The preparation and characterization of silicon-based composites doped with BaSO4, WO3, and PbO nanoparticles for shielding applications in PET and nuclear medicine facilities

Document Type: Research Paper


1 Medical Radiation Sciences Research Team, Tabriz University of Medical Sciences, Tabriz, Iran

2 Department of Nuclear Physics, Faculty of Physics, University of Tabriz, Tabriz, Iran

3 Department of Medical Physics, Oncology Institute, Istanbul University, Istanbul, Turkey

4 Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran


Objective(s): The present study aimed to design new nanoparticle-based shielding materials for photons used in single-photon emission computed tomography and positron emission tomography facilities.
Materials and Methods: Initially, the mass attenuation coefficients and half value layer (HVL) of the composites were comprehensively investigated based on a silicon rubber containing various ratios of micro- and nano-barium sulfate (BaSO4), lead oxide (PbO), and tungsten oxide (WO3) particles at 60, 80, 100, 150, 200, 300, 400, 500, and 600 keV photon energies using the MCNP-X6 Monte Carlo (MC) code and WinXCOM software. In the second stage, the composites composed of 10 wt% and 20 wt% WO3 and PbO particles were constructed in a liquid silicone rubber-based matrix. The mass attenuation coefficients and HVL of the designed shields were experimentally assessed using Cs-137 and Am-241 radioactive sources.
Results: The particles sizes of PbO and WO3 were within the range of 50-200 nanometers. The MC and measurement results indicated that the linear attenuation coefficients of the composites were augmented with the addition of all the studied nano- and micro-particles. However, the PbO composites had more significant shielding properties compared to the BaSO4 and WO3 composites.
Conclusion: According to the results, the nanocomposites had better ability to shield γ-rays at both energies compared to the micro-composites.


1. Ell PJ, Gambhir S. Nuclear medicine in clinical diagnosis and treatment. Churchill Livingstone. 2004.
2. Mettler A, Bhargavan M, Faulkner K, Gilley D, Gray J, Ibbott G, Lipoti J, Mahesh M, McCrohan JL, Stabin M. Radiologic and nuclear medicine studies in the United States and worldwide: frequency, radiation dose, and comparison with other radiation sources 1950–2007. Radiology. 2009; 253(2): 520-531.
3. Rangacharyulu C, Roh C. Isotopes for combined PET/SPECT imaging. J Radioanal Nucl Chem. 2015; 305(1): 87-92.
4. Madsen M, Anderson J, Halama J, Kleck J, Simpkin D, Votaw J, Wendt R, Williams L, Yester M. AAPM task group 108: PET and PET/CT shielding requirements. Med Phys. 2006; 33(1): 4-15.
5. Mattsson S. Introduction: The Importance of Radiation Protection in Nuclear Medicine. In: Radiation Protection in Nuclear Medicine. 2013; Springer: 1-3.
6. Huang B, Law M, Khong P. Whole-body PET/CT scanning: estimation of radiation dose and cancer risk. Radiology. 2009; 251(1): 166-174.
7. Ahasan M. Assessment of radiation dose in nuclear medicine hot lab. Inter J Radiat Res. 2004; 75-78.
8. Soylu H, Lambrecht F, Ersöz O. Gamma radiation shielding efficiency of a new lead-free composite material. J Radioanal Nucl Chem. 2015; 305(2): 529-534.
9. Mehnati P, Malekzadeh R, Sooteh MY, Refahi S. Assessment of the efficiency of new bismuth composite shields in radiation dose decline to breast during chest CT. Egypt J Radiol Nucl Med. 2018; 49(4): 1187-1189.
10. Mehnati P, Yousefi Sooteh M, Malekzadeh R, Divband B. Synthesis and characterization of nano Bi2O3 for radiology shield. Nanomed J. 2018; 5(4): 222-226.
11. Cataldo F, Prata M .New composites for neutron radiation shielding. J Radioanal Nucl Chem. 2019; 1-9.
12. Mehnati P, Malekzadeh R, Yousefi Sooteh M. New Bismuth composite shield for radiation protection of breast during coronary CT angiography. Iran J Radiol. 2019; 16(3).
13. Verdipoor K, Alemi A and Mesbahi A. Photon mass attenuation coefficients of a silicon resin loaded with WO3, PbO, and Bi2O3 Micro and Nano-particles for radiation shielding. Radiat Phys Chem. 2018; 147: 85-90.
14. Mehnati P, Sooteh MY, Malekzadeh R, Divband B, Refahi S. Breast conservation from radiation damage by using nano bismuth shields in chest CT scan. Crescent J Med Biol Sci. 2018; 6 (1): 46-50.
15. Mahmoud ME, El-Khatib AM, Badawi MS, Rashad AR, El-Sharkawy RM, Thabet A. Fabrication, characterization and gamma rays shielding properties of nano and micro lead oxide-dispersed-high density polyethylene composites. Radiat Phys Chem. 2018; 145: 160-173.
16. Mesbahi A, Alizadeh G, Seyed-Oskoee G, Azarpeyvand A. A new barite–colemanite concrete with lower neutron production in radiation therapy bunkers. Annal Nucl Energ. 2013; 51: 107-111.
17. Sayyed M, Issa SA, Tekin H, Saddeek Y. Comparative study of gamma-ray shielding and elastic properties of BaO–Bi2O3–B2O3 and ZnO–Bi2O3–B2O3 glass systems. Material Chem Phys. 2013; 217: 11-22.
18. Malekzadeh R, Mehnati P, Yousefi Sooteh M, Mesbahi A. Influence of size of nano and micro-particles and photon energy on mass attenuation coefficients of bismuth-silicon shields in diagnostic radiology. Radiol Phys Technol. 2019; 12(1): 6-25.
19. Mesbahi A, Ghiasi H. Shielding properties of the ordinary concrete loaded with micro-and nano-particles against neutron and gamma radiations. Appl Radiat Isot. 2018; 136: 27-31.
20. Berger M (2010) XCOM: photon cross sections database. http://www nist gov/pml/data/xcom/index.
21. Mehnati P, Malekzadeh R, Divband B, Yousefi Sooteh M. Assessment of the effect of nano-composite shield on radiation risk prevention to Breast during computed tomography. Iran J Radiol. 2020; 17(1).
22. Tekin H, Sayyed M, Issa S. Gamma radiation shielding properties of the hematite-serpentine concrete blended with WO3 and Bi2O3 micro and nano particles using MCNPX code. Radiat Phys Chem. 2018; 150: 95-100.
23. Mehnati P, Malekzadeh R and Sooteh MY. Use of bismuth shield for protection of superficial radiosensitive organs in patients undergoing computed tomography: a literature review and meta-analysis. Radiol Phys Technol. 2019; 12(1): 6-25.
24. Kim JY, Ahn S, Lee W. Shielding 140 keV gamma ray evaluation of dose by depth according to thickness of lead shield. J Radiol Sci Technol. 2018; 41(2): 129-134
25. Gaikwad D, Sayyed M, Obaid SS, Issa SA, Pawar P. Gamma ray shielding properties of TeO2-ZnF2-As2O3-Sm2O3 glasses. J Alloy Compoun. 2018; 765: 451-458
26. Mesbahi A. A review on gold nanoparticles radiosensitization effect in radiation therapy of cancer. Rep Pract Oncol Radiother. 2013; 15(6): 176-180.