Slit needle for radiotherapy
By adding a partially open section to the proximal end of the hollow needle, the problem of difficult insertion of the radioactive source applicator in the prior art is solved, and more efficient delivery of the radioactive source is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2026-03-10
AI Technical Summary
The insertion process of existing radiation source applicators is difficult and time-consuming, especially due to the small diameter and tight tolerance of the hollow needle and applicator tube, which makes insertion difficult.
A partially open section is added to the proximal end of the hollow needle to provide a larger opening for easy insertion of the applicator tube, and the partially open section acts as a guide to reduce insertion difficulty and time.
By increasing the proximal end opening of the hollow needle, the insertion process of the applicator tube is simplified, the operation difficulty and time are reduced, and the efficiency of radioactive source delivery is improved.
Smart Images
Figure CN121646489A_ABST
Abstract
Description
Cross-references to related applications
[0001] This application claims the benefit of U.S. Provisional Patent Application 63 / 520,654, filed August 21, 2023, which is incorporated herein by reference. Invention Field
[0002] This invention relates generally to radiotherapy, and more specifically to the delivery of a radiation source to a patient. Background of the Invention
[0003] Placing a sealed radiation source (also known as a seed source) inside or near a tumor is an effective treatment for many types of tumors, such as prostate or breast tumors. When the source is correctly positioned within the patient's body, radiation from the source affects only the localized area around the source, thus reducing exposure to healthy tissues far from the source.
[0004] The source is very small (approximately 1 mm in diameter) and is typically positioned using a specialized applicator, which contains the source. However, the applicator itself is small because it must be inserted into the patient and is therefore very precise. This precision means that working with the applicator is often difficult and time-consuming. Invention Overview
[0005] Embodiments of the present invention provide a needle for delivering a radioactive source, comprising: An elongated needle having a distal end and a proximal end, and having a circumferential tube defining an inner lumen; A sharp tip, defined at the distal end of the needle; and A partially open section, which extends along a portion of the length of the elongated needle, adjacent to the proximal end of the needle.
[0006] In the disclosed embodiments, the partially open section includes a semi-cylinder.
[0007] In a further disclosed embodiment, the cross-section of the partially open section includes the shape of a step. The step may have a runner parallel to the axis of symmetry of the circumferential tube and at least one riser orthogonal to the axis of symmetry. The runner may coincide with the axis of symmetry. The at least one riser may consist of a first riser and a second riser of equal length.
[0008] In another, further disclosed embodiment, the partially open section faces an angle of at least 90° at the axis of symmetry of the circumferential tube. Alternatively or additionally, the partially open section faces an angle of at least 120° at the axis of symmetry of the circumferential tube. Further alternatively or additionally, the partially open section faces an angle of less than 270° at the axis of symmetry of the circumferential tube. In some embodiments, the partially open section faces an angle between 160° and 200° at the axis of symmetry of the circumferential tube.
[0009] In an alternative embodiment, the partially open section has a length of at least 3 mm. Alternatively or additionally, the partially open section has a length of no more than 10 mm.
[0010] The length of the partially open section can be at least 1% of the needle length. Alternatively or additionally, the length of the partially open section can be less than 5% of the needle length.
[0011] According to an alternative embodiment of the invention, a method for delivering one or more radioactive sources to a tumor is also provided, comprising: An elongated needle is provided having a distal end and a proximal end, and a circumferential tube defining an inner lumen and having a partially open section adjacent to the proximal end along a portion of the length of the elongated needle; Insert the distal end of the long needle near the tumor; Place the applicator, which carries one or more radiation sources, on the partially open section of the needle; and The applicator is pushed distally into the needle through a partially open section, so that one or more radiation sources are positioned relative to the tumor at a predetermined location.
[0012] This disclosure will be more fully understood from the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, in which: Brief description of the attached diagram Figure 1A and Figure 1B A hollow needle according to an embodiment of the present invention is shown; Figure 2 A to Figure 2 G schematically illustrates different aspects of a hollow needle according to an embodiment of the present invention; Figure 3A and Figure 3B This is a schematic diagram showing a partially open section of a needle according to an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating an applicator according to an embodiment of the present invention; and Figure 5 This is a flowchart of the steps of a source placement procedure for tumor surgery using a needle, according to an embodiment of the present invention. Detailed Implementation
[0013] Overview Brachytherapy is an effective procedure for treating tumors and involves inserting one or more radiation sources (also referred to herein as seed sources) into the tumor. The sources can be formed into an applicator comprising a hollow, flexible tube having an inner lumen for holding the sources. Prior to the procedure, a predetermined number of sources are positioned within the lumen of the tube and spatially separated.
[0014] To properly position the applicator into the patient's tumor, a hollow needle can first be introduced into the tumor. The hollow needle is constructed with a lumen that houses the applicator, and the applicator can then be introduced into the tumor by passing it through the lumen of the needle.
