Portal dosimetry system

Patent metadata

Field	Value
Publication number	US-2016125602-A1
Application number	US-201614992117-A
Country	US
Kind code	A1
Filing date	Jan 11, 2016
Priority date	Jun 26, 2013
Publication date	May 5, 2016
Grant date	—

Abstract

Embodiments of the invention provide systems and methods for evaluating treatment parameters for a patient undergoing radiotherapy. The method includes the step of generating a portal dosimetry image showing differences between a planning image obtained prior to a treatment session and a portal image obtained during the treatment session. A database of prior portal dosimetry results is accessed, and a processor is used to perform a similarity measurement between the portal dosimetry image and the prior portal dosimetry results. Based on the similarity measurement, the system determines whether radiation was delivered as planned during the treatment session.

First claim

What is claimed is:

1 - 24 . (canceled)

25 . A method of evaluating treatment parameters for a patient undergoing radiotherapy, wherein a portal imaging device is located under the patient such that a radiation beam passes through the patient to the portal imaging device, the method comprising:
obtaining a planning image of the patient prior to radiotherapy, the planning image including an expected portal image of the target region of the patient; obtaining a portal image during radiotherapy from the portal imaging device, the portal image corresponding to an actual dose distribution delivered to the target region of the patient when a radiation beam is turned on; generating, by a processor, during radiotherapy, a difference image identifying one or more differences between the planning image and the portal image; accessing a database configured to store a plurality of prior portal dosimetry images identifying differences between prior planning images and prior portal images and one or more corresponding decisions made regarding the prior portal dosimetry images; performing a similarity measurement, by the processor, between the difference image and the one or more prior portal dosimetry images from the database; determining, by the processor, whether to interrupt radiotherapy, wherein the determination is based on an analysis of the similarity measurement and the corresponding decisions made regarding the one or more prior portal dosimetry images; and providing, by the processor, an indication of whether to interrupt radiotherapy.

26 . The method of claim 25 , wherein the processor further generates a ranked list of likely explanations for any differences seen in the difference image.

27 . The method of claim 25 , wherein the corresponding decisions are related to at least one of: whether the patient is the wrong patient, whether the patient is in the wrong position, whether the dose is being delivered to the wrong location, whether the target has changed position substantially, or combinations thereof.

28 . The method of claim 25 , wherein the portal image comprises a 3D image reconstructed from a plurality of 2D images of the target region obtained during radiotherapy.

29 . The method of claim 25 , wherein the planning image comprises a 3D image that includes a plurality of predicted 2D images of the target region.

30 . The method of claim 25 , wherein the similarity measurement is performed between the difference image and the one or more prior portal dosimetry images for the same patient from previous treatment sessions.

31 . The method of claim 25 , wherein the processor further determines a gamma index based on differences between the planning image and the portal image, wherein a gamma test is failed if the gamma index exceeds a threshold value.

32 . The method of claim 25 , wherein the interruption of radiotherapy includes making one or more changes to a treatment plan.

33 . A system for evaluating treatment parameters for a patient undergoing radiotherapy, the system comprising:
a database storing a plurality of prior portal dosimetry images, wherein each prior portal dosimetry image has one or more corresponding decisions made regarding the prior portal dosimetry image; an initial imaging device configured for obtaining a planning image including an expected portal image of the target region of the patient; a portal imaging device located under the patient such that a radiation beam passes through the patient to the portal imaging device, wherein the portal imaging device is configured to take a portal image corresponding to an actual dose distribution delivered to the target region of the patient when a radiation beam is turned on during radiotherapy; a processor configured to: generate, during radiotherapy, a difference image identifying one or more differences between the planning image and the portal image; perform a similarity measurement between the difference image and the one or more prior portal dosimetry images from the database; determine whether to interrupt radiotherapy, wherein the determination is based on an analysis of the similarity measurement and the corresponding decisions made regarding the one or more prior portal dosimetry images; and provide an indication of whether to interrupt radiotherapy.

34 . The system of claim 33 , wherein the processor is further configured to generate a ranked list of likely explanations for any differences seen in the difference image.

35 . The system of claim 33 , wherein the corresponding decisions are related to at least one of: whether the patient is the wrong patient, whether the patient is in the wrong position, whether the dose is being delivered to the wrong location, whether the target has changed position substantially, or combinations thereof.

36 . The system of claim 33 , wherein the portal image comprises a 3D image reconstructed from a plurality of 2D images of the target region obtained during radiotherapy.

37 . The system of claim 33 , wherein the planning image comprises a 3D image that includes a plurality of predicted 2D images of the target region.

38 . The system of claim 33 , wherein the similarity measurement is performed between the difference image and the one or more prior portal dosimetry images for the same patient from previous treatment sessions.

39 . The system of claim 33 , wherein the processor is further configured to determine a gamma index based on differences between the planning image and the portal image, wherein a gamma test is failed if the gamma index exceeds a threshold value.

40 . The system of claim 33 , wherein the interruption of radiotherapy includes making one or more changes to a treatment plan.

41 . A system for evaluating treatment parameters for a patient undergoing radiotherapy using a portal imaging device located under the patient such that a radiation beam passes through the patient to the portal imaging device when a radiation beam is turned on during radiotherapy, wherein the portal imaging device is configured to take a portal image corresponding to an actual dose distribution delivered to the target region of the patient when a radiation beam is turned on during radiotherapy, the system comprising:
a database storing a plurality of prior portal dosimetry images, wherein each prior portal dosimetry image has one or more corresponding decisions made regarding the prior portal dosimetry image; an initial imaging device configured for obtaining a planning image including an expected portal image of the target region of the patient; and a graphical display configured to provide an indication of whether to interrupt radiotherapy based on a difference between the planning image and the portal image.

42 . The system of claim 41 , further comprising:
a processor configured to: generate, during radiotherapy, a difference image identifying one or more differences between the planning image and the portal image; perform a similarity measurement between the difference image and the one or more prior portal dosimetry images from the database; and determine whether to interrupt radiotherapy, wherein the determination is based on an analysis of the similarity measurement and the corresponding decisions made regarding the one or more prior portal dosimetry images.

43 . The system of claim 42 , wherein the processor further generates a ranked list of likely explanations for any differences seen in the difference image.

44 . The system

Assignees

• Elekta Ab

Inventors

• Winfield Colin
• Sayeed Abdul

Classifications

• G06K9/6202

  Physics · mapped topic

• G06F19/3481

  Physics · mapped topic

• G06F19/321

  Physics · mapped topic

• G06F19/345

  Physics · mapped topic

• A61N5/1071

  for verifying the dose delivered by the treatment plan · CPC title