Author(s):
1. Goran Kolarević, Republic of Srpska, Bosnia and Herzegovina
2. Dragoljub Mirjanić, Akademija nauka i umjetnosti Republike Srpske, Republic of Srpska, Bosnia and Herzegovina

Abstract:
Brachytherapy is a type of radiotherapy with closed radioactive sources that can be placed in body cavities, tumor (tissue) or in its immediate vicinity. In clinical practice, several radionuclide’s are used (192Ir-average energy of gamma radiation 0.37 [MeV], 60Co-1.25 [MeV],...), of different energies, which requires specially designed bunkers with different thicknesses of protective walls. Bunkers should provide sufficient protection to limit the dose of ionizing radiation received by other patients, medical staff and the surrounding population to the permitted levels (0.3 [mSv/year]), while all walls, floors and ceilings represent the primary barrier. A safety door (lead) is also usually required if the maze is not included in the design. The aim of the study was to calculate the values of the primary barrier protection thicknesses for concrete, lead and steel in the case of application of 192Ir as a brachytherapy source, based on IAEA recommendations. The calculation is based on an average workload: 40 patients (applications) per week, an average duration of 10 minutes to deliver an absorbed dose of 7.5 [Gy] at a distance of 1 cm from the source, a source activity of 370 [GBq] (10 [Ci]), a reference air kerma rate (RAKR) of 0.111 [mGy MBq-1 m2 h-1]. The design limit is 6 [Sv/week] for the public area (presence factor T = 0.1) at 3 [m] from the source treatment site. The resulting thickness of the barrier in all directions for concrete is 411.2 [mm], lead 43.3 [mm] ie 116.4 [mm] for steel. Environmental measurements (on the outer edges of all barriers) are used to check the level of protection achieved and detect possible errors.

Key words:
brachytherapy,protective barrier,iridium 192

Thematic field:
SYMPOSIUM B - Biomaterials and nanomedicine

Date of abstract submission:
04.08.2025.

Conference:
Contemporary Materials 2025 - Savremeni Materijali

Applied paper from author