Determination of age specific I-131 S-factor values for thyroid using anthropomorphic phantom in geant4 simulations

作者：Rahman Ziaur; Ahmad Syed Bilal; Mirza Sikander M; Arshed Waheed; Mirza Nasir M^*; Ahmed Waheed

来源：Applied Radiation and Isotopes, 2014, 90: 15-22.

DOI：10.1016/j.apradiso.2014.03.004

• Iodine-131
• S-factor values
• Thyroid
• Anthropomorphic phantom
• Geant4 simulations

Using anthropomorphic phantom in Geant4, determination of beta- and gamma-absorbed fractions and energy absorbed per event due to I-131 activity in thyroid of individuals of various age groups and geometrical models, have been carried out. In the case of I-131 beta-particles, the values of the absorbed fraction increased from 0.88 to 0.97 with fetus age. The maximum difference in absorbed energy per decay for soft tissue and water is 7.2% for gamma-rays and 0.4% for beta-particles. The new mathematical MIRD embedded in Geant4 (MEG) and two-lobe ellipsoidal models developed in this work have 4.3% and 2.9% lower value of S-factor as compared with the ORNL data.

• 出版日期2014-8