Markers for medical imaging

Abstract

Embodiments of the present disclosure may be directed to brachytherapy markers. Exemplary markers may include an inner ring composed of one or more of copper, brass, gold, silver, or titanium; an outer coating composed of one or more of nickel or iron oxide, wherein the outer coating may have a thickness of about 1 μm to about 30 μm; and a central opening, wherein the diameter of the central opening may be about 0.50 mm to about 3.00 mm.

Description

Technical Field

[0001] The present disclosure relates generally to brachytherapy, and in particular, to brachytherapy markers designed for use across multiple imaging modalities. Background Art

[0002] During high dose rate (HDR) brachytherapy treatment, a radiation source is introduced into or adjacent to a patient's target volume, e.g., a tumor. The radiation source may be introduced manually or by using an afterloader device. Typically, an afterloader device is used to deliver a radiation source to an internal region of a patient at a predetermined dwelling position over a given period of time. The radiation source may be introduced via a cable or catheter and may be positioned within a brachytherapy applicator that is pre-positioned within the patient's body.

[0003] Accurate positioning of the radiation source in the target area of ​​the body is important for the administration of a prescribed brachytherapy treatment. For example, if the radiation therapy source is not accurately positioned, the correct dose of radiation may not be delivered to the intended target area. Additionally, surrounding healthy structures may receive radiation instead of, or in addition to, the intended target area. Exposing the wrong area to radiation may ultimately harm or kill surrounding healthy cells, and may leave cancer cells untreated or undertreated.

[0004] In order to determine whether the radiation source and / or brachytherapy applicator are correctly positioned, thereby determine whether the radiation source is introduced into the correct target area, a large marker that can be visualized using computed tomography (CT) images is often used, or an electromagnetic coil for electromagnetic tracking can be used. However, such methods may not be accurate or reliable enough when determining the correct positioning of the radiation source. In addition, traditional markers may not be used across multiple different imaging modes. For example, a marker compatible with CT imaging may be incompatible with that used for magnetic resonance imaging (MRI). Therefore, it is difficult or impossible to use traditional markers during treatment planning and treatment administration. Summary of the invention

[0005] Embodiments of the present disclosure may be directed to brachytherapy markers. Exemplary markers may include an inner ring composed of one or more of copper, brass, gold, silver, or titanium; an outer coating composed of one or more of nickel or iron oxide, wherein the outer coating may have a thickness of about 1 μm to about 30 μm; and a central opening, wherein the diameter of the central opening may be about 0.50 mm to about 3.00 mm.

[0006] Various embodiments of the present disclosure may include one or more of the following aspects: the inner ring may be copper or brass; the marker may have an annular shape; the outer diameter of the marker may be about 1.00 mm to about 5.50 mm; the thickness of the outer coating may be about 4 μm to about 20 μm; or the diameter of the central opening may be about 0.75 mm to about 2.25 mm. The marker may be attached to a distal region of a brachytherapy applicator, a brachytherapy needle, a brachytherapy catheter, or a brachytherapy delivery tube.

[0007] Embodiments of the present disclosure may also relate to a method of positioning a brachytherapy apparatus within a subject. The method may include inserting a brachytherapy apparatus within a subject, wherein the brachytherapy apparatus includes a marker. The marker may include an inner ring composed of one or more of copper, brass, gold, silver, or titanium; an outer coating composed of one or more of nickel or iron oxide, wherein the thickness of the outer coating may be about 1 μm to about 30 μm; and a central opening, wherein the diameter of the central opening may be about 0.50 mm to about 3.00 mm. The method may also include: generating a magnetic resonance image of the brachytherapy apparatus and the marker when inserted into the subject, wherein the inner ring and outer coating of the marker may be configured to create an artifact in the image.

[0008] Various embodiments of the present disclosure may include one or more of the following: adjusting the position of a brachytherapy apparatus within a patient based on the artifact created in the image; generating a computed tomography image of the brachytherapy apparatus; inserting an afterloader cable into the brachytherapy apparatus, wherein the afterloader cable may include an electromagnetic sensor and detecting a marker using the electromagnetic sensor; inserting a source cable into the brachytherapy apparatus and positioning a radiation source relative to the artifact. In other embodiments, the afterload cable may be a dummy cable, the source cable may include a second electromagnetic sensor, or the electromagnetic sensor may be a coil.

[0009] Embodiments of the present disclosure may also be directed to a kit including a brachytherapy apparatus and a marker. The marker may include an inner ring composed of one or more of copper, brass, gold, silver, or titanium; an outer coating composed of one or more of nickel or iron oxide, wherein the thickness of the outer coating may be about 1 μm to about 30 μm; and a central opening, wherein the diameter of the central opening may be about 0.50 mm to about 3.00 mm; and the marker may have an annular shape.

[0010] Additional objects and advantages of the disclosed embodiments will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosed embodiments.

[0011] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments.

[0013] For the sake of simplicity and clarity of explanation, the accompanying drawings depict the general structure and / or construction mode of the different embodiments described herein. For ease of explanation, the accompanying drawings can depict various parts as uniform and smooth shapes. However, those skilled in the art will recognize that, in fact, these different parts can have uneven thickness and / or irregular shapes. The description and details of well-known features (e.g., delivery mechanisms, cables, capsules, catheters, etc.) and technologies can be omitted to avoid blurring other features. The elements in the accompanying drawings are not necessarily drawn to scale. The sizes of some features can be enlarged relative to other features to improve the understanding of the exemplary embodiments. Those skilled in the art will understand that the cross-sectional views are not drawn to scale and should not be considered to represent the proportional relationship between different regions / layers. In addition, although some features are shown as having straight 90 degree edges or regular planes, in reality or practice, such features can be more "rounded" and gradually inclined.

