Analysis of Lag Behind Thyrotropin State After Radioiodine Therapy in Hyperthyroid Patients

Abstract

Introduction: A good number of hyperthyroid patients may show delayed recovery of Thyroid Stimulating Hormone (TSH) level in clinically evident euthyroid condition after radioiodine therapy. This group of patients need to be addressed in therapeutic decision making. The purpose of the study was to evaluate the duration and pattern of lag in TSH recovery after I -131 therapy and the relationship between clinical parameters with stable thyroid function status. Materials and Methods:Total 192 hyperthyroid patients treated with I-131 were included in this study. These patients were followed up clinically and biochemically at three month, six month and one year after radioiodine therapy. Patients having suppressed TSH with normal Free Triiodothyronine (FT3) / Free Thyroxin (FT4) level and clinically euthyroid condition were followed-up for one year without giving antithyroid drug. Results Conclusion:Lagging state of TSH may be unexpectedly prolonged in some hyperthyroid patients treated with I-131. These patients should be followed up with both TSH and thyroid hormone levels. Most of them do not require further therapy with short period of time.