LISA-study : Levothyroxin in Nodular Goiter

Inclusion Criteria: * Caucasian * Normal TSH value (target range between 0.6 - 3.0 mU/l) * Thyroid nodules in a normal sized or enlarged thyroid at least one nodule (smaller/equal 20 % of volume with cystic change) with greater/equal 1.0 cm diameter, for nodules greater 1.0 cm the diagnosis must be performed according to the guideline for diagnostic standards of thyroid disorders. Exclusion Criteria: * Thyroid therapy within the last 3 years * Known focal or diffuse structure autonomous thyroid * Contraindication to iodine * Concomitant treatment with iodine containing medication (i.e. amiodarone) * Use of iodine-containing contrast medium within the last 6 weeks * Presence of TPO antibodies (maximum two fold normal value) * Symptomatic coronary heart disease * Endocrine orbitopathy * Known autoimmune thyreopathy * Former radioiodine therapy or surgery * Dermatitis herpetiformis * Pathological laboratory results * Participation in another clinical study with investigational medication within the last 30 days * Pregnant or nursing female patients * Female patients of childbearing potential, not using and not willing to continue using a medically reliable method of contraception for the entire study duration, such as oral, injectable, or implantable contraceptives, or intrauterine contraceptive devices, unless they are surgically sterilized/hysterectomized or who are not using any other method considered sufficiently reliable by the investigator in individual cases. * Severe or unstable cardiovascular diseases (e.g. severe angina pectoris, postmyocardial infarction syndrome and ventricular extrasystoles, symptomatic coronary heart disease), clinically relevant renal or hepatic diseases or disorders, any other clinically relevant condition that might enhance the risk for the study participant. The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.