Abstract:
A patient portable photodynamic therapy device securable to a patient includes a lightweight rechargeable battery and a cold cathode fluorescent (CCF) tube powered thereby. The CCF tube is coupled in light channeling relation to a proximal portion of a biocompatible optical fiber, which includes a distal portion with an optional diffuser that uniformly distributes light as it exits the distal portion. The distal end of the optical fiber is optionally provided with an anchoring balloon that can be inflated after the optical fiber is properly positioned at a treatment site within a patient&#39;s body. The balloon securely lodges the distal portion within the tissue at the treatment site, and is deflated to facilitate the removal of the optical fiber once the treatment is complete.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to a light therapy device for activation of medicaments at one or more treatment sites within a living body, and more specifically, to photodynamic therapy devices adapted to reduce dislodgment risk over long treatment periods and enable a patient to be ambulatory without interruption of the therapy. 
     BACKGROUND OF THE INVENTION 
     Photodynamic therapy (PDT) is a two-step treatment process which has been found to be effective in destroying a wide variety of cancers. PDT is performed by first systemically or topically administering a photosensitizer compound, and subsequently illuminating a treatment site with light in a waveband, which corresponds to an absorption waveband of the photosensitizer. The light energy activates the photosensitizer compound, causing it to destroy the diseased tissue. 
     Numerous systems have been proposed to effectively deliver the activating light to the treatment site. Examples of such systems can be found in U.S. Pat. No. 5,519,534 issued May 21, 1996 to Smith, et al., U.S. Pat. No. 5,344,434 issued Sep. 6, 1994 to Talmore, and U.S. Pat. No. 4,693,556 issued Sep. 15, 1987 to McCaughan. The systems disclosed in these patents generally comprise a laser light source coupled to a proximal end of a flexible biocompatible optical fiber having a distal end adapted to be positioned within the body of a patient, either inside or adjacent to an internal treatment site. The optical fiber conducts and guides activating light from the laser light source to the treatment site at the distal end of the optical fiber. A diffuser enclosing the distal end of the optical fiber diffuses the light, and thus delivers the light to the treatment site at a uniform intensity to effect activation of the photosensitizer compound. In these systems, the diffuser may comprise a sphere positioned on the distal end of the fiber and having an inner partially reflective surface that aids in diffusing light transmitted through the sphere. Other light delivery devices can be found, for example, in U.S. Pat. No. 5,709,653 issued Jan. 20, 1998 to Leone, U.S. Pat. No. 5,700,243 issued Dec. 23, 1997 to Nariso, and U.S. Pat. No. 5,645,562 issued Jul. 8, 1997 to Hann, et al., and U.S. Pat. No. 4,998,930 issued Mar. 21, 1991 to Lundahl. While disclosing systems that are generally similar to the aforementioned systems, these references described diffusers that have an added component. The diffusers of these devices either alternatively or additionally incorporated transparent balloons mounted coaxially around the distal end of the optical fiber. Once the distal end is positioned at the treatment site, the balloon may be inflated in order to increase the area of the treatment site which will be exposed to the activating light, and in some cases, to effect or at least aid in the diffusion of the activating light. Once the light therapy provided by delivery of the light to the treatment site is completed, the balloon may be deflated, and the optical fiber removed from the body of the patient. 
     A conventional PDT treatment is of very short duration, on the order of minutes, and is typically used to treat superficial and small volume lesions. In order to apply PDT successfully against large lesions, which may be located subcutaneously, more extended treatment sessions must be undertaken. Extending the time of treatment overcomes tumor resistance and enables the extent of the treatment site to be greatly enlarged, thus allowing effective therapy of a much greater tumor volume. Indeed, destruction of a large tumor volume by extended duration PDT has been demonstrated in a clinical treatment. The treated patient suffered from a very large retroperitoneal tumor, which had eroded through the skin. The protruding tumor was treated by inserting multiple light emitting probes, such as is described in commonly assigned U.S. Pat. No. 5,445,608, into the substance of the tumor. The probes were energized for more than forty hours after orally administering a dose of a photosensitizer called aminolevulinic acid. This treatment resulted in destruction of just under one-half kilogram of tumor mass over the ensuing four weeks. 
