Therapeutic optical fiber probe

Abstract

An optical fiber probe for treatment is provided with: an optical transmission structure (3) capable of outputting light in a predetermined direction; and a mirror structure (4) provided at a position at which the light output from the light transmission structure can be received. Furthermore, the mirror structure reflects a portion of the received light, which is necessary for treatment, in a direction different from the predetermined direction at a reflectance of 90% or more, and generates a light spot that exhibits a uniform light energy distribution throughout the entire light spot.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Japanese Patent Application No. 2023-112807, filed on July 10, 2023, the entire contents of which are incorporated herein by reference.

[0003] This invention relates to a therapeutic fiber optic probe. Background Technology

[0004] Currently, there is a treatment method consisting of two stages: administering a drug containing a complex of a photosensitive dye and components that selectively accumulate in specific cells, and irradiating the patient with light of a specific wavelength that triggers the photosensitive dye. The photosensitive dye is a substance that reacts with light within a specific wavelength range. After the drug (complex) is administered to selectively target specific cells, irradiating these cells with light of a specific wavelength for a certain period activates the photosensitive dye, which then kills or eliminates the specific cells through biochemical and physical processes. When irradiating specific tissues, a fiber optic probe is used for treatment. Examples include phototherapy involving surface irradiation (including laser light) of the affected area from outside the body, or surface irradiation (including laser light) of the affected area from inside the body.

[0005] [Existing Technical Documents]

[0006] (Patent Documents)

[0007] Patent Document 1: US8,425,500B

[0008] Patent Document 2: US9,323,005B

[0009] Patent Document 3: US2018 / 0214211A Summary of the Invention

[0010] [The problem the invention aims to solve]

[0011] However, the fiber optic probes used in phototherapy as described above are generally front-facing (front-facing) irradiation type fiber optic probes (i.e., existing front diffusers) that irradiate light from their front end forward (front).

[0012] In this case, the direction of light irradiation in the front diffuser is limited to from its front end forward (front). Therefore, during phototherapy, it is necessary to change the orientation of the front diffuser or bend it so that its front end is directly opposite the affected area.

[0013] However, the front diffuser has a certain allowable bending radius, and its bending direction and amount are limited. Furthermore, the irradiation distance from the front diffuser tip to the irradiation surface must also be maintained at a certain level. Therefore, for example, in narrower lumens, there may be areas where light is difficult to irradiate. When there is a diseased area in that area, there is a risk of difficulty in successfully performing phototherapy or photoimmunotherapy on that affected area.

[0014] As a solution, a front end can be constructed that can irradiate light in a direction different from the front (front view), such as the side (side view). However, if a general mirror is used for reflection, the reflectivity will be low. For example, the JIS mirror material standard (JIS R3220:2011) specifies that the reflectivity of the mirror should be 83% or higher. Furthermore, in order for the photosensitive dye to be activated by light of a specific wavelength, a certain level of light energy is required. Therefore, it is necessary to irradiate the irradiated surface with uniform light energy. Furthermore, it is also assumed that the fiber optic probe is used with an endoscope or conduit. Therefore, it is also required that the size (diameter) of the fiber optic probe, including the front end, be set to a size that allows it to be inserted into the endoscope or conduit.

[0015] Therefore, the object of the present invention is to provide a therapeutic fiber optic probe that is sized to be inserted into an endoscope or catheter and has a front end that can efficiently irradiate uniform light to the side.

[0016] [Technical means to solve the problem]

[0017] To achieve this objective, the present invention includes: a light transmission structure 3 that can output light in a predetermined direction; and a mirror structure 4 that is disposed at a position that can receive light output from the light transmission structure; and the mirror structure causes a portion of the received light required for treatment to be reflected with a reflectivity of more than 90% in a direction different from the predetermined direction, thereby generating a light spot that has a uniform light energy distribution throughout its entirety.

[0018] (The effect of the invention)

[0019] According to the present invention, a therapeutic fiber optic probe is provided, which is configured to be inserted into an endoscope or catheter and has a front end that can efficiently irradiate uniform light to the side. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the front end of a therapeutic fiber optic probe according to an embodiment of the present invention.

[0021] Figure 2 This is a cross-sectional view of the front end of the therapeutic fiber optic probe, viewed from the opening side.

[0022] Figure 3It is a graph showing the results of the test on the uniformity of reflected light, reflectivity, and temperature rise of the mirror structure.

