Real time ultrasound monitoring of the motion of internal structures during respiration for control of therapy delivery

• US 20060241443A1
• Filed: 11/18/2005
• Published: 10/26/2006
• Est. Priority Date: 11/22/2004
• Status: Abandoned Application

• Current Assignee: CIVCO Medical Instruments Company Incorporated (Roper Technologies, Inc.)
• Original Assignee: CIVCO Medical Instruments Company Incorporated (Roper Technologies, Inc.)
• Inventors: Schenck, Arthur J., Whitmore, Willet F. III, Onik, Gary M.
• Application Number:
  US11/281,416
• Publication Number:
  US 20060241443A1
• Time in Patent Office: Days
• US Class Current: 600/439
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/5276 due to motion
• CPC Class Codes: A61B 8/565 involving data transmission via a network
• CPC Class Codes: A61N 2005/1058 using ultrasound imaging
• CPC Class Codes: A61N 5/1037 taking into account the movement of the target, e.g. 4D-image based planning
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1064 for adjusting radiation treatment in response to monitoring
• CPC Class Codes: A61N 5/107 in real time, i.e. during treatment

Abstract

A method of targeting therapy such as radiation treatment to a patient includes: identifying a target lesion inside the patient using an image obtained from an imaging modality selected from the group consisting of computed axial tomography, magnetic resonance tomography, positron emission tomography, and ultrasound; identifying an anatomical feature inside the patient on a static ultrasound image; registering the image of the target lesion with the static ultrasound image; and tracking movement of the anatomical feature during respiration in real time using ultrasound so that therapy delivery to the target lesion is triggered based on (1) movement of the anatomical feature and (2) the registered images.

Claims

1. A method of targeting therapy such as radiation treatment to a patient comprising:

identifying a target lesion inside the patient using an image obtained from an imaging modality selected from the group consisting of computed axial tomography, magnetic resonance tomography, positron emission tomography, and ultrasound;

identifying an anatomical feature inside the patient on a static ultrasound image;

registering the image of the target lesion with the static ultrasound image;

tracking movement of the anatomical feature during respiration in real time using ultrasound so that therapy delivery to the target lesion is triggered based on (1) movement of the anatomical feature and (2) the registered images.

2. The method of claim 1, wherein the movement of the anatomical feature is tracked using a target detection algorithm that correlates positions of the anatomical feature shown (1) on the static ultrasound image and (2) on live ultrasound images acquired during respiration in real time.

3. The method of claim 2, wherein the target detection algorithm comprises:

$E=\underset{x=1}{\overset{M}{\sum <br><br>}}<br><br>\underset{y=1}{\overset{N}{\sum <br><br>}}<br><br>T<br><br>\left(x,y\right)-F<br><br>\left(x,y\right)$

where;

E is the composite error in gray scale between template (T) and image (F);

M and N define the number of pixels in x and y, respectively; and

T and F are the digitized gray scale values at each x and y location.

4. The method of claim 2, wherein the target detection algorithm accounts for shape, texture, and location of the anatomical feature.

5. The method of claim 1, wherein the anatomical feature has a dimension between about 2 mm and about 10 mm.

6. The method of claim 1, further comprising:

delivering radiation therapy to the target lesion.

7. The method of claim 1, wherein the static ultrasound image and images acquired in real time using ultrasound are all acquired using an ultrasound transducer disposed in substantially the same fixed position with respect to the patient.

8. The method of claim 7, wherein the ultrasound transducer is further disposed in substantially the same fixed position with respect to the patient when the target lesion is identified.

9. The method of claim 1, further comprising:

supporting the patient on a first support during acquisition of the ultrasound images and on a second support during delivery of radiation, the first and second supports being the same.

10. A method of targeting radiation therapy to a patient comprising:

acquiring a first image of a target lesion using computed axial tomography;

acquiring a reference image using ultrasound simultaneously with acquisition of the first image, the reference image being of a reference organ selected from the group consisting of a surrogate organ and the target organ;

selecting a portion of the reference image that includes a repeatably identifiable anatomic feature of the reference organ;

correlating the first image with at least one selected from the group consisting of the reference image and a portion of the reference image;

aiming radiation delivery using the first image;

acquiring additional live images of the reference organ using ultrasound during delivery of radiation to the patient;

delivering radiation to the target organ when a portion of the live image matches the selected portion of the reference image.

11. The method of claim 10, wherein a target detection algorithm is used to determine when the portion of the live image matches the selected portion of the reference image, the target detection algorithm comprising:

$E=\underset{x=1}{\overset{M}{\sum <br><br>}}<br><br>\underset{y=1}{\overset{N}{\sum <br><br>}}<br><br>T<br><br>\left(x,y\right)-F<br><br>\left(x,y\right)$

where;

E is the composite error in gray scale between template (T) and image (F);

M and N define the number of pixels in x and y, respectively; and

T and F are the digitized gray scale values at each x and y location.

12. The method of claim 10, wherein the anatomic feature has a dimension between about 2 mm and about 10 mm.

13. The method of claim 10, wherein the ultrasound images are acquired using an ultrasound transducer retained in substantially fixed position with respect to the patient during the acquisition of the reference image and during the delivery of radiation to the patient.

14. The method of claim 13, wherein the ultrasound images are acquired using an ultrasound transducer retained in substantially fixed position with respect to the patient, and wherein the ultrasound transducer remains in substantially fixed position with respect to the patient during acquisition of the first image using computed axial tomography.

15. The method of claim 13, wherein the ultrasound transducer is disposed outside of an imaging plane of the computed axial tomography during acquisition of the first image.

16. The method of claim 10, wherein the first image and the reference image are acquired while the patient holds a breath.

17. A programmed computer system for targeting therapy such as radiation treatment to a patient comprising at least one memory having at least one region storing computer executable program code and at least one processor for executing the program code stored in said memory, wherein the program code comprises:

code to identify a target lesion inside a patient using an image obtained from an imaging modality selected from the group consisting of computed axial tomography, magnetic resonance tomography, positron emission tomography, and ultrasound;

code to identify an anatomical feature inside the patient on a static ultrasound image;

code to register the image of the target lesion with the static ultrasound image; and

code to track movement of the anatomical feature during respiration in real time using ultrasound so that therapy delivery to the target lesion is triggered based on (1) movement of the anatomical feature and (2) the registered images.

18. The system of claim 17, further comprising an imaging system comprising an x-ray source, a radiation detector array, and an x-ray controller.

19. The system of claim 17, further comprising an ultrasound imaging system comprising an ultrasound transducer and an ultrasound controller.

20. The system of claim 17, further comprising a radiation treatment system comprising a beaming apparatus and a treatment beam controller.