RESUMO
To construct a lead collar useful for shielding the electromagnetic radiation from the thyroid of patients treated with radioiodine 131I for hyperthyroidism, thereby reducing the radiation emitted from these patients. Materials and A specially designed cervical lead collar was used to shield radiation exposure from 'hot thyroids' of 20 patients treated with iodine-131 for hyperthyroidism. The collar was made of lead strips stacked together around a plastic neck support fastened around the patient's neck. Measurements of the radiation exposure rate were obtained at increasing distances from the patients [50, 100, 200 cm], with and without the lead collar, at various times after 131I treatment. Radiation exposure measurements over 3 weeks showed relatively high exposure rates in the first week after treatment. The radiation exposure from the patients wearing the lead collar was half that found in the same patients not wearing the collar. The use of the lead collar significantly reduced the radiation exposure of patients' surroundings. It was particularly useful in patients who could not abide strictly to the standard restrictive protocols after treatment with 131I