     While adequate for some applications, the lasers, other high-powered light sources, and optical fibers in current use for administering PDT to a treatment site suffer several drawbacks related to safety and their inability to accommodate the extended sessions necessary to effectively treat large tumors. First, high-powered sources such as dye lasers, laser diodes, large light emitting diode (LED) arrays, incandescent sources, and other electroluminescent devices are not efficient in converting electrical energy into light energy. They generate significant amounts of heat, and consume a substantial amount of electrical power. Prolonged use of high intensity light sources can lead to inadvertant tissue damage due to the effect of the high intensity light. Further, certain of these devices, e.g. laser light sources, generate sufficient heat that they must be cooled while activated. The need for cooling necessitates the incorporation of additional hardware such as fans cooling units that draw additional power from the main power supply. 
     Second, the amount of power consumed by high intensity light sources requires that they be supplied with power from an alternating current (AC) line power source. Movement by the patient or attendance efforts by hospital personnel during the treatment period that cause the patient to move can inadvertently disconnect or damage the power cord, not only interrupting the treatment, but also creating a risk of electric shock. Further, being tethered to a substantially fixed power source limits the application of optical extended treatments, inasmuch as the patient will invariably need to move or be moved during the treatment period. Movement of the patient will likely cause the treatment to be interrupted and thus, render it less effective. 
     Third, none of the prior art techniques for rendering PDT to an internal treatment site through an optical fiber provides an anchoring mechanism to effectively secure the optical fiber and its distal end within the body of the patient at the treatment site. Any movements by the patient or attendance efforts by hospital personnel during the treatment period could inadvertently pull or dislodge the optical fiber unless it is secured in place. In many cases, while it is easy to disconnect a power cable from a light source to allow the patient to temporarily move about before resuming treatment, it is not practical to remove the optical fiber from the patient&#39;s body at that time, as well. Instead, the optical fiber must remain in place while the patient moves about. Without an effective mechanism for securing the optical fiber in the patient&#39;s body and at the treatment site while the patient moves, the risk of tissue damage is increased by such activity. Not only can the tissue be torn or severe bleeding occur when the patient moves, but if the dislodgement is not so severe, that it is noticed, the distal end of the optical fiber can be displaced away from the treatment site, so that light is delivered to the wrong area in the patient&#39;s body, resulting in possibly severe and unwanted destruction of normal tissue. 
     Fourth, the methodology of short duration high intensity illumination has drawbacks when applied to treat moderate to large size tumors. These drawbacks include depletion of oxygen necessary for the photodynamic destruction of the tissue that has absorbed the photosynthesizer, incomplete activation of the circulating photosensitizer, mis-timing of the illumination session so that the light therapy is not administered during the peak concentration of the photosensitizer drug in the tumor, and the possible recovery of sub-lethally injured tumor cells, which were not completely destroyed due to the short treatment time. 
     Currently, PDT procedures using laser light sources may be performed during an operation in which a treatment site is surgically exposed, and as such, the period available for administering light therapy is approximately one to two hours at most. The extent of tumor necrosis resulting from such an illumination period is on the order of 1 to 2 centimeters in a zone radially surrounding the optical fiber. Thus, several devices have been developed in an attempt to increase the duration of PDT treatments, to enable the light therapy to continue after an incision in a patient undergoing surgery has been closed. For example, a number of solid state laser devices have been developed for administering PDT that are semi-portable. However, these devices are large, heavy, and must be transported on wheeled carts or other movable furniture. Such “desktop” or semi-portable devices suffer from the drawbacks enumerated above if employed for prolonged PDT treatment periods lasting hours. Furthermore, such light sources must remain connected to the wall power plug by power cables, and the optical fibers through which light produced by the laser is directed to an internal treatment site are prone to dislodgment. 
