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myQA FastTrack PT - Applications

  • Updated

Opening the myQA FastTrack PT Application

myQA FastTrack workspace with myQA FastTrack PT application selected (example)

The FastTrack workspace contains the following parts:

  • 1 (1a + 1b): Main Workspace Navigation panel.
    • 1a: Main Workspace Selection dropdown menu, which also displays the title and icon of the currently selected application.
    • 1b: Application type selection. Upper icon: Measurement with StarTrack / MatriXX / Dolphin. Lower icon (for myQA FastTrack PT application): Measurement with Lynx PT / myQA Phoenix / Sphinx Compact.
    • 1c: Navigation collapse button – click it to hide and show the Main Workspace Selection panel.
  • 2: Ribbons containing the commands for the selected measurement.
    • 2a: Ribbon collapse button – click it to hide and show the ribbon.
  • 3: Main display based on the selections in 1 and 2.

 

Procedure

  • Click the Main Workspace Selection button in the upper-left corner of the myQA window (1a) and then select myQA FastTrack in the dropdown list.
  • Select the lower icon for the myQA FastTrack PT workspace (1b).

 

Coordinates

Lynx PT

Here are the coordinate systems of the Lynx PT and its representation in myQA FastTrack PT. The Y direction is opposite to the tail of the Lynx PT.

Coordinates illustrated on a Lynx PT (left) and an image in the myQA FastTrack PT application (right)

Note: myQA Machines PT and myQA FastTrack PT coordinate systems are different. The myQA Machines PT           is in beam eye view (and can have a user-defined shift in Y); whereas the myQA FastTrack PT uses the           detector view and shifts 20 mm in Y to make the image match.

               myQA FastTrack PT (detector view)               myQA Machines PT (beam eye view)

 

myQA Phoenix

Coordinate system of the myQA Phoenix in myQA FastTrack PT

 

Sphinx Compact

Coordinate system of the Sphinx Compact in myQA FastTrack PT

 

Typical Workflows

Although the general workflows for measurements using the Lynx PT and myQA Phoenix are the same,
there are minor differences.

Note: If you cannot see the myQA FastTrack PT application icon in the FastTrack navigation panel, please               check whether your license has been activated or contact your local service team.

Note: If there are problems for acquiring or analyzing images, please run myQA with administrator rights.

 

CAUTION: EXPORT RAW IMAGE AS .OPG

To avoid a reduction of accuracy, it is recommended to export the image as .OPG before performing any normalization.

IMPORTANT NOTICE: RESTARTED A SESSION FROM SLEEP MODE

When a session is restarted from sleep mode, the Lynx PT / myQA Phoenix / Sphinx Compact connection may be lost although the display shows as if it is still connected and a measurement can be started. However, after a few minutes, an error message pops up and informs the user to reconnect the detector. The User should click the Disconnect button and then the Connect button in the Measurement ribbon.

 

Measurements with Lynx PT

Preconditions

  • A clinic, PT machine, and detector have been set up in the Equipment Setup page (see Chapter 6 in myQA Platform Instruction for Use).
  • The detector is connected to the PC.
  • The myQA FastTrack PT is licensed.

Procedure

Images are acquired with the Measurement ribbon. The general procedure follows the commands from left to right in this ribbon:

  • In the myQA FastTrack navigation panel, select the myQA FastTrack PT icon.
  • Open the Measurement ribbon by clicking the Measurement tab (1).
  • Select the machine and measurement device:
    Lynx PT (2) and machine (3) in the Equipment group using the two drop-down menus. If your Lynx PT is connected, it should appear in the drop-down menu.
  • Click on Connect (4):
    A waiting bar appears while the device is initialized. This should take no longer than a few minutes. Once the Lynx PT is ready to acquire an image (or a background), the Connect button will show a green sign ().
  • Select your desired parameters (profile, frame duration, iris) in the Settings group (5). See Section 3.3.3 for information about the Selected Profiles box. The default measurement settings are Frame duration = 2s and Iris opening = 100%. The details of the measurement options are given in Section 2.5 of myQA FastTrack PT Reference Guide. User can already acquire an image with default parameters. At each session start, the profile is set to ‘default’ to avoid errors.
  • In the Beam type group, select the beam type used for acquiring images (6).
  • Click the Background icon (7): A waiting bar appears while the background is acquired. This should take no longer than 40s.
    For the Lynx PT, the background is fixed and is made of a 20s single shot image and a movie. Once acquired, the icon will turn green. It can be reacquired if needed by clicking the Background icon again.
  • Perform measurement:
    • Select a Measurement mode (8).
    • Click Start (9). Measurement starts and a waiting bar appears. 

