Patent Application
20070088573
Adaptive radiation therapy, or ART, is the concept of incorporating feedback into radiation therapy practice. A wide array of processes have been referred to as ART, including: repositioning a patient using on-line imaging, recontouring and replanning a patient using a combination of patient images, and modifying a patient plan based upon dose recalculations.
One comprehensive version of ART builds upon modifying a patient plan based upon delivered dose. Before or during a patient's treatment delivery, an on-line image set is collected. Additional feedback may be received during the delivery indicating machine functional information and/or patient transmission data. This information, the patient images, and potential patient plan information is then processed to determine the dose that the patient actually received from the treatment. This processing can be performed either on-the-fly or as a post-process.
The delivered dose information can be added across each treatment fraction the patient received. As a result of patient anatomical and physiological changes, it is appropriate to determine the deformation and/or tissue-mapping that represents the patient anatomical and physiological changes that may have occurred during the course of treatment. Likewise, a contour set that defines the treatment and avoidance regions of the patient can change, and these contours can be updated.
Once all of this information is processed, the radiation therapy treatment system can determine the accumulated dose received by the patient, and organize that information according to specific targets or avoidance regions. Based upon this information, the system can create a new plan for the patient that better accounts for any changes in the patient or for any off-course delivery. Also, the system can evaluate hypothetical situations, such as how a patient treatment would have been affected by using different protocols, different plans, etc.
Many processing steps are usually performed in order to complete this type of ART evaluation, which results in many auxiliary data sets. For example, each fraction may require a deformation map relating a daily image to the planning image, an updated contour set, and an updated dose. Since each patient might receive upwards of 30 fractions, this is a large number of files to manage. Moreover, there can be many additional files, from important pre-processing steps, such as detector data analysis, or image manipulations to account for density calibrations or corrections, couch differences, incomplete image padding, etc. Finally, it should be noted that the number of files can then grow exponentially as hypothetical delivery options are explored, such as evaluating not only the planned and delivered doses, but the doses that would have been delivered for different patient positions, or with different combinations of delivery plans.
As such, one aspect of this invention is to provide a graphical user interface (“GUI”) and framework for managing this data. In particular, the user need not organize or maintain the plethora of data files required for the adaptive analysis, but instead can focus on a dashboard that provides an overview of all of the processing that has been performed.
The invention also provides a computer-generated user interface for presenting data relating to a radiation therapy treatment plan. The user interface comprises a list of fractions identified in the treatment plan, data identifying delivery status of the fraction, and data identifying a processing status of the fraction, and wherein the processing status relates to data acquired before, during, or after treatment to retrospectively analyze the delivery.
The invention also provides a system for developing and analyzing radiation therapy treatment plans. The system comprises a computer processor, a data store, and software. The data store is connected to the computer processor and stores information relating to at least one fraction of a radiation therapy treatment plan, which fraction has been delivered to a patient as part of the implementation of the radiation therapy treatment plan, information relating to a delivery status of the fraction, and information relating to a processing status of the fraction. The software is stored in a computer readable medium accessible by the computer processor and is operable to automatically process the information relating to the at least one fraction, and wherein the processing status relates to data acquired before, during, or after treatment to retrospectively analyze the delivery.
The invention also provides a method of evaluating a radiation therapy treatment plan. The method comprises the acts of acquiring a reference image of at least a portion of a patient, accessing a list of fractions identified in the treatment plan for the patient, each fraction being associated with a set of delivery conditions or parameters, retrieving an image associated with one of the fractions, generating a deformation map between the reference image and the image associated with one of the fractions, and evaluating a radiation dose that would have been delivered to the patient for at least one of the fractions if any of the delivery conditions or parameters were different.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
Although directional references, such as upper, lower, downward, upward, rearward, bottom, front, rear, etc., may be made herein in describing the drawings, these references are made relative to the drawings (as normally viewed) for convenience. These directions are not intended to be taken literally or limit the present invention in any form. In addition, terms such as “first”, “second”, and “third” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance.
In addition, it should be understood that embodiments of the invention include both hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the invention may be implemented in software. As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement the invention. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible.
The radiation module 22 can also include a modulation device 34 operable to modify or modulate the radiation beam 30. The modulation device 34 provides the modulation of the radiation beam 30 and directs the radiation beam 30 toward the patient 14. Specifically, the radiation beam 34 is directed toward a portion of the patient. Broadly speaking, the portion may include the entire body, but is generally smaller than the entire body and can be defined by a two-dimensional area and/or a three-dimensional volume. A portion desired to receive the radiation, which may be referred to as a target 38 or target region, is an example of a region of interest. Another type of region of interest is a region at risk. If a portion includes a region at risk, the radiation beam is preferably diverted from the region at risk. The patient 14 may have more than one target region that needs to receive radiation therapy. Such modulation is sometimes referred to as intensity modulated radiation therapy (“IMRT”).
