and anode  18  can be of the thermonic type, with x-ray energies of, say, 8 KeV to 20 KeV. The tube can be powered to utilize 3 watts or less to produce soft x-ray radiation. A typical treatment time at 3 watts is about one to 20 minutes. When the prescribed dose of ionizing radiation has been delivered, the x-ray tube is turned off and the x-ray distribution head  8  is removed. When a radioactive isotope source is used instead of an x-ray source, the tissue is exposed to ionizing radiation for a few minutes, usually from about 15 minutes to 30 minutes.  
         [0031]    The stomach in its relaxed state has a diameter of about 5-6 centimeters and cannot accommodate a rigid structure. In one embodiment, the device of the present invention can be inserted by being passed through a standard flexible laryngoscope or endoscope (not shown) that has a working lumen about 3 millimeters in diameter. Therefore, a coaxial cable used in this device must have a diameter small enough to be accommodated within the passage to be treated or within the scope-device used, and it must be able to carry the required voltages and have sufficient flexibility to make turns as it follows the passage. A diameter of less than or equal to 3 millimeters may be used for most applications. Standard high voltage coaxial cables are generally not flexible enough. Miniature high frequency coaxial cables are available with an outer diameter of approximately 1.0 mm to 3.0 mm which also exhibit sufficient flexibility and can carry the required voltage without breakdown. In one embodiment of the invention, a cable with an outer diameter of less than or equal to about 3 mm is used. Cables approximately 1-2 mm in diameter are also available, and are used in other embodiments. Such cables are manufactured by, for example, New England Electric Wire Corporation, Lisbom, N.H.  
         [0032]    In one embodiment, a getter  24  is disposed within the vacuum housing  28  in order to aid in creating and maintaining a vacuum condition of high quality. The getter  24  has an activation temperature at which it will react with stray gas molecules in the vacuum. After the vacuum housing is assembled under vacuum conditions and the housing pumped out or baked out, the device is heated to the activation temperature and maintained at that temperature for several hours. It is desirable that the getter used have an activation temperature that is not so high that the x-ray device will be damaged with heated to the activation temperature. An SAES ST 101 alloy getter may be used, which has an activation temperature in the range of 750° C. to 900° C. and is composed of approximately 64% zirconium and 16% aluminum. An ST 707 alloy getter also may be used, which has an activation temperature in the range of 300° C. to 500° C. and is composed of approximately 70% zirconium, 18.6% vanadium, and 5.4% iron. Other suitable getters such as alkali metals can be used, if desired.  
         [0033]    In order to most effectively decelerate the electrons striking the anode, a heavy metal material such as tungsten or gold can be used for the anode  18 . The cathode and anode will be shaped to produce the desired radiation pattern. In the embodiment of FIGS. 1 and 2, the anode  18  is cylindrically shaped with a flat, circular side disposed toward the cathode  16 , and the edge is rounded. The cathode  16  of this embodiment is cone-shaped.  
         [0034]    A wall of the vacuum chamber  28  should be transparent to x-rays in order to allow the full dosage to reach the wall of the body cavity being treated. The wall  28  can comprise pyrolytic boron nitride, or another metal or ceramic material which is transparent to x-rays. Other possibilities include beryllium, beryllium oxide, aluminum, aluminum oxide, or graphite. In one embodiment, the outer diameter of the x-ray device is sized as large as, say, 1 centimeter to deliver the localized radiation to the interior of the stomach. In another embodiment, the outer diameter of the x-ray device is less than or equal to about three millimeters.  
         [0035]    In some applications, such as use in the stomach, the diameter of the dilated balloon  20  should be able to vary with the pressure applied, so that the diameter of the balloon can be adjusted to fit the size of the patient&#39;s stomach or other passage. Therefore, an elastic balloon is particularly suited to gastric applications, where the elastic material will conform to the many surface features of the stomach and dilate the stomach more completely. However, in other applications, it may be desirable to employ an inelastic balloon with a fixed dilated diameter. It should be noted in FIG. 1 that the balloon  20 , when present, is preferably secured to the flexible shaft  7 , e.g., by means of a suitable adhesive  21  at a distance  7   a  spaced from the radiation head  8 . The distal end of the balloon  20  is free rather than being connected to the distribution head  8  or to anything else and is spaced from the source  8   a  of radiation by a distance  7   b  that is equal to  7   a . The distance  7   a + 7   b  equals the approximate radius of the balloon  20  so as to locate the source  8   a  of the radiation  9  at the center of balloon  20 , thus equalizing radiation flux in all directions. A round balloon is shown in FIG. 1.  