[0014] In addition, it will be understood by those skilled in the art that even if not specifically mentioned, the aspects described with reference to one embodiment may also be applicable to other embodiments and may be used together with other embodiments. There are many embodiments described and shown herein, and the present disclosure is not limited to any single aspect thereof nor to any embodiment thereof, nor to any combination and / or arrangement of such aspects and / or embodiments. Each aspect of the present disclosure and / or its embodiments may be used alone or in combination with one or more other aspects of the present disclosure and / or its embodiments. For the sake of brevity, certain permutations and combinations are not discussed and / or described separately herein.

[0015] Figure 1 shows exemplary markers according to embodiments of the present disclosure;

[0016] Figure 2A and Figure 2B shows a cross-sectional view of an exemplary marker according to an embodiment of the present disclosure;

[0017] Figure 3 An exemplary marker according to the present disclosure is shown, wherein the marker is placed on an exemplary brachytherapy needle or catheter;

[0018] Figure 4 shows an exemplary sensing signal report generated by an electromagnetic (EM) sensor device for detecting an exemplary marker according to an embodiment of the present disclosure;

[0019] FIG. 5A to FIG. 5D An exemplary 3D image showing a CT / cone beam computed tomography (CBCT) scan of a catheter of a brachytherapy apparatus with markers according to an embodiment of the present disclosure;

[0020] Fig. 6A and Figure 6B shows an exemplary magnetic resonance image of a nitinol marker compared to a nitinol marker with a coating according to an embodiment of the present disclosure; and

[0021] Figure 7 A flow chart is shown of an exemplary method of using markers to determine an afterload therapy plan according to the present disclosure. DETAILED DESCRIPTION

[0022] It should be noted that the descriptions set forth herein are merely illustrative in nature and are not intended to limit the embodiments of the subject matter, or the application and use of such embodiments. Any implementation described herein as exemplary should not be construed as being superior to or superior to other implementations. On the contrary, the term "exemplary" is used in the sense of an example or "illustrative", rather than "ideal". The terms "comprise", "include", "have", "with" and any variants thereof are used synonymously to represent or describe non-exclusive inclusions. Therefore, the device or method using such terms includes not only those elements or steps, but may also include other elements and steps that are not explicitly listed or inherent to such devices and methods. In addition, the terms "first", "second", etc. herein do not represent any order, quantity, or importance, but are used to distinguish one element from another. The term "distal end" refers to a direction away from a user or operator and into a subject. In contrast, the term "proximal end" refers to a direction closer to a user or operator and away from a subject.

[0023] Unless the context dictates otherwise, the singular forms "a", "an", and "the" include plural references. The terms "approximately" and "about" refer to being nearly identical to a reference number or value. As used herein, the terms "approximately" and "about" are generally understood to encompass ±5% of a specified amount or value. All ranges are understood to include endpoints, e.g., a distance between 1.0 cm and 5.0 cm includes distances of 1.0 cm, 5.0 cm, and all values ​​therebetween.

[0024] The term "brachytherapy apparatus" may be used to refer to one or more radiation sources or virtual sources; a brachytherapy applicator; a cable and / or capsule for moving the radiation source or virtual source; or a rod, delivery tube, needle, catheter, occluder or wire used during insertion or during use of a radiation source or virtual source.

[0025] Brachytherapy typically includes a treatment planning phase and a treatment delivery phase. Using medical three-dimensional (3D) imaging, such as CT, CBCT, and / or MRI, a conformal dose plan can be generated for HDR brachytherapy during treatment planning. Conformal dose planning can be performed during the treatment delivery phase, during which a radioactive brachytherapy source can be guided to one or more dwelling positions within the body. To this end, an afterload program, such as Elekta's Flexitron afterload program, can be calibrated with a dose plan based on one or more 3D patient images. Afterload calibration can typically occur by identifying landmarks in medical imaging (such as identifying a needle tip or applicator lumen tip), which may not be well defined or may be difficult to reconstruct in a 3D medical image.

[0026] In contrast, exemplary embodiments of the present disclosure relate to specially designed markers that can be associated with brachytherapy applicators, needles, or other brachytherapy instruments. These markers can provide improved measurements of their positions in CBCT, CT, and MR images, and can provide improved measurements by afterloaders (e.g., by indexer length). The fixed marker position of each applicator or catheter can be defined according to the type of applicator or catheter used, so that the distance from the starting point of the applicator or catheter (the original zero point of the afterloader like the Flexitron afterloader of Elekta) to the marker is a fixed distance. For example, the indexer length of the afterloader can be zeroed at the marked point in the 3D medical image, which can allow the 3D dwell position to be scaled to the indexer length in the afterload therapy plan. By integrating exemplary markers into brachytherapy instruments (e.g., applicators, needles, and / or catheters), the afterload source can be guided and calibrated to the dose planning system, e.g., the Elekta Oncentra Brachy dose planning system, to the afterload therapy plan to provide. Thus, embodiments of the present disclosure may provide for a more direct and more accurate afterload calibration.

[0027] Figure 1 A marker 10 configured for use with one or more brachytherapy apparatuses is shown. The marker 10 may be annular and may include a central opening 12. Those skilled in the art will recognize that the marker 10 may have a variety of shapes (e.g., Figure 2BFor example, the marker 10 can be sized to fit on or be integrated as a portion of a brachytherapy catheter or needle, a delivery tube, a catheter connector, and / or a brachytherapy applicator (e.g., along a channel or catheter within an applicator). Thus, the marker 10 can have an inner diameter (i.e., the diameter of the central opening 12) that is sized to fit around a conventional 2 mm needle or 3 / 4 mm catheter of an applicator.

