Controlled release of radionuclides

Patent metadata

Field	Value
Publication number	US-11969485-B2
Application number	US-201916979543-A
Country	US
Kind code	B2
Filing date	Mar 28, 2019
Priority date	Apr 2, 2018
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

A brachytherapy device including a base adapted for being at least partially introduced into a body of a subject and a plurality of radionuclide atoms of a first alpha-emitting isotope, coupled to the base in a manner that not more than 15% of the radionuclide atoms leave the base in 24 hours, in methods other than radioactive decay. When installed in a human subject, the brachytherapy device emits radionuclide atoms of the first alpha-emitting isotope at a rate of at least 0.1% of the number of radionuclide atoms of the first alpha-emitting isotope coupled to the base, per 24 hours.

First claim

The invention claimed is:

1. A brachytherapy device, comprising:
a seed base adapted for being at least partially introduced into a body of a subject; and
a plurality of radionuclide atoms of a first alpha-emitting isotope, coupled to the seed base, such that at least 0.1%, but not more than 25% of the plurality of radionuclide atoms coupled to the seed base leave the seed base in 24 hours, without radioactive decay,
wherein daughter nuclei of the plurality of radionuclide atoms are released from the seed base upon radioactive decay.

2. The brachytherapy device of claim 1 , wherein the first alpha-emitting isotope comprises Radium-224.

3. The brachytherapy device of claim 1 , wherein the first alpha-emitting isotope comprises Radium-223.

4. The brachytherapy device of claim 1 , further comprising a semi-porous polymer coating layer on the plurality of radionuclide atoms, configured to allow diffusion of a percentage of the plurality of radionuclide atoms, so that at least 0.1% of the plurality of radionuclide atoms of the first alpha-emitting isotope coupled to the seed base leave the seed base, per 24 hours.

5. The brachytherapy device of claim 4 , wherein the semi-porous polymer coating layer comprises PDMS (polydimethylsiloxane).

6. The brachytherapy device of claim 4 , wherein the semi-porous polymer coating layer has a thickness of no more than 0.5 microns.

7. The brachytherapy device of claim 4 , wherein the semi-porous polymer coating layer allows diffusion of the plurality of radionuclide atoms out of the brachytherapy device at a rate of at least 0.5% in 24 hours.

8. The brachytherapy device of claim 4 , further comprising a base polymer coating layer on the seed base, and wherein the plurality of radionuclide atoms are attached to the base polymer coating layer and thus coupled to the seed base in a manner allowing at least some of the plurality of radionuclide atoms to detach and diffuse, without nuclear decay.

9. The brachytherapy device of claim 8 , wherein the base polymer coating layer is configured to prevent diffusion of the plurality of radionuclide atoms therethrough.

10. The brachytherapy device of claim 8 , wherein the base polymer coating layer comprises polycarbonate.

11. The brachytherapy device of claim 8 , wherein the base polymer coating layer has a thickness of at least 0.25 microns.

12. The brachytherapy device of claim 1 , wherein the plurality of radionuclide atoms of the first alpha-emitting isotope are coupled to the seed base such that at least 3% of the plurality of radionuclide atoms of the first alpha-emitting isotope leave the seed base, per 24 hours.

13. The brachytherapy device of claim 1 , wherein the plurality of radionuclide atoms of the first alpha-emitting isotope are coupled to the seed base such that not more than 15% of the plurality of radionuclide atoms leave the seed base in 24 hours.

14. The brachytherapy device of claim 1 , wherein the plurality of radionuclide atoms of the first alpha-emitting isotope are coupled to the seed base such that not more than 8% of the plurality of radionuclide atoms leave the seed base in 24 hours.

15. The brachytherapy device of claim 1 , further comprising a bio-absorbable polymer coating layer on the seed base, wherein the plurality of radionuclide atoms are embedded in the bio-absorbable polymer coating layer, and wherein when installed in the subject, the bio-absorbable polymer coating layer dissolves causing at least 0.1% of the plurality of radionuclide atoms of the first alpha-emitting isotope coupled to the seed base, to leave the seed base per 24 hours.

