Effectiveness of radioactive iodine-131 therapy in patients with toxic nodular goitre

The aim of this retrospective study is to evaluate the treatment outcomes in patients with toxic nodular goitre that received radioiodine therapy and to determinate the influence of age, gender, nodule size, I-131 dose, underlying etiology and antithyroid drugs on the outcomes of radioiodine therapy.Two hundred thirty three patients with toxic nodular goitre that received radioiodine therapy between January 2007 and November 2011 were included in the study. Treatment success in relation with demografic data (age and gender) and clinical data (thyroid function tests before and after radioiodine therapy, thyroid ultrasound and scintigraphy, I-131 dose, antithyroid drugs) was analysed. A fixed dose of 555 MBq was administered to patients with nodules smaller than 2 cm in diameter and a dose of 740 MBq administered to patients with nodules larger than 2 cm. The result of treatment was evaluated on the basis of thyroid function tests after 6 months and 1 year. Development of euthyroidism or hypothyroidism after radioiodine therapy was considered succesfull cure of hyperthyroidism after 6 months.One hundred sixty three out of 233 patients (%70) were female and 70 patients (%30) were male. All patients were between 28-86 years old and mean age was 64±10 yaers. In our study after six months radioiodine therapy cure rate was %93,9 and hypothyroidism was observed in 74 (%31,7) patients, euthyroidism was achieved in 145 (%62,2) patients and 14 (%6) patients remained as hyperthyroidism.Age and gender didn?t affect treatment outcomes. No correlation was found between underlying etiology or antithyroid drugs and therapeutic effectiveness. In our study, the cure rate was higher in the patients that dose of a 555 MBq was administered and nodules smaller than 2 cm in diameter than in the patients that dose of a 740 MBq administered and nodules larger than 2 cm.In our study we observed that 555 MBq and 740 MBq doses of I-131 were obtained high cure rates in patients with toxic nodular goitre. Radioiodine therapy is an effective, easy and safe therapeutic modality in these patients.