[0023] Figure 4 It is a graph showing the test results of reflectivity evaluation at specific wavelengths (690 nm band, 530 nm band). Detailed Implementation

[0024] Contents of the first implementation method

[0025] Figure 1 and Figure 2 This is a diagram showing the internal structure of the front end 2 of the therapeutic fiber optic probe 1. Various phototherapies (including laser therapy) and / or photoimmunotherapy are performed on the affected area by irradiating light of a specific wavelength required for treatment from its front end 2 towards the affected area. As non-limiting examples of this treatment method, examples include phototherapy for cancer treatment and cell and tissue resection, or photoimmunotherapy for killing tumors or tumor cells, treating precancerous lesions and cancer.

[0026] The therapeutic fiber optic probe 1 is configured to be used in both a variant that can be used with an endoscope or catheter (not shown) and a variant that is not used with an endoscope or catheter (i.e., a variant that is used alone).

[0027] Therefore, the size (diameter) of the therapeutic fiber optic probe 1, including the tip 2, can be designed to be insertable into an endoscope or catheter. For example, according to the specifications of a typical upper gastrointestinal endoscope, it can be designed to be within the size of a jaw (working channel) with a diameter of 2.8 mm.

[0028] like Figure 1 and Figure 2 As shown, the therapeutic fiber optic probe 1 includes a light transmission structure 3, a mirror structure 4, a tubular structure 5, a cover structure 6, and a light-shielding structure 7. The light transmission structure 3 directly utilizes an existing front diffuser (i.e., an optical fiber), configured to transmit various types of light, including laser light. A lens structure 8 (objective lens) is mounted at the front end of the light transmission structure 3, and the light transmitted through the light transmission structure 3 is output from the lens structure 8 in a predetermined direction (e.g., front).

[0029] The mirror structure 4 is positioned to receive light (hereinafter referred to as output light L1) emitted from the light transmission structure 3. In this case, the mirror structure 4 is arranged opposite to the front end (lens structure 8) of the light transmission structure 3. The mirror structure 4 reflects a portion of the received output light L1 required for treatment in a direction different from a certain direction. Hereinafter, the light reflected from the mirror structure 4 will be referred to as reflected light L2. Furthermore, the configuration of the mirror structure 4 will be described below.

[0030] The aforementioned light transmission structure 3 and mirror structure 4 are housed inside the tubular structure 5. The tubular structure 5 extends in a manner that covers the light transmission structure 3 throughout its entire length, and covers the mirror structure 4 in a manner that maintains a fixed positional relationship between the front end (lens structure 8) of the light transmission structure 3 and the mirror structure 4.

[0031] The tubular structure 5 has a hollow cylindrical shape and a metal mesh structure. The metal mesh structure is, for example, constructed by winding thin, elongated wires (not shown) of metal (e.g., stainless steel) in one direction and in the opposite direction. In this case, the metal mesh structure is a flexible structure formed by winding stainless steel wires in different directions. This allows the tubular structure 5 to rotate with good following ability at its tip 5a. Consequently, the tip 2 of the therapeutic fiber optic probe 1 can also rotate with good following ability.

[0032] Furthermore, the front end 5a of the tubular structure 5 houses the aforementioned front end (lens structure 8) of the light transmission structure 3 and the mirror structure 4. This allows for free adjustment of the orientation of the reflected light L2 from the mirror structure 4, which receives the output light L1 from the light transmission structure 3, based on the rotation of the front end 5a of the tubular structure 5. As a result, for example, when used in phototherapy, the degree of freedom in the irradiation direction or irradiation range of the reflected light L2 from the mirror structure 4 can be increased.

[0033] Furthermore, the tubular structure 5 includes an opening 5b for allowing reflected light L2 from the mirror structure 4 to pass through. The cover structure 6 is provided to cover the front end 5a of the tubular structure 5 in such a way that the opening 5b is sealed from the outside. In this way, the front end (lens structure 8) of the light transmission structure 3 and the mirror structure 4 are housed inside the cover structure 6.

[0034] In this case, the cover structure 6 is made of a hollow transparent component (e.g., glass). Thereby, the reflected light L2 from the mirror structure 4 passes through the opening 5b of the tubular structure 5, is appropriately transmitted through the cover structure 6, and is directly emitted to the outside.

