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Mathematical Description / Repair Function
➢
External Beam RadioTherapy and HDR BrachyTherapy :
no repair during irradiation (min)
repair function
g = 1
2
T
1/2
4 6 8 Time [h]
. . .
2
T
1/2
4 6 8 Time [h]
. . .
(
)
−
− =
tn
sy ny
t
PDR g
2
1
2
(
)
2
1
2
1
t
nt
n
t
ke
e k enk k
nk
s
−
− +
−
−
+
−−
=
t
e
y
−
−=
1
21
T
2ln
=
x
e
k
−
=
… repair rate
T
1/2
…
half time for repair
t …
irradiation time
for each pulse
x …
time between pulses
without irradiation
n …
number of equal pulses
➢
PDR BrachyTherapy :
repair between successive pulses (hours) and during the
whole fraction (hours - days) is significant