The modulation device 34 can include a collimation device 42 as illustrated in
In one embodiment, and illustrated in
The radiation therapy treatment system 10 can also include a detector 78, e.g., a kilovoltage or a megavoltage detector, operable to receive the radiation beam 30. The linear accelerator 26 and the detector 78 can also operate as a computed tomography (CT) system to generate CT images of the patient 14. The linear accelerator 26 emits the radiation beam 30 toward the target 38 in the patient 14. The target 38 absorbs some of the radiation. The detector 78 detects or measures the amount of radiation absorbed by the target 38. The detector 78 collects the absorption data from different angles as the linear accelerator 26 rotates around and emits radiation toward the patient 14. The collected absorption data is transmitted to the computer 74 to process the absorption data and to generate images of the patient's body tissues and organs. The images can also illustrate bone, soft tissues, and blood vessels.
The CT images can be acquired with a radiation beam 30 that has a fan-shaped geometry, a multi-slice geometry or a cone-beam geometry. In addition, the CT images can be acquired with the linear accelerator 26 delivering megavoltage energies or kilovoltage energies. It is also noted that the acquired CT images can be registered with previously acquired CT images (from the radiation therapy treatment system 10 or other image acquisition devices, such as other CT scanners, MRI systems, and PET systems). For example, the previously acquired CT images for the patient 14 can include identified targets 38 made through a contouring process. The newly acquired CT images for the patient 14 can be registered with the previously acquired CT images to assist in identifying the targets 38 in the new CT images. The registration process can use rigid or deformable registration tools.
In some embodiments, the radiation therapy treatment system 10 can include an x-ray source and a CT image detector. The x-ray source and the CT image detector operate in a similar manner as the linear accelerator 26 and the detector 78 as described above to acquire image data. The image data is transmitted to the computer 74 where it is processed to generate images of the patient's body tissues and organs.
The radiation therapy treatment system 10 can also include a patient support, such as a couch 82 (illustrated in
The computer 74, illustrated in
The computer 74 can include any suitable input/output device adapted to be accessed by medical personnel. The computer 74 can include typical hardware such as a processor, I/O interfaces, and storage devices or memory. The computer 74 can also include input devices such as a keyboard and a mouse. The computer 74 can further include standard output devices, such as a monitor. In addition, the computer 74 can include peripherals, such as a printer and a scanner.
The computer 74 can be networked with other computers 74 and radiation therapy treatment systems 10. The other computers 74 may include additional and/or different computer programs and software and are not required to be identical to the computer 74, described herein. The computers 74 and radiation therapy treatment system 10 can communicate with a network 94. The computers 74 and radiation therapy treatment systems 10 can also communicate with a database(s) 98 and a server(s) 102. The database 98 is a data store or data storage location and operates as a depository for data. It is noted that the software program(s) 90 could also reside on the server(s) 102.
The network 94 can be built according to any networking technology or topology or combinations of technologies and topologies and can include multiple sub-networks. Connections between the computers and systems shown in
Communication between the computers and systems shown in
The two-way arrows in
The software program 90 generates a user interface embodied by a plurality of “screens” or “pages,” which the user interacts with to communicate with the software program 90. As such, all of the screens of the user interface are not limited to the arrangement as shown in any of the drawings. The screens may include, but are not limited to fields, columns, rows, dialog boxes, tabs, buttons, radio buttons, and drop down menus. Field titles may vary and are not limited to that shown in the drawings.
As illustrated in
The screen 110 also includes various buttons for manipulating the radiation therapy treatment plan data. Specifically, the screen 110 includes a Select IVDT button 146, a select button 150, an add button 154, a start button 158, a save button 162, and a load button 166. The Select IVDT button 146 functions to choose or override the default image calibration curve, or image-value-to-density table. This option can also be used to apply other density corrections or processes to the images. The select button 150 allows the user to select a patient and/or set of treatment fractions for analysis. The add button 154 allows the user to add additional treatment fractions to the evaluation. These can be existing fractions, perhaps stored in a different plan, that are brought into the processing, or these might be new fractions, potentially with new or modified plans. The start button 158 initiates processing of the data. The save button 162 functions to save any modifications to the treatment plan and also the processing results of the data. The load button 166 functions to retrieve the current processing status of a patient.
