Course book Advanced Treatment Planning 2018

Analytical Anisotropic Algorithm (AAA)

superposition of pencil beams, which are modified/scaled anisotropically based on tissue electron densities (3D PB kernel) – PB separated into depth-directed (total energy deposited by the pencil beam) and lateral components (sum of N radial exponential function) Build up and down correction needed source model for – Primary photon source – extra-focal source for photons scattered in accelerator head – electron contamination source Tillikainen – PMB 2008

▪ Reduced computation time