[0028] As mentioned above, when brachytherapy treatment is performed, it is desirable to achieve accurate placement of the radiation source. In order to determine whether an applicator, cable, line, catheter, needle or other brachytherapy instrument has been correctly placed in the patient, the instrument may include one or more markers 10 at a known position on the brachytherapy instrument. For example, if the marker 10 is included on the distal region of the line, catheter, cable or needle, then the distance that the line, catheter, cable or needle has been inserted into the patient can be tracked and thus known. In some cases, the position of the marker 10 can be imaged (using, for example, CT imaging) to determine the correct placement of the brachytherapy instrument in the main body. Then, the radiation source can be positioned in the subject using an afterloader so that the source poles are aligned with the marker 10. Traditionally, a large volume of spherical markers can be used so that the medical staff can guide the source to the central region of the marker, and software can be used to find the center of the marker for positioning purposes. The use of a large volume of spherical markers may not be used to deliver radiotherapy to a smaller area and / or for a smaller brachytherapy instrument.

[0029] In addition, conventional markers may only be compatible with CT images obtained during treatment planning and patient preparation, but they may not be compatible with MR imaging, which may be used during treatment administration. Therefore, in current brachytherapy workflows, a CT scan may be performed after placement of a brachytherapy applicator and before delivery of a radiation source to determine the correct placement of the applicator, thereby attempting to ensure correct placement of the radiation source during treatment. If the actual position of the radiation source is monitored directly, the positioning of the radiation source relative to the target area selected to be treated can be improved. Such direct monitoring can be achieved with a marker designed for CT imaging during treatment planning and for MRI (e.g., real-time MR imaging) performed during placement of the brachytherapy instrument and / or during delivery of the radiation source. Markers according to the present disclosure may address one or more of the problems listed above.

[0030] Reference Figure 1 and Figure 2A, the inner diameter of the marker is represented by B, which can range from about 0.50 mm to about 3.00 mm, about 1.00 mm to about 2.50 mm, or from about 1.50 mm to about 2.00 mm. In some embodiments, the inner diameter B can range from about 0.75 mm to about 2.25 mm. Depending on the brachytherapy apparatus with which the marker 10 is used in conjunction with (e.g., located in, within, or relative to), the inner diameter B can be, for example, about 0.50 mm, about 0.75 mm, about 1.00 mm, about 1.25 mm, about 1.50 mm, about 1.75 mm, about 2.00 mm, about 2.25 mm, about 2.50 mm, about 2.75 mm, or about 3.00 mm.

[0031] The thickness of the marker 10 is represented by C, which can range from about 0.25 mm to about 1.25 mm. The thickness C can be, for example, about 0.25 mm, about 0.30 mm, about 0.35 mm, about 0.40 mm, about 0.45 mm, about 0.50 mm, about 0.55 mm, about 0.60 mm, about 0.65 mm, about 0.70 mm, about 0.75 mm, about 0.80 mm, about 0.85 mm, about 0.90 mm, about 0.95 mm, about 1.00 mm, about 1.05 mm, about 1.10 mm, about 1.15 mm, about 1.20 mm, or about 1.25 mm. The outer diameter of the marker 10 is represented by A, which can range from about 1.00 mm to about 5.50 mm, such as about 1.25 mm to about 5.25 mm, about 1.50 mm to about 5.00 mm, or about 1.75 mm to about 4.75 mm. In other embodiments, the outer diameter A can range from about 2.00 mm to about 4.00 mm. The outer diameter can be, for example, about 1.00 mm, about 1.25 mm, about 1.50 mm, about 1.75 mm, about 2.00 mm, about 2.50 mm, about 3.00 mm, about 3.50 mm, about 4.00 mm, about 4.50 mm, about 5.00 mm, about 5.25 mm, or about 5.50 mm.

[0032] As discussed above, the marker 10 need not be annular. For example, one or more surfaces of the marker 10 may be flat and / or may have a change in curvature. Figure 2BIn an embodiment, the disc-shaped marker 20 has a flat distal surface 13, a flat proximal surface 15, an outer wall 17 extending between the distal surface 13 and the proximal surface 15, and an inner wall 19 extending between the distal surface and the proximal surface. The inner wall 19 can define a central opening of the marker 12. The marker 20 can have dimensions similar to those listed above for the marker 10, but the marker 20 can have, for example, a rectangular cross-sectional shape, and thus can have different lengths and thicknesses (i.e., widths). The length of the marker 10 is represented by D, which can range from about 0.25 mm to about 0.75 mm. The length of the marker can be, for example, about 0.30 mm, about 0.40 mm, about 0.50 mm, about 0.60 mm, or about 0.70 mm. In some embodiments, the length D can be different from the thickness C (as described above), or in some embodiments, the length D and the thickness C can have equal dimensions.

[0033] refer to Figure 2A and Figure 2B , a marker according to the present disclosure may include an inner ring 14 and an outer coating 16. The inner ring 14 may be copper, brass, gold, silver, titanium, or a combination or alloy thereof. In other embodiments, the inner ring 14 may be copper, brass, or a combination thereof. The outer coating 16 may be nickel, iron, or another ferromagnetic material, or a combination of ferromagnetic materials, such that the outer coating does not produce large artifacts in MRI imaging. In some embodiments, the outer coating 16 may be, for example, nickel, iron, cobalt, NiCo, magnetite, or iron oxide. In some embodiments, the outer coating 16 may not include magnetic steel. In some embodiments, the outer coating 16 may consist solely of nickel.

[0034] The thickness of the outer coating 16 is represented by E, which can range from about 1 μm to about 30 μm, for example, from about 2 μm to about 27 μm, from about 3 μm to about 24 μm, or from about 4 μm to about 20 μm. In some embodiments, the thickness of the outer coating 16 can be in the range of about 2 μm to about 12 μm. The thickness of the outer coating 16 can be, for example, about 4 μm, about 6 μm, about 8 μm, about 10 μm, about 12 μm, about 14 μm, about 16 μm, about 18 μm, about 20 μm, about 22 μm, about 24 μm, about 26 μm, about 28 μm, or about 30 μm. The thickness of the outer coating 16 can be uniform around the inner ring 14.

[0035] In some exemplary aspects, the exemplary marker 10 can have an inner ring formed from a copper or brass ring having a diameter of 0.25 mm to 0.5 mm, and can have a nickel or iron oxide coating of about 1 μm to about 14 μm, for example, about 2 μm to about 12 μm, about 5 μm to about 10 μm, or about 6 μm to about 8 μm.

