Dose Course 2018_Flipping book
Uncertainty in entrance dose measurements
18 MV X-rays
Physical quantity of procedure
Relative standard uncertainty (%)
TLD Ans Swinen PhD thesis 2005
1.7% 1.0% 0.5%
TLD calibration with IC
TLD reading of “unknown detector”
Non-lineality
Fading
<0.5%
Combined standard uncertainty of step 1
2.1%
Step 2: Correction factors Field correction factor
1.5% 1.5% 2.1%
SSD correction factor
Combined standard uncertainty of step 2
Step 3: measure on the patient Reading of the in vivo detector 1
1.2% 1.2%
Combined standard uncertainty of step 3
Combined standard uncertainty of steps 1+2+3
3.2%
1 reproducibility on positioning on patients was not tested.
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