Abstract:
Apparatus for illuminating comprises one or more fibers, the one or more fibers including fiber portions meeting at an apex and a bottom location to form a three dimensional cage; a detector attached to each of the fiber portions for receiving light and transmitting light along each of the fiber portions, respectively; and an illumination member situated within the cage. A method for illuminating a hollow member includes the steps of inserting one or more fibers into the hollow member, wherein one or more fibers include fiber portions that meet at a location to form a three-dimensional cage; permitting light to emit from within the three-dimensional cage and towards the fiber portions; receiving light at distinct locations on each of said fibers; and allowing each of the fibers to transmit the light received on each of the fiber portions out of the hollow member.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the delivery and monitoring of light within a body cavity. In particular, a method and apparatus are disclosed for providing light within a body cavity and/or hollow organ, such as a bladder or lung or other organ and for monitoring the irradiance, fluence or fluence rate within that body cavity and/or hollow organ from a single or multiple locations, during single or multiple procedures. 
       BACKGROUND OF THE INVENTION 
       [0002]    Photo Dynamic Therapy (“PDT”) is currently an active area of research for the treatment of diseases associated with unwanted and/or hyper-proliferating cells such as cancer and non-malignant lesions. PDT involves the use of one (1) or more Photo Dynamic Compounds (“PDCs”) and/or PhotoSensitizers (“PSs”) and/or formulations thereof used in conjunction with other compounds and /or other chemicals (herein “PSs”) delivered to a patient by various means, topically, intravenously, inhalation, intraperitoneally and/or intravesically, among others; wherein the PSs are activated when exposed to light to induce damage to a cell or tissue (e.g. cellular damage or damage via vascular acting photo sensitizers). PDT has been applied in various conditions including hollow organs such as the bladder. In the case of a hollow organ such as the bladder, a light source is inserted into the bladder via the urethra, and the internal wall of the bladder, which has been treated with one or more PSs is exposed to the light. U.S. Pat. No. 5,125,925 proposes a fiber optic light source and single sensing optical fibers inserted into the bladder that senses light at its tip or along its length at any sensor and/or detector location. All references are incorporated herein by reference. 
       SUMMARY OF THE INVENTION 
       [0003]    Apparatus for illuminating comprises one or more fibers, the one or more fibers including fiber portions meeting at an apex and a bottom location to form a three dimensional cage; a detector attached to each of the fiber portions for receiving light and transmitting light along each of the fiber portions, respectively; and an illumination member situated within the cage. A method for illuminating a hollow member includes the steps of inserting one or more fibers into the hollow member, wherein one or more fibers include fiber portions that meet at a location to form a three-dimensional cage; permitting light to emit from within the three-dimensional cage and towards the fiber portions; receiving light at distinct locations on each of said fibers; and allowing each of the fibers to transmit the light received on each of the fiber portions out of the hollow member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a line drawing that illustrates a probe in accordance with an exemplary embodiment of the present invention. 
           [0005]      FIG. 2A  illustrates the orientation of optical fibers relative to each other in a line drawing in accordance with an exemplary embodiment of the present invention. 
           [0006]      FIG. 2B-2G  are various embodiments of light sensors incorporated in an optical fiber. 
           [0007]      FIG. 3  is a cross-sectional view taken along cutline A-A shown in  FIG. 1 . 
           [0008]      FIG. 4A  illustrates the relative location of sensors and/or detectors situated along optical fibers extending from an arm in a perspective view in accordance with an exemplary embodiment of the present invention. 
           [0009]      FIG. 4B  illustrates the optical fibers extending from an arm in an expanded state compared with the configuration of optical fiber shown in  FIG. 4A . 
           [0010]      FIG. 5  is a flowchart diagram which illustrates a method in accordance with an exemplary embodiment of the present invention. 
           [0011]      FIG. 6  is a block diagram that illustrates connections between a light emitter, a light source, detectors, sensors and computer(s) in accordance with an exemplary embodiment of the present invention. 
           [0012]      FIG. 7A  and  FIG. 7B  are bar graphs that illustrate exemplary data that is obtained by performing data acquisition in accordance with an exemplary embodiment of the present invention. 
       
    
    