     Another light source device, disclosed in U.S. Pat. No. 5,616,140 issued Apr. 1, 1997 to Prescott, can be powered by rechargeable batteries and thus, can be worn by the patient. However, because this device generates only low power laser light, and is not designed to be coupled to optical fibers for directing the light it produces to an internal treatment site, its use is limited to superficial light therapy, e.g., to treating skin lesions. High power lasers currently used for PDT require cooling hardware, and a corresponding power source. Due to weight and size considerations, it is clearly not practical for a patient to move about pushing a high power laser, a cooling unit, and battery power supplies for the equipment sufficient to provide for a prolonged treatment session. 
     Accordingly, there is a need for a PDT system to administer light therapy, which reduces the risk of optical fiber dislodgement and allows a patient to move about without interruption of the PDT therapy over treatment periods lasting hours. 
     Citation of the above documents is not intended as an admission that any of the foregoing is pertinent prior art. All statements as to the date or representation as to the contents of these documents is based on the information available to the applicants and does not constitute any admission as to the correctness of the dates or contents of these documents. Further, all documents referred to throughout this application are incorporated in their entirety by reference herein. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a PDT device enabling efficacious treatment of relatively large tumors that are currently not treatable using conventional PDT delivery systems and methodologies and is specially adapted to reduce the risk of dislodging an optical fiber from a treatment site and when the patient moves about. The patient can thus be ambulatory without interruption of the light therapy over long treatment periods. In a preferred embodiment, the present invention comprises a belt or harness that supports and secures a lightweight rechargeable battery and a cold cathode fluorescent (CCF) tube powered thereby to a patient. The CCF tube is coupled to a proximal portion of the optical fiber. A distal portion of the optical fiber is provided with means for diffusing light as it exits the optical fiber. The distal portion of the fiber is adapted to be positioned at a treatment site within a patient&#39;s body by a medical practitioner. A balloon disposed at a distal end of the optical fiber can be inflated after the insertion of the optical fiber within the patient&#39;s body, to secure the distal portion of the fiber within the tissue at the treatment site; the balloon is deflated prior to the removal of the optical fiber, once administration of the light therapy is completed. 
     The present invention overcomes the limitations of the prior art PDT delivery devices in several respects. First, the use of a CCF tube provides increased effectiveness and efficiency compared to laser light sources. Light energy losses due to coupling of the light source to the optical fiber are minimized by employing a parabolic reflector and lens to focus the light into the proximal portion of the optical fiber. It is possible to obtain a greater zone of necrosis using non-laser light delivered to the tumor mass over a longer period of time, for example, 40 hours. Therefore, a CCF tube is preferred over other light sources, such as solid laser diodes, fiber lasers, LEDs, incandescent sources, halogen sources, polymeric luminescent devices or other electroluminescent devices, because CCF tube is generally more efficient in converting electrical power to light energy. As such, it not only generates a minimal amount of heat, but also consumes a minimal amount of power, thereby eliminating the need for cooling fans and large or substantially fixed power supplies. In contrast, the alternative light sources listed above suffer from lower conversion efficiencies, generate more heat, and require greater amounts of electrical power. 
     A second advantage is that the use of a CCF tube allows the present invention to be powered by a portable power supply that employs widely available and commonly used rechargeable batteries such as lithium ion, nickel metal hydride, and nickel cadmium rechargeable batteries, which are lightweight and inexpensive. In contrast, the need for at least some of the other types of light sources to be accompanied by cooling fans, and even cooling systems (with the need for an additional power supply to run the cooling system), makes it impractical for them to be adapted to a portable system, because they are too bulky, weigh too much, and are too expensive. It is not a trivial advantage for the present invention to be readily portable and free from being continuously linked to a stationary or permanent power source. As the present invention can be carried about by the patient on a belt or harness, there are no power cables, which can be severed or pulled from a fixed power source due to inadvertent movements by the patient. Thus, the risk of treatment interruption and electric shock is minimized. More importantly, the patient will be able to undergo optimal extended treatment sessions, as the patient will be able to move freely or be moved without interruption of the treatment. The ability of a CCF tube to be formed into various compact shapes, including “U”s, coils, spirals, and elongate forms, further facilitates the efficient administration of light to various correspondingly shaped treatment sites by the present invention and permits the system to be worn and transported by the patient easily and comfortably. 
