Comparison of Photon Contamination between Lead free and Flexible Internal Shield and Lead for 6 and 9 MeV Electron Beams of Varian 2100 C/D

In the recent decades the Monte Carlo simulation in the field of radiation therapy has been used a lot. In this study photon contamination of Lead free and flexible internal shield was investigated in the electron field.
Subjects and To evaluate photon contaminationthat caused by this new material in the electron field by Mont Carlo study. Varian 2100 C/D was validated within measurement and then by given energy spectrum shield thickness and photon contamination were obtained and compared to those of lead.
The results show that this material required 1.2 times thickness of those leadfor providing protection. In addition, it causes photon contamination approximately equal those of lead for energy 6 and 9 MeV.
It can be concluded that thickness of specific combination (70% W, 18.61% Ni, 11/39% c) which has equal transmission same as lead caused photon contamination equal those of Lead that it can be acceptable under clinical condition.