     OVERVIEW 
       [0013]    The stages of bladder cancer predominately follow a progression from Carcinoma in Situ (“CIS”), through to Ta or T1, known as Non-Muscle Invasive Bladder Cancer (“MMIBC”) through to T2 and T3, known as Muscle Invasive Bladder Cancer (“MIBC”) and finally T4, in which the cancer has spread from the bladder and has metastasized outside of the bladder. Bladder cancer, once metastasized, can become life threatening; therefore, it is important to limit the spread of the disease and destroy NMIBC and/or MIBC before it has metastasized. 
         [0014]    A bladder lesion (or tumor) may be located on the wall of the bladder. In PDT, the goal is to cause a PS to be absorbed or attached to the bladder tumor cells. To accomplish this objective, a catheter is inserted through the patient&#39;s urethra and a certain dose of a PS is instilled into the bladder. The larger the bladder, the greater the amount of drug in solvent that is inserted into the bladder. Furthermore, the larger the size of the bladder, the greater the surface area of the bladder; thus, it is desirable to have a homogeneous distribution of the drug throughout the bladder. In an exemplary embodiment of the present invention, the invention may be used in combination with a PS such as TLD-1433. In further embodiments of the device, the device may beused without a PS and be used to deliver light only to the target, such as inflamed bladder tissues delivered with Low Level Laser Therapy (“LLLT”). 
         [0015]    Again, TLD-1433 is merely exemplary, as other photo sensitizers may also be used (including, for example, vascular acting photosensitizers). 
         [0016]    The above explanation is exemplary with regard to PDT. It is understood that other therapies may also be used, including low-level laser therapy (LLLT). 
         [0017]    The above explanation is with regards to a photo sensitizer. To clarify, a photo sensitizer is a molecule that produces a chemical change in another molecule in a photochemical process. 
         [0018]    After the PS has been instilled into the bladder, the drug is activated by a light source. It is desirable to have a homogeneous distribution of light within the bladder to uniformly activate the PS. Theoretically, it would he desirable to drain the PS from the bladder, fill the bladder, with distilled water, insert a light emitter into the bladder, and activate the light source. While theoretically such a procedure is desirable, in actuality, such a procedure may not work safely or effectively because the bladder is not a perfect sphere. Bladders come in many shapes, and sizes, with unique geometrical features all to themselves, lending to different anatomical configurations. Therefore, the amount of light that is deposited onto a bladder wall surface from a light emitter may vary significantly. There may be hotspots (excessive irradiation) and cold spots (insufficient irradiation) leading to variations in the activation of the PS and hence ability of the PS to destroy cancerous tissue. As a result, over activation of a PS in some areas is possible. In other areas, under activation of the PS may occur. In further areas, the PS may not be activated at all. 
         [0019]    In one exemplary embodiment of the present invention, a light emitter and twelve (12) optical sensors, able to detect irradiance, fluence or fluence rate, are inserted into a bladder. The combination of the emitter and optical sensors (along with optical fibers to which the sensors are attached) typically is inserted through a channel of very small size, for example, 4.5 mm (13.5 French) in diameter, in the case of a rigid cystoscope and 2.5 mm (7.5 French) in diameter for a flexible cystoscope. The emitter and the optical fibers may be placed through the working channel of the cystoscope, inserted through the urethra of a patient and upon entering the bladder opened up like an umbrella. In this manner, it is possible to place the various detectors at strategic locations around the bladder wall, and thus compare the irradiance level at up to twelve (12) locations within the bladder. 
         [0020]    The detectors described herein are for measuring irradiance. It is understood that this is merely exemplary as other measurement, such as fluence rate, may be included. 
         [0021]    Because light is illuminating in a confined location, such as a bladder, the bladder may act like an integrating sphere. Thus, light will be reflected off the surface of the bladder and become incident onto another location of the bladder wall, from which it will be reflected again. Depending on the amount of reflected light, which varies according to the albedo (degree of “whiteness” or reflection coefficient), which may significantly affect the amount of light within a bladder at any particular location. This effect is known as the multiplication factor for integrating spheres and has been demonstrated to be between 2 and 6 for the human bladder) 
         [0022]    Reference:
       Integrating sphere effect in whole-bladder wall photodynamic therapy: III. Fluence multiplication, optical penetration and light distribution with an eccentric source for human bladder optical properties.   van Staveren Keijzer H J 1 , Keijzer M, Keesmaat T, Jansen H, Kirkel W J, Beek J F, Star W M. http://iopscience.iop.org/article/10.1088/0031-9155/41/4/001/meta       
 