         [0036]    In the x-ray device, an electric field exists at the cathode  16 , while on the outside of the vacuum housing a conductive braid or solder is held at ground. These two potentials can be insulated from each other to reduce the chance of electrical flashover. A vacuum tube wall of pyrolytic boron nitride can provide some insulation. If a metal is used as the wall of the vacuum chamber  28 , an insulating layer is beneficial to decrease the chance of electrical flashover. As additional protection against electrical flashover, an electrically insulating material can be placed at the joints on the outside of the vacuum chamber wall  28 . The insulating material could be a potting compound, an injection-molded polymer, and other materials with electrically insulating properties. The vacuum chamber further includes a biocompatible outer coating, such as polyethylene or Teflon® material. The joints between the vacuum chamber wall  28  and the anode  18  may be vacuum furnace brazed, or may be sealed by conventional crimping methods.  
         [0037]    The cathode  16  of the present invention consists of a material which displays emission characteristics when an electrical field is applied. One possible cathode material is a thin diamond film, which can be formed using conventional chemical vapor deposition techniques. A diamond film also may be formed using a laser ion source as described in U.S. Pat. 4,987,007 to Wagal, the contents of which are incorporated herein by reference. A graphite target and the substrate to be coated are disposed in a vacuum chamber. Between the two is an accelerating grid held at a high negative potential. The graphite target is radiated with a focused laser beam from a pulse laser. The laser beam ejects a plume of carbon vapor from the graphite target. A portion of the atoms in the plume are ionized by the focused laser beam, and the positive carbon ions are accelerated towards the substrate by the accelerating grid.  
         [0038]    One possible cathode material is described in U.S. Patent Application entitled “DEVICE FOR DELIVERING LOCALIZED X-RAY RADIATION TO AN INTERIOR OF A BODY AND METHOD OF MANUFACTURE”, having Ser. No. 08/806,244, the contents of which are incorporated herein by reference. The cathode material is a coating of carbon having diamond-like bonds which demonstrate negative electron affinity. It is also desirable to have sufficient conductivity to create a constant supply of electrons to the surface of the cathode. The presence of some graphite bonds in the diamond film will contribute to conductivity. Thus, a combination of a diamond film having both sp3 carbon bonds, to function as a cathode, and some sp2 carbon bonds, to facilitate conductivity, is particularly suited for use in many applications. Other elements may also be present in the film in small quantities. The diamond film will have the property that it can emit electrons at electrical fields greater than or equal to about 20 KV/micron. This required electric field is significantly lower when compared to that required for metal emitters such a molybdenum or silicon, which require greater than 1,000 KV/micron. If desired, the x-ray device and method can be constructed as described in co-pending patent application Ser. No. 09/027,010 (in which I am a co-inventor) and is incorporated herein by reference.  
         [0039]    When used to radiate the walls of an interior passage of the body, according to one embodiment of the invention, the x-ray device may be placed within a standard endoscope or laryngoscope. The x-ray device or other ionizing radiation described herein is introduced into the passage to be treated. The x-ray device, etc., is then guided through the passage, using techniques known in the art, until it is positioned near the area to be irradiated. The site to be irradiated may be viewed through the endoscope, and the area around the device may be flushed using the endoscope, if necessary. The dilating balloon  20  is then inflated by fluid, either liquid or gas, from the fluid pump to the desired diameter to expand the body cavity, in this case the stomach so as to hold the radiation distribution head  8  in the desired location and spread the rugae  5   c  apart so as to thereby flatten the stomach wall to insure uniform irradiation.  
         [0040]    During operation, the high voltage generator is activated and an electrical field is established across the cathode  16  and the anode  18 . The cathode  16  emits electrons which are accelerated toward the anode  18 . As the electrons are decelerated by the anode  18 , electromagnetic ionizing radiation is emitted. In this manner, x-ray radiation is produced by the Bremsstrahlung effect. As the x-ray radiation impinges upon the wall of the body cavity, such as the stomach, the  H. pylori  living on the surface of the passage are killed or debilitated by apoptosis as discussed above. In  H. pylori  infections, for example, the apoptosis eliminates the bacterial cells and reduces inflammation as well as the biochemical results of inflammation, thereby preventing ulcers, gastritis and cancer. When the desired dosage has been delivered, the voltage source is turned off and the balloon  20 , when present, is deflated. The device is then withdrawn from the body.  
         [0041]    The dosage of x-ray radiation to be applied to the interior of a body will generally be within the scope of the attending physician&#39;s judgment and will be based on individual conditions, such as the severity of the infection and the damage that has occurred at the site to be treated and the particular patient. In order to treat  H. pylori , only the surface of the epithelium needs to be irradiated.  