     A third advantage provided by the present invention is that it enables a CCF tube to be easily coupled in light channeling relation to the proximal portion of at least one biocompatible optical fiber. The biocompatible optical fiber is flexible not only inasmuch as its distal portion can be easily positioned within the tissue of the patient at a treatment site, but also because it can accommodate movement of surrounding tissue associated with patient respiration and ambulation. A parabolic mirror positioned in partially surrounding relation to the CCF tube and a focusing lens positioned between the CCF tube and the proximal portion of the fiber cooperate to channel light into the proximal portion of the fiber. Specifically, the parabolic mirror reflects light from the CCF tube onto the focusing lens which focuses the light into the proximal portion of the optical fiber. After the light travels through the optical fiber, it is diffused at the distal portion of the optical fiber by a diffuser of the types that are well known and documented in the art. The diffusion of the light emitted from the distal portion of the optical fiber enables the light to be administered more uniformly to the treatment site to activate the photosensitive compound previously administered. The length of the optical fiber is preferably limited to that necessary to reach the treatment site, in order to minimize light loss along the length of the optical fiber. The outer coating of the optical fiber is preferably opaque to light, in order to prevent light leaking from the optical fiber activating any photosensitizer absorbed by normal tissue along the length of the fiber. Additional biocompatible optical fibers may be connected to the parabolic mirror and focusing lens coupling the light into the proximal portions of the optical fibers or alternatively, may be spliced into the biocompatible optical fiber into which the light is focused. 
     A fourth advantage of the present invention over the prior art devices is that it optionally includes anchoring means for securing the optical fiber and particularly, its distal portion within the body of the patient at the treatment site. The balloon mounted to the distal end of the optical fiber can be inflated with a pressurized fluid such as air that flows through a lumen that extends substantially parallel to and which is disposed within or adjacent to the optical fiber. This lumen is thus maneuverable with the optical fiber. The lumen runs substantially the length of the optical fiber, from the pressurized fluid source that is external to the patient&#39;s body to the balloon at the distal end of the optical fiber. After positioning the distal portion of the fiber within the tissue of the patient at the treatment site, the balloon is inflated to secure the distal end of the optical fiber in the tissue. The inflated balloon also tamponades any bleeding, which may occur at the distal end of the optical fiber during its insertion. Thus, any movement by the patient during the treatment will not dislodge the optical fiber or its distal portion because the balloon anchors the optical fiber in place. Similarly, movement of the distal portion of the optical fiber will thus be avoided, preventing light from being administered to healthy tissue that has absorbed the photosensitizer. Overall, the risk of damage to normal tissue is minimized, and the need for the patient to interrupt treatment before moving about is eliminated. Once treatment is complete, the balloon is deflated to facilitate removal of the optical fiber from the patient&#39;s body. It should be noted that for some applications, the distal portion of the optical fiber should preferably abut, rather than be embedded in the treatment site. This may be the case where, for example, it is undesirable or difficult to penetrate the tumor or diseased tissue. In such a situation, the balloon may be positioned at an intermediate point along the length of the optical fiber and/or in coaxially surrounding relation to the optical fiber, rather than at its distal end. 
