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

Abstract

Introduction: The aim of study was to establish the effectiveness of radioiodine therapy using 131-I 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 cm³). 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), 131-I thyroid scintigraphy and fine needle biopsy to exclude neoplasmatic transformation. These studies and therapy with 22 mCi 131-I were repeated every 3 months.
Results: Before therapy median thyroid volume was approximately 145 cm³ and during therapy gradually decreased to 76 cm³ after 6 months and to 65 cm³ 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.