성인 남녀 메쉬형 참조 계산 팬텀을 이용한 거리와 위치 변화에 따른 99mTc 방사성 핵종에 의한 장기별 흡수 선량 평가: 몬테카를로 시뮬레이션

Abstract

Patients administered with radiopharmaceuticals for nuclear medicine examinations emit gamma rays from the decaying radionuclides in their bodies. Recently, advances in various radiation transport simulation codes have led to the wide- spread adoption of Monte Carlo simulation methods. This study aimed to evaluate the absorbed dose (Gy/source) received by various target organs based on distance and source position using adult male and female mesh-type reference computational phantoms (MRCPs) in conjunction with the Geant4 Monte Carlo simulation code. The Geant4 (ver.11.1) code was employed to model photon interactions with an average error below 4% in target organs. The radiation source was set to 140 keV in 99mTc, and photons were emitted from a total of 16 configurations, placing the source at 0.5 m and 1.0 m distances in anterior, posterior, left, and right positions from MRCPs. A total of 10 photons were emitted per condition, and the absorbed dose was analyzed to compare the differences in dose distribution by sex and anatomical location of organs. The results demonstrated that absorbed doses in all organs decreased with increasing distance from the source. Female generally exhibited higher absorbed doses compared to males across the evaluated organs. Furthermore, differences in absorbed doses were observed based on the anatomical location of the organs as confirmed through quantitative analysis.