         [0025]    If there is bladder cancer, then there will be diseased tissue and as a result bladder lesions will absorb more light than healthy bladder tissue at some of the potential treatment wavelengths, providing variations in the amount of light absorbed by any particular bladder wall surface area. 
         [0026]    If the light emitter moves during the above procedure and touches the bladder wall for any length of time, it is possible that the light emitter will cause irreparable thermal damage to the bladder wall, due to the high emission powers needed in order to achieve a PDT efficacy. Such damage will certainly affect safety and tolerability of the procedure. 
         [0027]    In an exemplary embodiment of the present invention, a fiber-optic cage is placed in a device such as a cystoscope. The cystoscope enters the bladder, and the cage is deployed like an umbrella (or similar to inflating a football); therefore detecting different amounts of light within various areas of the bladder. The fiber-optic cage desirably includes twelve (12) to sixteen (16) light detectors depending on the size of the bladder wall surface, the required spatial resolution of the irradiance, fluence or fluence rate on the bladder wall surface (although more or less may be included). The light detectors are situated so that they detect light from respectively different areas of the bladder. The values obtained from each respective light detector can then be looked at and evaluated by being displayed in a form such as a histogram or bar chart. in this manner, a urn-oncologist is able to identify several issues: 1) if data from one sensor indicates a value greater than data from other sensors, this can indicate that the fiber optic is too close to the bladder wall and possibly touching the bladder wall; 2) the data may indicate that the light emitter needs to be adjusted so that it is more at the geometric center of the bladder regardless of shape or size; and 3) the data may indicate that not enough light is reaching one area of the bladder wall and therefore activation of the drug at that location may be minimal or not occur at all. As a result of obtaining all this information, it is possible to deliver a more homogeneous amount of light throughout the bladder and therefore achieve more homogeneous activation of the PS. 
         [0028]    The above described use within the bladder is merely exemplary. It is understood that the present invention can be implemented within other body cavities and/or other types of organs, such as the lungs or brain. 
       DETAILED DESCRIPTION 
       [0029]    The Canadian Cancer Society estimates that 7,900 people in Canada will be diagnosed with bladder cancer this year, making it the 5 th  most common cancer in Canada (4 th  most common among men, with 5,900 cases and 12 th  most common among women with 2,000 cases). 
         [0030]    With a recurrence rate of nearly 80%, bladder cancer is the most expensive cancer to treat on a per patient basis. The high recurrence rate raises many issues affecting quality of life because of its persistence. 
         [0031]    The Canadian Urology Association Journal issued a guideline for the treatment of NMIBC in 2010. This guideline provides a Canadian consensus on the management of NMIBC. According to this guideline, the Transurethral Resection of Bladder Tumor (“TURBT”) procedure is the first-line and gold standard treatment for NMIBC. 
         [0032]    Intravesical therapy can be either chemotherapy or immunotherapy and is either therapeutic, prophylactic or adjuvant in the immediate postoperative setting. 
         [0033]    Treatment options for recurrent bladder cancers are limited and often consist of systemic chemotherapy combined with or without a radical cystectomy. A radical cystectomy is the removal of the entire bladder, nearby lymph nodes, part of the urethra, and nearby organs that may contain cancer cells. In men, the prostate, the seminal vesicles, and part of the vas deferens are also removed. In women, the cervix, the uterus, the ovaries, the fallopian tubes, and part of the vagina are also removed. 
         [0034]    Intravesical therapy for patients with superficial papillary bladder cancer at risk for tumor recurrence appears reasonable, provided the therapy requires a limited number of treatments to be delivered, causes minimal toxicity to the patient and can delay recurrence for a reasonable length of time. Other active agents with a more favorable safety profile than Bacillus Calmette-Guerin (“BCG”) need to be identified for prophylactic use in this patient population. Prevention of superficial recurrences is important as it would spare the patient further urinary symptoms and repeated TURBT procedures and the potential risk with associated complications and mortality, particularly in older patients, as well as to decrease the requirement for quarterly cystoscopic follow-up and the anxiety associated with discovery of new tumor growths. 
         [0035]    PDT is a promising strategy for treating cancer; whereby, light is used to activate an otherwise nontoxic PS in order to destroy tumors and tumor vasculature and to induce an immune response. Following photoactivation, the PS delivers a toxic burst of cytotoxic singlet oxygen and other Reactive Oxygen Species (“ROS”) that are confined spatially and temporally to the irradiated region, thus targeting malignant tissue while sparing healthy tissue. 
         [0036]    Although PDT technology has been known for many years, the use of PDT for cancer treatment has been limited. For example, a large number of variables may need to be optimized in certain situations, making the development of such therapies more challenging (i.e. PS, dose of PS light source, wavelength, light dose, drug-to-light interval between application, dosimetry, and protocol design) for each clinical application. 
         [0037]    PSs can be employed in PDT mediated treatment of various cancers including human bladder carcinoma. PSs selected for bladder cancer should have properties that increase the safety and efficacy of the PS for use in bladder carcinoma PDT:
       Able to be delivered effectively to the target tissue   Exceptional resistance to photobleaching (allows efficacy over longer treatment times without the need for reapplication)   Singlet oxygen quantum yield near unity (very efficient conversion of light photons into singlet oxygen)   Drive both Type I and Type II processes (a powerful and versatile PS in oxygen rich or poor environments)       
 
         [0042]    While the following description describes the use of TLD-1433, TLD-1433 is merely exemplary, and it is understood that other PSs may be used in place of TLD-1433. 
         [0043]    As explained in the Overview, and further described below, cage  200  will be deployed in an organ, such as a bladder, in order to measure light exposure at a plurality of locations within the organ. It is thus desirable to know the internal volume of the organ. This may serve several purposes. First, it is desirable to know how much TLD-1433 is to be instilled into the organ. Second, it is desirable to know a preferential dimension(s) to be chosen for cage  200 . A solution such as distilled water can be used to fill the organ until backpressure suggest to the physician that the bladder folds are removed or bladder unfolding has been verified by ultrasound. In the case of a bladder, exemplary bladder volumes, cage dimensions, power delivery, catheter sizes and detector locations are as follows: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Surface 
                 Arm 
                 Power Delivered 
               
             
          
           
               
