Systems and methods for visualizing fluid enhanced ablation therapy

• US 9,610,396 B2
• Filed: 03/15/2013
• Issued: 04/04/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic), Thermedical, Inc.
• Original Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic), Thermedical, Inc.
• Inventors: Curley, Michael G., Eberl, Gregory R., Packer, Douglas L., Madhavan, Malini
• Primary Examiner(s): CHAO, ELMER M
• Application Number:
  US13/842,561
• Publication Number:
  US 20140275977A1
• Time in Patent Office: 1,481 Days
• Field of Search: 606 41, 606 14, 606 15, 607 99, 607105, 607113
• CPC Class Codes: A61B 18/04 by heating by applying electromagnetic radiation A61B18/18; hyperthermia using electric or magnetic fields, radiation or ultrasound A61N
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/046 in liquid form
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/487 involving fluoroscopy
• CPC Class Codes: A61B 6/501 for diagnosis of the head, e.g. neuroimaging or craniography
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/507 for determination of haemodynamic parameters, e.g. perfusion CT
• CPC Class Codes: A61B 8/481 involving the use of contrast agent, e.g. microbubbles introduced into the bloodstream analysis of echo signal exploiting properties of a contrast enhancer in devices for short-range imaging with acoustic waves G01S7/52039
• CPC Class Codes: A61M 5/007 for contrast media
• CPC Class Codes: G01R 33/4808 Multimodal MR, e.g. MR combined with positron emission tomography [PET], MR combined with ultrasound or MR combined with computed tomography [CT]

Abstract

Systems and methods for visualizing fluid enhanced ablation therapy are described herein. In one embodiment, a method for ablating tissue is provided that includes inserting an elongate body into a tissue volume, heating an imageable fluid within the elongate body to transform the imageable fluid into an imageable therapeutic fluid, delivering the imageable therapeutic fluid into the tissue volume to deliver a therapeutic dose of thermal energy to the tissue volume, and imaging the tissue volume to determine the extent of the tissue volume containing the imageable therapeutic fluid. The imageable therapeutic fluid can indicate the extent of the tissue volume that has received the therapeutic dose of thermal energy.

Claims

1. A method for ablating tissue, comprising:

inserting an elongate body into a tissue volume where about ⅓

of the volume is extracellular space;

heating a fluid within the elongate body that contains saline and a contrast agent that can be viewed using an X-ray imaging technology;

delivering the heated fluid into the tissue volume through an outlet port formed in the elongate body;

delivering energy into the tissue volume from an ablation element disposed on the elongate body simultaneously with the heated fluid;

capturing an image of the tissue volume using the X-ray imaging technology, wherein the image shows a substantially circular portion of the tissue volume containing the contrast agent of the heated fluid and centered about the outlet port;

computing with a digital data processor a first radius of the substantially circular portion of the tissue volume containing the contrast agent of the heated fluid based on the captured image;

computing with a digital data processor a second radius that is about ⅔

of the first radius, wherein the second radius represents a portion of the tissue volume that has received a dose of thermal energy sufficient to destroy tissue; and

halting delivery of at least one of the heated fluid and energy when the second radius reaches a predetermined value.

2. The method of claim 1, wherein a heat capacity of the fluid is greater than about 2 J/ml-°

C.

3. The method of claim 1, wherein the fluid comprises saline and a contrast agent.

4. The method of claim 3, wherein a ratio of the saline to the contrast agent is about 1:

1.

5. The method of claim 3, wherein a ratio of the saline to the contrast agent is about 10:

1.

6. The method of claim 3, wherein a ratio of the saline to the contrast agent is about 20:

1.

7. The method of claim 3, wherein the contrast agent is iohexol.

8. The method of claim 1, wherein the fluid is heated by a heating element disposed within the elongate body.

9. The method of claim 1, wherein the ablation element comprises a source of electromagnetic energy.

10. The method of claim 9, wherein the electromagnetic energy is RF electrical energy.

11. The method of claim 9, wherein the electromagnetic energy is laser light energy.

12. The method of claim 9, wherein the electromagnetic energy is microwave electrical energy.

13. The method of claim 1, wherein the ablation element comprises a source of ultrasonic energy.

14. The method of claim 3, wherein the fluid includes a greater amount of saline than contrast agent.

15. The method of claim 3, wherein a ratio of the saline to the contrast agent is about 50:

1.

16. The method of claim 3, wherein a ratio of the saline to the contrast agent is about 200:

1.

17. A method for ablating tissue, comprising:

inserting an elongate body into a liver of a patient;

delivering a fluid including a contrast agent into the target volume of tissue from an outlet port formed in an elongate body, wherein the fluid is heated prior to being delivered into the target volume of tissue, and simultaneously delivering energy into the target volume of tissue from an ablation element adjacent to the elongate body;

capturing an image of the target volume of tissue with an X-ray imaging technology that shows a substantially circular portion of the target volume of tissue that contains the contrast agent centered about the outlet port;

computing with a digital data processor a first radius of the substantially circular portion of the target volume of tissue that contains the contrast agent based on the captured image;

computing with a digital data processor a second radius that is about ⅔

of the first radius, wherein the second radius represents a portion of the tissue volume that has received a dose of thermal energy sufficient to destroy tissue; and

stopping delivery of the fluid and the energy into the target volume of tissue when the second radius reaches a predetermined size.