ECE2006 Poster Presentations Thyroid (174 abstracts)
Department of Nuclear Medicine and Oncological Endocrinology, Clinic of Endocrinology and Metabolic Diseases, Medical University of Lodz, Lodz, Poland.
Introduction: An increase of thyroid iodine uptake (Tup) is one of the symptoms of thyrocyte stimulation by means of recombinant human thyrotropin (rhTSH). Low Tup, characteristic of iodine induced hyperthyroidism, creates serious problems, when 131I is considered, making this kind of treatment difficult, if not impossible.
Material and methods: We report a case of a 74 years old patient, with hyperthyroidism, induced by amiodarone administration, applied because of paroxysmal atrial fibrillation (AF). The failure of antiarrythmic therapy (after amiodarone withdrawal) in preventing AF, was the reason to attempt 131I treatment. Initial Tup of 4% after 24 hours rose to 36% following stimulation with rhTSH. Thyrogen (Genzyme) administered i.m. in a single dose of 80 μg resulted also in an increase of thyroid hormones concentration (see Table 1.)
The time point of study | FT3 (pg/mL) | FT4 (pmol/L) | TSH (μIU/mL) | Tup (%) |
Initial values | 4.9 | 24.6 | 0.18 | 4.4 |
12 h after rhTSH administration | 5.2 | 32.2 | 24.8 | |
24 h 131I diagnostics | 3.7 | 16.8 | 14.8 | |
48 h 131I therapy | 6.1 | 38.3 | 4.05 | 36.0 |
96 h | 6.6 | 41.6 | 0.62 | |
192 h, AF, thyrostatics | 5.3 | 35.1 | 0.02 |
Following the administration of 131I in therapeutic activity (888 MBq), despite increased thyroid hormone concentrations, no clinical symptoms of thyrotoxicosis were observed, except AF, which normalised within 12 h after increased propranolol dose.
Conclusion: Recombinant human TSH may enable 131I therapy, especially in cases of iodine induced hyperthyroidism.