Folie 1

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