                 Volume 
                 Radius 
                 Area 
                 Length 
                 Low albedo 
                 High albedo 
               
               
                 (ml) 
                 (cm) 
                 (cm2) 
                 (cm) 
                 (mW) 
                 (mW) 
               
               
                   
               
             
          
           
               
                 150 
                 3.3 
                 136.5 
                 10.4 
                 2275 
                 758 
               
               
                 175 
                 3.5 
                 151.3 
                 10.9 
                 2521 
                 840 
               
               
                 200 
                 3.6 
                 165.4 
                 11.4 
                 2756 
                 919 
               
               
                 225 
                 3.8 
                 178.9 
                 11.9 
                 2981 
                 994 
               
               
                 250 
                 3.9 
                 191.9 
                 12.3 
                 3000 
                 1066 
               
               
                 275 
                 4.0 
                 204.5 
                 12.7 
                 3000 
                 1136 
               
               
                 300 
                 4.2 
                 216.7 
                 13.0 
                 3000 
                 1204 
               
               
                 325 
                 4.3 
                 228.6 
                 13.4 
                 3000 
                 1270 
               
               
                 350 
                 4.4 
                 240.2 
                 13.7 
                 3000 
                 1334 
               
               
                 375 
                 4.5 
                 251.5 
                 14.1 
                 3000 
                 1397 
               
               
                 400 
                 4.6 
                 262.5 
                 14.4 
                 3000 
                 1458 
               
               
                 425 
                 4.7 
                 273.4 
                 14.7 
                 3000 
                 1519 
               
               
                 450 
                 4.8 
                 284.0 
                 14.9 
                 3000 
                 1578 
               
               
                 475 
                 4.8 
                 294.4 
                 15.2 
                 3000 
                 1635 
               
               
                 500 
                 4.9 
                 304.6 
                 15.5 
                 3000 
                 1692 
               
               
                 525 
                 5.0 
                 314.7 
                 15.7 
                 3000 
                 1748 
               
               
                 550 
                 5.1 
                 324.6 
                 16.0 
                 3000 
                 1803 
               
               
                 575 
                 5.2 
                 334.4 
                 16.2 
                 3000 
                 1858 
               
               
                 600 
                 5.2 
                 344.0 
                 16.4 
                 3000 
                 1911 
               
               
                   
               
             
          
         
       
     
         [0044]    The resulting three catheter sizes are:
       TLC-3410S is for bladder volumes from 135-264 ml and detectors at 2.5 cm, 5 cm, 7.5 cm, 10 cm from the bladder dome   TLC-3420M is for bladder volumes from 233-456 ml and detectors at 3 cm, 6 cm, 9 cm, 12 cm from the bladder dome   TLC-3430L is for bladder volumes from 370-724 and detectors at 3.5 cm, 7 cm, 10.5 cm, 14 cm from the bladder dome       
 