         [0042]    According to the present invention, x-ray radiation typically in the range of 0.1 to 50 Grays, and most preferably 1-2 Grays, may be applied. The treatment is typically structured to last about 2 to 10 minutes, and most preferably, 3 to 5 minutes. The x-ray emitter may be repositioned by moving it from one part of the stomach to another, either continuously or intermittently during the course of radiation treatment, depending on the length of the area requiring treatment.  
         [0043]    It will be noted that because the source of radiation in the distribution head  8  is at the center of the balloon  20 , all of the rays  9  will be of the same length when they strike the microorganisms, thereby assuring uniform radiation flux and, consequently, uniform exposure to radiation wherever the radiation strikes the wall of the cavity that is being treated. Uniform radiation exposure is also aided through the flattening of the stomach wall that is accomplished by the expansion of the balloon  20 . The expanded balloon  20  also locks or wedges the radiation-supplying head  8  in place within the stomach  5 , so that stomach contractions, which take place normally, cannot displace the instrument  6 . During use, the balloon  20  should not be expanded to the point where the blood supply to the epithelium lining the stomach is cut off, since oxygen is necessary in forming free radicals which are important in the destruction of the microorganisms.  
         [0044]    Refer now to FIG. 2 which illustrates a positioning balloon  20  of a different shape. In this case, the balloon  20  is generally elliptical in shape and is secured as already described in FIG. 1 by means of adhesive  21  at a distance  7   a  from the energy-supplying head  8 , the space  7   a  being a substantial distance that is determined so as to place the energy distribution head  8  in approximately the center of the elliptically-shaped balloon  20 . The axis of the ellipse is aligned with the distribution head  8 . If desired, in order to prevent the head  8  from dangling away from the center of the balloon  20 , optional radially extending tethers  23  that serve as positioning ligaments can be bonded at each end to extend between the distribution head  8  and the wall of the balloon  20 . The tethers  23  can be formed from short lengths of cord, tape or narrow strips of cloth, etc. Other positioning means for locating the head  8  at the center of the balloon  20  will be apparent to those skilled in the art. The tethers  23  can be attached to the balloon  20  by adhesive during assembly while the balloon is inverted, i.e., inside out over the distal end of the distribution head  8 .  
         [0045]    Refer now to FIGS. 6 and 7 illustrating a modified form of the invention in which the same numerals refer to corresponding parts already described. In this case, ultraviolet light rays  60  are provided by the energy distribution head  8  which is formed from a transparent material, e.g., glass or fused quartz. The ultraviolet light  60  is projected both laterally at  61  as well as passing forwardly at  62  through the balloon  20  striking the wall of the stomach  5 . The balloon  20  holds the radiant energy distribution head  8  in the desired position and also distends the wall of the stomach  5  so as to spread out the rugae  5   c  and thereby allow uniform exposure of the portion of the wall of the stomach that is being treated. As the ultraviolet light rays  60  strike the columnar epithelium lining the stomach, the  H. pylori  infecting the cells is killed or debilitated. The part of the stomach exposed to the ultraviolet light rays  60  can be changed by the physician, either by moving the balloon  20  and head  8  along the length of the stomach  5  toward the esophagus  5   a  or by changing the angle of the head  8  with respect to the longitudinal axis of the stomach  5  as will be described more fully below. The position of the instrument can also be confirmed using fluoroscopy or a CAT scan, if desired.  
         [0046]    In this case, the cathode  16  and anode  18 , as well as the conductor  30 , are eliminated and replaced by a fiber optic bundle  64  (FIG. 7) which extends from a light source  66  (FIG. 6) through the entire length of the flexible shaft  7  via the esophagus  5   a  into the stomach  5 , so as to carry ultraviolet light from the source  66  through the distribution head  8  to a light reflector or diffuser, e.g., of conical shape, inside the distribution head  8  which spreads the ultraviolet light rays  60  so that they pass through the balloon  20 , string the wall of the stomach  5  to the side and in front of the distribution head  8 . As shown in FIG. 7, the inflation fluid for the balloon  20  is supplied through a lumen  40  as already described. The flexible shaft  7  can be provided with a plurality of longitudinally extending, radially spaced apart cables  68  that are slidably mounted in the flexible body portion  70  of the shaft  7 . Using a suitable commercially available steering mechanism for shortening or lengthening the cables  68 , the distribution head  8  can be made to point toward the right, left or up and down as directed by the physician to distribute the beam of ultraviolet light to various parts of the stomach as desired. The shaft  7  can be enclosed in a protective cover or sheath  74 , e.g., polypropylene plastic that will slide easily through the esophagus  5   a.    
