Real time radiation treatment planning system

• US 5,391,139 A
• Filed: 02/23/1994
• Issued: 02/21/1995
• Est. Priority Date: 09/03/1992
• Status: Expired due to Fees

• Current Assignee: William Beaumont Hospital (Beaumont Health)
• Original Assignee: William Beaumont Hospital (Beaumont Health)
• Inventors: Edmundson, Gregory K.
• Primary Examiner(s): Sykes, Angela D.
• Application Number:
  US08/201,484
• Time in Patent Office: 363 Days
• Field of Search: 600/3, 600/7, 600/1-2, 600/4-6, 600/8, 600/10, 128/898, 128/653.1, 607/154, 364/413.26
• US Class Current: 600/7
• CPC Class Codes: A61N 5/1027 Interstitial radiation therapy
• CPC Class Codes: A61N 5/103 Treatment planning systems

Abstract

A radiation treatment planning system utilizes a standard interface circuit to continuously digitize and display image data generated by an anatomical imaging device, such as an ultrasound unit. The acquired image data includes positional information of one or more radiation delivery devices relative to an anatomical area to be treated. The acquired data is processed to rapidly determine a radiation dose plan, which is displayed in real time as a superimposed image over the image of the anatomical area being treated.

Claims

1. A real time radiation treatment dosage planning system for use in effecting radiation therapy of a preselected anatomical portion of an animal body, the system comprising:

radiation delivery means for defining a plurality of positions having a spatial relationship within a volume of the anatomical portion and for placing a radiation source at said plurality of positions;

imaging means for generating real time visual image data corresponding to the anatomical portion;

means responsive to the real time visual image data for monitoring said plurality of positions to detect a change in the spatial relationship of said positions;

processing means for automatically generating, in response to a detected change in the spatial relationship of said positions, a treatment plan including a generated value of the radiation source and a generated time period the radiation source is to be placed at each position by the radiation delivery means.

2. The system of claim 1, wherein the processing means further comprises means for generating a visual representation of a radiation dosage distribution effected by the radiation source value and time periods and for superimposing the visual representation over an image of the anatomical portion.

3. The system of claim 1, wherein the processing means further comprises means for transmitting the time periods to the radiation delivery means.

4. The system of claim 3, wherein the radiation delivery means includes a plurality of guide tubes arranged for insertion into the anatomical portion, a radiation source adjustably positionable within the tubes and control means for varying a position of the radiation source within the tubes, and

wherein the means for automatically generating produces a plurality of indications of positions within the tubes and a dwell time for each position of the radiation source.

5. The system of claim 1, wherein the imaging means comprises an ultrasound scanner.

6. The system of claim 1, wherein the radiation delivery means includes a plurality of guide tubes arranged for insertion into the anatomical portion, a radiation source adjustably positionable within the tubes and control means for varying a position of the radiation source within the tubes, and

wherein the means for automatically generating produces a plurality of indications of positions within the tubes and a dwell time for each position of the radiation source.

7. The system of claim 6, wherein the imaging means comprises an ultrasonic scanner.

8. The system of claim 7, wherein the anatomical portion comprises a human prostate gland.

9. In a therapy system for applying radiation to a preselected anatomical portion of an animal body by using means responsive to control data for indexing a position and holding each position for predetermined time periods of a radiation source within a plurality of guide members inserted into the anatomical portion, placement of each guide member with respect to the anatomical portion being monitored by scanning means, the improvement comprising:

processing means including means coupled to the scanning means for capturing real time visual image data generated thereby and using said real time visual image data to monitor said plurality of positions to detect a change in the spatial relationship of said positions, and means for automatically generating, in response to a detected change in the spatial relationship of said positions, revised control data for use by the means for indexing and indicating each indexed position of the radiation source within the plurality of guide members and each dwell time of the source at each indexed position.

10. The improvement of claim 9, wherein the processing means further comprises means for generating a visual representation of a radiation dosage distribution profile effected by use of the control data by the means for indexing and superimposing the visual representation over an image of the anatomical portion.

11. The improvement of claim 10, wherein the processing means further comprises means for transmitting the control data to the means for indexing.