     The above features and advantages of the present invention will be better understood upon a reading of the following detailed description with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a patient portable PDT device according to a preferred embodiment of the present invention; 
     FIG. 2 is an expanded cut-away perspective view of a light source used in the patient portable PDT device, according to a preferred embodiment of the present invention; 
     FIG. 3 is an expanded sectional view of light channeling coupling means of the patient portable PDT device, according to a preferred embodiment of the present invention; 
     FIG. 4 is an expanded view of a distal portion anchoring means of the patient portable PDT device; 
     FIG. 5 is a perspective view of the patient portable PDT device being worn by a patient; 
     FIG. 6 is a cut away illustration of the positioning of a needle having a peel away sheath that is employed for inserting an optical fiber used in the patient portable PDT device; 
     FIG. 7 is a cutaway illustration of the positioning and anchoring of a distal portion of the optical fiber; 
     FIG. 8 is cutaway illustration of the positioning and anchoring of the distal portion of the optical fiber; and 
     FIG. 9 is a cutaway illustration of the positioning and anchoring of the distal portion of the optical fiber in the bladder, with the light diffuser portion of the optical fiber disposed in the prostatic portion of a patient&#39;s urethra. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     While the present invention will be described more fully hereinafter with reference to the accompanying drawings, it is to be understood that persons skilled in the art may modify the invention herein described while achieving the functions and results of the invention. Accordingly, the descriptions which follow are to be understood as illustrative and exemplary of specific structures, aspects and features within the broad scope of the present invention and not as limiting of such broad scope. 
     Referring now to FIGS. 1,  2  and  3 , a patient portable PDT device  12  according to the present invention comprises a power source, or lithium ion rechargeable battery pack  14 ; a light source, or CCF tube  16  formed into an elongated “U” shape (best shown in FIG. 2) and adapted to draw power from the battery pack  14 ; at least one biocompatible optical fiber  18  (only one is shown) having a proximal portion  20  and a distal portion  22 , and adapted to channel light between the proximal portion  20  and the distal portion  22 ; and a coupling means  24  for coupling the CCF tube  16  in light channeling relation to the proximal portion  20  of the optical fiber  18  (best shown in FIG.  3 ). The optical fiber  18  is equipped with a diffusion means  26  (best shown in FIG. 1) for diffusing light as it exits the distal portion  22  of the optical fiber  18 . The battery pack  14  includes a warning light  28  and backup power reserve  30 . 
     It should be readily apparent to one skilled in the art, based on the instant disclosure, to alternatively use the following items in addition to or in place of their respective presently shown components, without departing from the broad scope of the present invention. For the lithium ion rechargeable battery pack  14 , one may use one or more nickel cadmium rechargeable batteries, one or more nickel metal hydride rechargeable batteries, or fuel cells, any other type of electrical power source polymer batteries, one or more, other rechargeable batteries or non-chargeable batteries that are sufficiently compact and substantially lightweight to be readily portable, i.e., readily carried about by the patient. Such a power source should preferably operate at a relatively low or ambient temperature. In addition, instead of the CCF tube  16 , one or more laser diodes, fiber lasers, LEDs, incandescent lights, halogen lights, polymeric luminescent devices, other types of fluorescent lights, discharge lamps, or other electroluminescent devices can be employed for the light source, including those having at least one of the characteristics of being substantially compact, substantially lightweight, operating at a substantially low temperature, or being self-contained so that the light source is suitable for a portable system that is readily carried about by the patient. For the diffusion means  26 , any of the diffusers well known and documented in the prior art are suitable. 
     Referring now specifically to FIGS. 2 and 3, the preferred coupling means  24  employed to channel light emitted by the light source in the proximal end of the optical fiber comprises a focusing lens  32  having a convex receiver side  34  and a convex delivery side  36 ; and a parabolic mirror  38  positioned so that the CCF tube  16  is generally disposed at or adjacent to the focal point of the parabolic mirror. The focusing lens  32  is positioned between the CCF tube  16  and the proximal portion  20  of the optical fiber  18 , so that the focusing lens receives the directly transmitted light from the CCF tube and the light reflected by the parabolic mirror  38  and focuses the light into the proximal end of the optical fiber  18 . It should be readily apparent to one skilled in the art, based on the instant disclosure, to alternatively use in addition to or in place of the components disclosed for coupling means  24 , one or more mirrors, concave lenses, or convex lenses, in appropriate configurations that channel light emitted by the light source into the proximal portion of the optical fiber, without departing from the broad scope of the present invention. 