[0036] When it comes to CT and MRI scans, artifacts are anomalies seen during visual representation, where the anomaly does not exist in the original object. Large artifacts may blur and / or obstruct MRI scans, making it impossible to visually assess the region of interest. However, small artifacts may be beneficial. For example, small artifacts can provide landmarks relative to surrounding anatomical structures so that a radiation source or a virtual source can be accurately guided to the target area. The material and / or size of the marker 10 can be designed to produce small artifacts in MRI and CT scans and can be compatible with both imaging modes. For example, copper and brass are good conductors and can therefore be used for CT scans, while nickel, when used for MRI scans, can produce small but visible artifacts compared to other materials (such as magnetic steel) that can produce large artifacts. Therefore, the inner ring 14 is visible in CT / CBCT scans, while the outer coating 16 is visible in MRI scans. Therefore, the marker 10 according to the present disclosure can be used for both CT / CBCT and MRI scans.

[0037] Reference Figure 3 One or more markers 10 according to one or more embodiments of the present disclosure may be used in a brachytherapy apparatus 30. For example, in Figure 3 The central opening of the marker 10 in can be configured to fit around at least a portion of a brachytherapy instrument 30. The brachytherapy instrument 30 can be, for example, a needle, a catheter, a delivery tube, an applicator, a cable, or a wire. For example, one or more markers 10 can be associated with a predetermined position on the applicator, which can be a known distance from a suitable reference point. For example, the marker 10 can be used to indicate the distal end of an associated structure, such as a cavity within an applicator, or the marker 10 can be used to indicate an associated position within a brachytherapy instrument, such as a source dwell position. One or more markers 10 can be placed on the applicator to define a position, and the distance from the starting point of the applicator to the marker 10 can be a fixed distance.

[0038] In some embodiments, one or more markers 10 can be integrated as part of a mammary duct button for endpoint detection of a brachytherapy source. In some aspects, one or more markers 10 can be integrated with a delivery tube / catheter connector to help determine that the catheter and / or applicator is properly connected to the delivery tube. In yet other aspects, one or more markers 10 can be integrated at the end of an applicator or catheter for endpoint detection of a brachytherapy source.

[0039] The marker 10 may be included as part of a brachytherapy instrument so that the afterloader can measure the indexer length, which pertains to the location of the marker 10. The measurement may be performed using electromagnetic induction caused by a conductive ring (e.g., marker 10) and a coil included on (e.g., built-in or added to) one or more of the source cable, the test cable, and / or the dummy cable. The marker 10 may also be clearly visible in a 3D patient image so that the 3D location of the center of the ring may be measured in a CT, CBCT, and / or MR image with the aid of a marker point in a dose planning system (e.g., Oncentra Brachy). By using this method of measuring the marker using the afterloader source indexer length, and in the patient coordinate system of the 3D image, the afterloader may be calibrated to or with a 3D image of the dose plan. Thus, the brachytherapy source may be more accurately positioned to a predetermined dwell position generated by the dose plan.

[0040] As described above, one or more markers 10 according to the present disclosure may be used as part of or in conjunction with a high dose rate (HDR), low dose rate (LDR), or pulsed dose rate (PDR) of an integrated brachytherapy treatment system. The integrated brachytherapy treatment system may include an afterloader and a radiation source associated with an electromagnetic coil. Alternatively, in place of the electromagnetic coil, the integrated brachytherapy treatment system may include a Hall sensor associated with a cable and a permanent magnet associated with the one or more markers 10. In other embodiments, a capacitive sensor may be used in the integrated brachytherapy system to measure changes in capacitance.

[0041] In an exemplary embodiment described herein, the afterloader can be configured to measure the induction of a magnetic source caused by a coil. The marker 10 can be integrated as part of one or more brachytherapy instruments (e.g., an applicator, a catheter, or a needle). The marker 10 can be clearly identified on MRI, CT, and CBCT images. The integrated system can also include a planning system, such as an HDR planning system, which is configured to reconstruct the applicator and marker in the 3D image, and the 3D position of the reconstruction marker 10. The HDR planning system can also be configured to generate a dose dwell position for irradiation. The software associated with the afterloader can be configured to calculate the indexer length for the dwell position of the dose plan. The calibration software module can also be designed to calibrate the indexer length treatment plan to the dose plan using the calibration of the marker 10 of the afterloader by the planning system.

[0042] like Figure 3As shown, and as discussed above, markers according to the present disclosure can be connected to an applicator of a brachytherapy instrument. Once the applicator with the associated marker is inserted into the patient, CT and MRI scans can be performed in real time because the components of the marker (e.g., inner ring and outer coating) can be adapted for use across both imaging modalities, as discussed in detail above. Utilizing high-quality 3D imaging of the patient, including CT, CBCT, and / or MRI, a more accurate conformal dose plan can be developed for HDR brachytherapy.

[0043] After creating a conformal dose plan, an HDR brachytherapy source or a virtual source can be directed to the predetermined dwell positions of the treatment plan. To guide the radiation source, the afterloader can be calibrated using a dose plan based on patient images. Currently, there is no direct way to calibrate a dose plan to an afterload therapy plan. In current treatments, this can be done by identifying the needle tip or applicator lumen tip, but these tips may not be well defined or may be difficult to reconstruct in a 3D image. Typically, the accuracy of brachytherapy source positioning can be about + / -1.5mm, or by using Elekta's Flexitron afterloader, about + / -0.8mm. And, for MRI, this type of treatment plan may not be available due to incompatibility of markers with MR imaging.

