880 / 1544
Relative seriality model (Källman
et al
1992)
Basic assumptions
:
•
Cell survival: Poisson statistics
•
Normal tissue organized in
serial
and
parallel
substructures
•
P (non-uniform irradiation):
the contribution from each step of the DVH is calculated
Formal equations:
for uniform irradiation: (with dose D)
for non-uniform irradiation: (D
i
, D
v
i
, for each step of the DVH)
•
Parameters
:
D
50
dose to the whole organ 50% P of complications
γ
steepness
s
relative seriality of the organ/tissue
(serial organ:
s
=1, parallel organ
s
=0)
( )
(
)
s
n
i
v s
i
i
DP
P
/1
1
1 1
− − =
∏
=
∆
(
)
50 /
1
2 ) (
DD e
e
DP
−
−
=
γ