1008-1009 / 1173
0.54
0.55
0.56
0.57
0.58
0.59
0
10
20
30
40
50
60
Loss in effective dose:
Acute to 60 min: 9%
5 min to 45 min: 6%
5 min to 30 min: 4%
2 Gy in 6 “fields”
Surviving Fraction
Time (min)
/
= 7.6 Gy
t
1/2
= 24.5 min
Potential loss of effect in IMRT:
Prostate PC-3 cell survival in vitro
(Joiner et al, Wayne State University, Detroit)