             

Once the measurement is finished, the image will appear on the reference panel and on the Image tree, for post-processing or further analysis. The name is the acquisition time by default and can be renamed with the context menu (opens by right clicking).

IMPORTANT NOTICE: MEASURED IMAGES ARE NOT SAVED BY DEFAULT

Measured images are not saved by default. The user needs to export them.

 

Measurements with myQA Phoenix / Sphinx Compact

Preconditions

  • A clinic, PT machine, and detector have been set up in the Equipment Setup page (see Chapter 6 in myQA Platform and Devices).
  • The detector is connected to the PC.

Note: For measurements using the myQA Phoenix / Sphinx Compact, please wait optimally 2 minutes between connecting the device and starting a measurement.

Device active area

  • The active area of the myQA Phoenix / Sphinx device is 41 cm × 41 cm / 205 mm × 205 mm. However, to obtain spot characteristics with high accuracy, it is recommended to avoid irradiating any spot at a distance inferior to 3σ from the edge of the active area, where σ represents the one sigma spot size.

About background measurements with the myQA Phoenix

  • Collecting background measurements is mandatory with myQA Phoenix / Sphinx Compact and is
    dependent on the gain value. By default, the background duration is 20 seconds. The duration value can be modified, but it is recommended to use a minimum of 5 seconds.

Warm-up

  • A warm-up of 10 minutes for myQA Phoenix / Sphinx Compact is recommended.

IMPORTANT NOTICE: BACKGROUND SHOULD NOT BE OLDER THAN 10 MINUTES

The background should not be older than 10 minutes before acquiring an image.

Procedure

Images are acquired with the Measurement ribbon. The general procedure follows the commands from left to right in this ribbon:

  • In FastTrack navigation panel, select the PT measurement icon (the lower Measure button).
  • Open the Measurement ribbon by clicking the Measurement tab (1).
  • Select the machine (2) and your measurement device (3) in the Equipment group of the ribbon using the corresponding drop-down menus. If your measurement device is configured, it should appear in the drop-down menu.
  • Click on Connect (4):
    A waiting bar appears while the device is initialized. This should take no longer than a few minutes. Once the Lynx PT is ready to acquire an image (or a background), the Connect button will show a green sign ().
  • Select your desired parameters (profile, frame duration, gain, etc.) in the Settings group (5). See Section 3.3.3 for information about the Selected Profiles box. The default measurement settings are Frame duration = 2s and gain = 2 pF.The details of the measurement options are given in Section 2.5 of myQA FastTrack PT Reference Guide. User can already acquire an image with default parameters. At each session start, the profile is set to ‘default’ to avoid errors.
  • In the Beam type group (6), select the beam type used for acquiring images.
  • Click the Background icon (7): the default background value is 20 seconds and it is adjustable. A
    correction is then automatically applied to the response of the detector.
    Once acquired, the icon will turn green. It can be reacquired if needed by clicking the Background icon again.
    Note: For myQA Phoenix / Sphinx Compact, the background is mandatory. It is not possible to acquire           an image without a background acquired. The icon is red if it is not measured and turns green             once it is measured.
  • Perform measurements:
    • Select a Measurement mode (8).
    • Click Start (9). Measurement starts and a waiting bar appears.

