900-901 / 1578
Gated SABR: 4DCT planning study
PT
V
1
0bi
ns
P
T
V
g
ati
ng
Analysis of 4DCT scans in 34 patients with stage I NSCLC
≥ 50%
reduction in PTV achieved in
15 %
of tumors
≥ 30%
reduction in PTV achieved in
38 %
of tumors
Underberg R, 2005
Non-gated PTV
Gated PTV
PTV
10bin
s
PTV
gating
Lack of positional verification
during delivery