Endocrine Abstracts

Assessment of basal calcitonin as the main marker of medullary thyroid cancer (MTC) was introduced into routine practice in the Republic of Belarus more than 10 years ago. A number of laboratory and clinical factors can influence the result of this parameter determination. Equally important is the gender, age, weight, the deviation of the serum calcium level, certain medications.

The aim: Of the study was to develop and implement of stimulated calcitonin test to solve the problem of low specificity of basal calcitonin test for MTC diagnosis.

Materials and methods: The test protocol includes 1) determination of basal calcitonin level in the serum - blood sampling before the administration of calcium gluconate; 2) determination of the stimulated calcitonin level in the serum - blood sampling in 2 and 5 minutes after intravenous administration of a 10% solution of calcium gluconate. Tubes with blood must be immediately placed on ice, as calcitonin decomposes at room temperature. It is recommended the estimated dose of a 10% solution of calcium gluconate is indicated in terms of elemental calcium and is 2.0-2.5 mg/kg. The maximum allowable dose (all patients weighing more than 70 kg) is 20 ml of a 10% calcium gluconate solution. The drug is administered intravenously slowly over at least 30 seconds. In this case, the patient must be in a horizontal position.

Results and discussion: In the Republic of Belarus stimulated calcitonin test was carried out in 2017 in the consultative and diagnostic department of thyroid pathology of the Republican Center for Thyroid Tumors. Within the framework of the project, the test was carried out in 50 patients, preventive thyroidectomy was performed in 20, the systematization and analysis of the results continues. Possible adverse reactions during the test are a feeling of heat, a decrease in blood pressure, heart rhythm disturbances, fainting, cardiac arrest. Contraindications to the test are hypercalcemia and the simultaneous intake of cardiac glycosides.

Conclusions: Thus, the introduction and conduct of a calcitonin stimulated test showed its effectiveness for the differential diagnosis of nodular thyroid pathology (primary diagnosis of MTC in patients with nodal pathology of uncertain malignancy potential, taking into account the hereditary factor and with elevated levels of calcitonin); to verify the progression of the tumor process in patients with MTC (detection of early biochemical recurrence). This method can confirm a stable remission of the disease and allow women with MTC to plan pregnancy.