[0035] Depending on the situation, multiple marks 9 may be provided at equal intervals (e.g., 2.5 mm) along the outer periphery of the tubular structure 5. For example, the multiple marks 9 may each be in the form of a continuous ring along the outer periphery of the tubular structure 5 and fixed by printing or the like. In this case, the thickness or spacing of each mark 9 can be arbitrarily set according to the intended use or application of the therapeutic fiber optic probe 1. These multiple marks 9 can be used as positioning "rulers" during treatment; for example, when used with an endoscope, the size or position of the object being observed (tissue, affected area) can be visually determined by these marks.

[0036] Next, the mirror structure 4 described above will be explained in detail.

[0037] like Figure 1 and Figure 2 As shown, the mirror structure 4 includes a flat, non-protruding reflective portion 4p. The reflective portion 4p is disposed opposite to the front end (lens structure 8) of the light transmission structure 3. The reflective portion 4p is disposed at a predetermined angle θ and is configured to have a slope that rises as it moves away from the front end (lens structure 8) of the light transmission structure 3.

[0038] Here, the tilt angle θ can be defined as the angle θ between the reflector 4p and the imaginary axis Ax, which extends parallel to the output light L1 from the light transmission structure 3 (i.e., the angle θ between Ax and the reflector 4p).

[0039] In this case, the tilt angle θ can be set according to the intended use or application of the therapeutic fiber optic probe 1. For example, when the reflected light L2 from the mirror structure 4 is tilted by 90° relative to the output light L1 from the light transmission structure 3, the tilt angle θ of the reflector 4p can be set to 45°.

[0040] Thus, by setting the tilt angle θ of the reflector 4p, the reflected light L2 from the mirror structure 4 can be emitted in a direction different from the direction of the output light L1 from the light transmission structure 3 (i.e., a predetermined direction).

[0041] Furthermore, if a certain direction is defined as the output direction of the output light L1 from the light transmission structure 3, i.e., "front", then different directions can be defined as directions other than this certain direction, such as "side" including directions that intersect or are orthogonal to the certain direction. In this way, all the light emitted outward through the opening 5b of the tubular structure 5 can become therapeutic light output "side" from the front end 2 of the therapeutic fiber optic probe 1.

[0042] In this embodiment, the reflective portion 4p of the mirror structure 4 has a structure formed by laminating a dielectric multilayer film (not shown). The dielectric multilayer film refers to a reflective mirror having a reflective film formed by alternately stacking multiple layers of dielectric thin films with high and low refractive indices. The reflective portion 4p of the mirror structure 4 is configured as this reflective mirror.

[0043] Furthermore, in some embodiments, the reflective portion 4p (also referred to as the light-transmitting portion) of the mirror structure 4 is configured to allow light other than the reflected light L2 reflected in different directions from the received light to be transmitted. In this case, a light-shielding structure 7 (e.g., a structure that blocks light emission by coating with black paint or using other methods) is provided on the opposite side of the reflective portion 4p in the mirror structure 4 to block the transmitted light. This prevents light transmitted through the reflective portion 4p from leaking to the outside or reaching the reflective portion 4p as reflected light.

[0044] Here, the light received by the mirror structure 4 (reflector 4p) includes multiple wavelengths that are different from each other. The mirror structure 4 (reflector 4p) is designed to reflect light of all wavelengths, but the target wavelength is reflected the most. For example, among the target wavelengths, light that can be used for phototherapy or photoimmunotherapy includes, for example, light in the wavelength range of 650 to 800 nm, but is not limited to this. For example, light with wavelengths of 690 nm, 680 nm, 675 nm, and 670 nm can be listed. Also, as guiding light, light with a wavelength around 530 nm is used, for example.

[0045] When a specific wavelength of light is required, the reflectivity of the mirror structure 4 (reflective part 4p) is preferably set to 90% or more relative to the multiple wavelengths contained in the received light, including at least one wavelength of the required specific wavelength.

[0046] Furthermore, regarding the amount of light reflected by the mirror structure 4 (reflecting part 4p), if the amount of light received by the mirror structure 4 (reflecting part 4p) is set to 100%, then the amount of light reflected by the mirror structure 4 (reflecting part 4p), including the amount of light of a specific wavelength, is preferably set to at least 90%.