Once the measurement is finished, the image will appear on the reference panel and on the Image tree, for post-processing or further analysis. The name is the acquisition time by default and can be renamed with the context menu (opens by right clicking).

 

IMPORTANT NOTICE: MEASURED IMAGES ARE NOT SAVED BY DEFAULT

Measured images are not saved by default. The user needs to export them.

Note: Multiple Shots option is not available for myQA Phoenix / Sphinx Compact.

WARNING: SATURATED IMAGES

When using myQA Phoenix or Sphinx Compact at 4 pF or 8 pF gains with myQA software, detector saturation may not be detected by the software. The software only detects the charge amplifier saturation (level equal or higher than 65536 counts including background) but not the diode saturation (level depends on the panel and temperature).

The undetectable image saturation due to the myQA Phoenix or Sphinx Compact detector saturation might lead to a wrong determination of counts and spot sizes for machine QA.

If the myQA Phoenix detector is used for the commissioning of the TPS, the undetectable image saturation due to the detector saturation might lead to transferring inaccurate spot profiles to the TPS.

It is thus recommended to use gains of 2 pF or lower.

 

If 4 pF or 8 pF is selected, a warning tooltip will appear:

On the other hand, it is recommended to avoid acquiring images with too low count values. If the maximum count value of images is below 30,000 counts, you can decrease the gain value. For example, if an image is acquired with a gain of 1 pF and the count values are around 20,000, the same acquisition with a gain of 0.5 pF should provide an image with count values around 40.000.

 

Profile Measurement Settings

The profile can be selected in the upper-left dropdown box under Selected profile in the Measurement ribbon:

Selected profile for a Lynx PT

For the three items on the right side of Selected profile (Uniformity, Geometry, and Deformation), the
green round button is an indicator that this item was ticked in the selected profile and thus it will be applied to all the measured images.

Note: The Geometry and Deformation functions are only relevant and thus available for Lynx PT.

IMPORTANT NOTICE: DEFAULT PROFILE

By default, at each session start, the selected profile is set to default.

 

In a profile, the ticked items will be applied to the measured images. It is recommended to use the Default profile. To view/change the settings or create a new profile, click the Manage profiles box to open the User profiles dialog.

User profile for Lynx PT                                      User profile for myQA Phoenix

 

About uniformity calibration for the Lynx PT and myQA Phoenix

A uniformity calibration is needed to compensate for the inhomogeneity due to:

  • non-uniformity response of the detector,
  • and device aging under radiation.

For the Lynx PT:

The uniformity calibration file (*.MC) for the Lynx PT is specific to each unit and depends on the radiation
quality (mainly in photon beam). It is calculated using a reference water phantom profile in either MV LINAC beam or Cobalt beam. It is recommended to use the one created in Cobalt beam.

For myQA Phoenix:

The uniformity calibration file (*.uc) for the myQA Phoenix provided by IBA Dosimetry is specific to each unit. It is calculated using a reference water phantom profile in Cobalt beam by IBA Dosimetry.

WARNING: UNIFORMITY CALIBRATION FILES

Uniformity calibration file of a Lynx PT or myQA Phoenix must be applied to the measured data.

It is recommended to recalibrate the uniformity every year or after every intensive use. If an issue with the uniformity of the response of a detector is observed, it must be recalibrated before any further use. It must be sent back to IBA dosimetry for recalibration. Then load the new uniformity calibration file to the myQA Platform > Equipment setup > [detector name] > Edit > Detector Editor dialog > Add files button and then select this file the Default .mc box (for the Lynx PT) or in the Default Uniformity box (for the myQA Phoenix).

