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EP-4321210-B1 - METHODS AND SYSTEMS FOR LIGHT FIELD VERIFICATION ON A PATIENT SURFACE

EP4321210B1EP 4321210 B1EP4321210 B1EP 4321210B1EP-4321210-B1

Inventors

  • SABEL, Martin
  • HUBER, MICHAEL

Dates

Publication Date
20260513
Application Date
20230801

Claims (9)

  1. A method comprising: obtaining a two-dimensional, 2D, first image (815), the first image (815) including a light field (515) on a patient, the light field being generated by a treatment system (10); detecting an outline (820) of the light field on the patient; obtaining a three-dimensional, 3D, patient surface image being a 3D reference surface (810); obtaining a treatment plan outline (805), the treatment plan outline (805) including an area of the patient for a treatment, the treatment plan outline (805) being projected onto the 3D reference surface (810); registering the 3D reference surface (810) to the 2D first image (815); transforming the treatment plan outline (805) projected onto the 3D reference surface (810) to a treatment plan outline (805') projected onto the 2D first image (815); and determining positioning information based on the outline (820) of the light field on the 2D first image (815) and the treatment plan outline (805') on the 2D first image (815), the positioning information including an indicator of a position of the treatment system (10) with respect to the patient.
  2. The method of claim 1, wherein the determining the positioning information includes, comparing the treatment plan outline (805') on the first image (815) and the outline (820) of the light field on the first image (815), the positioning information being based on the comparing.
  3. The method of any one of claims 1-2, wherein the treatment system (10) includes a collimator and the method further comprises: projecting the light field through the collimator and onto the patient.
  4. The method of any one of claim 1-3, further comprising: preventing the treatment when the positioning information is greater than or equal to a threshold; and/or notify a user that treatment for the patient is permitted when the positioning information is less than or equal to a threshold.
  5. A system (18, 1600) comprising: processing circuitry (54, 156, 1604) configured to cause the system to, obtain, via at least one camera (154), a two-dimensional, 2D, first image (815), the first image (815) including a light field (515) on a patient, the light field being generated by a light source (130) activated by the treatment system (10); detect an outline (820) of the light field on the patient; obtain, via at least one stereo camera (154), a three-dimensional, 3D, patient surface image being a 3D reference surface (810); obtain a treatment plan outline (805), the treatment plan outline (805) including an area of the patient for a treatment, the treatment plan outline (805) being projected onto the 3D reference surface (810); register the 3D reference surface (810) to the 2D first image (815); transform the treatment plan outline (805) projected onto the 3D reference surface (810) to a treatment plan outline (805') projected onto the 2D first image (815); and determine positioning information based on the outline (820) of the light field on the 2D first image (815) and the treatment plan outline (805') on the 2D first image, the positioning information including an indicator of a position of the treatment system (10) with respect to the patient.
  6. The system of claim 5, wherein the processing circuitry is configured to cause the system to, compare the treatment plan outline (805') on the first image (815) and the outline (820) of the light field on the first image (815), the positioning information being based on the comparing.
  7. The system of any one of claims 5-6, further comprising: a collimator, the processing circuitry being configured to cause the system to project the light field through the collimator and onto the patient.
  8. The system of any one of claims 5-7, wherein the processing circuitry is configured to cause the system to, generate a command to activate the light field, the command being generated external to the treatment system (10).
  9. The system of any one of claims 5-8, wherein the processing circuitry is configured to cause the system to, prevent the treatment when the positioning information is greater than or equal to a threshold; and/or notify a user that treatment for the patient is permitted when the positioning information is less than or equal to a threshold.

Description

TECHNICAL FIELD One or more example embodiments relate to methods and systems for light field verification on a patient surface, such as a 3D patient surface image. BACKGROUND Radiation therapy involves medical procedures that selectively expose certain areas of a human body, such as cancerous tumors, to doses of radiation. The radiation therapy irradiates the targeted biological tissue such that undesirable tissue is destroyed. Radiation has also been-used to obtain images of tissue for diagnostic or treatment purposes. On treatment delivery systems, a light field projected through the beam collimation is used to verify the patient setup or to check a multi-leaf collimator (MLC) shape for a given beam. The light field setup is a visual process done by a user of the treatment delivery system (e.g., a therapist). An exemplary system using such a light field is described in publication US 2019/209866 A1. The user may be able to verify the patient setup for a first light field of a treatment as part of the setup before starting the treatment. However, the same verification process for following fields in the treatment require an interruption of the treatment during which the user has to enter the treatment room. SUMMARY The scope of protection sought for various example embodiments is set out by the independent claims. The example embodiments and/or features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments. Current treatment systems do not provide independent verification of the light field projected onto the skin of a patient. Moreover, the verification process for following light fields in the treatment subsequent to the first light field require an interruption of the treatment during which the user has to enter the treatment room. At least some example embodiments provide an independent verification of the light field. According to the invention, a method includes obtaining a first image, the first image including a light field on a patient, the light field being generated by a treatment system; obtaining a treatment plan outline, the treatment plan outline including an area of the patient for a treatment; and determining positioning information based on the first image and the treatment plan outline, the positioning information including an indicator of a position of the treatment system with respect to the patient. The method further includes obtaining a three-dimensional (3D) patient surface image being a 3D reference surface, the treatment plan outline being projected on the 3D reference surface, wherein the obtaining the first image includes detecting an outline of the light field on the patient, and the determining the positioning information includes projecting the treatment plan outline onto the first image, the positioning information being based on the outline of the light field on the first image and the treatment plan outline on the first image. According to at least one example embodiment, the determining the positioning information includes comparing the treatment plan outline on the first image and the outline of the light field on the first image, the positioning information being based on the comparing. The first image is a two-dimensional (2D) image. The projecting the treatment plan outline includes registering the 3D reference surface to the first image. According to at least one example embodiment, the treatment system includes a collimator and the method further includes projecting the light field through the collimator and onto the patient. According to at least one example embodiment, the method further includes generating a command to generate the light field, the command being generated external to the treatment system. According to at least one example embodiment, the obtaining the first image includes capturing the first image using a camera of the treatment system. According to at least one example embodiment, the controlling includes preventing the treatment when the positioning information is greater than or equal to a threshold. According to at least one example embodiment, not forming part of the invention, the controlling includes performing the treatment on the patient when the positioning information is less than or equal to a threshold. According to at least one example embodiment the method further includes issuing a warning to a user when the positioning information is greater than or equal to a threshold. According to at least one example embodiment the method further includes notify a user that treatment for the patient is permitted when the positioning information is less than or equal to a threshold. According to the invention, a system includes processing circuitry configured to cause the system to obtain, via at least one camera, a first image, the first image including a light field on a patient, the light field being generated by a