         [0048]    The target light delivery interval delivers a set fluence, fluence rate or irradiance to the target tissue. Said target irradiance includes the primary irradiance delivered by the isotropic emitter and the diffuse reflectance from all bladder segments. The latter contribute to the M-factor of the bladder which acts as an integrating sphere. M-factors for the bladder have been reported to range from 2 to 6, with the lower M factor equivalent to a low albedo case with extensive disease and little to none “normally white appearing” bladder wall; whereas, high M factors are for high quantities of “normally white appearing” bladder wall with little distention 
         [0049]    The last two columns in the table list the initial power setting for the laser to deliver the desired optical dose of 90 Jcm-2 for the low and the high albedo case. As the maximum power output of the system is 3 W, for the low albedo case the target light delivery may not be attained, within 45 minutes thus at the maximum power setting the illumination time will be required to be extended. 
         [0050]    Prior to use, the treatment power settings for emitter fiber  305  (and emitter  325 ) are verified. In one exemplary embodiment of the present invention, a closed container that is referred to as an integrating sphere may be used. The integrating sphere may be filled, for example, with 100 milliliters (“ml”) of sterile USP water. Emitter fiber is inserted through the top aperture of the integrating sphere after removal of the cap and then activated. The integrating sphere detects the actual emitted optical power of the emitter fiber. The resulting signal is measured, where it is translated in to Watts (“W”) and displayed. Calibration may also occur by inserting emitter fiber  305  into a transparent calibrating sleeve prior to insertion into the integrating sphere. 
         [0051]    TLD-1433 may be supplied in a borosilicate vial and subsequently reconstituted. Depending on the high or low target dose, desirable concentration of TLD-1433 may be achieved depending upon the patient&#39;s bladder volume. An appropriate volume of sterile water may be added to achieve a clinical dilution of 0.35mg/cm2 or 0.70 mg/cm2. The final solution may be instilled in the bladder cavity for sixty (60) minutes. Any surface bound photosensitizer is removed by flushing the bladder three times with sterile water. The bladder is desirably distended during the third flush to try to prevent folds in the bladder wall that may prevent uniform light illumination. 
         [0052]    A cystoscope with preferably a 4.5 mm (13.5 French) working channel is then placed through the urethra to the bladder neck. Cage  200  is then introduced into the bladder as more clearly described below. 
         [0053]      FIGS. 1, 4A and 4B  illustrate a probe in accordance with an exemplary embodiment of the present invention. Probe  100  includes main shaft  105 , in an exemplary embodiment of the present invention, main shaft  105  is a cystoscope that may be used for introducing cage  200  into the bladder. Cystoscopes are well known in the art. An exemplary cystoscope is a Karl Storz Hopkins II Telescope 4 mm/30 degree cystoscope (Model #27026DA). Further exemplary cystoscopes are manufactured by Olympus. Protruding from a top end of the cystoscope is cage  200 . Cage  200  includes a plurality of fiber strands (or fiber portions)  210  (more clearly shown in  FIG. 2 ). The fiber strands are desirably separated into three groups of four strands each so that three arms  220  are formed. The three arms  22 . 0  all merge near the top of cage  200  at apex  227 . The three arms  220  all merge near the bottom of cage  200  at neck  228 . Neck  228  is shown in  FIG. 1  as being at the end of main shaft  105 , i.e. at the location where arms  220  exit main shaft  105 , but it is understood that neck  228  may be situated as other locations away from main shaft  105  as well. 
         [0054]    The above explanation refers to “fiber strands” but a single fiber with multiple fiber portions may also be used to form cage  200 . 
         [0055]    When the word “cage” is being used, what is meant is a three dimensional space that is defined by a plurality of fibers. The fibers are situated so that they can bend and thus vary at least one dimension of the three dimensional space. The at least one dimension varied may result in the cage expanding outward or bulging as more fully described below. The outward expansion or bulging may be accompanied by a simultaneous reduction in dimension of the cage from an apex to a bottom thereof. Again, this motion is further described below and illustrated in the accompanying drawings. 
         [0056]    Cage  200  may be a 3.3 mm outer diameter assembly comprising, for example 12×250 micron light sensors and an 850 micron light delivery sphere. The twelve light sensors are assembled in three linear arrays (arms  220 ) with four detectors  215  each. The three arms  220  cover the bladder wall surface separated by 120 degrees of longitude. Upon insertion, the three arms surround emitter  325  (shown in  FIGS. 4A and 4B ). Upon placement in the bladder, arms  220  are adjusted to resemble a hemispherical shape in a manner so that detectors  215  (covered by a medical grade heat shrink tubing, ie. an industry-standard polyethylene material) are abutting the bladder wall surface. The arms may be fixed at apex  227  and at the opening of main shaft  105  using a fitting made from polyether ether ketone (“PEK”) plastic, while other materials may also be suitable. 
         [0057]    Cage  200  also includes central member  230  is also included. Central member  230  may be moved within main shaft  105  via motion from rod  130 . Thus, as rod  130  is moved up within shaft  105 , central member  230  also moves up. Furthermore, while rod  130  moves down, central member  230  moves down. 
         [0058]    Central member  230  moves up and down. The motion of central member  230  can be independent from the motion of arms  220  into and out of main shaft  105 . Thus, as more clearly explained below, if central member  230  is drawn into main shaft  105 , sensors located on arms  220  will move away from each other. Furthermore, as central member  230  extends further out of main shaft  105 , sensors located on arms  220  will move towards each other. This motion is more clearly described below. 
