374 / 879
MEASURE IN 1D
− Field by field
(gantry at 0
°
)
100cm
4 cm
IC PTW Semiflex (0.125cm
3
)
•
Detector:
•
Indicator of comparison:
− Absolute dose in 1 pt
•
Method:
•
Target:
%0 (%)
•
Clinical specifications:
*
%
4
(%)
Portal Dosimetry
Gamma index (
) passing rate
criteria : 4% / 3mm
95%
MEASURE IN 2D
AS 500
100%
Exact Arm
12
M
E
A
S
U
R
E
A
N
A
L
Y
S
I
S
3. The IMRT pre-treatment QC process
D
EFINE
100
(%)
calculated
measured
calculated
D
D D
Difference
* Zefkili, “Recommendations for a head and neck IMRT quality assurance protocol”
Cancer/Radiother
(2004)
03/10/17
38