Investigation of the radiological properties of various phantoms for their application in low energy X-rays dosimetry

It has been previously proven that the radiological properties of materials are strongly dependent on the incident radiation energy. Hence, the present study aimed to evaluate the radiological properties and soft tissue equivalency of conventional phantoms at the 1–50 keV photon energy as well as the feasibility study of using a more appropriate material instead of water. The equivalence of water and a number of conventional phantoms with breast and muscle were evaluated in terms of mass density (ρ), effective electron density (Neff), effective atomic number (Zeff), photon mass energy-absorption coefficient (μen/ρ), photon mass attenuation coefficient (μ/ρ), total stopping power of electrons (S/ρ)tot and the absorbed depth dose by using the Auto-Zeff software and XCOM, ESTAR database and Monte Carlo simulation method. The differences of ρ, Neff, Zeff and (S/ρ)tot between investigated materials and breast were 0.5–17%, 0.2–9%, 0.7–26%, and 2–11%, respectively. Additionally, the differences of μen/ρ, μ/ρ, and the absorbed depth dose between the investigated phantom materials and breast tissue were 18–56%, 16–53%, and 5–79% respectively. Also, the differences of ρ, Neff, Zeff, μen/ρ, μ/ρ , (S/ρ)tot, and the absorbed depth dose between the investigated phantom materials and muscle were 1–14%, 2–9%, 1–33%, 4–67%, 6–63%, 1–15% and 3–93%, respectively. Water cannot be considered as breast tissue equivalent phantom in the energy range of 1–50 keV. Moreover, the results of depth dose investigation showed that the GENIPIN gel is the most suitable breast tissue substitute in intraoperative radiotherapy method. •The average difference of absorbed depth dose between water phantom and muscle tissue is 1.34%.•Water is the best choice as a muscle tissue substitute in the energy range of 1–50 keV.•The average difference of absorbed depth dose between water phantom and breast tissue is 3.8%.•The average difference of absorbed depth dose between GENIPIN gel and breast tissue is 2.11%.•GENIPIN gel can be considered as an appropriate breast tissue substitute in 1–50 keV energy range.