880-881 / 3107
8
displacement
(mm)
time trend
8
displacement
(mm)
sudden change
Potential limitations of NAL
-
only has set-up measurements in first few fractions
-
used for corrections in all other fractions (without imaging)
On the other hand: on-line corrections may involve too
much workload and prolongation of fraction duration
0
5
15
4
-4
20
fraction
0
5
15
4
-4
20
fraction