ESTRO course Dose Modelling and Verification 2017

Source size effects, focused leafs

Focused leafs (Siemens MLC geometry)

1.2



.

1.2

Source sizes Point



1.1 1.1

2 10 10 cm x

1.0

0.35 cm 0.70 cm

1

0.9 .

Fieldsize 5x5cm 2 Fieldsize 1x1cm 2

0.8

0.8 .

0.7 .

0.6

.

0.6

0.5 .

0.4

0.4 .

0.3 .

0.2

0.2

0.1

0.0

0

-5 -5

-4 -4

-3 -3

-2 -2

-1 -1

0 0

1 1

2 2

3 3

4 4

5 5

cm

When the source “fills” the “inverse” view we get dramatic decrease in fluence output with increasing source size!

16