[Value of preoperative nuclear medicine diagnosis in hyperthyroidism and thyroid cancer]

The optimal diagnostic procedure before surgery in thyrotoxicosis and thyroid malignancies is a combination of scintigraphy, sonography and fine-needle-aspiration biopsy. In diffuse toxic goiters the differentiation of immunogenic and non immunogenic thyrotoxicosis is predominant. In toxic nodular goiters the sonographic localisation in relation to the thyroid capsule is necessary to prevent recurrent autonomies. Malignomas should be subclassified (fine-needle-aspiration biopsy, calcitonin) to differentiate between carcinomas with necessary aggressive or conservative surgical treatment. After thyroidectomy in differentiated carcinomas a high I-131-uptake requires once more surgical resection to decrease radiation exposure during I-131-therapy.