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KR-20260065960-A - ACTIVITY LEVELS FOR DIFFUSING ALPHA-EMITTER RADIATION THERAPY

KR20260065960AKR 20260065960 AKR20260065960 AKR 20260065960AKR-20260065960-A

Abstract

A method for treating a cancerous tumor by implanting at least one diffuse alpha-emission radiation therapy (DaRT) source (21) having a suitable radon emission rate for a given period into the cancerous tumor, such that the source (21) provides a cumulative activity of emitted radon of at least 10 megabecquerels (MBq) of time per centimeter length for a given period. Optionally, the source (21) is implanted into an array (160) of sources (21), and each source is separated from adjacent sources (21) in the array by no more than 4.5 millimeters.

Inventors

  • 켈슨 이츠하크
  • 두만치 미르타
  • 루즈 이샤이
  • 바타레스쿠 마얀 헤드바
  • 케이사리 요나
  • 가트 암논
  • 덴 로버트
  • 마겐 오페르
  • 도만케비치 베레드
  • 아라지 리오르
  • 쿡스 토머
  • 헤거 가이

Assignees

  • 알파 타우 메디컬 리미티드

Dates

Publication Date
20260511
Application Date
20220608
Priority Date
20210610

Claims (20)

  1. As a method of treating tumors, Steps to identify cancerous tumors; and A step of implanting at least one diffuse alpha-emission radiation therapy (DaRT) source having a suitable radon emission rate for a given period into a cancerous tumor such that the source provides a cumulative activity of emitted radon of 5.6 megabecquerels (MBq) to 8 MBq hours per centimeter length during a given period. A method including
  2. A method according to claim 1, wherein the step of implanting at least one radiation therapy source comprises implanting an array of sources, wherein each source is separated from an adjacent source in the array by no more than 4.5 millimeters.
  3. A method according to paragraph 2, wherein the step of implanting at least one radiation therapy source comprises implanting an array of sources, wherein each source is separated from an adjacent source in the array by no more than 4 millimeters.
  4. A method according to any one of claims 1 to 3, characterized in that at least one radiation therapy source has a radon emission rate of 1.2 to 2 microcuries per centimeter length.
  5. A method according to claim 4, characterized in that at least one radiation therapy source has a radon emission rate of 1.3 to 1.6 microcuries per centimeter length.
  6. The method of claim 1, characterized in that the method comprises the steps of selecting a given period before implanting at least one DaRT source into a tumor, and removing the source from the tumor after the given period has elapsed since the implantation of the source.
  7. As a method of preparing for radiation therapy, Steps to identify cancerous tumors; Step of receiving an image of a tumor; and A method comprising the step of providing a layout of a diffuse alpha-emission radiation therapy (DaRT) source for a cancerous tumor, wherein the source has a radon emission rate of 1.2 to 2 microcuries per centimeter length.
  8. A method according to claim 7, characterized in that the step of providing a layout includes providing a layout in which the spacing between sources within the tumor is 4 millimeters or less.
  9. A method according to claim 7, characterized in that the source has a radon emission rate of 1.3 to 1.6 microcuries per centimeter length.
  10. As a device for preparing radiation therapy, Input interface for receiving information about a tumor; A processor configured to generate a layout of diffuse alpha emission radiation therapy (DaRT) sources for a tumor, wherein the sources of the layout have a radon emission rate of 0.75 to 2 microcuries per centimeter length and the sources of the layout are arranged in a regular pattern having a distance between adjacent sources not exceeding 5 millimeters; and Output interface for displaying layout to a human operator A device including
  11. As a method of preparing for radiation therapy, A step of receiving a request for a source of diffuse alpha emission radiation therapy (DaRT) for a tumor; Step of determining the number of radiation therapy sources required for the tumor; and A step of providing a sterile kit containing a determined number of radiation therapy sources, wherein the sources have a radon emission rate of 1.2 to 1.7 microcuries per centimeter length. A method including
  12. A method according to claim 11, characterized in that the step of determining the number of radiation therapy sources required includes determining the number of sources required such that the tumor area is covered by the sources with a spacing between sources not greater than 4 millimeters.
  13. A method according to claim 11 or 12, characterized in that the source has a radon emission rate of 1.3 to 1.6 microcuries per centimeter length.
  14. As a source of diffuse alpha-emission radiation therapy (DaRT) for implantation into a tumor, the DaRT source has a radon emission rate of 1.2 to 1.7 microcuries per centimeter length.
  15. A DaRT source according to claim 14, characterized in that the radon emission rate is 1.3 to 1.6 microcuries per centimeter length.
  16. As a kit of a diffuse alpha emission radiation therapy (DaRT) source for implantation into a tumor, Package; and A plurality of DaRT sources disposed in a package, wherein the sources have a radon emission rate of 1.2 to 2 microcuries per centimeter length. A kit including
  17. A kit according to claim 16, characterized in that the radon emission rate of the source is 1.3 to 1.6 microcuries per centimeter length.
  18. As a method of treating tumors, Steps to identify cancerous tumors; and Step of implanting an array of diffuse alpha emission radiation therapy (DaRT) sources into the identified tumor in a regular arrangement with a spacing of 3 to 4.5 millimeters between each of two adjacent sources. A method including
  19. A method according to claim 18, wherein the step of transplanting an array of sources includes transplanting them into a hexagonal array, and each source is separated from an adjacent source in the array by no more than 4 millimeters.
  20. As a method of treating tumors, Steps to identify cancerous tumors; and A step of implanting at least one diffuse alpha-emission radiation therapy (DaRT) source having a suitable radon emission rate during a given period into a cancerous tumor such that the source provides a cumulative activity of emitted radon of at least 10 megabecquerels (MBq) of hours per centimeter length within a given period. A method including

