Radiation delivery catheters and dosimetry methods

• US 6,491,619 B1
• Filed: 08/25/2000
• Issued: 12/10/2002
• Est. Priority Date: 01/31/1997
• Status: Expired due to Fees

• Current Assignee: Radiance Medical Systems, Inc.
• Original Assignee: Endologix
• Inventors: Trauthen, Brett, Smith, Edward F., Tam, Lisa, Fazio, Robert, Strathern, Gary, Crocker, Michael
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): VENIAMINOV, NIKITA R
• Application Number:
  US09/648,563
• Time in Patent Office: 837 Days
• Field of Search: 600/3, 604/103, 623/1.42, 623/1.21, 606/198, 606/1, 427/5
• US Class Current: 600/3
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61K 51/1279 Plasters, bandages, dressings, patches or adhesives
• CPC Class Codes: A61K 51/1282 Devices used in vivo and carrying the radioactive therapeutic or diagnostic agent, therapeutic or in vivo diagnostic kits, stents
• CPC Class Codes: A61K 9/1641 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poloxamers
• CPC Class Codes: A61M 2025/1075 having a balloon composed of several layers, e.g. by coating or embedding
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00
• CPC Class Codes: A61M 25/1002 characterised by balloon shape A61M25/1006, A61M25/1009 take precedence
• CPC Class Codes: A61N 2005/1004 having expandable radiation sources
• CPC Class Codes: A61N 2005/1005 with asymmetrical radiation pattern
• CPC Class Codes: A61N 5/1002 Intraluminal radiation therapy
• CPC Class Codes: G03C 5/02 Sensitometric processes, e.g. determining sensitivity, colour sensitivity, gradation, graininess, density; Making sensitometric wedges
• CPC Class Codes: G21G 4/06 characterised by constructional features
• CPC Class Codes: Y10S 977/949 Radiation emitter using nanostructure

Abstract

Disclosed are sources and methods for delivering a radioactive dose to a site in a body lumen. The sources are preferably mounted on a balloon or other expandable or deployable mechanical structure. The source and methods enable delivery of a clinically significant dose of radiation into a vessel wall in a relatively short time while using a relatively low activity. The sources also enable delivery of a substantially uniform dose into the vessel wall, whether or not such delivery is through the wall of a stent.

Claims

1. A method of optimizing an in stent radiation delivery profile, comprising the steps of:

identifying a stent positioned against the wall of a vessel;

positioning a radiation source within the stent; and

exposing the vessel to radiation through the stent such that variations in the dose delivered to a reference depth of at least about 1 mm in the wall of the vessel along the length of the source do not exceed about 20%.

2. A method of optimizing an in stent radiation delivery profile as in claim 1, wherein the variations in the dose delivered to the reference depth in the wall of the vessel along the length of the source do not exceed about 15%.

3. A method of optimizing an in stent radiation delivery profile as in claim 1, wherein the positioning a radiation a source step comprises positioning a source having an activity of no greater than about 60 mCi, and the average dose delivered to a depth of about 1 mm in the wall of the vessel is at least about 8 Gy.

4. A method of optimizing an in stent radiation delivery profile as in claim 3, wherein the exposing step is accomplished in no more than about 15 minutes.

5. A method of optimizing an in stent radiation delivery profile as in claim 4, wherein the exposing step is accomplished in no more than about ten minutes.

6. A method of optimizing an in stent radiation delivery profile as in claim 5, wherein the exposing step is accomplished in no more than about eight minutes.

7. A method of optimizing an in stent radiation delivery profile as in claim 1, wherein the positioning a radiation a source step comprises positioning a source having an activity of no greater than about 200 mCi, and the average dose delivered to a reference depth of about 2 mm in the wall of the vessel is at least about 6 Gy.

8. A method of optimizing an in stent radiation delivery profile as in claim 7, wherein the exposing step is accomplished in no more than about 40 minutes.

9. A method of optimizing an in stent radiation delivery profile as in claim 8, wherein the exposing step is accomplished in no more than about 30 minutes.

10. A method of optimizing an in stent radiation delivery profile as in claim 9, wherein the exposing step is accomplished in no more than about 20 minutes.

11. A method of optimizing radiation dose uniformity in a vessel wall behind a stent, comprising the steps of:

positioning a radiation delivery catheter within a stent in a body vessel;

delivering a first dose of beta radiation along a first axis past a first side of a stent strut and into the vessel wall; and

delivering a second dose of beta radiation along a second axis past a second side of the strut and into the vessel wall;

wherein the first axis and the second axis converge behind the strut.

12. A method as in claim 11, wherein the convergence point is at a depth of no more than about 3 mm.

13. A method as in claim 12, wherein the convergence point is at a depth of no more than about 2 mm.

14. A method as in claim 11, wherein a dose of at least about 8 Gy is delivered at a depth of about 1 mm.

15. A method as in claim 11, wherein the dose depth profile varies by less than 10% along the length of the source inside the 90% isodose crossing of the horizontal plane.