[0044] Because the markers according to the present disclosure can be better defined and visible in 3D images, the location of the marker can be more accurately measured in the image or by the afterloader to generate the indexer length. This measurement step can be performed by measuring the electromagnetic induction caused by the marker and the coil on the source cable of the afterloader. Since the exemplary markers of the present disclosure are visible in CT and MRI images, the location of the center of the marker can be determined by The marker points in the Brachy dose plan are measured in the image. The indexer length of the afterloader can be zeroed at the marker points in the 3D image, whereby the 3D dwell position can be scaled to the indexer length in the afterload therapy plan. Thus, the markers integrated in the applicator can allow calibration of the afterload source to the dose planning system, which can allow for the use of the afterload source in the dose planning system (such as Brachy dose planning system) to the afterload therapy plan. The ability to generate CT and MRI images while positioning the applicator can allow the radiation source to be more accurately guided to the determined dwell position required by the dose plan. In some embodiments, this use of direct calibration of the afterloader indexer length to the 3D patient image can improve the accuracy of brachytherapy source positioning to approximately + / - 0.5 mm, and MRI calibration is also available.

[0045] Reference Figure 4, the brachytherapy apparatus 40 may include an afterloader 42. The afterloader 42 may include a selector 44 and a safe 46. The safe 46 may be located within the selector 44. One or more delivery tubes 48 may be used to connect the afterloader 42 to an applicator 50 that may be located within a subject. An electromagnetic sensor (e.g., a coil) may be located at the end region of the cable. For example, a source cable, a check cable, and / or a dummy cable may include an electromagnetic sensor located at a distal region. In an exemplary embodiment in which the source cable includes an electromagnetic sensor, the sensor may be located at, for example, the proximal or distal end of the radiation source. In either case, the distance between the source and the sensor may be known. The source cable, the check cable, and / or the dummy cable having an electromagnetic sensor in the distal region may move from the afterloader 42 through the delivery tube 48 and into the applicator 50. The sensor (e.g., a coil) may be used to measure changes in electromagnetic induction when the sensor moves through the marker of the present disclosure. For example, a copper or brass ring marker can produce a strong change in the electromagnetic induction signal when the cable and accompanying electromagnetic sensor pass through the marker or through the marker due to the good electrical conductivity properties of copper and / or brass. Once the electromagnetic source is placed within the applicator, the sensor can detect the change in magnetic induction as the sensor passes through the marker associated with the brachytherapy apparatus or through the marker associated with the brachytherapy apparatus. The markers can each be located at a dwell position, and thus the electromagnetic signal can indicate the corresponding dwell position.

[0046] For example, Figure 4 The three markers in can cause corresponding signal changes in the area specified by AA. Marker 52a can cause a change in the electromagnetic induction measured at point 53a, marker 52b can cause a change in the electromagnetic induction measured at point 53b, and marker 52c can cause a change in the electromagnetic induction measured at point 53c. In addition, marker 52d can be located at the distal end of the transmission tube 48, causing a change in the electromagnetic induction measured at point 53d to indicate that the cable is passing from the transmission tube 48 and entering the applicator 50. As discussed above, markers 52a, 52b, 52c can be separate from the applicator 50 and can be assembled to the applicator 50 before insertion into the patient, or markers 52a, 52b, 52c can be integrated as part of the applicator 50 or any other suitable brachytherapy instrument. The markers 52a, 52b, 52c may be oriented adjacent to the path traveled by the afterload cable and / or associated radiation source, or may at least partially surround the path traveled by the afterload cable and / or associated radiation source. Figure 4 Three markers are depicted in FIG. 5 , but one of ordinary skill in the art will recognize that fewer (eg, one or two) or more markers may be associated with the applicator 50 .

[0047] In embodiments where an electromagnetic sensor is incorporated as part of a dummy cable and / or a check cable, after the locations of the markers have been detected by the sensor, the cable and the electromagnetic sensor device can be withdrawn from the applicator 50 and the delivery tube 48 and directed back into the afterloader 42. The brachytherapy source cable can then be inserted into the delivery tube 48 and into the applicator 50. In some embodiments, the source cable can also include an electromagnetic sensor (e.g., a coil) proximal or distal to the radiation source. In some aspects, after the HDR source has been inserted, the dummy cable and / or the check cable with the electromagnetic sensor can be passed through the delivery tube 48 and the applicator 50 to confirm the target location of the HDR source.

[0048] FIG. 5A to FIG. 5D Shown are exemplary 3D images and exemplary markers from a CT / CBCT scan of a catheter of a brachytherapy device in accordance with one or more embodiments of the present disclosure. FIG. 5A to FIG. 5D Describes the use of a suitable treatment planning system (such as Elekta's Brachy) oblique cross-sectional 3D CT / CBCT images. Treatment planning system (like Brachy) can create a 3D representation of one or more brachytherapy devices with associated markers by combining multiple two-dimensional (2D) images. For example, a 2D sagittal view ( Figure 5A ), 2D Horizontal View( Figure 5B ) and 2D coronal view ( Figure 5C ) can be combined to form a 3D image ( Figure 5D ). Figure 5D is a 3D visualization of such a catheter. A catheter (e.g., a plastic catheter) and one or more marker rings according to the present disclosure are clearly visible and can be reconstructed as marker points in the dose plan. In the CT / CBCT image, the marker (in this case, a copper marker ring) can be seen as a white dot with 2800-3000 Hounsfield units (HU) (in FIG. 5A to FIG. 5D The plastic tube may be visible with 750HU because the plastic may have been improved with BaSO4 for CT visibility and BaSO4 may give better CT / CBCT contrast when measured on a HU scale. In other CT / CBCT images, the contrast of these markers may be even clearer because standard applicator tubes are often made of normal, unreinforced plastic, so the plastic may appear closer to 100HU, the air in these tubes may be negative 1000HU, and the contrast may be 1100HU.

[0049] In actual CT images, the markers are represented by two white dots, and the catheter may appear as a softer white line. FIG. 5A to FIG. 5C In the figure, for clarity, the two markers are depicted as two black dots, and the catheter is represented as an outline. In Brachy's treatment planning software, markers for dose planning and optimized dwell positions can be stored in 3D coordinates and used to define the reconstructed catheter. These markers can be used to indicate Official landmarks used in Brachy planning or other suitable treatment planning software.

