L0_2016_Athens_Physics_Programme

Early 90s:

The “Collapsed cone” (CC) method, that speeds up the PSF-

convolution was proposed

In parallel, the

pencil beam

method - a 2D convolution approach

was developed for photons (PB) (Mohan

et al

.).

–

PB implemented in several commercial systems and much

faster than 3D convolution

–

Good agreement with measurement for irregular fields in flat-

surface water tank.

–

Poor agreement between measurement and calculations in

heterogeneous media (e.g. lung)

Analytical methods, photon beam calculation