Description

Activity Levels for Diffused Alpha-Emitter Radiation Therapy Technology field The present invention generally relates to an apparatus and method for providing tumor-specific radiation administration in radiation therapy, particularly in radiation therapy treatment. Background of the Invention Ionizing radiation is generally used to destroy tumor cells in the treatment of certain types of tumors, including malignant cancerous tumors. However, since ionizing radiation can also damage a patient's healthy cells, caution is required to minimize the radiation dose delivered to healthy tissues outside the tumor while maximizing the dose delivered to the tumor. Ionizing radiation destroys cells by causing damage to their DNA. The biological efficacy of different types of radiation in cell death is determined by the type and severity of the DNA lesions produced by the cells. Alpha particles are a powerful tool for radiation therapy because they induce clustered double-strand breaks on DNA that cells cannot repair. Unlike conventional types of radiation, the destructive effect of alpha particles is also not significantly affected by low oxygen levels in cells, making them equally effective against hypoxic cells—a leading cause of failure in conventional photon or electron-based radiation therapy—when present in tumors. Furthermore, short-range alpha particles (less than 100 micrometers) ensure that surrounding healthy tissue survives, provided the emitting atoms are confined to the tumor volume. On the other hand, the use of short-range alpha radiation in cancer treatment has been limited to date because there has been no practical way to distribute alpha-emitting atoms at sufficient concentrations across the entire tumor volume. For example, diffuse alpha-emission radiation therapy (DaRT) described in U.S. Patent No. 8,834,837 granted to Kelson extends the therapeutic range of alpha radiation by using radium-223 or radium-224 atoms that produce multiple radiation decay chains with dominant half-lives of 3.6 days for radium-224 and 11.4 days for radium-223. In DaRT, the radium atoms are attached to a source (also referred to as a "seed") implanted in the tumor with sufficient intensity so as not to escape the source in a manner that would be discarded (by being removed from the tumor via the blood), but a substantial percentage of its daughter radionuclides (radon-220 for radium-224 and radon-219 for radium-223) remain in the source within the tumor upon radium decay. These radionuclides, and their own radioactive daughter atoms, spread around the source by diffusing to a radius of several millimeters before decaying due to alpha emission. Therefore, the destructive range in the tumor is increased compared to the radionuclides remaining on the source along with their daughters. For tumor treatment to be effective, the DaRT seeds used in the treatment must emit a sufficient number of radon atoms to destroy the tumor with a high probability. If an insufficient amount of radiation is used, too many cancerous cells will remain in the tumor, and these cells may regenerate and reform into a malignant tumor. On the other hand, the seeds must not emit too many radon atoms, as some of their molecules are eliminated from the tumor through the bloodstream and can thus damage distal healthy tissues, including organs such as the patient's bone marrow, kidneys, and/or ovaries. The amount of radium atoms on the DaRT source is quantified in terms of activity, that is, the radium decay rate. DaRT source activity is measured in units of microcuries (μCi) or kilobecquerels (kBq), where 1 μCi = 37 kBq = 37,000 decays per second. When using DaRT, the radiation dose delivered to tumor cells depends not only on the radium activity of the source but also on the probability that daughter radon atoms leave the source for the tumor upon the alpha decay of radium. This probability is referred to herein as the "detachment probability." Therefore, instead of referring to the source activity, those skilled in the art may use the "radon emission rate," defined herein as the product of the activity on the source and the detachment probability of radon from the source, as a measure of the DaRT-related activity of the source. Like activity, the radon emission rate is provided in μCi or kBq. Unless otherwise indicated, the activity and radon emission rate values provided herein are those of the source at the time of implantation of the source into the tumor. U.S. Patent No. 8,834,837 granted to Kelson mentioned above suggests using an activity of “about 10 nanocuries to about 10 microcuries, more preferably about 10 nanocuries to about 1 microcury”. FIG. 1 is a schematic diagram of a system for planning radiation therapy treatment according to an embodiment of the present invention; FIG. 2 is a flowchart of operations performed to prepare for radiation therapy treatment of a tumor according to an embodiment of the present invention; FIG. 3 is a schemat