[0050] FIG. 6A to FIG. 6B The standard nitinol marker ( Fig. 6A ) and an exemplary marker according to the present disclosure ( Figure 6B ) for comparison. Fig. 6A MR image showing Nitinol markers positioned on a 6F catheter. The Nitinol markers can be positioned at predetermined locations toward the distal end of the catheter, such as 15 mm, 20 mm, and / or 24 mm from the distal end. These Nitinol markers are typically only used in CT scans. The catheter and Nitinol markers can be inserted into the patient until the markers are at a specified distance within the patient. The afterloader can then be used to place radiation sources within the catheter so that the sources are aligned at the center of the markers. Fig. 6A As seen in the MR images of FIG. 1 , the nitinol marker is barely visible among the dark lines representing the catheter, making it an inadequate marker.

[0051] Figure 6B : represents an MR image obtained on an inclined plane in which a 6 French (F) catheter is located. The catheter includes an annular marker formed of copper with a nickel coating (in this case, a 10 μm nickel coating). The marker is Figure 6B The nickel artifact can be clearly seen in MRI scans of . The nickel artifact can be a visible, dipole artifact, and the center of the artifact can coincide with the center of the copper ring. Figure 6B MR imaging of the markers can allow the clinician to more accurately guide the brachytherapy source to the target area and accurately align the source with the center area of ​​the marker. Because the marker can be aligned with a predetermined dwell position, the markers of the present disclosure can increase the accuracy of brachytherapy placement. Figure 6B The markers are located in The accuracy of the markers in the Brachy can be equal to or better than + / - 0.5 mm.

[0052] As discussed above, conventional markers can be used only for CT scans. Markers according to the present disclosure can allow either or both of CT or MRI scans to be performed while treating a patient or confirming the location of an applicator or other brachytherapy instrument within the body, for example, using a dummy cable or a check cable. This benefit can allow a medical professional performing brachytherapy treatment to determine (e.g., in real time) whether the radiation source is pointing to the correct location and / or can provide a more direct measurement of the location of the marker, and thus provide the location of the radiation source or virtual source. In radiation therapy, accurate location is required to ensure that normal healthy tissue is not damaged and that targeted cancerous tissue is treated.

[0053] The afterload software can be integrated with a dose planning software (e.g., Oncentra Brachy) to generate an afterload treatment plan. In such embodiments, the marker positions measured by Oncentra Brachy in the 3D image and the results of the electromagnetic induction sensor (e.g., coil) measurement from the afterloader can be considered for the calibration indexer length of the dwell position, as described below.

[0054] As discussed above, markers according to the present disclosure can allow for a more direct and / or real-time calibration of the afterloader indexer length using the 3D position of the marker in the patient imaging system. The brachytherapy workflow can be changed to accommodate the new calibration. An additional software module in the afterloader can be configured to handle the calibration so that the new software module can read the 3D dwell position from the dose planning system. The 3D position of the marker can be indicated or highlighted, for example, by being shown in a contrasting color (e.g., red, yellow, orange, green, or blue). The indexer length of the marker position can be obtained from the calibration. The indexer length of the dwell position of the dose plan can be calculated from the distance between the marker point and the continuous dwell position, starting from the closest marker, or alternatively, from the dwell position farthest from the marker. The calculated indexer length can then be stored in the treatment plan for the afterloader.

[0055] Figure 7Flowchart showing a method for determining an afterload therapy plan according to the present disclosure using a marker according to one or more embodiments of the present disclosure. The method can be performed by a single processor or by multiple processors communicating with each other. In order to directly calibrate the source position, a brachytherapy applicator can be placed in the patient. Then, a three-dimensional CT, CBCT and / or MR image of the patient can be obtained, and a dose plan with a dwell position can be formulated in the 3D image. The marker position can be indicated in the 3D image. The patient can be removed from the MRI or CT machine, and then the afterloader can be connected to the brachytherapy applicator. In order to calibrate the brachytherapy system, the virtual source can be moved to the farthest dwell position (or, in some aspects, the nearest dwell position). An electromagnetic sensor (e.g., a coil) as part of the source can pass through the marker and generate a signal, which can allow the indexer length to be measured by the afterloader.

[0056] To execute Figure 7 In the step of, the indexer length of the marker position can be received by the afterloader. Step 70 may include determining the closest dwell position relative to the 3D marker position. Step 72 may include calculating the distance difference between the closest dwell position and the marker position. The distance Δ(ΔD) may be equal to ΔD=d(dwell (proximal position)-marker (position)). Step 74 may include calculating the indexer length by the distance from the dwell to the marker and the measured calibrated indexer length. In this case, the indexer length dwell of the closest dwell position = the indexer length of the marker + ΔD. Step 76 may include repeating steps 70, 72 and 74 until the indexer length of all dwell positions in the positive direction is calculated. For example, indexer length dwell (n+1) = indexer length (n) + Δ(dwell (n+1)-dwell (n)). Step 78 may include repeating steps 70, 72 and 74 to calculate the indexer length of all dwell positions in the negative direction. The same loop can be performed in the opposite direction until all dwell positions in the negative direction are also determined. One skilled in the art will recognize that the dwell position may be determined in the negative direction and then in the positive direction, as opposed to first in the positive direction and then in the negative direction, and thus the equation will simply change. The dwell position may be stored in the afterload therapy plan as an indexer length.

[0057] In some aspects, rather than obtaining a base indexer length from the afterloader, the indexer length to the marker can be used as the base indexer length. In this regard, in the planning system, the distance from the marker to the dwell position (i) can be measured, which can be Δ(i). The indexer length for the dwell position (i) can then be determined. In such a case, the indexer length (i) can be equal to the base indexer length, which can be equal to Δ(i).