12. The improvement of claim 9, wherein the scanning means comprises an ultrasound scanner.

13. The improvement of claim 12, wherein the anatomical portion comprises a human prostate gland.

14. A method for generating a radiation treatment dosage plan for use in applying radiation to a preselected anatomical portion of an animal body by a radiation delivery system operable to place a radiation source in a plurality of positions within a volume of the anatomical portion, the method comprising:

generating real time visual image data corresponding to the anatomical portion with a scanner;

capturing the real time visual image data at a stored program processor and automatically generating, using the captured real time visual data, a time period during which the radiation source is to be placed at each of the plurality of positions;

monitoring the real time visual image data to detect a change in at least one of said plurality of positions and, in response to a detected change, automatically regenerating said time period during which the radiation source is to be placed at each of the plurality of positions; and

transmitting an indication of the value of the time periods to the radiation delivery system.

15. The method of claim 14, further comprising the step of generating a visual representation of a radiation dosage distribution effected by the time periods and radiation source and superimposing the visual representation over a displayed image of the anatomical portion.

16. The method of claim 14, wherein the scanner comprises an ultrasonic scanner.

17. The method of claim 16, wherein the anatomical portion comprises a human prostate gland.

18. A method for generating a radiation treatment dosage plan for use in applying radiation to a preselected anatomical portion of an animal body with a radiation source indexable to a plurality of dwell positions within each of a plurality of guide tubes inserted at a plurality of locations within the anatomical portion, the method comprising:

(a) generating real time visual image data corresponding to the anatomical portion with a scanner;

(b) selecting a location within the anatomical portion for one of the guide tubes and placing the one guide tube at the selected location;

(c) generating, with the scanner, real time visual image data of the location selected in step (b) and combining it with the visual image data corresponding to the anatomical portion and to any previously positioned guide tubes;

(d) capturing the real time visual image data generated by steps (a) and (c) and automatically generating, using the captured image data, a dwell time period for each position of the radiation source within all guide tubes currently in place; and

(e) repeating steps (b) through (d) for successive ones of the plurality of guide tubes while automatically revising dwell time periods previously generated, in response to a change in position of any previously positioned guide tubes, until a volume of the anatomical portion is enveloped by a preselected radiation dose profile.

19. The method of claim 18, wherein step (d) further comprises:

(i) reconstructing dimensional coordinates of all dwell positions for all previously considered locations of guide tubes and a currently selected guide tube;

(ii) optimizing and normalizing relative dwell times of the radiation source at each dwell position of all guide tubes currently in place; and

(iii) generating a normalization factor for converting relative dwell times to actual dwell times for maintaining the radiation source at each dwell position of each guide tube currently in place.

20. The method of claim 19, wherein the step of reconstructing further comprises:

using a template of guide holes with known geometry to hold the guide tubes;

using scanner data to determine a depth of each guide tube within the anatomical portion;

using coordinates of each guide tube at the template and at a known reference scanning plane transverse to lengths of the guide tubes to interpolate coordinates for every dwell position in each guide tube; and

for each dwell position, saving a dwell number, guide tube number and interpolated three dimensional coordinates.

21. The method of claim 20, wherein the step of optimizing further comprises:

for each dwell position, calculating a dwell time value as a function of contributions of the radiation source positioned at all other dwell positions not within the same guide tube;

determining a maximum value of calculated dwell times; and

normalizing each calculated dwell time to the maximum value.

22. The method of claim 21, wherein the step of generating a normalization factor further comprises:

(1) assigning a preselected number as a reference dose at a reference location;

(2) selecting two dwell locations at random from all dwell locations of all guide tubes currently in place;

(3) calculating a dose value at a point midway between the randomly selected dwell locations;

(4) comparing the calculated dose value to the reference dose and whenever the calculated dose value is less than the reference dose, setting the reference dose equal to the calculated dose and the reference location equal to the point midway between the randomly selected dwell locations;

(5) repeating steps (1) through (4) for a preselected number of times; and

(6) setting a normalization factor equal to a prescribed dose divided by the reference dose.