16. The brachytherapy device of claim 15 , wherein the plurality of radionuclide atoms are distributed evenly in a thickness of the bio-absorbable polymer coating layer.

17. The brachytherapy device of claim 1 , further comprising a plurality of radionuclide atoms of a second alpha-emitting isotope, which decays into the first alpha-emitting isotope, which are coupled to the seed base such that the plurality of radionuclide atoms of the second alpha-emitting isotope do not leave the brachytherapy device, but upon nuclear decay, a daughter radionuclide atom leaves the device.

18. The brachytherapy device of claim 17 , wherein the plurality of radionuclide atoms of the second alpha-emitting isotope have an activity level of less than 20% of an activity level of the plurality of radionuclide atoms of the first alpha-emitting isotope included in the device.

19. The brachytherapy device of claim 18 , wherein the plurality of radionuclide atoms of the second alpha-emitting isotope have an activity level of less than 10% of the activity level of the plurality of radionuclide atoms of the first alpha-emitting isotope included in the device.

20. The brachytherapy device of claim 18 , wherein the plurality of radionuclide atoms of the second alpha-emitting isotope have an activity level of less than 5% of the activity level of the plurality of radionuclide atoms of the first alpha-emitting isotope included in the device.

21. The brachytherapy device of claim 17 , wherein the plurality of radionuclide atoms of the second alpha-emitting isotope have an activity level greater than 1% of the activity level of the plurality of radionuclide atoms of the first alpha-emitting isotope included in the device.

22. The brachytherapy device of claim 1 , wherein the plurality of radionuclide atoms of the first alpha-emitting isotope provide at least 50% of an activity of the brachytherapy device.

23. The brachytherapy device of claim 1 , wherein the plurality of radionuclide atoms of the first alpha-emitting isotope have a density of at least 5*10 10 atoms per square centimeter of the seed base.

24. A brachytherapy device, comprising:
a seed base adapted for being at least partially introduced into a body of a subject;
a first coating layer on the seed base, configured to prevent passage of Radium-224 or Radium-223 therethrough;
particles of a Radium-224 or Radium-223 radionuclide placed on the first coating layer; and
a second coating layer on the particles of the Radium-224 or Radium-223 radionuclide, configured to allow diffusion of at least 0.1% of the particles of the Radium-224 or Radium-223 radionuclide.

25. The brachytherapy device of claim 24 , wherein the seed base comprises a tube defining an internal channel.

26. The brachytherapy device of claim 24 , wherein the first coating layer comprises polycarbonate.

27. The brachytherapy device of claim 24 , wherein the first coating layer has a thickness of at least 0.05 microns.

28. The brachytherapy device of claim 24 , wherein the first coating layer has a thickness of at least 0.1 microns.

29. The brachytherapy device of claim 24 , wherein the first coating layer has a thickness of at least 0.3 microns.

30. The brachytherapy device of claim 24 , wherein the first coating layer has a thickness of no more than 1 micron.

31. The brachytherapy device of claim 24 , wherein the first coating layer has a thickness of no more than 0.5 microns.

32. The brachytherapy device of claim 24 , wherein the second coating layer comprises PDMS (polydimethylsiloxane).

33. The brachytherapy device of claim 24 , wherein the second coating layer has a thickness of no more than 0.5 microns.

Assignees

• Alpha Tau Medical Ltd

Inventors

• Kelson Itzhak
• Keisari Yona
• Schmidt Michael
• Gat Amnon
• Magen Ofer
• Keret Guy
• Sosnovitch Amitai
• Berkowitz Avia

Classifications

• A61K51/1282 Primary

  Devices used in vivo and carrying the radioactive therapeutic or diagnostic agent, therapeutic or in vivo diagnostic kits, stents · CPC title

• A61N5/1001 Primary

  using radiation sources introduced into or applied onto the body; brachytherapy · CPC title

• A61K9/0004

  Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas · CPC title

• A61K9/0009

  involving or responsive to electricity, magnetism or acoustic waves; Galenical aspects of sonophoresis, iontophoresis, electroporation or electroosmosis · CPC title

• A61K9/0024

  Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue (compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L) · CPC title