Study of the Effectiveness of Radiation Retaining Materials for the Entrance of LINAC 6 MV Radiotherapy Room

Abstract

LINAC radiotherapy devices can produce scattering radiation and leak radiation from the gantry. The doses of scattering radiation result from the scattering radiations from the wall (HST) and the patient (HPS). Gantry leak radiation is gantry leak radiation through the labyrinth hall (HLS) and the one that goes directly to the entrance (HLT). These four components play a role in producing radiation doses at the entrance. The scattering radiation in the LINAC 6 MV radiotherapy installation can spread in all directions. Therefore, there is a need for a special review to examine the scattering radiation to the entrance of the room. The constituent of the radiation retaining wall also influences the reflection coefficient of the wall (α). Therefore, it is important to pay attention to the α value in evaluating the radiation dose at the labyrinth entrance. Radiation protection efforts for radiation workers and the community around the radiotherapy room need to be considered by creating a radiation barrier that can minimize the radiation received. With that in mind, the purpose of this study is to examine several possible materials for radiation shielding, especially at the entrance of the radiotherapy room. Materials used for the entrance are lead (Pb), borated polyethylene (BPE), aluminum (Al), and iron (Fe) with a thickness of 6 mm, respectively. The variation of the reflected angle used in the calculation of HST, HLS, and HPS values starts from an angle of 50° to 80°. The result showed that the most effective material for reducing the amount of radiation is lead with effectiveness of 86.79%.