US5117829A — Patient alignment system and procedure for radiat…

Claim 1

Independent Claim 220 words

A method for irradiating a volume of tissue within a patient with a charged-particle beam, said method comprising the steps of: (a) immobilizing the patient; (b) obtaining CT scan data of a region of tissue within said immobilized patient that includes said volume of tissue; (c) preparing a treatment plan using said CT scan data by identifying an isocenter point having a fixed geometrical relationship relative to said volume of tissue at which said charged-particle beam is to be directed, determining an entry angle for said charged-particle beam, and generating an image reconstructed from said CT scan data that identifies how the volume of tissue should appear when viewed along said entry angle through said isocenter point; (d) verifying said treatment plan by performing a physical simulation of the irradiation of said volume of tissue by said charged particle beam, said physical simulation including, (1) directing an image-forming beam along said entry angle at said isocenter point, said image-forming beam producing an image of the tissue through which it passes, and (2) comparing the image formed by said image-forming beam with said reconstructed image from said CT scan data along said entry angle verify that the charged particle beam will properly irradiate said volume of tissue; (e) executing said treatment plan by directing said charged-particle beam at said isocenter point.

Claim 2

Independent Claim 220 words

A method for irradiating a volume of tissue within a patient with a charged-particle beam, said method comprising the steps of: (a) immobilizing the patient; (b) obtaining CT scan data of a region of tissue within said immobilized patient that includes said volume of tissue; (c) preparing a treatment plan using said CT scan data by identifying an isocenter point having a fixed geometrical relationship relative to said volume of tissue at which said charged-particle beam is to be directed, determining an entry angle for said charged-particle beam, and generating an image reconstructed from said CT scan data that identifies how the volume of tissue should appear when viewed along said entry angle through said isocenter point; (d) verifying said treatment plan by performing a physical simulation of the irradiation of said volume of tissue by said charged particle beam, said physical simulation including, (1) directing an image-forming beam along said entry angle at said isocenter point, said image-forming beam producing an image of the tissue through which it passes, and (2) comparing the image formed by said image-forming beam with said reconstructed image from said CT scan data along said entry angle verify that the charged particle beam will properly irradiate said volume of tissue; (e) executing said treatment plan by directing said charged-particle beam at said isocenter point.

Claim 3

Dependent Claim 66 words

The method of claim 1 wherein the step of immobilizing the patient comprises immobilizing the patient relative to a holding device, and wherein the method further includes preparing repositioning reference radiographs of the patient and the holding device before releasing the patient from the holding device, said repositioning reference radiographs providing reference information that identifies the position of the immobilized patient relative to the holding device.

Claim 4

Dependent Claim 75 words

The method of claim 2 further including the steps of: releasing the patient from the holding device after said CT scan data has been obtained; and repositioning said patient within said holding device prior to verifying said treatment plan, said repositioning being performed by using said reference information to verify that the patient is positioned relative to said holding device in the same manner as the patient was originally positioned relative to said holding device.

Claim 5

Dependent Claim 60 words

The method of claim 1 wherein the step of preparing said treatment plan includes: identifying a tissue isocenter within said volume of tissue defined by said CT scan data that is to be irradiated with said charged-particle beam; marking said identified tissue isocenter; and reconstructing orthogonal reference radiographs from the CT scan data that pass through said marked tissue isocenter.

Claim 6

Dependent Claim 25 words

The method of claim 4, wherein the step of preparing said treatment plan further includes performing a computer simulation of irradiation with said charged-particle beam.

Claim 7

Dependent Claim 31 words

The method of claim 5 wherein said computer simulation is performed by directing a simulated charged-particle beam at said isocenter point through said marked tissue isocenter of said CT scan data.

Claim 8

Dependent Claim 73 words

The method of claim 4 wherein said physical simulation further includes: positioning the immobilized patient to receive said image-forming beam; comparing the image formed by said image-forming beam with at least one of the reconstructed orthogonal radiographs; and adjusting the position of the immobilized patient relative to the image-forming beam as required in order to align the image focused by said image-forming beam with said at least one of the reconstructed orthogonal radiographs.

Claim 9

Dependent Claim 56 words

The method of claim 7 wherein the step of executing said treatment plan includes delivering said charged-particle beam to the volume of tissue within said patient only when the position of the patient relative to the charged-particle beam is adjusted so that the charged-particle beam enters the patient with the same alignment as said image-forming beam.

Claim 10

Independent Claim 186 words

A method for aligning a charged-particle beam with a volume of tissue, such as a tumor, of a patient undergoing radiation therapy, said method comprising the steps of: immobilizing the patient; digitally mapping tissue densities of the patient in a region surrounding said volume of tissue; within data defining said digitally mapped tissue densities identifying and marking a portion of the data that defines the volume of tissue to be irradiated by said charged-particle beam; reconstructing at least one image of the tissue densities from said digitally mapped tissue densities, said at least one reconstructed image having a view line normal thereto that passes through said marked data; forming a radiographic image of the tissue of said patient taken along said view line; quantitatively comparing said radiographic image to said reconstructed image; adjusting the position of the immobilized patient relative to the radiographic image until any difference between said radiographic image and said reconstructed image is minimized; and aligning the charged-particle beam to be delivered to said volume of tissue with the view line of said radiographic image after the step of adjusting has been completed.

