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Urinary bladder (mouse)
•
Original tolerance restored between 25-50 days
15
0
20
40
60
80
100 120
0
5
10
15
20
25
30
initial RT: 5x5.3 Gy / 5 d
retreatment alone
Time after first treatment (days)
Retreatment ED
50
(Gy)
First treatment:
5 × 5.3 Gy over 1 week
Endpoint:
50% reduction in bladder
storage capacity at 1–3
weeks
post retreatment
Basic Clinical Radiobiology, 4th Ed, page 262; Satthoff & Dörr unpublished
Retreatment principles: early effects
•
Can achieve complete restoration of the initial
tolerance
•
Epidermis: 2-3 months (rodents)
•
Oral mucosa: 12 days (but long term effects possible)
•
Restoration of the stem cell compartment may take
longer than “morphological” recovery
16