Create a user-defined profile for the Lynx PT

  • Click Manage profiles to open the User profiles dialog.
  • Click New, enter the name of the profile (cannot be empty), and then click Enter.
  • For Geometry calibration and Deformation correction, only one can be applied in one profile.WARNING: DO NOT USE GEOMETRIC AND DEFORMATION CORRECTION TOGETHER
    Geometrical correction should not be used with the deformation correction .Using both may lead to wrong results.
  • Select Median Filter and enter the number of pixels for the mask size if desired (1 to 5). The median filter (e.g. mask size 5) is substituting the value of each pixel with the average of its neighboring pixel. The mask size defines the number of pixels that are taken in consideration for the average.CAUTION: MEDIAN FILTER SIZE
    It is recommended to use a median filter of size 5 for consistency with Lynx2D.
    Be aware that median filter can be only performed while the image is taken.
  • Select MC File in the dropdown box to match the latest uniformity correction available for this Lynx PT. It is strongly recommended to use latest MC file provided by manufacturer.WARNING: UPDATE EQUIPMENT SETUP WHEN LYNX PT IS RECALIBRATED
    Make sure you update the equipment setup with new calibration file(s) when your Lynx PT is recalibrated
  • Select Y Slope Calibration if needed.WARNING: APPLYING Y SLOPE CALIBRATION
    The Y slope correction compensates a slight slope in Y observed in large fields and resulting from the optical design. It is recommended to apply Y slope calibration, especially for large fields.
    Be aware that Y slope calibration can be only performed while the image is taken with the selected Y Slope Calibration button. It cannot be applied later once the image is taken.
  • Click Save. The newly created profile will be listed in the profile dropdown list and ready to be used. User-defined profile (Lynx PT) CAUTION: BE CAUTIOUS WHEN A NON-DEFAULT PROFILE IS USED
    When a non-default profile is used, a warning sign in the dropdown menu appears to remind the user that the selected profile can lead to different results.

Create a user-defined profile for the myQA Phoenix

  • Click Manage profiles to open the User profiles dialog.
  • Click New, enter the name of the profile (cannot be empty), and then click Enter.
  • Select Median Filter and enter the number of pixels for the mask size if desired (only odd integer number, i.e. 1,3 or 5). The median filter (e.g. mask size 5) is substituting the value of each pixel with the average of its neighboring pixel. The mask size defines the number of pixels that are taken in consideration for the average.
  • Select *UC File in the dropdown box to match the latest uniformity correction available for this myQA Phoenix. It is strongly recommended to use latest MC file provided by manufacturer.WARNING: UPDATE EQUIPMENT SETUP WHEN MYQA PHOENIX IS RECALIBRATED
    Make sure you update the equipment setup with new calibration file(s) when your myQA Phoenix / Sphinx Compact is recalibrated
  • Click Save. The newly created profile will be listed in the profile dropdown list and ready to be used.

Importing Images for Analysis

In addition to acquiring images by measurement, they can also be imported by clicking the Import button in the Home ribbon.

For more information on importing and exporting images in the Images panel, see myQA FastTrack PT Reference Guide.

 

Warnings in the Images Panel

The SW validates the the measured image and the image during import. If errors are found in the image, a warning message will appear or a warning sign appear next to the filename.

Warning 1: Image position is not well defined (only for Lynx PT)

A warning message will appear if the DICOM image position is not well defined (RTImage Position differs
from [-149.75; -149.75]). It can appear when importing DICOM acquired with some Lynx2D versions and it is therefore recommended to use the shift function in Tools to correct (here shift +0.25 mm in X and +0.25 mm in Y).

Warning 2: Incorrect matrix size

In case the image does not have the correct matrix size, an error message will be displayed, and no image will be imported. myQA FastTrack PT creates 600 × 600 matrix for Lynx PT images and 2048 ×2048 matrix for myQA Phoenix images.

Warning 3: Saturated image

If an image is saturated (if more than 1 pixel is > 1023 counts for the Lynx PT images and if the pixels in a cluster of pixels in one frame (of 1 s) are higher than 65,535 counts for the myQA Phoenix / Sphinx Compact images), a warning will be displayed in the Image tree (during import or acquisition):

Please note that saturated image should be disregarded as analysis may give incorrect results.