Claim 11

Independent Claim 186 words

A method for aligning a charged-particle beam with a volume of tissue, such as a tumor, of a patient undergoing radiation therapy, said method comprising the steps of: immobilizing the patient; digitally mapping tissue densities of the patient in a region surrounding said volume of tissue; within data defining said digitally mapped tissue densities identifying and marking a portion of the data that defines the volume of tissue to be irradiated by said charged-particle beam; reconstructing at least one image of the tissue densities from said digitally mapped tissue densities, said at least one reconstructed image having a view line normal thereto that passes through said marked data; forming a radiographic image of the tissue of said patient taken along said view line; quantitatively comparing said radiographic image to said reconstructed image; adjusting the position of the immobilized patient relative to the radiographic image until any difference between said radiographic image and said reconstructed image is minimized; and aligning the charged-particle beam to be delivered to said volume of tissue with the view line of said radiographic image after the step of adjusting has been completed.

Claim 12

Dependent Claim 32 words

The alignment method of claim 9 wherein the step of reconstructing at least one image of the tissue densities comprises reconstructing at least two orthogonal images from the digitally mapped tissue densities.

Claim 13

Dependent Claim 34 words

The alignment method of claim 9 wherein the step of quantitatively comparing said radiographic image to said reconstructed image comprises comparing distances between anatomical landmarks appearing in both images to a common reference point.

Claim 14

Dependent Claim 67 words

The alignment method of claim 9 wherein the step of immobilizing the patient comprises immobilizing the patient relative to a holding device, and wherein the method further includes preparing repositioning reference radiographs of the patient and the holding device before releasing the patient from the holding device, said repositioning reference radiographing providing reference information that identifies the position of the immobilized patient relative to the holding device.

Claim 15

Dependent Claim 47 words

The method of claim 12 further including the steps of: removing the patient from the holding device once the digitally mapped tissue densities has been obtained; and repositioning the patient in said holding device prior to forming the radiographic image of the patient along said view line.

Claim 16

Independent Claim 211 words

A system for aligning a charged-particle beam with a volume of tissue in a patient undergoing radiation therapy, said system comprising: means for immobilizing the patient; means for digitally mapping tissue densities of the patient in a region surrounding said volume of tissue, said digitally mapping means providing digitally mapped tissue density data that defines the tissue surrounding and including said volume of tissue; means for identifying and marking data within said digitally mapped tissue density data that defines the volume of tissue that is to be irradiated by a charged-particle beam; means for reconstructing at least one image of the tissue densities from said digitally mapped tissue density data, said at least one reconstructed image having a view line normal thereto that passes through said marked data; means for forming a radiographic image of the tissue of said patient taken along said view line; means for quantitatively comparing said radiographic image to said reconstructed image; means for adjusting the immobilized patient until any postition difference between said radiographic image and said reconstructed image are minimized; and means for aligning the charged-particle beam to be delivered to said volume of tissue with the view line of said radiographic image after the differences between the radiographic and reconstructed images have been minimized.

Claim 17

Independent Claim 211 words

A system for aligning a charged-particle beam with a volume of tissue in a patient undergoing radiation therapy, said system comprising: means for immobilizing the patient; means for digitally mapping tissue densities of the patient in a region surrounding said volume of tissue, said digitally mapping means providing digitally mapped tissue density data that defines the tissue surrounding and including said volume of tissue; means for identifying and marking data within said digitally mapped tissue density data that defines the volume of tissue that is to be irradiated by a charged-particle beam; means for reconstructing at least one image of the tissue densities from said digitally mapped tissue density data, said at least one reconstructed image having a view line normal thereto that passes through said marked data; means for forming a radiographic image of the tissue of said patient taken along said view line; means for quantitatively comparing said radiographic image to said reconstructed image; means for adjusting the immobilized patient until any postition difference between said radiographic image and said reconstructed image are minimized; and means for aligning the charged-particle beam to be delivered to said volume of tissue with the view line of said radiographic image after the differences between the radiographic and reconstructed images have been minimized.

Claim 18

Dependent Claim 22 words

The alignment system of claim 14 wherein said means for reconstructing at least one image comprises means for reconstructing two orthogonal images.

Claim 19

Dependent Claim 17 words

The alignment system of claim 15 wherein said orthogonal images comprise AP (Anterior Posterior) and lateral images.

Claim 20

Dependent Claim 52 words

The alignment system of claim 16 wherein said means for reconstructing at least one image includes means for reconstructing a beam's eye view image, said beam's eye view image comprising an image depicting the tissue densities as would be seen by an eye placed at the source of the image forming beam.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-06-02	1995-12-02	1996-06-02	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-06-02	1999-12-02	2000-06-02	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-06-02	2003-12-02	2004-06-02	$7700.00	Window Closed / Lapsed

Patient alignment system and procedure for radiation treatment

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