At a glance, it is easy for a user to see which fractions have been both delivered and have had adaptive processing performed (shaded regions, rows 1-18); which fractions have been delivered but not processed (rows 19-23); and which fractions have not yet been delivered (rows 24-35). The contents of each box in the processing columns indicate the type of processing that is to be used. For example, the dose accumulation was performed using deformation. In principle, steps could be evaluated in multiple ways, and a cell might indicate that different types of dose accumulation were performed.
In one form, the computer 74 is programmed to automatically determine what data and/or fractions have been processed, what data and/or fractions are ready for processing, and what data and/or fractions are not available for processing (such as fractions that have not been delivered). Based on this information, the computer 74 performs many or all of the processing tasks with minimal user setup or intervention.
In one exemplary scenario, a user may access the software program 90 that generates the screen 110 roughly once per week for the patient 14. As shown in
The software program 90 includes default settings for the screen 110 and the methods of processing the treatment plan data. The user is not required to use the default settings, but may override them (such as on a cell-by-cell level, by column, by patient, etc.). In some cases, such overrides will not affect the automatic processing of the data. In other cases, user intervention may be required during the processing. For example, one option for the registration column 126 might be to evaluate the dose delivered based upon how the patient 14 was set-up or registered for the treatment fraction. Nonetheless, a user may wish to explore how the dose would have been delivered had the patient 14 been treated differently.
As another example, the dose delivered to the patient 14 can be evaluated using a gamma index. The gamma (γ) index is used to simultaneously test both percent dose difference in plateau regions and distance to agreement in high gradient regions. Percent dose difference is a useful metric in regions of uniform dose—the plateau regions - but is not appropriate for high gradient regions. Distance to agreement is a more appropriate metric for high dose gradient regions. The γ index was introduced by Low et. al. (Daniel A. Low, William B. Harms, Sasa Mutic, James A. Purdy, “A technique for the quantitative evaluation of dose distributions,” Medical Physics, Volume 25, Issue 5, May 1998, pp. 656-661.) Given a percent-dose/distance criterion (e.g., 5%-3mm) γ is calculated for every sample point in a dose profile (1-D), image (2-D), or volume (3-D). Wherever γ<=1 the criteria is met; where γ>1 the criteria is not met.
As another example, the dose delivered to the patient 14 can be evaluated using a xi index. The xi (ξ) index is a generalization of the procedure outlined by Van Dyk et al. (1993) for treatment planning commissioning. With this method, both distributions be compared in their gradient components first, followed by a dose-difference (ΔD) and distance-to-agreement (DTA) analysis. Since there are two dose distributions and two dose gradient classifications (high dose gradient or low dose gradient), there are four possible combinations. Given Vref is the voxel in the reference distribution and Veval is the voxel in the evaluation distribution, these combinations are:
In the proposed comparison tool, for regions in which both the reference and comparison distributions have low dose gradients, ΔD values are obtained. For all other cases, DTA analysis is done. The gradient comparison accounts for the fact that there may be a complete mismatch of dose gradients between the reconstructed and planned distributions. Once ΔD and DTA values are obtained, a numerical index for each voxel can be found that is similar the gamma index proposed by Low et al. (1998). The numerical index ξ is found by the following:
A ξ value of one or less is considered acceptable. Though a volume can have both high and low gradient voxels, this approach is amenable to averaging or display since the ξ values are dimensionless.
In these types of cases, the software program 90 can organize the data processing to maximize speed and/or to minimize the number of user interventions. For example, in the case of registration, the user may wish to have all of the data pre-processing to be calculated first by the program, then be able to check or enter some or all of the registration scenarios at once, and then have the software program 90 complete all remaining processing. In this manner, even when user intervention is desired to decide on the details of the processing or evaluation, it can be streamlined and easily understood. Similarly, all of the contours may be automatically generated for each fraction image, but these can all be reviewed (and edited, if necessary) at one discrete time, instead of requiring disparate interactions with the software.
The user interface can also include a scripting language, or macro ability that lets a user more precisely define and record complex preferences. This feature allows the user to specify when and how they wish to be notified, how the processing should be done, or how the results should be evaluated. Similarly, the user interface can include an alerting function, which when processing data, notifies a user if the patient dose exceeds certain thresholds or tolerances. This alerting feature could be used with application processing occurring in the background or automatically, and notifications could include on-screen messages, pages, e-mails, or other methods of rapid communication.
Another aspect of this invention is its flexibility to evaluate hypothetical situations. The columns 114-142 illustrated in
Various features of the invention are set forth in the following claims.
This application claims priority to U.S. Provisional Patent Application No. 60/726,548, filed on Oct. 14, 2005, titled “METHOD AND INTERFACE FOR ADAPTIVE RADIATION THERAPY”, the entire content of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60726548 | Oct 2005 | US |
