Restriction periods for carers, comforters and members of the public in the treatment of hyperthyroidism

People treated for hyperthyroidism are normally outpatients who pose a potential radiological risk to some members of the public. In this study, measurements of the uptake in 30 patients were used to estimate the values of the activity of 131I in the whole body of patients, AWB, by using a model of two compartments. Restriction periods to be followed by patients for different values of the administered activity of 131I were calculated. To perform calculations, the following were used: the curve obtained for AWB; the value of the dose rate at one metre from patients after the administration of the treatment; and the estimated time that carers, comforters and members of the public will spend at certain distances from patients. Results show that protection from radiation for carers, comforters and members of the public related to patients treated for hyperthyroidism can become a cumbersome matter as patients may have to follow very long restriction periods. (authors)