361 / 1578
A Practical Example: SBRT Lung Case
▪
T1 primary lung lesion: 3 x 18 Gy @ 80%
N = 3,
b
= 0.84
▪
Alignment on time-averaged tumor position by CBCT
▪
SD of the penumbra is 6.4 mm
s
pen
= 6.4 mm
▪
E2E test device error (
S
) = 0.4 mm
S
1
= 0.4 mm
▪
Localization (delineation) error = 2.0 mm (1 SD)
S
2
= 2.0 mm
▪
Systematic error = 1.0 mm (1 SD)
S
eff
= 1.0 mm
▪
Random error = 1.0 mm (1 SD)
s
eff
= 1.0 mm
▪
Intra-fraction amplitude = 1 – 25 mm
s
r
= 0.4 – 9.0 mm