Radiotherapy treatment monitoring using ultrasound

• US 8,366,618 B2
• Filed: 12/28/2009
• Issued: 02/05/2013
• Est. Priority Date: 09/20/2004
• Status: Active Grant

• Current Assignee: Elekta Ltd. (Elekta AB)
• Original Assignee: Elekta Ltd. (Elekta AB)
• Inventors: Falco, Tony, Lachaine, Martin
• Primary Examiner(s): CHENG, JACQUELINE
• Application Number:
  US12/647,852
• Publication Number:
  US 20100099989A1
• Time in Patent Office: 1,135 Days
• Field of Search: 600/439, 600/436, 378/65, 601 1- 3
• US Class Current: 600/437
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: G01S 15/899 Combination of imaging systems with ancillary equipment
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation
• CPC Class Codes: G01S 7/5206 Two-dimensional coordinated display of distance and direction; B-scan display

Abstract

Methods and systems for assessing the effects of therapy on a patient include obtaining baseline and treatment ultrasound scans of a treatment area of a patient where the treatment ultrasound scans are taken subsequent to the baseline scan and at various times during a course of radiotherapy treatment sessions. The baseline and treatment ultrasounds are compared, and as a result a damage map representing cell death within the treatment area can be constructed.

Claims

1. A method of assessing cell condition in response to treatment, the method comprising the steps of:

a. obtaining a baseline ultrasound scan of a treatment area of a patient;

b. obtaining, subsequent to the baseline scan, one or more temporally distinct treatment ultrasound scans of the treatment area at various times during a course of treatment sessions;

c. comparing at least one of the one or more treatment ultrasound scans to the baseline ultrasound scan; and

d. based on the comparison, assessing cell condition in the treatment area in response to the treatment sessions, wherein the baseline ultrasound scan and the one or more treatment ultrasound scans are taken at a frequency below 20 MHz.

2. The method of claim 1 wherein the baseline ultrasound scan is rendered in two dimensions.

3. The method of claim 1 wherein the one or more treatment ultrasound scans are rendered in two dimensions.

4. The method of claim 1 wherein the baseline ultrasound scan is rendered in three dimensions.

5. The method of claim 1 wherein the one or more treatment ultrasound scans are rendered in three dimensions.

6. The method of claim 1 wherein the treatment sessions include one or more sessions of radiation treatment, chemotherapy, cryotherapy, and brachytherapy.

7. The method of claim 1 wherein each of the one or more treatment ultrasound scans are obtained substantially just following one of the treatment sessions.

8. The method of claim 1 wherein each of the one or more treatment ultrasound scans is obtained substantially just prior to treatment delivery.

9. The method of claim 1 further comprising obtaining, prior to obtaining the baseline ultrasound scan, a B-mode scan to determine an anatomical feature of interest within the treatment area.

10. The method of claim 9 further comprising creating a segmented representation of the anatomical feature of interest using the B-mode scan.

11. The method of claim 1 further comprising obtaining, prior to obtaining the one or more treatment ultrasound scans, a B-mode scan to determine an anatomical feature of interest within the treatment area.

12. The method of claim 1 wherein assessing cell condition in the treatment area comprises characterizing a power spectrum from one or more of the baseline scan and the treatment scans.

13. The method of claim 12 wherein the power spectrum is characterized by estimating an acoustic concentration of scatters in one or more of the baseline scan and the treatment scans.

14. The method of claim 1 further comprising using the results of the comparison to plan a subsequent treatment session.

15. The method of claim 1 wherein assessing cell condition in the treatment area comprises determining an average cell condition value over a region of interest.

16. The method of claim 1 wherein assessing cell condition in the treatment area comprises constructing one or more damage maps representing cell damage within the treatment area.

17. The method of claim 16, further comprising superimposing the one or more damage maps with the baseline ultrasound scan.

18. The method of claim 1 wherein the baseline ultrasound scan and the one or more treatment ultrasound scans are taken at a frequency below about 10 MHz.

19. The method of claim 1 wherein the baseline ultrasound scan and the one or more treatment ultrasound scans are taken at a frequency of about 3 MHz.

20. The method of claim 1 wherein assessing cell condition comprises assessing cell death.

21. A system for determining cell condition in response to treatment, the system comprising:

a storage unit configured to receive ultrasound scans of a treatment area, the ultrasound scans comprising;

a baseline ultrasound scan; and

one or more temporally distinct treatment ultrasound scans of the treatment area taken subsequent to the baseline scan and at various times during a course of treatment sessions, wherein the baseline ultrasound scan and the one or more treatment ultrasound scans are taken at a frequency below 20 MHz; and

a comparator module configured to;

(i) compare the baseline ultrasound scan and at least one of the one or more treatment ultrasound scans, and

(ii) based on the comparison, determine cell condition in the treatment area in response to the treatment sessions.

22. The system of claim 21 wherein the comparator module is configured to construct a plurality of damage maps representing cell condition within the treatment area, the system further comprising a display for displaying one or more of the damage maps.

23. The system of claim 21 further comprising an ultrasound scanning device for obtaining the baseline ultrasound scan and the one or more temporally distinct treatment ultrasound scans.

24. The system of claim 21 further comprising an input device for facilitating one or more of manipulating the ultrasound images, adjusting treatment parameters, and entering analysis data.

25. A non-transitory computer readable medium having computer-readable programs embodied thereon for determining cell condition in response to treatment, the medium comprising computer-readable instructions for:

a. obtaining a plurality of temporally distinct ultrasound scans of a treatment area at various times during a course of treatment sessions, wherein the plurality of ultrasound scans are taken at a frequency below 20 MHz;

b. comparing the plurality of ultrasound scans; and

c. based on the comparison, determining cell condition in the treatment area in response to the treatment sessions.

26. The non-transitory computer readable medium of claim 25 wherein the computer-readable programs further comprise computer-readable instructions for characterizing a power spectrum from one or more of the plurality of ultrasound scans.

27. The non-transitory computer readable medium of claim 25 wherein the computer-readable programs further comprise computer-readable instructions for constructing a series of damage maps representing cell condition within the treatment area.