538-539 / 2239
Derivation of formalism to convert ionisation in plastic to dose to water
Converting ionisation measurement in plastic to dose in water
Phantoms irradiated with
the same MV photon
beam
In water at a reference depth
ref
z
In solid plastic at an equivalent depth
eq
z
( )
( )
Qw, s,
QQ,
Qw, D,
eq Qs,
ref
Qw,
o
o
k k
N z M z D
=
How does one determine:
equivalent depths
and
phantom dose conversion factors?