         [0059]    Probe  100  includes lock  125 . When lock  125  is actuated, central member  230  is prevented from moving independently of arms  220 . Thus, loosening lock  125  allows rod  130  to move in and out, thus causing central member  232  to move in and out of main shaft  105 , thus in turn causing detectors situated on arms  220  to move towards and away from each other. Again, there are other ways to describe this motion as explained below. The fiber strands that comprise arms  220  extend downward into main shaft  105  and into probe tube  115  before terminating at connectors  120 . Appropriate electronics may then be connected to connectors  120  no that it is possible to measure the amount of light that is striking each detector  215  situated on each fiber strand  210 . 
         [0060]    Probe tube  115  is connected to main shaft  105  via Y-connector  110 . In this manner, movement of central member  230  may be controlled by moving rod  130  in and out. 
         [0061]      FIG. 2A  illustrates a portion of cage  200  before it is inserted into main shaft  105 . As shown, cage  200  is comprised of six fiber strands  210  which each include a bend in a central portion thereof. The bend within each fiber strand  210  terminates at apex  227 . Furthermore, suture  225  is placed around apex  227  in order to maintain all of the fiber strands  210  together at apex  227 . Along each portion of fiber strand  210  that descends from apex  227  into main shaft  105 , a respective detector  215  is formed. Each detector is coupled to appropriate electronics for measuring the amount of light entering each detector  215 . 
         [0062]    Each fiber strand  210  is cut to an appropriate size in order to form desired dimensions for cage  200 . In one exemplary embodiment of the present invention, the fiber strands may be comprised of six 6.2 m long 250 micrometer POE. While fiber strands are well known in the art, an exemplary fiber strand is Mitsubishi Rayon Super Eska SK-10. This is a high performance plastic optical fiber, although other optical fibers may also be used. 
         [0063]    Detectors  215  are formed into fiber strands  210  as follows. At an appropriate location along each fiber, a plurality of ablation cuts may be performed using a heating element. Each fiber may be ablated close to half way through. At each ablation location, scattering material may be filled in to create a detector. The scattering material may include 2 parts resin, one part hardner, mixed for example with twice the weight of barium sulfate and combined. Using a needle, the epoxy can be applied to the ablated hole. In this manner, detectors  215  are formed in fiber strands  210 . 
         [0064]    The fiber strands are then oriented as shown in  FIG. 2A .  FIG. 2A  illustrates the manner in which fiber strands  210  are placed relative to each other. The location where the fiber strands  210  bend will become apex  227 . Around the area which will be designated as apex  227 , suture  225  is placed. Furthermore, fiber strands  210  are grouped into three separate groups this forming three arms  220 , each with four fiber strand portions and each with four detectors  215 . The resulting anns  220  will then descend into main shaft  105 . The three arms are oriented at approximately 120 degrees relative to each other. 
         [0065]    Various embodiments of optical sensors that are integrated in the optical fibers are possible. Reference is made to  FIGS. 2B-2G , Optical fibers are multimode silica or plastic optical fibers preferably with a high NA to achieve good sensitivity. These include: 
         [0066]    A bare length of fiber where in the fiber end is polished roughly as shown in F which is detecting light predominantly along the axis of the optical fiber. 
         [0067]    A polished fiber with a section cut out of it as shown in  FIG. 2C . The fiber is cut with a scalpel as illustrated in 3c, with the first cut peeling back a section of the core and cladding, resulting in a fiber with an acceptance angle approximating 2 Pi sterad, albeit with unknown azimuth and polar angle dependence. (cut can also be achieved using thermal denaturation for plastic optical fibers. 
         [0068]      FIG. 2D , a cut fiber as in  FIG. 2C  has the cut filled in with epoxy. The epoxy can includes barium sulfate or other diffusing materials. In a further embodiment, a cut fiber has the notch filled with just epoxy (no barium sulfate), resulting in a fiber with an acceptance angle approximating 2 Pi Sterad, albeit with homogenous azimuth and polar angle dependence. 
         [0069]      FIG. 2E  shows an epoxy-filled fiber painted with black paint on the side opposite the cut along a small length of the fiber. The cut side of the fiber is then cleaned. The application of the paint is verified using a laser pointer at one end and ensuring that on one side, the laser light is visible and a 180° rotation causes the light to be blocked out entirely. This results in a sensor that is sensitive only to one hemisphere or Pi Sterad, and hence acts as an irradiance sensor. 
         [0070]      FIG. 2F  shows a section of a polished (otherwise un-modified) fiber is painted with black paint. 
         [0071]      FIG. 2G  shows a fiber with the notch cut by laser is polished roughly on one end. In a further embodiment, the notch is filled with epoxy as described above resulting in a 180° rotation causes the light to be blocked out entirely. This results in a sensor that is sensitive only to one hemisphere or Pi Sterad, and hence acts as an irradiance sensor. 
         [0072]      FIG. 3  is a cross-sectional view taken along section line A-A that appears in  FIG. 1 . Along the very outside is main shaft  105 . Within main shaft  105  is catheter  315 . Within catheter  315  is fiber guide  310 . Between fiber guide  310  and catheter  315  is situated each fiber strand  210 . Within fiber guide  310  is a matter fiber  305 . 
         [0073]      FIG. 4A  and  FIG. 4B  illustrate how the distance between detectors  215  can be increased or decreased so that detectors  215  are able to be situated along the walls of the bladder.  FIG. 4A  illustrates how three arms  220  are extending out of main shaft  105  at approximately  120  degrees relative to each other. Further extending out of main shaft  105  is central member  230 . Central member  230  is comprised of emitter fiber  305 , emitter  325  from which light is emitted, and guide wire  320 . The end of guide wire  320  is connected to apex  227 . As shown in  FIG. 4A  various detectors  215  are shown. These detectors  215  are located a certain distance away from each other. The exemplary distance illustrated in  FIG. 4A  may correspond to one bladder shape. While there are a total of 12 detectors in the exemplary embodiment, only three detectors are shown in  FIG. 4A  for the sake of clarity. Looking now at  FIG. 4B , detectors  215  are still shown. However, detectors  215  shown in  FIG. 4B  are further apart then detectors  215  shown in  FIG. 4A . That is because guide wire  320  has been retracted into main shaft  105  without also retracting arms  220  into main shaft  105 . Thus, as guide wire  320  retracts into main shaft  105 , cage  200  effectively bulges outwards. In this manner, the configuration shown in  FIG. 4B  may be better suited for a bladder with a different size or shape in the bladder that may receive cage  200  with the configuration shown in  FIG. 4A . 
