Measurements and prediction of the ambient dose rate from patient receiving radioiodine administration after thyroid ablation

Empirical equations were proposed for the prediction of the ambient dose equivalent rates from patients administered with radioiodine for the treatment of thyroid cancers. Ambient dose equivalent rates were measured for 59 patients who received high-dose I-131 treatment after thyroid ablation at different times after the administration. An ion chamber was used to measure the dose equivalent rates at 1 m away from the body and on contact to the thyroid of the patients. The resulting equations for estimating dose equivalent rates at 1 m from the body and on contact to the thyroid are, respectively, dot H(body)(1)0.236e(0.0501t) (mSv h(1) GBq(1)) and dot H(thy)(c)2.676e(0.0443t) (mSv h(1) GBq(1)). The effective half-times in total body appeared to be 13.86 h.This work was supported by the Korean ISO research project of Korean Agency for Technology and Standards (A Study on the Incorporation of the International Standards into Korean Nuclear Laws and Regulations)