[0047] Features and advantages of one embodiment

[0048] According to this embodiment, the size (diameter) of the therapeutic fiber optic probe 1, including the tip 2, can be set to a size suitable for insertion into an endoscope or catheter, and therapeutic light can be output laterally from the tip 2 of the therapeutic fiber optic probe 1. Furthermore, the tip 2 of the therapeutic fiber optic probe 1 can be rotated well by means of a tubular structure 5 having a metal mesh structure. Therefore, for example, assuming a narrow lumen (e.g., for treatment purposes), conventional anterior irradiation diffusers have areas where light is difficult to irradiate, and when a lesion is present in that area, phototherapy (e.g., phototherapy or photoimmunotherapy) cannot be performed smoothly on that lesion. However, using the therapeutic fiber optic probe 1 of this embodiment, therapeutic light can be effectively irradiated onto the entire lesion present in a narrow lumen. As a result, the selectivity and effectiveness of treatment of the lesion are improved.

[0049] According to this embodiment, the tilt angle θ of the mirror structure 4p can be set according to the intended use or application of the therapeutic fiber optic probe 1. For example, the direction of the therapeutic light output from the front end 2 of the therapeutic fiber optic probe 1 to the "side" can be freely set.

[0050] According to this embodiment, a plurality of marks 9 are provided at equal intervals (e.g., 2.5 mm) along the outer periphery of the tubular structure 5. This eliminates the need for separate measuring tools such as rulers, and when used in conjunction with an endoscope, the size and location of the observed object (tissue, affected area) can be visually determined. As a result, the selectivity and effectiveness of phototherapy to the affected area can be significantly improved.

[0051] According to this embodiment, the reflective portion 4p of the mirror structure 4 allows only light of a specific wavelength required for treatment (e.g., light in the 650-800 nm band, such as 690 nm, used for phototherapy or photoimmunotherapy, or green light in the 530 nm band used as a guide light) to be reflected and output "to the side" from the front end 2 of the therapeutic fiber optic probe 1. In this case, the reflectivity of the mirror structure 4 (reflective portion 4p) is set to 90% or higher relative to the multiple wavelengths contained in the received light, including at least one wavelength of the required specific wavelength. Furthermore, the amount of light reflected by the mirror structure 4 (reflective portion 4p) is set to 100%, meaning that the amount of light reflected from the mirror structure, including the specific wavelength, is at least 90%. By monitoring the reflection intensity of the guide light, phototherapy can be performed safely and with high precision using the therapeutic light.

[0052] Figure 3 These are exemplary evaluation test results of the therapeutic fiber optic probe 1 having the aforementioned characteristics or effects. In the evaluation test, 10 therapeutic fiber optic probes 1, for example, samples 1 to 10, were randomly selected from a plurality of manufactured therapeutic fiber optic probes 1. The irradiation diameter of the light spot generated in the target was measured when the distance between the target and the therapeutic fiber optic probe 1 (specifically, the reflector 4p) was set to a certain value (e.g., 50 mm), and it was confirmed to be in the range of 30.5 ± 1.5 mm.

[0053] In this case, if the target radiation intensity within the flat irradiation surface is set to 100%, it is confirmed that the radiation intensity in the irradiation circle measured above is in the range of 100% ± 15% (i.e., around 100%, in the range of -15% to +15%).

[0054] The evaluation results clearly show that each sample has a lower and upper limit of radiation intensity, but the average of each sample and the whole falls within 100% ± 15% of the target radiation intensity. Meanwhile, regarding the reflectivity of the reflective portion 4p of the mirror structure 4, it is also determined to have the characteristics mentioned above, namely, a reflectivity of over 90% for light of a specific wavelength (e.g., therapeutic light in the 690 nm band, guiding light in the 530 nm band). Furthermore, this value is measured after reflection from the mirror structure 4 and transmission through the cover structure 6; therefore, the reflectivity of the mirror structure 4 can be considered slightly greater than... Figure 3 The value. Also, regarding the temperature of the tip 2 of the therapeutic fiber optic probe 1, the actual temperature rise after starting from room temperature (20°C) is measured.

[0055] Figure 4 The results of exemplary evaluation tests were conducted on 10 therapeutic fiber optic probes 1, which are different from the aforementioned new samples 101-110, focusing on light at specific wavelengths (therapeutic light in the 690 nm band and guide light in the 530 nm band). The evaluation test results clearly demonstrate that the two lights (therapeutic light and guide light) exhibit almost equal reflectivity. This means that the light spot generated by the therapeutic light and the light spot generated by the guide light have the same size and shape on the target surface, as well as the following uniform optical characteristics.

