The treatment of multinodular large non-toxic goiter using repeated doses of radioiodine (preliminary report)

INTRODUCTION: The aim of study was to establish the effectiveness of radioiodine therapy using 131I in the group of patients with multinodular large non-toxic goiter. MATERIAL AND METHODS: Therapy was undertaken in female patients disqualified from surgery due to high risk and these patients who didn't agree to surgery. Studies were performed in 7 women (age range: 62-82 yrs) with large goiters (2nd degree according to WHO classification and goiter volume assessed by USG over 100 cm(3)). Serum TSH, fT4, fT3, antithyroid antibodies (TPOAb, TgAb, TRAb) levels, urinary iodine concentration (UIE) were estimated in all patients parallel with radioiodine uptake test (after 5 and 24 hours), 131I thyroid scintigraphy and fine needle biopsy to exclude neoplasmatic transformation. These studies and therapy with 22 mCi 131I were repeated every 3 months. RESULTS: Before therapy median thyroid volume was approximately 145 cm(3) and during therapy gradually decreased to 76 cm(3) after 6 months and to 65 cm(3) after 12 months. Increase of TRAb can be a inhibiting factor of thyroid volume reduction. Other antithyroid antibodies showed marked tendency to rise but without significant correlation with radioiodine uptake and goiter reduction. After 12 months we found 2 patients with clinical and laboratory hypothyroidism. CONCLUSIONS: In some cases of multinodular large non-toxic goiter, the radioiodine therapy can be the best alternative way for L-thyroxine treatment or surgery therapy. The fractionated radioiodine therapy of multinodular large non-toxic goiter is safe and effective method but continuation of nodules observation is necessary.