Selective contribution of concrete shielding on the equivalent and effective doses in a prostate radiotherapy treatment

Within a radiotherapy room, in addition to the primary beam, there is also secondary radiation that leaks from the accelerator head and scattering caused by surrounding objects, the patient’s body and even the walls of the shielded room itself, designed to protect the external individuals, disregarding effects on the patient. The aim of this work is to study the radiation effect on the patient’s healthy tissues caused by scattering from a concrete shield expressed as equivalent and effective doses. MCNPX simulations of the linear accelerator Varian 2100/2300C/D were performed for a MAX phantom of a patient in a typical radiotherapy room. In addition, calculations were made with and without shielding. It was concluded that the concrete shielding affects in 5% the effective dose absorbed by the patient.