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Lung
•
Retreatment tolerance of the mouse lung
19
0
1
2
3
4
5
6
Retreatment-LD50 (Gy)
6
8
10
12
14
pneumonitis
post 6 Gy
treatment alone
post 8 Gy
post 10 Gy
Time after first treatment (months)
Terry Int J Radiat Oncol Biol Phys 1988
Initial dose <50% tolerance:
full recovery
, 2 months
Higher initial doses:
partial recovery
, 3 months
Only applies for pneumonitis
phase: retreatment tolerance
fibrosis might be poorer
Kidney
•
Retreatment tolerance mouse kidney
20
Stewart Int J Radiat Oncol Biol Phys 1989
No recovery between 1
day and 6 months after
initial treatment
Progression of
(subclinical) damage
Retreatment tolerance
decreases with time
Extreme caution when
re-irradiating kidneys!
Reirradiation dose (Gy)
0 2 4 6 8 10 12 14 16
Reduced kidney function
0
2
4
6
8
10
12
14
treatment alone
6.5 mo post 6 Gy
2 wks post 6 Gy