Physics Bucharest 2017

Mechanism of NAL

AP displacements (mm) Prostate cancer patient

NO REDUCTION OF RANDOM ERROR

15

f  3, image, do not correct

f>3, no imaging, correct

10

No NAL

5

0

Fraction

0

5

10

15

20

25

30

35

Residual systematic error with NAL

-5

: initial set-up on ( original ) tattoos (prior to NAL correction)

: after NAL a priori setup correction