[0015] However, the diameters of the applicator tube and the hollow needle are very small, typically around 1 mm. Furthermore, the tolerance between the inner diameter of the hollow needle cavity and the outer diameter of the applicator tube is also very small, making it difficult and time-consuming to insert the applicator tube into the cavity of the hollow needle.
[0016] Embodiments of the present invention overcome the aforementioned difficulties by increasing the size of the opening at the proximal end of the hollow needle. This increase is achieved by removing a portion of the proximal end, such that the indwelling needle includes a partially open proximal section. When the applicator tube is inserted into the proximal end, the partially open proximal section acts as a guide for the applicator tube and provides a larger opening than the unmodified opening of the hollow needle. Both of these features reduce the time required to insert the applicator tube and lower the associated difficulty.
[0017] Detailed description In the following description, the same elements in the figures are identified by the same numbers. Furthermore, all directional references (e.g., up, down, upward, downward, left, right, top, bottom, above, below, vertical, and horizontal) are used for identification purposes only to aid the reader in understanding the invention and do not impose limitations, particularly not limitations on the positioning, orientation, or use of embodiments of the invention.
[0018] Now for reference Figure 1A and Figure 1B The accompanying drawing illustrates a hollow needle 20 according to an embodiment of the invention. The hollow needle 20, also referred to herein as a slit needle 20, is attached to a detachable handle 24 for holding the needle. Figure 1A The outer surfaces of the hollow needle 20 and the handle 24 are shown, and Figure 1B It is the cross-section of the handle and the needle.
[0019] Although the hollow needle 20 may be curved or straight, in the following description, unless otherwise stated, it is assumed that the needle is straight, and those skilled in the art will be able to make the necessary modifications to the description for non-straight needles.
[0020] The hollow needle 20 is tubular, having a circumferential tube 26 defining a central cavity 28. The needle 20 is biocompatible and, in one embodiment, is formed of stainless steel. While the needle 20 is typically formed from a single tubular element, it comprises three regions: a proximal end 32, a central region 36, and a distal end 40. As an example, the single tubular element forming the needle 20 is assumed herein to be cylindrical, such that both the central region 36 and the cavity 28 have a cylindrical shape. Both the proximal end 32 and the distal end 40 include modifications to the cylindrical shape, and are referenced below. Figure 2 A to Figure 2 G is described further.
[0021] For simplicity and clarity, the hollow needle 20 and handle 24 are drawn on a set of Cartesian axes, where the z-axis is parallel to the axis of symmetry 44 of the cavity 28, the y-axis lies in the plane of the paper, and the yz plane is the plane of symmetry of the needle. This plane of symmetry is described below.
[0022] The needle 20 serves as a guide for an applicator (described in more detail below) used to place one or more radioactive seed sources (also referred to herein as sources) into a patient undergoing surgery to remove a tumor from their body. The surgeon using the needle may attach a handle 24 to the proximal end 32 of the needle, manipulate the needle as needed, and then detach the handle from the proximal end.
[0023] When manipulating the needle 20, the surgeon typically uses the handle to insert the sharp distal end 48 of the distal tip 40 into the patient and guides the distal tip to the desired location, usually near or within the tumor being operated on. Once the distal tip is in its desired position, the surgeon can remove the handle, leaving the needle 20 temporarily in place.
[0024] Figure 2 A to Figure 2 G schematically illustrates different aspects of the needle 20 according to an embodiment of the invention. Figure 2 A shows the complete needle, and Figure 2 B and Figure 2 C is a different two-dimensional (2D) view of the proximal end 32 and the partially open section 52 included in that end. Figure 2 E and Figure 2 F is a different 2D view of the distal end 40. Figure 2 B Figure 2 C Figure 2 E and Figure 2 F is a cross-sectional view drawn on the Cartesian axis. Figure 2 D is a three-dimensional (3D) perspective view of the proximal end 32 and the partially open section 52. Figure 2 G is a 3D perspective view of the distal end 40.
[0025] As from the Figure 2 B Figure 2 C and Figure 2 D's observation clearly shows that the partially open segment 52 produces a symmetrical mirror plane 66 containing axis 44, and the yz axes of the Cartesian coordinates are plotted in this mirror plane. Figure 2 Mirror plane 66 is shown in C.
[0026] like Figure 2 As shown in D, the proximal end 32 includes a partially open section 52. Figure 2 B is a cross-section taken in the yz plane at the proximal end 32, and Figure 2 C is a cross-section taken in the xy plane near the end of the needle, showing a view of the needle looking inwards along axis 44. (As shown) Figure 2 As shown in Figure B, the partially open section 52 has a cross-section in the form of a step 56. Step 56 has a "tread" 60 parallel to the z-axis and therefore parallel to the axis of symmetry 44, and "kicks" 64 and 68 orthogonal to the axis of symmetry. The positions of the tread 60 and the kicks 64 and 68 are also... Figure 2 As shown in C.