     Referring now also to FIG. 4, the present invention further comprises an anchoring means  40  for anchoring the distal portion  22  of the optical fiber  18  within a patient&#39;s body. The anchoring means  40  preferably comprises a balloon  42  attached to the optical fiber  18 , a pressurized air source  44  which may be a syringe which is configured to deliver pressurized air (or other pressurized fluid) to the balloon  42 , a lumen  46  communicating between the air source  44  and the balloon  42 , and a selection means, or control  48  and valve  50  for selectively delivering pressurized air from the pressurized air source  44  to the balloon  42  and exhausting the pressurized air from the balloon  42 , so as to enable the selective inflation and deflation of the balloon. In this preferred embodiment, the optical fiber  18  has a distal end  52  on which the balloon  42  is mounted. The lumen  46  extends in substantially parallel relationship to the optical fiber  18  and runs substantially the length of the optical fiber  18 , affixed to the side of the optical fiber over much of its length. Alternatively, the lumen is disposed within the optical fiber. Hollow optical fibers are well known in the optical fiber prior art. 
     It should be readily apparent to one skilled in the art, based on the instant disclosure, that one or more balloons (or other devices inflatable with pressurized fluids), lumens (or other channels capable of transporting gases or fluids), pressurized fluid sources, and/or other types of selection means (such as valves, switches, plugs or computer-, electrically- or mechanically-controlled components), can be employed in the present invention, in various configurations and combinations, without departing from the broad scope of the present invention. For example, a heat activated shape memory metal anchor, for example, one activated by heat developed by passing an electrical current therethrough, can be employed to hold the optical fiber in place. 
     Referring now also to FIG. 5, the battery pack  14 , CCF tube  16  (best shown in FIG. 2) and coupling means  24  (best shown in FIG. 3) are mounted to means for enabling a patient to easily transport the battery pack  14 , CCF tube  16 , and coupling means  24 , i.e., at least one belt  54  (only one is shown) and are thus supported and substantially secured to a patient&#39;s body  56  as shown. While the pressurized air source  44  (best shown in FIG. 4) can also be mounted to the belt  54  an thus supported and substantially secured to a patient&#39;s body  56 , it is likely that the air source, preferably a syringe will be used to initially inflate the balloon after the distal end of the optical fiber is properly positioned at the treatment site and thereafter be disconnected, provided that the pressurized fluid is retained within balloon until the optical fiber can be removed from the patient after the treatment is completed. It should be readily apparent to one skilled in the art, based on the instant disclosure, to alternatively use in addition to or in place of belt  54 , one or more other belts, one or more harnesses, vests, straps, pockets, flaps, buckles, or hook-and-loop or other connection straps, in various combinations and configurations, to secure at least the light source and portable power supply to the patient&#39;s person, without departing from the broad scope of the present invention. 
     Referring now to FIGS. 6 and 7, after the photosensitizer drug (not shown) is administered to the treatment site  58  within the patient&#39;s body  56  (not shown in full), a needle  60  having a peel away sheath  62  is inserted into the patient&#39;s body while observed using an appropriate imaging system (such as CT, Ultrasound, MRI, X-ray) to the treatment site  58  within the patient&#39;s body  56  (not shown in full). Though image guidance is preferred for achieving an accurate disposition of the optical fiber, it is optional and is not necessary, especially for disposition of the optical fiber to treat superficial lesions. The needle  60  is removed and the optical fiber  18  with the balloon  42  deflated is passed through the peel away sheath which was previously properly positioned at the treatment site. The position of the distal portion  22  is confirmed via the imaging modality used to pass the needle  60 , and the peel away sheath  62  is pulled up and split apart. The position of the distal portion  22  is then reconfirmed. The proximal portion of the optical fiber  18  is secured to the skin of the patient at an exit point  64  by way of suture, adhesive tape, or other fixation means (not shown). The pressurized air source  44  (best shown in FIG. 4) is coupled to the lumen  46 , and pressurized air from the pressurized air source  44  is delivered to the balloon  42  in volume sufficient to inflate the balloon  42  so as to anchor the distal portion  22  of the optical fiber  18  at the treatment site  58  and tamponade any bleeding, which may have occurred during the introduction of the optical fiber  18  into the patient&#39;s body. Once the balloon  42  is sufficiently inflated, the pressurized air source  44  is uncoupled from the lumen  46 . The pressurized air is prevented from escaping from the lumen  46  by the valve  50  (best seen in FIG.  4 ). Any dislodgment or displacement of the optical fiber  18  or its distal portion  22  due to movement of the patient will be resisted by the inflated balloon  42 . 