16. A method of optimizing an intraluminal radiation delivery profile, comprising the steps of:

identifying a treatment site in the wall of a vessel;

positioning a radiation source against the wall; and

exposing the vessel to radiation such that variations in the dose delivered to a reference depth of at least about 1 mm in the wall of the vessel along the length of the source do not exceed about 20%.

17. A method of optimizing an intraluminal radiation delivery profile as in claim 16, wherein the variations in the dose delivered to a reference depth of at least about 1 mm in the wall of the vessel along the length of the source do not exceed about 15%.

18. A method of optimizing an intraluminal radiation delivery profile as in claim 16, wherein the positioning a radiation a source step comprises positioning a source having an activity of no greater than about 60 mCi, and the average dose delivered to a depth of about 1 mm in the wall of the vessel is at least about 8 Gy.

19. A method of optimizing an intraluminal radiation delivery profile as in claim 18, wherein the exposing step is accomplished in no more than about 15 minutes.

20. A method of optimizing an intraluminal radiation delivery profile as in claim 18, wherein the exposing step is accomplished in no more than about ten minutes.

21. A method of optimizing an intraluminal radiation delivery profile as in claim 18, wherein the exposing step is accomplished in no more than about eight minutes.

22. A method of optimizing an intraluminal radiation delivery profile as in claim 16, wherein the positioning a radiation a source step comprises positioning a source having an activity of no greater than about 200 mCi, and the average dose delivered to a depth of about 2 mm in the wall of the vessel is at least about 6 Gy.

23. A method of optimizing an intraluminal radiation delivery profile as in claim 22, wherein the exposing step is accomplished in no more than about 40 minutes.

24. A method of optimizing an intraluminal radiation delivery profile as in claim 22, wherein the exposing step is accomplished in no more than about 30 minutes.

25. A method of optimizing an intraluminal radiation delivery profile as in claim 22, wherein the exposing step is accomplished in no more than about 20 minutes.

26. A method of treating a site in a vessel, comprising delivering radiation from a source having an activity of no more than about 200 mCi at a dose of at least about 8 Gy, at a depth of 1 mm into the vessel wall, over a time of no more than about 15 minutes.

27. A method of treating a vessel as in claim 26, wherein the time is no more than about 10 minutes.

28. A method of treating a vessel as in claim 26, wherein the time is no more than about 8 minutes.

29. A method of treating a vessel as in claim 26, wherein variations in the delivered dose at a depth of 1 mm do not exceed about 20%.

30. A method of treating a vessel as in claim 29, wherein variations in the delivered dose at a depth of 1 mm do not exceed about 15%.

31. A method of treating a vessel as in claim 26, wherein the delivering step comprises delivering radiation from a source having an activity of no more than about 60 mCi.

32. A method of treating a vessel as in claim 26, wherein the delivering step comprises positioning a source against the vessel wall.

33. A method of treating a vessel as in claim 32, wherein the positioning step is accomplished by inflating a balloon.

34. A method of treating a vessel as in claim 33, further comprising the steps of deflating the balloon to permit perfusion and reinflating the balloon.

35. A method of treating a vessel as in claim 33, wherein the source is attached to the balloon.

36. A method of treating a vessel as in claim 26, wherein the site is in a coronary artery.

37. A method of treating a vessel as in claim 26, wherein the site is in a coronary artery bypass graft.

38. A method of treating a site in a vessel, comprising delivering radiation from a source having an activity of no more than about 60 mCi at a dose of at least about 8 Gy, at a depth of 1 mm into the vessel wall, over a time of no more than about 15 minutes.

39. A method of treating a vessel as in claim 38, wherein the time is no more than about 10 minutes.

40. A method of treating a vessel as in claim 38, wherein variations in the delivered dose at a depth of 1 mm do not exceed about 20%.

41. A method of treating a vessel as in claim 38, wherein variations in the delivered dose at a depth of 1 mm do not exceed about 15%.

42. A method of treating a vessel as in claim 38, wherein the delivering step comprises positioning a source against the vessel wall.

43. A method of treating a site in a vessel, comprising delivering radiation to a site in a coronary artery bypass graft at a dose of at least about 8 Gy, at a depth of 1 mm into the vessel wall, over a time of no more than about 15 minutes.

44. A method of treating a vessel as in claim 43, wherein the time is no more than about 10 minutes.

45. A method of treating a vessel as in claim 43, wherein variations in the delivered dose at a depth of 1 mm do not exceed about 20%.

46. A method of treating a vessel as in claim 43, wherein the delivering step comprises delivering radiation from a source having an activity of no more than about 200 mCi.

47. A method of treating a vessel as in claim 43, wherein the delivering step comprises positioning a source against the vessel wall.