Advanced Physics for Brachytherapy 2018

Equations for the transport of scerma generated at each point along a transport line

1. I need to be efficient

Δr

1

Δr

2

Under the collapsed cone approximation: • Scerma does not vary with θ within ΔΩ (Bθ, bθ constant along transport line) and scerma generated, emitted and absorbed along transport line

1

θ

2

and assuming:

• Scerma generated per unit r is constant within the same voxel (scerma does not vary considerably within voxels)

Averaging dose over all points along Δr2 in voxel 2 :

Δr

Δr

2

2

dr

)] b r dr

D

[1 exp(

− −





1sc2 2 →



0

0

D1sc2 2 →

=

=

=

Δr

Δr

2

2



S { Δr [1 exp( − − 1sc,2 b

b

−

Δr )}



2



2

B



b

b

Δr2