[0027] In some embodiments, the partially open section 52 can be formed by laser-cutting a cylindrical hollow needle; however, in other embodiments, section 52 can be formed by any other convenient manufacturing method. Figure 2 As shown in D, the partially open section 52 is formed as a partially cylindrical section that connects to the remaining fully cylindrical portion of the needle 20, and it should be understood that the tread and kick surfaces of the step 56 refer to the appearance of the cross-section of the partially open section 52.
[0028] like Figure 2 As shown in D, a partially open section 52 is formed in the hollow needle 20, such that the tread surface 60 corresponds to two straight surfaces 60S1 and 60S2, and the kick surfaces 64 and 68 correspond to semi-circular surfaces 64S and 68S, respectively.
[0029] like Figure 2 C and Figure 2 As shown in D, the partially open section 52 is a semi-cylinder, that is, a semi-cylinder formed by longitudinally cutting a cylinder along its axis of symmetry. Because it is a semi-cylinder, the angle between surfaces 60S1 and 60S2 at the axis of symmetry is 180°.
[0030] As described above, the partially open section 52 is a semi-cylinder. However, it should be understood that this is only one example of a partially open section.
[0031] Figure 3A , Figure 3BThis is a schematic diagram illustrating an alternative partially open section 152 according to an embodiment of the invention. Apart from the differences described below, the operation and structure of the partially open section 152 are generally similar to that of the partially open section 52 ( Figures 1A to 2 The operation and structure of G) and the elements indicated by the same reference numerals in both partially open sections 52 and 152 are generally similar in construction and operation.
[0032] As mentioned above, Figure 3A and Figure 3B Draw on the Cartesian axis. Figure 3A It is a cross-section of the proximal end 32 taken in the yz plane. Figure 3B It is a cross-section taken in the xy plane near the end, and presents a view of the needle 20 as seen inward along axis 44.
[0033] like Figure 3B As shown, compared to the partially open section 52 of a semi-cylinder facing 180° at the axis of symmetry 44, the partially open section 152 faces an angle θ different from 180° at the axis of symmetry. In the disclosed embodiment,
[0034] According to expression (1), the disclosed embodiments may have an angle θ of at least 90°, 120°, 150° or even 170°, as well as other values given by expression (1).
[0035] In a further disclosed embodiment, the angle θ of the partially open section 152 is given by expression (2):
[0036] According to expression (2), further disclosed embodiments may have an angle θ less than 270°, 240°, 210° or even 190°, as well as other values given by expression (2).
[0037] In some embodiments, the partially open segments 52 and 152 typically have lengths given by expression (3):
[0038] Where L is the length of the partially open section, measured in millimeters.
[0039] However, some embodiments may have a length different from that of the partially open section given by expression (3).
[0040] According to expression (3), the length of the partially open section can be at least 1 mm, at least 2 mm, at least 3 mm, or even at least 4 mm. Alternatively, also according to expression (3), the length of the partially open section can be no greater than 10 mm, no greater than 7 mm, or even no greater than 5 mm.
[0041] The needle 20 typically has a length between 2 cm and 30 cm, although in some embodiments, the needle length may be outside this range. In the disclosed embodiments, the needle length is at least 2 cm, at least 3 cm, at least 5 cm, or even at least 10 cm. Optionally, the needle is not longer than 30 cm, not longer than 20 cm, not longer than 15 cm, or even not longer than 12 cm. In the above procedure, the surgeon typically selects the needle length based on the location of the tumor within the patient's body.
[0042] In the disclosed embodiments, the length of the partially open section 52 or 152 is at least 1% of the needle length. In alternative embodiments, the length of the partially open section 52 or 152 is less than 5% of the needle length.
[0043] The needle 20 typically has an outer diameter between 0.5 mm and 1.7 mm, although some embodiments may have a diameter outside this range. In the disclosed embodiments, the outer diameter is at least 0.5 mm, at least 0.6 mm, at least 0.8 mm, or even at least 1 mm. In alternative embodiments, the outer diameter is no greater than 1.7 mm, no greater than 1.5 mm, or even no greater than 1.2 mm. The inner diameter of the needle 20 may optionally be between approximately 0.5 mm and approximately 1.5 mm, depending on the outer diameter.
[0044] The size of the needle 20 is typically selected based on the procedure to be performed, the location of the tumor, and the applicator to be used during the procedure. The applicator includes a system that delivers one or more radiation sources to the patient, and the applicator is known in the art. Examples of applicators are described below.