     Once the balloon  42  has been inflated, the patient fastens the belt  54  (best shown in FIG.  5 ), which supports and secures the battery pack  14 , CCF tube  16  (best shown in FIG.  2 ), and coupling means  24  (best shown in FIG. 3) to the patient. The battery pack  14 , CCF tube  16 , and coupling means  24  collectively are sufficiently compact and lightweight to be easily transported by the patient, and movement about by the patient during extended treatments is thus greatly facilitated. The CCF tube  16  is coupled to the battery pack  14  so as to draw electrical power. The proximal portion  20  of the optical fiber  18  is coupled to the CCF tube  16  by the coupling means  24  (best shown in FIG.  3 ). Other coupling means are possible as well, such as those described in U.S. Pat. No. 5,769,844. Different lengths of optical fiber  18  are available so that the shortest length possible can be employed to minimize light loss. A slight amount of slack in the optical fiber is allowed so that bending, twisting, turning, and other movements by the patient are accommodated. To begin treatment, the CCF tube  16  is activated with electrical current from the battery pack. As best shown in FIG. 3, a quantity of light from the CCF tube  16  is reflected by the parabolic mirror  38  onto the receiver side  34  of the focusing lens  32 . The focusing lens  32  focuses light from the parabolic reflector and from the CCF tube into the proximal portion  20  of the optical fiber  18 . The light is channeled through the optical fiber  18  to the distal portion  22  of the optical fiber  18 , where it exits the distal portion  22  and is diffused by the diffusion means  26 . This diffused light is thus delivered to the treatment site  58  in a uniform manner. 
     The battery pack  14  preferably provides at least  2  to  3  hours of operating time, depending on the power consumption of the light source, before it must be recharged. However, inasmuch as it is removable and modular, it can be immediately replaced with a fresh battery pack and later recharged without interruption of the therapy. Once the battery pack  14  begins to lose power, the warning light  28  on the battery pack  14  alerts the patient that the battery pack  14  must be replaced soon. The backup power reserve  30  provides the CCF tube  16  with power while the patient replaces the battery pack  14  with a fresh battery pack (not shown). 
     Once treatment is complete, or in the event that treatment must be halted prior the completion, the CCF tube  16  can be deactivated, the optical fiber  18  can be uncoupled from the coupling means  24 , and the valve  50  can be opened to allow the pressurized air in the balloon  42  to escape, to deflate the balloon  42 . Under the supervision of medically trained personnel, the suture or adhesive tape securing the proximal portion of the optical fiber  18  to the patient&#39;s body  56  at the exit point  64  can be removed, and the optical fiber  18  can be withdrawn from the patient+s body. 
     Referring now to FIG. 8, alternate preferred embodiments may incorporate a different positioning of the balloon  42 , such as at an intermediate point along the length of the optical fiber  18  to enable the distal portion  22  of the optical fiber  18  to abut a treatment site  58  as shown, rather than to be inserted within the treatment site  58 . In this embodiment, light is directed toward the treatment site by a microlens  59  attached to the distal end of the fiber optic. The lens  59  enables light to be focused onto the peripheral boundary of the treatment site and penetrate into its depths without actually having to insert the fiber optic into the treatment site. Administering light therapy to the surface of the treatment site is preferable when the site should not be punctured with a needle, such as in the care of a highly vascular lesion, which would bleed excessively if the needle passed through a blood vessel. 
