Dose Course 2018_Flipping book

Summary: in-air output ratio, Sc isocentric conditions

1,05

E lekta P rec is e

1,03

1,01

• To quantify variations in energy fluence incident on the patient • Function of the collimator setting • Depends on the photon beam quality and on treatment head design • Depends on the field orientation for rectangular beams (CEE) • Almost independent of the source-detector distance • Does not depend on depth if z > R contam. electrons

0,99

6 MeV

O O

0,97

10 MeV

0,95

25 MeV

0,93

0 5 10 15 20 25 30 35 40 S quare F ield s iz e [c m]

0,94 0,96 0,98 1,00 1,02 1,04 1,06 1,08 1,10

6 MeV

O O

E lekta P rec is e (ML C ) G E S at 43 (ML C ) G E S at 43 (C C )

0 5 10 15 20 25 30 35 40 S quare F ie ld s iz e [cm]