1038 / 1245
z
max
Ideal situation
:
When changing the irradiation
conditions the reading of the in vivo
detector changes in the same
proportion as changes the i.c.
reading
cal
F
T)
wedge,
SSD,
R(r,
T)
wedge,
SSD,
(r,
entD
Reality
:
Detector+
build up
response
dependence in dose rate, energy,
temperature may differ of those of
an i.c.
Due to the calibration geometry the
detectors “see” different scatter
conditions.
Calibration: Entrance dose
dose at the depth of dose maximum