Table of Contents Table of Contents
Previous Page  1021 / 1542 Next Page
Information
Show Menu
Previous Page 1021 / 1542 Next Page
Page Background

Influence of margin on volume

• GTV, 2 cm diameter, volume 4.2 cm

3

Add 1 cm to

• CTV, 4 cm diameter, volume 33.5 cm

3

Add 1 cm to

PTV, 6 cm diameter, volume 113 cm

3

GTV

CTV

PTV

Verellen D, Ridder MD, Linthout N, Tournel K, Soete G, Storme G: Innovations in image-guided radiotherapy. Nat

Rev Cancer 2007, 7(12):949-960.

• Third-power relationship between radius of

a sphere and volume (4/3π

r

3

)

• Small reduction in margin (5mm) yields a

50% reduction in volume

• The volume of the outer layer equals the

volume of the core of the orange