         [0047]    The ultraviolet light source  66  can comprise any suitable commercially available lighting source, e.g., a mercury vapor lamp. There are three classes of ultraviolet light: UVA (320 nanometers to 400 nanometers), UVB (290 nanometers to 320 nanometers), and UVC (200 nanometers to 290 nanometers). UVA can be provided from an incandescent source such as a tungsten, halogen or quartz iodide lamp. UVB can be provided by means of a suitable arc lamp such as a high pressure mercury lamp or a hot quartz lamp. UVC can be provided from an arc lamp using mercury vapor, a cold quartz lamp or a carbon arc lamp which mimics sunlight with a spectrum of from 280 nanometers to near infra-red. While any suitable ultraviolet light beam can be provided, it is preferred to use UVB or UVC light because of their greater effectiveness in killing or debilitating microorganisms through apoptosis.  
         [0048]    To use the apparatus of FIGS. 6 and 7, the shaft  7  and head  8  are passed through the esophagus  5   a  conventionally with the balloon  20  in a collapsed position surrounding the head  8 . After the head  8  is properly positioned in the stomach  5  under the control of the physician, the balloon  20  is inflated by passing a suitable fluid, e.g., air, through the inflation lumen  40  until the balloon  20  has expanded the stomach S at the desired location, thereby distending the rugae so that the pockets otherwise present are spread out evenly over the surface of the balloon  20 . The light source  66  is then turned on, causing the UV light to pass through the fiber optic bundle  64  and out through the distribution head  8 . The distribution head  8  and the balloon  20  can then be repositioned in the stomach as desired to expose all of the infected areas or, alternatively, the control cables  68  can be manipulated so as to point the head  8  toward the areas of the stomach that require treatment. Observations can be carried out by means of a viewing port and eyepiece  72  of known construction or through a separate endoscope (not shown) that is passed through the esophagus  5   a  into the stomach S alongside the flexible shaft  7 .  
         [0049]    In another form of the invention, the same apparatus is employed as already described in FIGS. 6 and 7, except that the light source  66  comprises a suitable commercially available infrared light source. The light source  66  can, for example, be an erbium laser, which is preferably operated intermittently and on low power compared to the power used for removing skin blemishes, scars, tattoos, etc., to enable the microorganisms to be killed without damaging the surrounding tissue.  
         [0050]    Refer now to FIG. 8 which illustrates the use of the invention with radioactive isotopes to provide ionizing radiation for killing or debilitating H. pylori or other microorganisms through apoptosis. Radioactive isotopes provide the ionizing electromagnetic radiation through radioactive decay that can expose healthcare workers to radiation and require a shielded room. The present invention provides a way of shielding the isotope before and after use. In this case the flexible shaft  7  has a body portion  80  that is uniform throughout and contains a longitudinally extending lumen  82  in which a control cable  84  is slidably mounted. The distal end  86  of the control cable  84  is secured to a cylindrical slug  88  that is formed mostly of a shielding material such as lead but has a central portion  90  which is formed from a radioactive isotope. The slug  88  is slidably mounted in a bore  92  within the energy supply head  8  which includes two shielding portions including a distal portion  94  and a proximal portion  96 , both formed of a suitable shielding material such as lead that is useful in shielding radioactive material. The shields  94 ,  96  are joined by an annular central portion  98  formed from a radiation-transparent material such as a suitable ceramic or plastic resinous material which allows radiation to be emitted when the slug  88  is moved under the direction of the physician distally so that the radioactive isotope  90  is exposed in the radiation transparent area  98  at the center of the distribution head  8 . The distribution head  8  is enclosed in a sheath or coating of biocompatible material  100  such as polyethylene or Teflon®.  
         [0051]    During use with the cable  84  pulled up, the shaft  7  and head  8  are inserted through the esophagus Sa into the stomach  5  conventionally, with the balloon  20  in a collapsed condition. Inflation fluid is then forced through the inflation lumen  40  into the balloon  20  to expand it sufficiently to spread out the walls of the stomach as described above. The cable  84  is then moved distally so as to shift the slug  88  containing the radioactive isotope  90  downwardly in FIG. 8 until the radioactive material  90  is aligned with the annular radiation-transparent wall  98 , thereby allowing the ionizing radiation to pass from the radioactive isotope  90  radially in all directions from the head  8 . After passing through the balloon  20 , the radiation will strike the wall of the stomach  5  or other body cavity, killing or debilitating the  H. pylori  or other pathogenic microorganisms lining the wall of the cavity being treated. As treatment progresses, the balloon  20  and/or head  8  are repositioned under the control of the physician so as to redirect the ionizing radiation to the desired areas and for the length of time required to accomplish the required treatment. Because bacteria are much more sensitive to ionizing radiation than human tissue, the  H. pylori  and other bacteria can be killed or debilitated by apoptosis with little, if any, damage to the host tissue. As soon as the treatment is completed, the cable  84  is pulled, causing the slug  88  to slide proximally in the head  8  until the isotope  90  is completely surrounded by the lead shielding. The balloon  20  is then deflated and the instrument is withdrawn. As described above, the instrument shown in FIG. 8 can be positioned in any suitable manner, e.g., by observation through an endoscope (not shown) that is inserted through the esophagus alongside the shaft  7  into the stomach  5 .  