[0056] Therefore, to utilize this property, a dielectric multilayer film is formed on the reflective portion 4p of the mirror structure 4 (also known as a microlens) (i.e., multiple dielectric films are laminated to cover the reflective portion 4p of the mirror structure 4), so that the light spot generated by the reflected light L2 on the target (e.g., the affected area) surface is perfectly circular and exhibits a uniform distribution of light energy (i.e., light intensity distribution) throughout the entire surface. As a result, in treatment methods for the target tissue in the subject, such as photodynamic therapy (PDT), photothermal therapy (PTT), photoimmunotherapy (PIT), and other phototherapies, a photoactivated compound (e.g., a photoactivated dye or complex) is administered to the subject beforehand, thereby activating a chemical reaction and enabling effective and efficient application of treatment to the affected area.

[0057] In this embodiment, when treating the target tissue in the subject, the distance between the therapeutic fiber optic probe 1 (specifically, the reflector 4p) and the surface of the target (affected area) is set to be approximately 5 mm to approximately 80 mm. Furthermore, by configuring the reflective portion 4p of the mirror structure 4 to form a dielectric multilayer film formed by laminating two or more dielectric thin films, it is possible to achieve a dielectric multilayer film with wavelengths of approximately 660 nm to approximately 820 nm, for example, approximately 660 nm to approximately 740 nm, or for example, approximately 660 nm, approximately 670 nm, approximately 675 nm, approximately 677 nm, approximately 680 nm, approximately 685 nm, approximately 690 nm, approximately 695 nm, approximately 700 nm, approximately 705 nm, approximately 710 nm, approximately 715 nm, approximately 720 nm, approximately 725 nm, approximately 730 nm, approximately 735 nm, approximately 740 nm, approximately 745 nm, approximately 750 nm, approximately 755 nm, approximately 760 nm, approximately 765 nm, approximately 770 nm, approximately 775 nm, approximately 780 nm, approximately 785 nm, approximately 790 nm, approximately 795 nm, approximately 800 nm, 805 nm, and approximately 810 nm. Light with wavelengths of approximately 815 nm, 820 nm, or 875 nm is preferred. In one embodiment, light is emitted at two or more wavelengths, such as the therapeutic light band (e.g., therapeutic light in the 675 nm, 677 nm, 690 nm, 780 nm, or 800 nm bands) and the guide light band (e.g., guide light in the 530 nm band). In this example, it is possible to reflect only two types of light at specific wavelengths (e.g., therapeutic light in the 675 nm, 677 nm, 690 nm, 780 nm, or 800 nm bands and guide light in the 530 nm band) with high precision.

[0058] In several embodiments of the treatment method applied to a subject's target tissue, a photoactivating compound (dye or a complex of dyes) is administered to the subject prior to light irradiation. For example, the photoactivating compound may be a pharmaceutical agent. Examples of exemplary photoactivating compounds include dyes (e.g., phthalocyanine dyes, silica phthalocyanine dyes, any dye described in WO2021 / 207691, or IRDye (registered trademark) 700DX (Rakuten Medical, Inc.)) and such photoactivating compounds bound to a targeting agent, but are not limited thereto. Where appropriate, the targeting agent may have target specificity, binding to the extracellular surface of cells such as cancer cells, pre-cancer cells, or immune cells.

[0059] Among the exemplary targeting agents are antibodies, peptides, or antigen-binding fragments that have the specificity to bind to a target on cancer cells or in the tumor microenvironment. In one example, the targeting molecule is a bispecific antibody, scFv, sdAb or nanobody, VHH, an isolated single variable domain, afibody, or z-domain structure, DARPin, a monomer, anticalin, affilin (registered trademark), affiimer type 1 molecule, affiimer type 2 molecule, affitin, alphabody, avimer, fynomer, kunitz domain peptide, or nanoclamp, or a combination thereof. A targeting agent specifically binds to a target molecule, such as a target molecule on the surface of a cell. Target molecules on the cell surface can be extracellular proteins or receptors. Non-limiting examples of target molecules on the cell surface include epidermal growth factor receptor (EGFR), CD25, PD-1, PD-L1, or prostate-specific membrane antigen (PSMA). In one example, the target agent is an anti-EGFR antibody such as cetuximab.

[0060] Exemplary conjugates include, but are not limited to, any of the conjugates described in US8,524,239, WO2017 / 031363 and WO2023 / 159182.