         [0074]    Furthermore, it is possible for guide wire  320  to extend out of main shaft  105 , again without arms  220  also extending out of main shaft  105 . In this manner, cage  200  shrinks inward, or in other words transitions from the shape shown in  FIG. 4B  to the shape shown in  FIG. 4A . However, there are other ways to express this motion as described below. 
         [0075]    When transitioning from the shape shown in  FIG. 4A  to the shape shown in  FIG. 4B , cage is bulging, but the difference in cage  200  between the two figures can be described in other ways as well. For example, the motion causes detectors  215  situated along fiber strands  215  to move away from each other. The motion can be described as cage  200  opening outward (i.e.: the motion made by an umbrella when it opens). The motion can be described as cage  200  expanding along a plane. The motion can be described as cage  200  expanding along a plane in multiple directions. The plane can be described as perpendicular to guide wire  320 . The motion can be described simply as expansion of cage  200 . The motion can be described as cage  200  expanding while the distance from apex  227  to bottom  228  decreases. 
         [0076]    To clarify, emitter fiber  305  extends from emitter  325 , through main shaft  105 , and is coupled to rod  130 . The end of emitter fiber  305  is connected to apex  227  via guide wire  320 . Thus, motion of rod  130  into and out of main shaft  105  causes cage  200  to expand and contract (which can be described in other ways as explained above). In one exemplary embodiment of the present invention, main shaft  105  is a cystoscope and guide wire  320  is sliding through a catheter within the cystoscope. This motion of rod  130  also enables a change in the location of emitter  325  relative to the sidewalk of the bladder. Thus, rod  130  can be moved until the (twelve) detectors  215  indicate that they are receiving substantially similar amounts of light (plus or minus an acceptable deviation). Once it can be verified that detectors  215  are receiving substantially similar amounts of light, the position of emitter  325  can then be locked in place for the duration of the procedure. 
         [0077]    As cage  200  expands, detectors  215  will move closer to the bladder wall, and then either will be situated along the bladder wall, or sufficiently close thereto in order to measure the amount of light being received from emitter  325 . It is desirable for detectors  215  to face towards the geometric center of the bladder and thus towards emitter  325 . In this manner, detectors  215  are able to receive irradiance delivered to the bladder wall both by emitter  325  and scattered (laser) light from the bladder wall. In one exemplary embodiment of the present invention, close proximity of detectors  215  to the bladder wall is sufficient as irradiance inside an integrating sphere such as a a bladder may be homogenous. 
         [0078]    Furthermore, cage  200  may be available in multiple sizes and/or with respectively different dimensions. Therefore, if the volume of the bladder is known prior to insertion of cage  200 , the dimensions of cage  200  can be selected so that cage  200  when fully expanded touches or is sufficiently close to the bladder wall. 
         [0079]    As previously explained, rod  130  may be moved in order to vary the location of emitter  325  within a bladder. In one exemplary embodiment of the present invention, linear motion of rod  130  may cause expansion (and alternatively contraction) of cage  200  while simultaneously causing the location of emitter  325  within the bladder to change. As previously explained, a surgeon may wish to change the location of emitter  325  within a bladder if all of the detectors  325  are not receiving a sufficiently similar amount of light. The surgeon will those manipulate rod  130  to cause the location of emitter  325  to change. While the manipulation of rod  130  will also cause expansion/contraction of cage  200 , the amount of expansion/contraction of cage  200  is relatively minor and does not (by itself) have an adverse affect on the ability of detectors to receive light from emitter  325 . 
         [0080]    It is understood that emitter  325  can have multiple forms, in a point emitter, a cylindrical emitter, a cut end fiber, etc. 
         [0081]    In an alternative embodiment of the present invention, independent controls are provided for independent control of expansion/contraction of cage  200  and location of emitter  325 , respectively. 
         [0082]      FIG. 5  is a flowchart diagram which illustrates the operation of the exemplary embodiment of the present invention. At optional step  501 , after the volume of the bladder is measured (or approximated), the photosensitizing agent, TLD-1433, is instilled into the bladder cavity via the urethra. Instillation of TLD-1433 should be approximately 60 minutes. The bladder is then drained, optionally filled and drained with distilled water (perhaps multiple times), and then filled with distilled water again. At step  505 , cage  200  is retracted into main shaft  105 . At step  510 , main shaft  105  is inserted into a bladder. At step  515 , cage  200  is extended out of main shaft  105 . At step  520 , arms  220  are locked into place so they neither extend out of nor retract into main shaft  105 . At step  525 , lock  125  is actuated and rod  130  is pulled downward in order to expand cage  200 . At step  530 , rod  130  continues to be pulled down until detectors  215  situated on fiber strands  210  come into contact with (or are sufficiently close to) the bladder wall. At step  535 , rod  130  is locked into position by actuating lock  125 . 