         [0052]    Any of the instruments  6  (including the shaft  7 , head  8  and balloon  20 ) of FIGS.  18  can be inserted into the body cavity alone or, if desired, through the lumen of a commercially available endoscope of suitable known construction.  
         [0053]    Isotopes emit ionizing radiation through the phenomenon of nuclear disintegration The ionizing radiation supplied by the isotope  90  can be either beta or gamma radiation. The beta radiation does not have the penetrating power of the gamma radiation, which will pass entirely through the body and into the room surrounding the patient, therefore requiring a radiation-shielded operating room. It is preferred that the ionizing radiation used have relatively shallow penetrating power, since there is usually no reason to go to any substantial depth.  H. pylori , for example, is located on the surface of the epithelium lining the stomach. It is contemplated in accordance with the present invention to select the penetration depth of the ionizing radiation so that it penetrates only into the surface layer where the  H. pylori  is located, thereby protecting the patient from unnecessary radiation damage. For that reason, when an isotope is used to supply ionizing radiation, beta radiation is preferred to gamma radiation because of its reduced penetrating power.  
         [0054]    In general, the use of non-radioactive sources is preferred to the radioactive source described in connection with FIG. 8, since the use of radioactive sources requires special handling, environmental considerations, and is subject to greater radiation danger. In the United States, only radiation oncologists can prescribe a therapy and dose involving radioactive isotopes. Moreover, gamma sources require a shielded catheterization laboratory. Because of the penetrating power of gamma radiation, the healthcare workers must leave the room while the patient is being treated. When gamma radiation is employed, the isotope  90  can comprise radioactive iridium-192 (Ir 192 ) which is available in the hospital because of its use in cancer treatment. Alternatively, a suitable beta radiation source such as potassium- 32  or strontium- 90  can be used as the isotope  90 . Beta sources typically have a soft tissue penetration depth of less than one-half inch and therefore reduce the unwanted exposure of health tissue compared to gamma radiation. Beta sources are also easier to handle than gamma sources and pose a smaller risk to the patient and healthcare worker.  
         [0055]    Radio waves and microwaves can also be used in accordance with the invention for destroying pathogenic microorganisms such a  H. pylori  in the lining of a body cavity. Microwave energy can be supplied to the distribution head  8  of the device shown in FIGS. 6 and 7 by removing the fiber optic bundle  64  to provide a hollow wave guide through the flexible shaft  7  for conveying microwave energy from a suitable thyratron at the source  66  to the radiant energy distribution head  8  where it is directed through the balloon  20  onto the walls of the body cavity surrounding the head  8 . The microwave energy is preferably adjusted to heat the inner surface of the body cavity so as to preferentially kill bacteria and other microorganisms living at the surface or lining of the body cavity.  
         [0056]    Radio wave energy can be provided using the apparatus of FIGS. 3 and 4, but without a vacuum in the tube  28  between the electrodes  16  and  18 . Instead, a radio frequency field can be set up between the electrodes  16  and  18  to produce heating of the body tissue when the body tissue is placed adjacent to or between the electrodes. To provide the radio frequency field, a powerful RF oscillator can be applied across the electrodes  16  and  18  so as to heat the body tissue between them, as the body tissue acts as a dielectric of a capacitor in which dielectric losses cause heating within the tissue. The RF oscillator can, if desired, be followed by RF amplifier stages for generating high frequency currents that produce heat within the part of the body cavity that is being treated for destroying the pathogenic bacteria on or within the tissue. Other forms of radio wave energy known to those skilled in the art can also be used for destroying microorganisms. In this embodiment of the invention, the balloon  20  can be eliminated since it is generally desirable to position the tissue being treated against or between the electrodes  16  and  18 .  
         [0057]    All publications and patents are herein incorporated by reference to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference.  
         [0058]    Many variations of the present invention within the scope of the appended claims will be apparent to those skilled in the art once the principles described herein are understood.