     Referring again to FIGS. 1 and 7, another aspect of the present invention is directed to a method for delivering light to a treatment site, comprising the steps of employing the power source, or battery pack  14  to energize the light source, or CCF tube  16 ; coupling the CCF tube  16  in light channeling relation to the proximal portion  20  of the biocompatible optical fiber  18 ; positioning the distal portion  22  of the optical fiber at the treatment site  58  within a patient&#39;s body; and administering the light through the optical fiber  18  to the treatment site  58 . More specifically, the CCF tube  16  can be coupled in light channeling relation to the proximal portion  20  by the coupling means  24  described in detail above and shown in FIG.  3 . However, as noted above, it should be readily apparent to one skilled in the art, based on the instant disclosure that in addition to or in place of the presently shown coupling means  24 , one or more mirrors, concave lenses, or convex lenses, in varying configurations can be used to channel the light into the optical fiber, without departing from the broad scope of the present invention. The distal portion  22  can be positioned at the treatment site  58  in the manner outlined in detail above and shown in FIG. 6 where a needle  60  having a peel away sheath  62  is passed under image guidance (such as CT, Ultrasound, X-ray) to the treatment site  58 . After the needle  60  is withdrawn, the optical fiber  18  with the balloon  42  deflated is inserted through the peel away sheath. The position of the distal portion  22  is confirmed via the imaging modality used to position the needle  60 , and the peel away sheath  62  is pulled up and split apart. The position of the distal portion  22  is then reconfirmed. However, it should be readily apparent to one skilled in the art, based on the instant disclosure, that alternative steps maybe used in addition to or in place of those described above, without departing from the broad scope of the present invention. 
     FIG. 9 illustrates treatment of a bladder  65  wherein the balloon  42  is inflated on the inside of the bladder wall  66  to keep the diffusion means  26  properly inserted in the urethra  67 . The prostrate gland  68  is also schematically represented. 
     Referring now again also to FIG. 4, another aspect of the present invention is directed to a method for anchoring the distal portion  22  of the optical fiber  18  at the treatment site  58 . This method includes the steps of mounting the balloon  42  to the optical fiber  18 ; coupling the pressurized air source  44 , configured to deliver pressurized air, in selective fluid communication with the balloon  42 ; positioning the balloon  42  (deflated) with the distal portion  22  into the treatment site  58 ; and activating the pressurized air source  44  to inflate the balloon  42  after positioning of the distal portion  22  of the optical fiber at the treatment site  58 . More specifically, the pressurized air source  44  can be selectively coupled in fluid communication to the balloon  42  by the lumen  46  described in detail above, and employing the control  48  and valve  50  to control the inflation and deflation of the balloon, as described. 
     As further explained above, the balloon  42  may be positioned at the distal end  52  of the optical fiber  18  as shown in FIG. 7, or at any intermediate point along the length of the optical fiber  18  as shown in FIG.  8 . As noted above, it should be readily apparent to one skilled in the art, based on the instant disclosure, to alternatively use in addition to or in place of the components described for anchoring means  40 , one or more balloons (or other devices inflatable by gases or fluids), lumens (or other channels capable of transporting gases or fluids), pressurized fluid sources (or other gas or fluid sources), and selection means (such as valves, switches, plugs, or computer-, mechanically- or electrically-controlled components, such as shape memory metal anchoring devices), in various configurations and combinations, without departing from the broad scope of the present invention. 
     Referring now again also to FIG. 5, yet another aspect of the present invention pertains to a method for securing the battery pack  14  and the CCF tube  16  to a patient. This method comprises the steps of securing the battery pack  14  and the CCF tube  16  to the belt  56  and attaching the belt  56  to a patient, as shown in FIG.  5 . As noted above, it should be readily apparent to one skilled in the art, based on the instant disclosure, to alternatively use in addition to or in place of the belt  54 , one or more other belts, harnesses, vests, straps, pockets, flaps, buckles, or hook-and-loop straps, or other connectors, in various combinations and configurations, without departing from the broad scope of the present invention. 
     Although the present invention has been described in connection with the preferred form of practicing it and in regard to alternative embodiments, those of ordinary skill in the art will understand that many other modifications can be made thereto within the scope of the claims that follow. Accordingly, it is not intended that the scope of the invention in any way be limited by the above description, but instead be determined entirely by reference to the claims that follow.