[0061] In one example of the therapeutic fiber optic probe used as described in this specification, the target tissue is the lumen or opening of the test body, such as the esophagus, uterus, vagina, rectum, or colon. The target tissue is cancerous tissue, cancer cells, tumors, lesions, or cancer, or endometriosis, within the opening of the target (affected) body, such as the esophagus. In one example, before irradiating the test body with light of approximately 690 nm using the therapeutic fiber optic probe described in this specification, a complex of an anti-EGFR antibody (such as cetuximab) and a photoactivated dye (such as IRDye (registered trademark) 700DX (Rakuten Pharmaceutical Co., Ltd.)) is administered to the test body.

[0062] Therefore, this embodiment provides a system for treating a person suffering from a disease or condition by means of a light-activatable conjugate, such as any of the conjugates described herein, or a pharmaceutical composition containing any of the conjugates described herein, including a laser capable of emitting light at a specific wavelength. Specific wavelengths include, for example, approximately 650 nm to approximately 820 nm, or approximately 660 nm to approximately 800 nm, or approximately 660 nm to approximately 740 nm, or for example, approximately 660 nm, approximately 670 nm, approximately 675 nm, approximately 677 nm, approximately 680 nm, approximately 685 nm, approximately 690 nm, approximately 695 nm, approximately 700 nm, approximately 705 nm, approximately 710 nm, approximately 715 nm, approximately 720 nm, approximately 725 nm, approximately 730 nm, approximately 735 nm, approximately 740 nm, approximately 745 nm, approximately 750 nm, approximately 755 nm, approximately 760 nm, approximately 765 nm, approximately 770 nm, approximately 775 nm, approximately 780 nm, approximately 785 nm, approximately 790 nm, approximately 795 nm, approximately 800 nm, 805 nm, approximately 810 nm, approximately 815 nm, or approximately 820 nm. The therapeutic fiber optic probe described in this specification is operatively connected to a laser to transmit the light to a target area of ​​the subject. In one example, the system provided for treating a subject suffering from a disease or symptom includes a laser capable of emitting light at approximately 675 nm. In another example, the system provided for treating a subject suffering from a disease or symptom includes a laser capable of emitting light at approximately 677 nm. In another example, the system provided for treating a subject suffering from a disease or symptom includes a laser capable of emitting light at approximately 690 nm. In another example, the system provided for treating a subject suffering from a disease or symptom includes a laser capable of emitting light at approximately 780 nm. In another example, the system provided for treating a subject suffering from a disease or symptom includes a laser capable of emitting light at approximately 800 nm.

[0063] The methods and systems provided in this specification include methods and systems for treating cancer as the target disease or symptom. In several aspects, the cancer is selected from the group consisting of colon cancer, colorectal cancer, pancreatic cancer, breast cancer, skin cancer, lung cancer, non-small cell lung cancer, renal cell carcinoma, thyroid cancer, prostate cancer, head and neck cancer, gastrointestinal cancer, gastric cancer, small bowel cancer, spindle cell tumor, liver cancer, hepatic liver cancer, bile duct cancer, peripheral nerve cancer, brain cancer, skeletal muscle cancer, smooth muscle cancer, bone cancer, adipose tissue cancer, cervical cancer, uterine cancer, genital cancer, lymphoma, and multiple myeloma. In several aspects of the treatment methods in this specification, the steps of administering the complex and irradiation are repeatedly performed. In several aspects, the methods and systems provided in this specification further include the administration of additional therapeutic agents, such as immunotherapy, radiotherapy, chemotherapy, etc. In several aspects, the additional therapeutic agent is a checkpoint inhibitor such as an anti-PD-1 antibody or an antigen-binding fragment.

[0064] In medical applications of photodynamic therapy (PDT) or photoimmunotherapy (PIT), it is required to generate the aforementioned uniform light spot on the surface of the target (affected area). Here, in the therapeutic fiber optic probe 1, the output light L1 emitted from the light transmission structure 3 generally (usually) diverges within an angular range of 30° to 40°. Therefore, the reflective portion 4p of the mirror structure 4, located at a position capable of receiving the output light L1, has its tilt angle θ set to 45° and is constructed by laminating the aforementioned dielectric multilayer film.

[0065] The reflective portion 4p, formed by laminating dielectric multilayer films, exhibits the characteristic of reflecting only the specific wavelength of light required from the received light (e.g., therapeutic light in the 690 nm band, guide light in the 530 nm band) within a range of 45° ± 17° (i.e., the range from -17° to +17° around 45°). This generates a uniform light spot on the target (affected area) surface as described in this specification.

