Radiotherapy treatment monitoring using ultrasound

• US 7,662,097 B2
• Filed: 09/20/2005
• Issued: 02/16/2010
• Est. Priority Date: 09/20/2004
• Status: Active Grant

• Current Assignee: Elekta Ltd. (Elekta AB)
• Original Assignee: Resonant Medical Incorporated (Elekta AB)
• Inventors: Falco, Tony, Lachaine, Martin
• Primary Examiner(s): Casler; Brian
• Assistant Examiner(s): RAMIREZ, JOHN FERNANDO
• Application Number:
  US11/230,920
• Publication Number:
  US 20060064014A1
• Time in Patent Office: 1,610 Days
• Field of Search: 600/439, 600/436, 378/65, 601/1, 601/2, 601/3
• 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;

d. based on the comparison, constructing one or more damage maps representing cell damage within the treatment area thereby providing a predictive model of tissue damage due to the treatment;

e. selecting a hypothetical radiation dosage and delivery pattern; and

f. using the predictive model, generating a map of expected tissue damage resulting from the hypothetical radiation dosage and delivery pattern.

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 baseline ultrasound scan is taken at a frequency below 20 MHz.

7. The method of claim 1 wherein the one or more of treatment ultrasound scans are taken at a frequency below 20 MHz.

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

9. 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.

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

11. 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.

12. The method of claim 11 further comprising creating a segmented representation of the anatomical feature of interest using the B-mode scan.

13. 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.

14. The method of claim 1 wherein constructing the damage map comprises characterizing the power spectrum from one or more of the baseline scan and treatment scans.

15. The method of claim 14 wherein the power spectrum is characterized by estimating the acoustic concentration of scatters in one or more of the baseline scan and treatment scans.

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

17. The method of claim 1 further comprising using the results of the comparison to determine an average damage value depicting an average measure of cell damage over a region of interest.

18. The method of claim 1 further comprising superimposing the damage map with the baseline ultrasound scan.

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

a storage unit for receiving 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; and

a comparator module for;

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

(ii) based on the comparison, constructing a plurality of damage maps representing cell condition within the treatment area, thereby providing a predictive model of tissue damage due to the treatment; and

an analysis module for;

(x) selecting a hypothetical radiation dosage and delivery pattern; and

(y) using the predictive model, generating a map of expected tissue damage resulting from the hypothetical radiation dosage and delivery pattern.

20. The system of claim 19 further comprising a display for displaying the damage map.

21. The system of claim 19 further comprising an ultrasound scanning device for obtaining the baseline ultrasound scan and the one or more temporally distinct treatment ultrasound scans.

22. The system of claim 19 further comprising an input device for facilitating one or more of manipulating the ultrasound images, adjusting treatment parameters, and entering analysis data.

23. An article of manufacture having computer-readable program portions embodied thereon for determining cell condition in response to treatment, the article 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;

b. comparing the plurality of ultrasound scans;

c. constructing a series of damage maps representing cell condition within the treatment area based on the comparison;

d. constructing a predictive model of tissue damage due to treatment based on the series of damage maps;

e. selecting a hypothetical radiation dosage and delivery pattern; and

f. using the predictive model, generating a map of expected tissue damage resulting from the hypothetical radiation dosage and delivery pattern.

24. The article of manufacture of claim 23 further comprising computer-readable instructions for characterizing a power spectrum from one or more of the plurality of ultrasound scans.

25. The article of manufacture of claim 23 further including computer-readable instructions for superimposing the damage map with the baseline ultrasound scan.