[0058] Alternatively, the source can also be calibrated indirectly, for example, when a marker is integrated into a brachytherapy applicator or needle at a predetermined distance from the entrance of a brachytherapy instrument (e.g., a needle or catheter). For example, the marker can be located 20 cm from the catheter entrance. A calibration ruler associated with the afterloader can be used to guide the source to 20 cm (with an accuracy of, for example, 0.25 mm), and the indexer length can be stored. This value can be used as a basic indexer length, and based on 3D CT and / or MR images (with Δ(i) for each dwell position (i)), the indexer length (i) can be calculated. In this way, the indexer length can be calculated using the basic indexer length and the ΔD for each dwell position as determined from the 3D image.

[0059] In some embodiments, each catheter or needle can use at least two markers, wherein at least one marker is positioned at the distal end of the catheter or needle and at least one marker is positioned at the proximal end of the catheter or needle. The path and step of the afterloader can be controlled and measured. If the marker positions are also visible in the 3D planning image, a dual direct calibration can be performed. Alternatively, if both markers are placed at predetermined locations on the catheter or needle and the markers are visible in the 3D image, an indirect calibration can be performed.

[0060] As with any programmable logic, such logic can be executed on a commercial processing platform or a dedicated device. One of ordinary skill in the art will appreciate that embodiments of the disclosed subject matter can be practiced with a variety of computer system configurations, including multi-core multiprocessor systems, minicomputers, mainframe computers, linked or clustered computers with distributed functionality, and microcomputers that are pervasive or can be embedded in almost any device.

[0061] For example, the above embodiments may be implemented using at least one processor device and memory. The processor device may be a single processor (e.g., associated with a postloader), multiple processors (e.g., associated with a postloader and / or a separate processor for treatment planning, etc.), or a combination thereof. The processor device may have one or more processor "cores".

[0062] As above Figure 7The various embodiments of the present disclosure described in the examples can be implemented using a processor device. After reading this description, it will become apparent to a person skilled in the relevant art how to use other computer systems and / or computer architectures to implement the embodiments of the present disclosure. Although operations can be described as sequential processes, some operations can actually be performed in parallel, concurrently, and / or in a distributed environment, and have program code stored locally or remotely for access by a single processor or a multi-processor machine. In addition, in some embodiments, the order of operations can be rearranged without departing from the spirit of the disclosed subject matter.

[0063] It should be understood that the device for accessing the backloader processing platform 80, such as a user device or a source device, may include a central processing unit (CPU). Such a CPU may be any type of processor device, including, for example, any type of dedicated or general purpose microprocessor device. As will be appreciated by those skilled in the art, the CPU may also be a single processor in a multi-core / multi-processor system, such a system operating alone, or in a cluster of computing devices operating in a cluster or server group. The CPU may be connected to a data communications infrastructure, such as a bus, a message queue, a network, or a multi-core messaging scheme.

[0064] It should also be understood that the device for accessing the backloader processing platform 80, such as a user device or a source device, may also include a primary memory, such as a random access memory (RAM), and may also include an auxiliary memory. The auxiliary memory, such as a read-only memory (ROM), may be, for example, a hard disk drive or a removable storage drive. Such a removable storage drive may include, for example, a floppy disk drive, a tape drive, an optical disk drive, a flash memory, etc. The removable storage drive in this example reads from and / or writes to a removable storage unit in a well-known manner. The removable storage unit may include a floppy disk, a tape, an optical disk, etc. that is read and written by the removable storage drive. As will be understood by those skilled in the relevant art, such a removable storage unit typically includes a computer-usable storage medium having computer software and / or data stored therein.

[0065] In alternative embodiments, the secondary memory may include other similar means for allowing computer programs or other instructions to be loaded into the device. Examples of such means may include program cartridges and cartridge interfaces (such as those found in video game devices), removable storage chips (such as EPROM or PROM) and associated slots, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to the device.

[0066] It should also be understood that a device for accessing the afterloader processing platform 80, such as a user device or a source device, may also include a communication interface ("COM"). The communication interface allows software and data to be transferred between the afterloader device and an external device. The communication interface may include a modem, a network interface (such as an Ethernet card), a communication port, a PCMCIA slot and card, etc. The software and data transmitted via the communication interface may be in the form of signals, which may be electronic, electromagnetic, optical, or other signals capable of being received by the communication interface. These signals may be provided to the communication interface via a communication path of the device, which communication path may be implemented using, for example, a wire or cable, an optical fiber, a telephone line, a cellular phone link, an RF link, or other communication channel.

[0067] The hardware components, operating systems and programming languages ​​of this equipment are conventional in nature, and it is assumed that those skilled in the art are fully familiar with them. The equipment for accessing the afterloader processing platform may also include input and output ports to connect input and output devices such as keyboards, mice, touch screens, monitors, displays, etc. Of course, different server functions can be implemented in a distributed manner on multiple similar platforms to distribute the processing load. Alternatively, the server can be implemented by the appropriate programming of a computer hardware platform.

[0068] The systems, devices, equipment and methods disclosed herein are described in detail by way of example and with reference to the accompanying drawings. The embodiments discussed herein are merely examples and are provided to help explain the devices, devices, systems and methods described herein. Unless specifically designated as mandatory, the features or components shown in the drawings or discussed below should not be considered mandatory for any specific implementation of any device, device, system or method. In the present disclosure, any identification of a specific technology, arrangement, etc. relates to a specific instance presented or is merely a general description of such technology, arrangement, etc. The identification of specific details or examples is not intended to be, and should not be interpreted as, mandatory or restrictive, unless specifically indicated. Any combination or sub-combination that fails to specifically describe a component should not be understood as an indication that any combination or sub-combination is impossible. It should be understood that the disclosed and described examples, arrangements, configurations, components, elements, devices, equipment, systems, methods, etc. may be modified and may be desirable for specific applications. Furthermore, for any method described, whether or not the method is described in conjunction with a flowchart, it should be understood that, unless otherwise specified or required by the context, any explicit or implicit ordering of steps performed in the execution of the method does not imply that those steps must be performed in the order presented, but may instead be performed in a different order or in parallel.