WARNING: SATURATED IMAGES

If the image is saturated, a warning sign will appear next to the filename. The tooltip message indicates that the image may be saturated.

If it is an imported image, it is not qualified to be used for analysis. If it is a measured image, the measurement should be repeated with a different Iris opening of the Lynx PT or a different gain value of the myQA Phoenix / Sphinx Compact, or with a modified map by decreasing spot intensity where the image is saturated.

Warning 4: Data was acquired with older SW Lynx 2D version (only for Lynx PT)

A warning message will appear if the data was acquired with Lynx2D versions older than 5.2 as the information tag cannot be read:

The image will still be imported, but the image information box will be empty.

Warning 5: The beam is cut (only for Lynx PT)

For images taken with the Lynx PT, a warning sign “Image may have cut beam.” may appear on the right side of an image filename in the Images panel. If the beam is larger than Lynx active area (300 mm × 300 mm), i.e., if there is some signal (above 5% of the Lynx range) on the 3 pixels of the border of the Lynx, a warning about ‘cut beam’ is displayed:

Images with cut beam should be used with caution as analysis may give incorrect results.

Warning 6: Frame lost (only for myQA Phoenix / Sphinx Compact)

If there are lost frames detected, a warning sign will be displayed next to the filename in the Image tree.

When frame loss has occurred, it is recommended that the user acquire a new image.

 

Analysis Procedures

WARNING: DO NOT USE SATURATED IMAGES

Please avoid using images that are saturated or where beam is cut, which can lead to wrong results.

 

Analysis procedures are the same for all images acquaired with Lynx PT, myQA Phoenix, or Sphinx Compact.

Analyses are divided into two categories and is accessed in Analysis group on the Home ribbon: analysis of single image or multipe images.

 

Single image analysis

Analysis tab

  • Set an image as Reference image (drag to upper left windows or use right click menu).
  • If necessary, adjust the ROI (Region Of Interest), visualized with the white a rectangle.
  • Click the Test Category dropdown list and select the desired test type, e.g.,Note: See Section 2.6 and Section 2.7, myQA FastTrack PT Reference Guide, for explanations of                        analysis parameters. For more information on defining analysis parameters for the multiple                  spot analysis, see Section 3.3.6.3. For the complete algorithms of spot analysis, see Ch. 3, myQA            FastTrack PT Reference Guide.
  • When an analysis method is selected, a set of parameters will be displayed. Modify them if necessary.
  • Click to start the calculation. When it finishes, the results will be displayed.Example 1: Single image > Multiple Spot Analysis:
    Detail description for different test type analysis, see Section 2.6 of myQA FastTrack PT Reference Guide.

Profile Tab

When the Profile tab is selected, the inline and crossline of the displayed image(s) is shown. Ticking a box will refresh the display. Both profiles can be zoomed in/out and data points can be displayed.

The user can choose to display only reference (in green), only comparison (in orange), or both.

The user can choose the display scale in the dropdown menu: raw data (in counts) or image renormalized to image maximum (in %). When two images are selected, they are both renormalized to their own maxima.

1: Select one or both images to be displayed; 2: Select scale: raw data or normalized to each image max; 3: Profile pane-specific viewing tools; 4: Cursor.

A cursor is also available to compare intensity (values given below graphs), as well as a distance cursor.

 

Comparison Tab

When both Reference and Comparison images are loaded, the Comparison tab becomes available. Three comparison calculation methods are provided:

Gamma index

The gamma calculation direction is the Reference image dataset vs. the Comparison image dataset.

WARNING: ENSURE CORRECT REFRENCE AND COMPARISON IMAGES FOR GAMMA ANALYSIS

Wrongly assigned Reference and/or Compare datasets may lead to incorrect gamma analysis or other comparison results. Imported images and their order are up to the user.

 

More information about these comparison methods are described in myQA FastTrack PT Reference Guide.

