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• Database driven daily QA
• Rapid setup and simple beam acquisition
• Automatically corrects for temperature and pressure
• Verify flatness, symmetry, dose, photon energy, and electron energy
The Daily QA Check 2 is an advanced Linac QA tool offering the user many advancements designed to save time and deliver more accurate and meaningful data. In designing the Daily QA Check the aim was to create a product that imposes minimal time demands while optimizing data analysis functionality. This led to a compact all-in-one design that uses a single cable to interface with advanced PC software.
The Daily QA Check 2 uses six ion chambers with temperature and pressure correction built in. These chambers are vented and have a collection volume of 0.6cc. The automatic temperature and pressure corrections save the user from having to measure, record, and apply these readings manually.
Five of the chambers are used for flatness, symmetry, and dose constancy. A sixth chamber is included for electron and photon energy QA.
The Daily QA Check 2 software allows the user to define their own unique QA requirements. This highly versatile system results in a “scheme tree”, which is an outline that starts with a Linac, and branches out to include days of the week and specific tests to be done on each day. Once the scheme tree is set in the software, daily measurements are automated and involve three simple steps. The first two steps involve selecting the appropriate LINAC and pressing START. The Daily QA Check 2 software then drills down to the appropriate day of the week, and instructs the operator to begin the first measurement that is specified for that day. Once the measurement is complete, the Daily QA Check 2 evaluates the dose data and notifies the operator if it is within tolerance. The final step is to accept, reject, or redo the measurement based on the results.
After step 3, the software continues to drill down the QA scheme tree until all energies are tested. To the right of the scheme tree is a setup section that updates setup instructions for the current energy check.
At the end of each measurement, a status bar will turn either red or green indicating if the test passed or failed the defined acceptance criteria. Regardless of status, data can be viewed instantly by selecting the Details and Data buttons. When a measurement is ready to be written to the database, click the Accept button. This will write all chamber data to the QA trend analysis database for later viewing. Accepting the data will also initiate the next measurement (if applicable) in the scheme tree.
The Daily QA Check 2 writes all accepted data to a trend analysis database. The database provides a graphical presentation of measured and calculated data for each template as a function of time. Data parameters include Dose, Axial Symmetry, Transverse Symmetry, Flatness, and Energy Constancy.
Graphing the parameters gives the user a means to visualize trends emerging in the beam output. The user has the option to choose which data parameters to view, and over what period of time to view them. Users can identify sections of data to scrutinize further by zooming in. A single measurement instance can be further examined by double clicking on a particular data point (which corresponds to a particular day).
The Daily QA Check 2 makes it’s data available for printing regular QA reports. These reports can span any defined time frame and are suitable for presentation.
The Daily QA Check 2 has an optional gantry attachment, which firmly holds the Daily QA Check 2 in place beneath your accelerator head. The gantry attachment is ideal for shortening setup time and for measurements where the gantry angle is not orthogonal to the treatment couch.
Specifications
Detector Array
Type: Vented ionization chamber, fully guarded
Quantity: 6 - One center detector, Four quadrant detectors, 8 cm from center, one energy detector, 5.6 cm from center
Parallel Plate Separation: 4 mm
Collection Electrode: 1.38 cm dia. carbon
Inherent Buildup:
Actual; Acrylic, 0.79 cm; Mylar, 0.038 cm
Effective: 1.0 ± 0.1 g/cm2
Inherent Backscatter: Acrylic, 2.3 cm
Buildup Plates:
2 cm acrylic plate with attenuator for energy detector;
One 1 cm acrylic plate
Radiation Measured:
Photons, Co-60 to 25 MV
Electrons, 5 MeV to 25 MeV
Beam Limits:
Maximum dose per pulse, 0.055 Gy
Maximum average dose rate, 2.5 Gy/s
Warranty: 1 Year
Alignment Template
Light Field Alignment: 20 x 20 cm
Calibration
Array: Patented (#6125335) wide field calibration utility to determine relative correction factors for each array detector at any energy and store in PC files.
QA Field: Central axis output calibration performed on each QA field in the QA database.
Temperature: Internal temperature measurement adjusted to user stated value.
Pressure: Internal pressure measurement adjusted to user stated value.
Power Supply
Input: 110 or 220 VAC, switchable; 50/60 Hz General Purpose IEC 320, Class I Power Inlet for straight cable entry.
Output: +20 VDC, 20 watt, 8 pin DIN
Size: 10.5 cm W x 13.8 cm L x 6.4 cm H
Weight: 1.0 kg
System Requirements
Operating System: Recommend Windows 98, NT4.0, or higher
CPU: Pentium or higher
Hard Drive: Installed software, 4.6 Meg Byte
Database memory / measurement, 0.25 kByte
32 MEG of RAM or higher
CD Drive
One serial or USB port
SVGA Monitor (Color, 640x480)
Cables:
Power/DATA: 25 meter, connects Daily QA Check 2 to power supply
Serial: 9 pin D, M/F, connects power supply to computer.
IEC straight plug line cord
Construction:
Dimensions: 26 cm wide x 40 cm long, 4 cm thick
Weight: 3.9 kg
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