Characterization of megavoltage linear accelerator Bremsstrahlung by means of Monte Carlo simulations.

M. VALENTE; F. MALANO; P. PÉREZ; N. CASTRO; F. CARRASCO

X-RAY SPECTROMETRY

JOHN WILEY & SONS LTD

Lugar: Chichester; Año: 2010 vol. 39 p. 384 - 390

0049-8246

This work presents a method for megavoltage X-ray Bremsstrahlung  assessment by means of Monte Carlo (MC) (PENELOPE) simulations. The proposed method provides suitable spectrum   characterisation by means of a few parameters, namely the acceleration potential and incident angle of electron beam on the anode. The obtained spectra have been used as incident beam for in-depth dose distribution determination with the aim of performing further comparisons with experimental data. This comparison procedure has been employed for Bremsstrahlung  assessment optimisation. Once the Linac Bremsstrahlung is well established, it may be used as incident beam for further dosimetric  purposes, such as spatial dose distribution calculations.The whole process has been applied for the characterisation of the  megavoltage Bremsstrahlung from a typical Linac, namely the 10MV Varian Clinac 18. The obtained results for in-depth dose distributions, when compared with experimental measurements, show an overall good agreement, which may suggest the feasibility of the method.