Method and apparatus for intraocular brachytherapy

• US 20050277802A1
• Filed: 02/11/2005
• Published: 12/15/2005
• Est. Priority Date: 02/12/2004
• Status: Active Grant

• Current Assignee: Oraya Therapeutics, Inc.
• Original Assignee: Neovista, Inc.
• Inventors: Larsen, Charles E., Humayun, Mark, Trip, Roelof, Hillstead, Richard A., Fritz, Eberhard, Pintaske, Rainer, de Juan, Eugene
• Granted Patent: US 7,744,520 B2
• Time in Patent Office: Days
• US Class Current: 600/1
• CPC Class Codes: A61N 5/1017 Treatment of the eye, e.g. for "macular degeneration"

Abstract

A method for performing intraocular brachytherapy and an apparatus for performing the same is disclosed. The apparatus preferably comprises a hand-held delivery device that advances a radiation source into an associated cannula or probe that is positioned adjacent the target tissue. The handpiece provides for shielded storage of the radiation source when retracted from the cannula and includes a slider mechanism for advancing and retracting the radiation source. The radiation source is mounted to a wire that has a flexible distal end and a relatively stiffer proximal end. A positioning system for the cannula is also disclosed.

Claims

1. A method for delivering radiation to a target tissue in an eye from the interior of the eye with a radiation delivery device having an elongated probe associated therewith, the probe having a distal end through which radiation can be selectively administered to the target tissue, the method comprising:

creating an access to the interior of the eye through a surface of the eye;

introducing the probe into the interior of the eye through the access;

positioning the distal end of the probe a predetermined distance from the target tissue;

protecting non-target tissue from radiation emitted from the distal end of the probe;

delivering a dose of radiation to the target tissue, including attenuating the peak radiation dose delivered by the probe to the target tissue closest to the distal tip of the probe.

2. The method of claim 1 wherein the non-target tissue is protected by shielding structure associated with the distal tip of the probe.

3. The method of claim 1 wherein the non-target tissue is protected by introducing a radiation attenuating fluid into the interior of the eye.

4. The method of claim 1 wherein the non-target tissue is protected by deploying a mask of a radiation-blocking material over the non-target tissue.

5. The method of claim 1 wherein the target tissue comprises choroidal neo vascularization (CNV) associated with macular degeneration, and the radiation dose is delivered to the target tissue epi-retinally.

6. The method of claim 1 wherein the target tissue comprises choroidal neo vascularization (CNV) associated with macular degeneration, and the radiation dose is delivered to the target tissue sub-retinally.

7. The method of claim 6 further comprising:

detaching a portion of the retina from the target tissue to form a bleb;

maintaining the bleb by injecting a high viscosity fluid into the sub-retinal space; and

after exposing the sub-retinal region to radiation, removing the high viscosity fluid from the bleb.

8. The method of claim 6 further comprising:

detaching a portion of the retina from the target tissue to form a bleb by means of retinotomy;

introducing saline into the bleb; and

maintaining the bleb by applying a sealing substance to one or both of the probe and the retinotomy.

9. The method of claim 6 further comprising:

detaching a portion of retina from the target tissue by forming a bleb; and

maintaining the bleb by periodically injecting an inflation agent.

10. The method of claim 9 in which the inflation agent comprises saline.

11. The method of claim 6 further comprising:

detaching a portion of the retina from the target tissue by means of a retinotomy to form a bleb; and

cauterizing the retinotomy.

12. The method of claim 6 further comprising:

detaching a portion of the retina from the target tissue to form a bleb;

injecting an anticoagulant into the bleb; and

after exposing the sub-retinal region to radiation, removing the anticoagulant from the bleb.

13. The method of claim 6 further comprising:

detaching a portion of the retina from the target tissue to form a bleb; and

after exposing the target tissue to radiation, introducing an antiproliferating agent into the bleb.

14. The method of claim 6 further:

providing the distal end of the probe with an inflatable balloon;

detaching the retina from the target tissue by forming a bleb to provide direct access to the target tissue;

introducing the distal end of the probe into the bleb;

inflating the balloon to space the distal end of the probe from the detached retina and the target tissue and to maintain the bleb.

15. The method of claim 6 further comprising:

providing the probe with a lumen having an opening at the distal end of the probe in which an elongated wire is slidingly received, the wire having a distal end that is moveable in and out of the distal end of the probe and having a structure on the distal end thereof that expands as the distal end of the wire is advanced out the distal end of the lumen;

detaching the retina from the target tissue by forming a bleb to provide direct access to the target tissue;

introducing the distal of the probe and lumen into the bleb;

advancing the distal end of the wire out of the lumen so that the structure at the distal end thereof expands to space the probe from the target tissue.

16. A method of treating target tissue below the retina of the eye, comprising:

separating a portion of the retina from target tissue therebelow;

injecting a radiation attenuating material between the retina and the target tissue;

introducing a radiation source between the retina and target tissue; and

exposing the target tissue to radiation from the radiation source.

17. The method of claim 46 including restricting flow of radiation attenuating material from between the retina and target tissue.

18. A method of treating target tissue below the retina of the eye, comprising:

injecting a radiation attenuating material into the interior of the eye;

positioning a radiation source in proximity to target tissue; and

exposing the target tissue to radiation from the radiation source.

19. The method of claim 18 wherein the radiation source is positioned epi-sclerally.

20. The method of claim 18 wherein the radiation source is positioned epi-retinally.