IGRT 2016 Madrid

Margins in lung hypo (3 x 18 Gy)

Systematic

Random

Delineation

2 mm SD

-

Registration/couch shift 1.5 mm SD

1.5 mm SD

Intra-fraction motion

1.5 mm SD

1.5 mm SD

Total

3 mm SD

2.2 mm SD

Margin A=10 mm

7 mm +

0 mm

Margin A=20 mm

7 mm +

2 mm

s s 84.0 ) ( 84.0 5.2 2 2  + +S = s

s p  7.8 mm

M

p

p

Ensures 80% isodose encompasses GTV 90% of time in lung