         [0083]    At step  540 , irradiation begins. Emitter  325  may comprise, for example, a spherical diffuser of 850 μm diameter that is mounted on emitter fiber  305  having a 400 μm core diameter (isotropy &gt;±10%). Emitter fiber  305  may be connected to an external light source as illustrated in  FIG. 6  and further described below. After optimum positioning of the light-emitting diffuser associated with emitter  325  (deviation from the mean fluence rate &lt;10% across the whole bladder wall area is the desired target) the patient is ready to commence photo activation of the photosensitizer. 
         [0084]    The target irradiance is 33.3 mWcm-2 with a target radiant exposure of 90 Jcm-2 to avoid tissue damage by PDT. Irradiation is at 525 nm for a target time of 45 minutes; however, information that is made available in accordance with an exemplary embodiment of the present invention is desirably considered when deciding at what time the irradiance is completed. 
         [0085]    For optimization purposes, upon inserting cage  200  into the bladder, a source such as a laser is switched on at a setup power (10% of target power) and irradiance readings are obtained and displayed on a screen. At step  545 , the position of emitter  325  within the bladder is manipulated until all twelve detectors  215  indicate irradiance readings are within a threshold, such as ±10% relative to each other. An audible alarm may also be sounded when the readings are within the threshold. 
         [0086]    At step  550 , radiant exposure readings (Jcm)-2) at the twelve sensor locations may be displayed on a screen. The light source (e.g. laser) is then switched to a target power and operation is commenced. In one exemplary embodiment of the present invention, irradiance measurements are collected every five to ten seconds and the radiant exposure is integrated over this time, providing a physician with a graphical representation of the accumulated radiant exposure at each of the twelve detectors  215  since the treatment has commenced. In one exemplary embodiment, three horizontal lines are displayed representing: i) Target Dose (90 Jcm-2); ii) Min. Dose (81 Jcm-2); iii) Max. Dose (99 Jcm-2). 
         [0087]    In a further exemplary embodiment of the present invention, the ongoing irradiance can be monitored and a prediction can be made as to when the target ±10% irradiance in all areas monitored by detectors  215  is attained based on the current position of the light source. If the prediction is unsatisfactory, the surgeon has the option to return to the low power option to further adjust the position of emitter  325  and retry the treatment to adjust for equal light delivery. 
         [0088]    After the desirable amount of time has elapsed, emitter  325  is turned off, cage  200  is retracted into main shaft  105 , and main shaft  105  is retracted from the bladder. 
         [0089]      FIG. 6  is a block diagram which illustrates connection of various components in accordance with an exemplary embodiment of the present invention. As illustrated in  FIG. 1 , connectors  120  are included for providing connection to detectors  215  and emitter  325 . As light is captured by detectors  215 , the light is transmitted through fiber strands  210  until reaching connector  120 . From connector  120 , the signals may be transmitted to optical sensors  605 . Optical sensors  605  measure magnitude of the light signals that have been received by detectors  215 . The magnitude of the light signals received by detectors  215  is then stored in computer  615 . Furthermore, a light source such as laser  610  may be included. Light source  610  may provide a source of light which is transmitted via a further fiber strand  210  until reaching and then being emitted by emitter  325 . 
         [0090]    As previously explained, depending upon numerous factors such as the location of emitter  325  within the bladder, the size of the bladder, the shape of the bladder, the existence of cancer within the bladder, etc., the magnitude of light received by each of the detectors  215  may be very different. After the magnitude of light received by each of the detectors  215  is stored in computer  615 , computer  615  may generate a visual display which allows a surgeon to understand the relative amount of light being received by each of the detectors  215 .  FIG. 7A  illustrates one such visual display. As shown in  FIG. 7A , sensors  15  and  11  are receiving much more light than average, while sensors  2 ,  8  and  9  are receiving much less light than average. After seeing the visual display that is exemplified in  FIG. 7A , the surgeon may change the location of emitter  325  within the bladder. After changing the location of emitter  325  within the bladder, the surgeon may then view a further visual display of the relative magnitude of light being received by all of the sensors. A further exemplary visual display is illustrated in  FIG. 7B . As shown in  FIG. 7B , the average magnitude of light being received by all of the sensors is substantially the same. In one exemplary embodiment of the present invention, the magnitude of light received by each of the detectors  215  may not be exactly equal, but may be sufficiently close so that subsequent irradiation and activation of the photodynamic drug may occur. In any event, once a surgeon sees from a visual display that the relative magnitude of light received by each of the detectors  215  is sufficiently close, light source  610  may be energized to provide a sufficient amount of light for activation of the photodynamic drug, and the light may remain at that level for a sufficient time period, e.g. one hour.
       While the present invention has been described herein with reference to exemplary embodiments, it should be understood that the invention is not limited thereto. Those skilled in the art with an access to the teachings herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the invention would be useful.   Embodiments of the invention also may be directed to computer program products comprising software stored on any computer useable medium. Such software, when executed in one or more data processing device, causes a data processing device(s) to operate as described herein. Embodiments of the invention employ any computer useable or readable medium. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storage devices, and optical storage devices, MEMS, nanotechnotogical storage device, etc.).   The present application has set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, is not intended to limit the present invention and the appended claims in any way.   The present invention has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.   The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein, it is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.   The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.