Age-Specific Experimental and Computational Calibration of Thyroid in vivo Monitoring

Age-specific thyroid phantoms corresponding to 5, 10, 15 years-old and the adult case have been designed and manufactured with a 3-D printer. Reference measurements of the counting efficiency have been carried out for thyroid
in vivo
monitoring of
¹³¹
I with all these phantoms. These measurements were performed for the emergency mobile units of Institut de Radioprotection et de Sûreté Nucléaire. The full efficiency curve, between 29 and 1000 keV, was then obtained by Monte-Carlo calculations and validated by comparison of a large set of measurements. The obtained efficiency curves are consistent and show that the relative difference in efficiency between the adult and the children case are energy dependent.