Document Type : Technical Note

Authors

1 Department of Biomedical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Advanced Health Technologies Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

The aim of this report is to present a new two-piece thyroid-neck phantom produced by the concurrent use of epoxy resin and poly(methyl methacrylate) (PMMA: plexiglass) soft tissue equivalent materials. Accordingly, mass attenuation coefficients of the epoxy resin and the plexiglass compounds were obtained from simulation (NIST XCOM 3.1) and measurements (practical dosimetry) and compared to those related to human soft tissue (ICRU 44). The thyroid-neck phantom and thyroid gland dimensions were derived from scientific references and the atlas of human anatomy, respectively. The thyroid phantom was designed by CATIA V5R16 software and produced by the epoxy resin compound by three-dimensional printer. Other organs were designed by ProNest software and made by the plexiglass sheets by CNC laser cutting machine. The mass attenuation coefficients for the epoxy resin (50 keV- 20 MeV) and the plexiglass (0-20 MeV) were comparable to human soft tissue (ICRU 44), all with standard relative deviation beneath 5%. In addition, the SPECT images indicated the similarity between human thyroid tissue and its phantom. In conclusion, this study proves the feasibility and reliability of epoxy resin application in the production of two-piece thyroid-neck phantom. This phantom can be applied in the calibration of gamma camera systems, dosimetry and gamma spectrometry in the nuclear medicine field.

Keywords

  1. Agency IAE. Direct methods for measuring radionuclides in the human body. Wien: International Atomic Energy Agency Vienna; 1996.
  2. Dantas BM, Lucena EA, Dantas AL, Araujo F, Rebelo AM, Teran M, et al. A protocol for the calibration of gamma cameras to estimate internal contamination in emergency situations. Radiat Prot Dosimetry. 2007;127:253-7. doi: 10.1093/rpd/ncm278. PubMed PMID: 17562649.
  3. Siegel JA, Thomas SR, Stubbs JB, Stabin MG, Hays MT, Koral KF, et al. MIRD pamphlet no. 16: Techniques for quantitative radiopharmaceutical biodistribution data acquisition and analysis for use in human radiation dose estimates. J Nucl Med. 1999;40:37S-61S. PubMed PMID: 10025848.
  4. Hanscheid H, Canzi C, Eschner W, Flux G, Luster M, Strigari L, et al. EANM Dosimetry Committee series on standard operational procedures for pre-therapeutic dosimetry II. Dosimetry prior to radioiodine therapy of benign thyroid diseases. Eur J Nucl Med Mol Imaging. 2013;40:1126-34. doi: 10.1007/s00259-013-2387-x. PubMed PMID: 23576099.
  5. Rezaei H, Mostaghimi H, Mehdizadeh AR. Modification of Source Strength in Low-Dose-Rate Lung Brachytherapy with (125)I and (103)Pd Seeds. J Biomed Phys Eng. 2017;7:191-204. PubMed PMID: 29082211; PubMed Central PMCID: PMC5654126.
  6. Mostaghimi H, Mehdizadeh AR, Darvish L, Akbari S, Rezaei H. Mathematical formulation of (125)I seed dosimetry parameters and heterogeneity correction in lung permanent implant brachytherapy. J Cancer Res Ther. 2017;13:436-41. doi: 10.4103/jcrt.JCRT_978_16. PubMed PMID: 28862205.
  7. Rezaei H, Zabihzadeh M, Ghorbani M, Goli Ahmadabad F, Mostaghimi H. Evaluation of dose enhancement in presence of gold nanoparticles in eye brachytherapy by (103)Pd source. Australas Phys Eng Sci Med. 2017;40:545-53. doi: 10.1007/s13246-017-0555-1. PubMed PMID: 28509080.
  8. Hermosilla A, Diaz Londono G, Garcia M, Ruiz F, Andrade P, Perez A. Design and manufacturing of anthropomorphic thyroid-neck phantom for use in nuclear medicine centres in Chile. Radiat Prot Dosimetry. 2014;162:508-14. doi: 10.1093/rpd/ncu022. PubMed PMID: 24567500.
  9. Berger MJ, Hubbell J. XCOM: Photon cross sections on a personal computer. National Bureau of Standards, Washington, DC (USA) Washington: National Bureau of Standards: Center for Radiation Research; 1987.
  10. Berger M, Hubbell J, Seltzer S, Chang J, Coursey J, Sukumar R, et al. XCOM: Photon cross sections database, 2010. Available from: URL http://www nist gov/pml/data/xcom.
  11. Bouchet LG, Bolch WE, Weber DA, Atkins HL, Poston JW, Sr. MIRD Pamphlet No. 15: Radionuclide S values in a revised dosimetric model of the adult head and brain. Medical Internal Radiation Dose. J Nucl Med. 1999;40:62S-101S. PubMed PMID: 10086719.
  12. Govoni AF. Pocket atlas of sectional anatomy. Computed tomography and magnetic resonance imaging. Elsevier; 2008.
  13. Zhang J, Xu Y, Huang P. Effect of cure cycle on curing process and hardness for epoxy resin. Express Polymer Letters. 2009;3:534-41.
  14. Zhang J, Xu Y, Huang P. Effect of cure cycle on temperature/degree of cure field and hardness for epoxy resin. e-Polymers. 2010;10.