Radiation safety and shielding evaluation of newly installed medical LINAC facility in Bangladesh

Medical linear accelerator (Linac) is widely used for radiotherapy purposes which is one of the modalities for radiation therapy. When a Linac is being installed, an initial survey is required during the first beam and a complete shielding survey must be carried out after the Linac has been operational and calibration is completed. Based on the detailed survey report, the facility license is issued. Worldwide several organizations provide various recommendations regarding shielding design and radiation safety issues. The purpose of this paper is to show how to assess or validate the radiation safety and shielding status of the newly installed Linac facility in Bangladesh. In this study, one of the Linac facilities in Dhaka city has been chosen which was installed in 2021. The dose rate meter RadEYE PRD and tele survey meter TELE-STTC are used for x-ray/gamma-ray dose measurement and REM 12/4 count rate meter for neutron measurement. A maximum photon dose of 5.56 μSvh−1 was observed at a gantry angle of 900 along the center front of the door, while a maximum neutron dose of 1 μSvh−1 was found at three different locations. The obtained results are in line with the recommendations by controlling organizations. This study found that the Linac can be operated safely for both conventional and IMRT modes, and the same shielding procedure can be followed all over the country for the same Linac setting.