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myQA StarTrack3 - Setting up a Measurement

  • Updated

Measure

On the Measure page, the user can perform the following functions:

  • Measurement Acquisition (Section 7.1)
  • Measurement Analysis (Section 7.2)
    • Data selection (1)
    • Plots and numerical analysis (2)
    • Measurement data view and editing (3)

CAUTION: ENERGY VERIFICATION
Do not perform energy verification tests with a field size smaller than 20 cm x 20 cm as this may lead to wrong results and potentially patient harm.

 

Measure

7.1.1. Connect Device

A device must be online and connected to perform measurements in the Web App

  • In the Device Selection section, click the Connect button for the device.
    Check the Show offline devices to include previously saved offline devices.

  • Once the Device is connected (as indicated by a green check), move on to Background.

    CAUTION: DEVICE IN ERROR STATE
    Do not perform measurements if the measurement detector is in an error state as this can result in inaccurate measurements and may pose a risk of patient harm.

 

Background

  • Select the Background measurement type:

    • Automated
    • Manual
    • None

    Automated - Collects the background automatically when the device is connected and can be
    refreshed anytime by the user.

  • The background measurement can be collected/renewed by clicking the (refresh) icon.

  • The most recent background measurement is show at the bottom.

  • A green check shows that the background has been collecSted.

    Manual - The Background measurement will be collected manually.

  • Set the preferred sampling time.

  • Click Start to start the Background collection.

  • The most recent background measurement is show at the bottom.

  • A green check shows that the background has been collected.

    None - No background measurement is collected.

  • Once the Beam type has been selected and a green check appears (if applicable), move on to Measurement mode.

    CAUTION: ENSURE BACKGROUND HAS BEEN MEASURED
    Do not perform measurements without background compensation as this can result in inaccurate measurements and may pose a risk of patient harm.

 

Measurement Mode

  • Select the Measurement Mode type:

    • Beam triggered - The user must define (Start / Stop) the time interval during which the beam is expected. Within this period, acquisition is automatically performed when the signal of pixels in the central area exceeds the selected threshold.
    • Manual - Measurements will be collected when the Start / Stop button is clicked.
    • Fixed time - Measurement will be collected over a predefined period of time.

  • Click the Settings icon to set the specifics (i.e., Sampling time) for the Measurement mode selected. Beam Triggered:

    Manual:

    Fixed time:

  • Once the Measurement mode has been selected, move on to Calibration & Correction.

 

Output Calibration procedure

CAUTION: DO NOT USE CALIBRATION FILES OLDER THAN SIX MONTHS
Do not use calibration files older than six months. Using calibration files older than six months might have a negative effect on the measurement accuracy

If a calibration that is older then 6 months is used there will be a warning in the Web App.

  • If the kTp and Output Calibration are already applied, move onto the Measurement.
    If an Output Calibration has not been created, follow the below procedure:

  • To create an Output Calibration, open the Device page.

  • Select a device and click the Output calibration button . The Output Calibration dialog opens.

 

Step 1: Connect

  • Connect the detector and click Continue.

  • If the selected device is already connected, the Output Calibration will open on Step 2.

Step 2: Parameters

  • Set the parameters, including BEAM SETUP, PHANTOM SETUP, and kTp CORRECTION.

    IMPORTANT NOTICE: MUST HAVE THE SAME CONDITIONS AS REFERENCE DOSE
    The output calibration must be measured in the same conditions used to measure the reference dose. For an accurate evaluation of output calibration, the same measurement should be repeated at least three times.

    Depending on the machine type selected, the Beam Setup section maybe have different parameters (i.e., Dose rate or Dose and Delivered MU)

  • Click Continue once all the necessary parameters have been entered.

Step 3: Measure

  • Follow the Measure Output Calibration instructions:
  • Click the Start measuring button .
  • Turn on the beam.
  • Turn off the beam.
  • Stop the measurement. It will appear in the list of measurements.

  • Repeat the steps for acquisition above as many times as desired. Multiple measurements will be averaged (1).

  • Click the (2) of a measuremnt to delete it.
  • The new output calibration can be marked as Active to set it as the active output calibration for measurements with the device.
    • The newly measured calibration is set Active (3) by default.
    • It is specific to the Device / Machine / Energy combination, not just Device. It cannot be used for
      different machines and energies.
    • Only one Calibration at a time can be active for a given Device / Machine / Energy combination.
    • For matched Machines, the Output Calibration can be Duplicated to a new machine with the same energy of the original one.
  • Click the Save Output Calibration button .

  • All output calibrations for the device are listed in the Output Calibration section.

 

Measurement

  • Click on the Settings button.

  • Enter the Device and Beam Setup information.
    Please note, the parameters may change depending on the Machine selected under Beam Setup.
    DEVICE SETUP

    • Device position: Select between couch or
      gantry
    • Phantom name: Enter a new phantom
      or select from an existing phantom. If no
      phantom is used, the field can be left blank, or
      select None
    •  Phantom build-up thickness: Geometric and
      Water equivalent
    • Phantom build-up material (mm)
    • Device rotation (°): Rotation around the
      vertical axis. Rotation at 0° is the device
      aligned to the gantry-target direction, the
      sensor area close to the LINAC.
    • Source detector distance (mm)

    Corrected measurement name (Optional): Enter the name of the measurement. If no name is entered it will automatically be labeled with the date and time.
    Please note, it is possible to have measurements with identical names.

    BEAM SETUP

    • Machine

      Energy and Field size parameters become available once a machine is selected. The value typed in this field cannot exceed the maximum field size of the machine. This limit is independent from the fact that the field is limited by Machine's MLC or by jaws.

    • Energy

      When selecting an Energy, the dropdown list will show all available energies (1) for the selecte Machine. A warning sign indicates that an Output Calibration is not currently available for the energy
      (2).

    • Field size (mm): Crossline (LR) or Inline (GT)

      The maximum field size is defined by the machine configuration.

    • Delivered dose (cGy) and MU
    • Collimater and Gantry angle (°)
  • Click Save to confirm the entered values.
  • Turn on the beam before starting the measurement.

  • Click Start to begin the measurement.

    If a measurement acquisition is running in a page (either the Measure page, QA Test or Output Calibration), it is not possible to leave the page while the acquisition is running. To perform other tasks (e.g., Data import or Analysis) during a long acquisition, a second instance of the Web App can be
    opened in a new browser tab.

  • Click Stop to end measurement acquisition.
  • The new measurement will be automatically added to the Corrected Measurements list.

 

Measurement Acquisition Live View

If an acquisition is started in Measure workspace, frames are showed live (1D Profiles and 2D Chart).

  • The maximum refresh rate is 0.25s.

Additionally, the Analysis table is updated live during acquisition.

  • The Analysis table contents during the acquisition refers to the last acquired frame.
  • After stopping the acquisition, the integral is used for the analysis.

If a Measurement is set for comparison, it is superimposed to the 1D Plots and Analysis of the current
frame.