Design of a model for the estimation of the ambient equivalent dose received by the closest groups to the patients undergoing treatment of remains of thyroid Ca. with I-131
DOI:
https://doi.org/10.37004/sefm/2020.21.2.001Keywords:
Effective elimination time, Ambient equivalent dose rate, Dose restriction, Post-therapy recommendationsAbstract
The aim is to make an adequate estimate of the ambient equivalent dose received by the groups closest to the patient, once the patient has the radiological and clinical discharge.
As a first step, a patient's daily life pattern with its closest environment has been modelled. A maximum dose rate of 40 μSv/h at 1 meter has been set to give the patient the radiological discharge.
Secondly, a fitting equation that gives us the evolution of the dose rate with distance has been formulated. How the function fits to the experimental points after measuring 45 patients at the distances between 0.4 and 2 meters was verified obtaining R2 ≥ 0.98 for 75.55% of the cases. Besides, a smaller error is made than using the equation of the Radiological Protection in the Healthcare Enviroment in 93.33% of cases.
When models are simulated, modes of the dose distributions do not exceed the dose restriction, namely, 3 mSv per treatment when partner is under 60 years old and 15 mSv when companion is over 60 years old.
Finally, an experimental elimination time is obtained, being this less than the given in the Forum document, reducing the mode of distributions between a half and one tenth.
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