Accurate dose calculations are very important in radiotherapy
treatment planning. The Monte Carlo method has proven to be an accurate
and reliable method for simulation of the dose distributions from
electron beams and can provide theoretically more accurate distributions
than conventional planning system algorithms (e.g. the
Generalized Gaussian Pencil Beam algorithm) for more complex target
configurations. The aim of this work was to assess the parameters
and spectrum of a given electron beam (Varian CLINAC 2100 C/D) from experimental
depth dose distribution and then simulate dose distributions in
an experimental arrangement with a 3D polymer gel dosimeter. The
comparison of data from experimental measurements, Monte Carlo calculations
and the planning system enabled us to verify experimentally the
simulation model and technique as well as the planning system results. Both
simple and more complex systems (e.g. dose distributions close
to different material interfaces) can be studied. The generation
and influence of the “bremsstrahlung” photons in the electron beams
was also analyzed using the simulation technique. The computations,
experimental methods used and results obtained are presented and
discussed.