Backscatter factors for a clinical 6 MeV electron beam

Abstract

One of the utmost important in electron dosimetry is the determination of electron backscatter factor (EBF). It contributes to the patient dose when treating superficial tumors with lead shielding. In this study, we performed a comparative analysis of EBF between experimental measurements and Monte Carlo simulations in the low electron energy region. 6 MeV electron beams from a clinical linear accelerator machine were used to determine experimental measurements of EBF by measuring with polystyrene and radiochromic film with and without lead. The Penelope Monte Carlo code simulated the same apparatus of measurements. Values of EBF obtained show trends similar to the experimental and calculated results of the literature. The measured and calculated EBF's in this study have maxima at the mean energy of 3.59 MeV, which agrees on the data of the literature. However, our EBF's, in particular measured values, are 20%-30% higher in the mean energy investigated than the data of the literature. © 2009 Springer-Verlag.