 

Multipe Image Analysis

  • Select Multiple in the Home ribbon (1).
  • Select the images to be analyzed, using Shift-key and mouse (2).
  • Select a test type, e.g., Multiple Spot Analysis (3)
  • Enter /edit the analysis parameters (4).
  • Click . The calculation will start. When it finishes, the results will be displayed.Example: Multiple images > Multiple Spot Analysis

 

Algorithm of Multiple Spot Analysis

The multiple spot analysis operates on the entire image or a defined ROI of the image. The Multiple Spot algorithm is explained in the sub-sections below.

 

Spot Detection

The multiple spot algorithm can operate on a large region in an image, automatically detecting multiple spots. This is achieved by finding local maxima in the image that have an intensity above a given threshold. The threshold used to detect spots is defined in myQA by the Intensity % for Maximum parameter (1). It is an intensity expressed as a percentage of the maximum image intensity.

Analysis tab for Mutiple Spot Analysis parameters in myQA FastTrack PT measurement workspace

To avoid detecting local maxima, which are closely together, and thus detecting one spot multiple times, the multiple spot algorithm provides a parameter No. Neighbors to consider for Maximum (2). This parameter is used by multiple spot algorithm to determine the number of the neighboring pixels to be considered when detecting the spot maxima.

For all detected spots in the region of interest (ROI), the multiple spot algorithm creates new sub-ROIs. The size of the sub-ROIs is defined by the parameter Intensity % for Gaussian Cut (3). It defines the ROI in terms of how much signal of the spot is included in the analysis region. It creates a rectangular ROI around the spot’s maximum until the signal of the spot drops below the defined intensity.

1D Fit of Gaussian Spot

To compute the raw data where the 1D gaussian profile is fitted, the Multiple Spot algorithm creates one inline (vertical) and one crossline (horizontal) profile in the entire ROI. It is complished by summing up the row entries for the crossline profile and the column entries for the inline profile.

On the created profiles, a gaussian shape is fitted using an iterative fit routine. The fitting parameters are “Max no. Iterations for Fit” and “Chi Square Tolerance for Fit”.

Spot Position Computation

The computed spot position in the image is the center of the fitted spot.

Skewness Computation

Since the fitted spot has an ideal gaussian shape, it is unsuitable to compute the skewness. Instead, the raw values of the crossline and inline profiles are used to compute the skewness of the spot.

 

Troubleshooting

Missing Spot in the ROI

If a spot is missing in the analysis (1) the user has two options:

  • Increase the distance between 2 spots or,
  • Position the spots in a staggered row. Please note, the offset should be higher than the tolerance.

 

Analysis of the energy test with carbon ion beams

The goal of the energy test is to determine different quantities characterizing depth-dose curves (range, distal fall-off, etc.). The algorithm in the SW is based on the determination of the edge of the
energy block. However, in carbon ion beams, due to the fragmentation tail, it may be that the edge of the block is not well defined. In that case, the algorithm does not work.

To prevent this problem from happening, it is recommended to use a higher MU/spot for the spot close to the edge of the block (3) compared to the ROI (2). This ensures that the SW can distinguish it during analysis.

 

Manually install the 2017 Drivers

  • Open CMD.
  • Write "driverquery" and press Enter.
  • Check if Point Grey Lightweight Kernel of 2017 is installed.

If the wrong driver or no driver is installed do the following:

  • Go to the folder C:\Program Files\Point Grey Research\FlyCap2 Viewer\bin64
  • Open GigEConfigurator.exe
  • Select Firewall and Filter Driver Settings
  • Deselect Install Filter Driver and confirm that you wish to uninstall the driver by clicking Yes on the
    Confirm filter driver uninstallation.
  • A pop-up will appear confirming the uninstallation of the driver.
  • Select the Install Filter Driver check box. A pop-up will appear prompting you to choose the location manually. Click OK.
  • Select the folder C:\Program Files\Point Grey Research\FlyCap2 Viewer\driver64\PGRLWF and click OK.
  • A pop-up will appear confirming the installation of the driver.
  • Open cmd and enter “driverquery” to check that the correct driver is installed