424 / 1578
Thus:
IGRT resolves initial differences in set-up accuracy
However:
Mean localisation to post treatment CBCT time 34
±
7 min
6% of all fractions were within the tolerance (2mm) on localization CBCTs.
97% directly after IGRT
93% at mid-treatment,
82% at post-treatment.
Try to reduce treatment time!
Positioning for spine SBRT
Before IGRT: (a)
M:-0.4 to 1.5, SD of 2-3 mm
(b) and (c)
M: of -6.2 to 0.8, SD of 4-7 mm
After IGRT: SD of 0.6 to 0.9 mm and 0.9
°
to 1.6
°
Li IJROBP 84, 2012 p520