Monte Carlo calculation of shielding properties of newly developed heavy concretes for megavoltage photon beam spectra used in radiation therapy

Introduction: Globally, the need for radiotherapy as a part of cancer management increases every year. Thus, the shielding for megavoltage radiotherapy rooms is of great importance. Materials and Methods: In the present study, 14 types of developed highdensity concrete with densities ranging from 2.45 to 5.11 were simulated by using Monte Carlo method. The linear attenuation coefficient and the tenth value layer were also calculated. These dosimetric parameters were investigated for megavoltage photon beam spectra for various energies (4, 6, 10, 15, and 18 MeV) of the Varian linac and 60Co gamma rays. The results of simulation were compared with the available published results. Results: The results showed that the attenuation of highenergy photons is primarily administered by the atomic number and density of the concrete. Moreover, the variation of attenuation coefficient with density was not completely linear. Conclusion: It was concluded that the attenuation of highenergy photons not only depends on the density of concrete, but also on the atomic number of its composing elements. dependent on density of concrete but also on atomic number of composing elements.