[0069] Throughout this disclosure, references to components or modules generally refer to items that can be logically grouped together to perform a function or group of related functions. Components and modules can be implemented in software, hardware, or a combination of software and hardware. The term "software" is broadly used to include not only executable code, such as machine-executable or machine-interpretable instructions, but also data structures, data storage, and computing instructions stored in any suitable electronic format, including firmware, and embedded software. The terms "information" and "data" are widely used and include a wide variety of electronic information, including executable code; content such as text, video data, and audio data; and different codes or logos. When the context permits, the terms "information", "data", and "content" are sometimes used interchangeably.

[0070] The present invention further relates to the following embodiments:

[0071] First embodiment: A method for positioning a brachytherapy apparatus within a subject, the method comprising:

[0072] Inserting a brachytherapy apparatus into a subject, wherein the brachytherapy apparatus includes a marker, the marker comprising:

[0073] an inner ring composed of one or more of copper, brass, gold, silver or titanium;

[0074] an outer coating layer consisting of one or more of nickel or iron oxide, wherein the outer coating layer has a thickness of about 1 μm to about 30 μm; and

[0075] a central opening, wherein the central opening has a diameter of about 0.50 mm to about 3.00 mm; and

[0076] When inserted into the subject, a magnetic resonance image of the brachytherapy apparatus and the marker is generated, wherein the inner ring and outer coating of the marker are configured to create an artifact in the image.

[0077] The method according to the first embodiment further comprises adjusting a position of the brachytherapy apparatus within the patient based on the artifacts created in the image.

[0078] The method according to the first embodiment further comprises generating a computed tomography image of the brachytherapy apparatus.

[0079] The method according to the first embodiment further comprises:

[0080] inserting an afterload cable into a brachytherapy apparatus, wherein the afterload cable includes an electromagnetic sensor; and

[0081] The marker is detected using the electromagnetic sensor.

[0082] The method according to the aforementioned embodiment, wherein the rear load cable is a virtual cable.

[0083] The method according to the aforementioned embodiment, further comprising inserting the source cable into the brachytherapy apparatus and positioning the radiation source relative to the artifact.

[0084] The method according to the preceding embodiment, wherein the source cable comprises a second electromagnetic sensor.

[0085] The method according to the preceding embodiment, wherein the electromagnetic sensor is a coil.

[0086] Example 2: A kit:

[0087] Brachytherapy equipment; and

[0088] A marker, comprising:

[0089] an inner ring composed of one or more of copper, brass, gold, silver or titanium;

[0090] an outer coating layer consisting of one or more of nickel or iron oxide, wherein the outer coating layer has a thickness of about 1 μm to about 30 μm; and

[0091] A central opening, wherein the central opening has a diameter of about 0.50 mm to about 3.00 mm.

[0092] A marker according to a second embodiment, wherein the marker has a ring shape.

[0093] The subject matter disclosed above is to be considered illustrative rather than restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other implementations that fall within the true spirit and scope of the present disclosure. Therefore, to the maximum extent permitted by law, the scope of the present disclosure is determined by the broadest permissible interpretation of the appended claims and their equivalents, and should not be restricted or limited by the foregoing detailed description. Although different implementations of the present disclosure have been described, it will be apparent to those of ordinary skill in the art that more implementations and implementations may be within the scope of the present disclosure. Therefore, the present disclosure is not limited to the appended claims and their equivalents.

Claims

1. A brachytherapy marker for a medical device, the marker comprising: an inner ring having a closed annular shape and said inner ring being composed of one or more of copper, brass, gold, silver or titanium; an outer coating layer surrounding the inner ring and consisting of one or more of nickel or iron oxide, wherein the outer coating layer has a thickness of 1 μm to 30 μm; and a central opening defining an inner diameter of the marker, wherein the diameter of the central opening is 0.50 mm to 3.00 mm; Wherein the brachytherapy marker is electrically conductive and detectable by an electromagnetic sensor.

2. The brachytherapy marker according to claim 1, wherein: The inner ring and the outer coating of the marker are configured to create an artifact in a magnetic resonance image of a brachytherapy apparatus including the marker when the image is generated; and wherein the brachytherapy marker comprises a means for inserting a afterload cable within the brachytherapy apparatus, wherein the afterload cable comprises an electromagnetic sensor.

3. The brachytherapy marker according to claim 1, wherein: The inner ring is copper or brass.

4. The brachytherapy marker according to any one of the preceding claims, wherein: The outer diameter of the marker is 1.00 mm to 5.50 mm.

5. The brachytherapy marker according to any one of claims 1 to 3, wherein: The outer coating layer has a thickness of 4 μm to 20 μm.

6. The brachytherapy marker according to any one of claims 1 to 3, wherein: The diameter of the central opening is 0.75 mm to 2.25 mm.

7. The brachytherapy marker according to any one of claims 1 to 3, wherein: The marker is attached to a brachytherapy applicator.

8. The brachytherapy marker according to any one of claims 1 to 3, wherein: The marker is connected to the brachytherapy needle.

9. The brachytherapy marker according to any one of claims 1 to 3, wherein: The marker is connected to a brachytherapy catheter.

10. The brachytherapy marker according to any one of claims 1 to 3, wherein: The marker is attached to the distal region of the brachytherapy delivery tube.

11. The brachytherapy marker of claim 2, further comprising means for adjusting a position of the brachytherapy apparatus within a patient based on the artifact created in the image.

12. The brachytherapy marker of claim 2, wherein: The rear load cable is a virtual cable.

13. The brachytherapy marker of claim 12, further comprising means for inserting a source cable into the brachytherapy apparatus and positioning a radiation source relative to the artifact.

14. The brachytherapy marker of claim 13, wherein: The source cable includes a second electromagnetic sensor.

15. The brachytherapy marker of claim 2, wherein: The electromagnetic sensor is a coil.

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