[0045] Figure 4 This is a schematic diagram illustrating an applicator 200 according to an embodiment of the invention. The applicator 200 includes a narrow, flexible tube 204 having an inner cavity 208, a proximal end 210, and a distal end 214. Prior to the procedure of using the applicator 200, one or more radiation sources 212 (also referred to herein as seed sources 212) are positioned within the cavity 208. Figure 4 A cross-section 216 of the applicator 200 is shown, illustrating a single seed source 212. Each seed source 212 includes a cylindrical tube with an inner cavity through which the seed source retaining wire 220 passes.
[0046] Therefore, when assembled, the applicator 200 includes a tube 204, one or more seed sources 212, and a seed source holding wire 220. Typically, the proximal end 224 and the distal end 228 of the wire 220 are arranged within the cavity 208 such that the proximal and distal ends of the wire do not protrude beyond the proximal end 210 and the distal end 214 of the applicator tube.
[0047] Figure 5 This is a flowchart 300 of the steps of a source placement procedure for tumor surgery using a needle 20 according to an embodiment of the present invention. In the following description, it is assumed that the needle 20 has a partially open section 52, and those skilled in the art will be able to make necessary modifications based on the description using the partially open section 152.
[0048] In the initial step 304, it is basically as described above. Figure 4 The applicator 200 is assembled with the source 212, wherein the number of sources used in the applicator depends on the procedure to be applied. The handle 24 is used... Figure 1A The surgeon performing the procedure inserts the needle 20 into the patient until the distal end 48 is in the desired position relative to the tumor. Once inserted, the surgeon can remove the handle 24, leaving the needle 20 in place.
[0049] In step 308, the surgeon inserts the distal end 214 of the applicator into the lumen of the needle 20 via the partially open section 52 of the needle. The increased size of the opening provided by the partially open section and the guiding properties of the open section make insertion of the distal end of the applicator easier.
[0050] The surgeon continued inserting the applicator until the applicator and the source within it were correctly positioned relative to the tumor.
[0051] In release step 312, once the applicator has been correctly positioned, the surgeon releases the source from the applicator, typically placing the source within or near the tumor. Release is usually performed by pushing a stylet (not shown) into the proximal end of the applicator's cavity 208. The pushed stylet contacts the proximal end 224 of the seed source holding filament 220, such that further pushing of the stylet releases the filament and source 212 from the distal end 214 of the applicator.
[0052] In the final step 316, once the source 212 has been released from the applicator, both the applicator and the needle 20 are removed from the patient.
[0053] It should be understood that the embodiments described above are illustrated by way of example, and the invention is not limited to those specifically shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereto that would occur to those skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
Claims
1. A needle for delivering a radioactive source, comprising: an elongated needle having a distal end and a proximal end and having a circumferential tube defining an internal lumen; a sharp tip defined at the distal end of the needle; and a partially open section along a portion of the length of the elongated needle adjacent to the proximal end of the needle. The partially open section comprises a half-cylinder.
2. The needle of claim 1, wherein, The partially open section comprises a cross-section comprising the shape of a step.
3. The needle of claim 1, wherein, The step comprises a tread portion parallel to an axis of symmetry of the circumferential tube and at least one kick portion orthogonal to the axis of symmetry.
4. The needle of claim 3, wherein, The tread portion coincides with the axis of symmetry.
5. The needle of claim 4, wherein, The at least one kick portion comprises a first kick portion and a second kick portion having equal lengths.
6. The needle of claim 4, wherein, The partially open section subtends an angle of at least 90° at the axis of symmetry of the circumferential tube.
7. The needle of claim 1, wherein, The partially open section subtends an angle of at least 120° at the axis of symmetry of the circumferential tube.
8. The needle of claim 1, wherein, The partially open section subtends an angle of less than 270° at the axis of symmetry of the circumferential tube.
9. The needle of claim 1, wherein, The partially open section subtends an angle of between 160° and 200° at the axis of symmetry of the circumferential tube.
10. The needle of claim 1, wherein, The partially open section has a length of at least 3 millimeters.
11. The needle of claim 1, wherein, The partially open section has a length of no more than 10 millimeters.
12. The needle of claim 1, wherein, The length of the partially open section is at least 1% of the length of the needle.
13. The needle of claim 1, wherein, The length of the partially open section is less than 5% of the length of the needle.
14. The needle of claim 1, wherein, 15. A method of delivering one or more radioactive sources to a tumor, comprising: providing an elongated needle having a distal end and a proximal end and a circumferential tube defining an internal lumen and having a partially open section along a portion of the length of the elongated needle adjacent to the proximal end; inserting the distal end of the elongated needle into proximity of a tumor; placing an applicator carrying the one or more radioactive sources thereon on the partially open section of the needle; and pushing the applicator distally into the needle via the partially open section so that the one or more radioactive sources are in a predetermined position relative to the tumor.