[0066] For example, when the distance between the therapeutic fiber optic probe 1 (specifically, the reflector 4p) and the surface of the target (the affected part of the esophagus) is 18 mm, the irradiation diameter of the light spot generated on the surface of the target (the affected part of the esophagus) can be 11 mm, which is sufficient for the treatment of cancerous tissues such as early esophageal cancer.

[0067] When a photoactivated dye or complex is present in the target (affected area), a chemical reaction is activated by irradiating it with light of a specific wavelength, thereby killing the cells. As a result, the lesion (e.g., a tumor or tumor cells) shrinks or disappears, and the disease or symptoms are treated.

[0068] The foregoing has described one embodiment of the present invention, which is provided as an example and is not intended to limit the scope of the invention. This embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Furthermore, this embodiment is included within the scope or spirit of the invention, and is included within the scope of the claims and their equivalents.

[0069] Other advantages and modifications will readily occur to those skilled in the art. Therefore, the invention is not limited in its broader aspects to the specific details and representative embodiments shown and described herein. Consequently, various modifications may be made without departing from the spirit or scope of the overall conception of the invention as defined by the appended claims and their equivalents.

Claims

1. A therapeutic fiber optic probe, the therapeutic fiber optic probe comprising: An optical transmission structure, wherein the optical transmission structure can output light in a predetermined direction; and A mirror structure, wherein the mirror structure is positioned to receive light output from the light transmission structure; and... The mirror structure causes a portion of the received light required for treatment to be reflected with a reflectivity of over 90% in a direction different from the stated direction, generating a light spot that exhibits a uniform distribution of light energy throughout its entirety.

2. The therapeutic fiber optic probe as described in claim 1, wherein, The mirror structure is composed of a dielectric multilayer film formed by alternating layers of high-refractive-index and low-refractive-index dielectric films, and The dielectric multilayer film causes a portion of the light received by the mirror structure to be reflected in the different directions with a reflectivity of more than 90%, and generates the light spot that exerts a uniform light energy distribution throughout the entire structure.

3. The therapeutic fiber optic probe as described in claim 1 or 2, wherein, The mirror structure allows light other than light reflected in the different directions from the received light to be transmitted.

4. The therapeutic fiber optic probe according to any one of claims 1 to 3, wherein, The light received by the mirror structure includes multiple wavelengths that are different from each other, and The mirror structure reflects only the specific wavelength of light required for treatment from among the multiple wavelengths contained in the received light.

5. The therapeutic fiber optic probe as described in claim 4, wherein, The mirror structure includes light of at least one wavelength above the specified wavelength relative to the plurality of wavelengths contained in the received light, and is set to have a reflectivity of 90% or more.

6. The therapeutic fiber optic probe as described in claim 4, wherein, If the amount of light received by the mirror structure is set to 100%, then the mirror structure is configured such that the amount of light reflected from the mirror structure, including the amount of light of the specific wavelength, is at least 90%.

7. The therapeutic fiber optic probe according to any one of claims 1 to 6, wherein, The therapeutic fiber optic probe has a tubular structure that houses the light transmission structure and the mirror structure inside. On the tubular structure, multiple marks are selectively and equally spaced along its outer periphery, and The aforementioned markings can be used as a ruler during treatment.

8. A treatment system comprising the therapeutic fiber optic probe of any one of claims 1 to 7, and a photoactivated compound.

9. The treatment system of claim 8, wherein, The photoactivated compound is a phthalocyanine dye or a complex of the phthalocyanine dye.

10. The treatment system of claim 9, wherein, The phthalocyanine dye or the complex of the phthalocyanine dye is a silicon phthalocyanine dye.

11. A method of using the treatment system according to any one of claims 8 to 10, the method of use being for the treatment of cancer.

12. The method of using the treatment system according to any one of claims 8 to 11, wherein, Before projecting light using the therapeutic fiber optic probe, the photoactivated compound is first applied to the target.

13. The method of using the treatment system according to any one of claims 8 to 12, wherein, The photoactivated compounds include IRDye (registered trademark) 700DX (Lotte Pharmaceuticals Co., Ltd.) and a targeting agent.

14. The method of using the therapeutic fiber optic probe as described in any one of claims 1 to 7, or the therapeutic system as described in any one of claims 8 to 13, the method of using for treating esophageal cancer, uterine cancer, vaginal cancer, colorectal cancer, or endometriosis.

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