Standard Imaging QA BEAMCHECKER PLUS User Manual

QA BEAMCHECKER™ PLUS 59
M
raw
the raw or uncorrected reading of appropriate chamber
T temperature in °C measured by on-board sensor
P pressure in Torr measured by on-board sensor
Output Constancy
Output Constancy is determined by using the following algorithm on the temperature and
pressure corrected values from the following chambers over time (values are shown in
percent):
Static 5 Channel: Center
TomoTherapy: Left, Center, Right
Dynamic 5 Channel: Top, Left, Center, Right, Bottom
where:
time t time at which new constancy measurement is being taken
time t
0
time at which initial benchmark value was taken
12.2 Applicable to Static 5 Channel Mode Only
The following values are determined by using the specified algorithm on the raw data values
collected from the indicated ion chambers (values are shown in percent):
Flatness = (Max - Min) / (Max + Min)
where:
Max maximum value of Top, Center, Left, Right, Bottom
Min minimum value of Top, Center, Left, Right, Bottom
Axial Symmetry = (Top - Bottom) / Bottom
Transverse Symmetry = (Right - Left) / Left
12.3 Applicable to TomoTherapy Mode Only
The following values are determined by using the specified algorithm on the raw data values
collected from the indicated ion chambers (values are shown in percent):
Energy Measurement = Pb-filtered / Center
NOTE: The center ion chamber has approximately 3.5 cm of water-equivalent buildup, while
the Pb-filtered ion chamber has roughly 9.7 cm of water-equivalent buildup.
Lateral Profile = Left / Right

Standard Imaging QA BEAMCHECKER PLUS Specifications

General

Brand	Standard Imaging
Model	QA BEAMCHECKER PLUS
Category	Measuring Instruments
Language	English