RATIONALE FOR THE APPLICATION OF CALCITONIN LEVEL IN THE EARLY POSTOPERATIVE PERIOD TO EVALUATE THE EFFECTIVENESS OF SURGICAL TREATMENT OF MEDULLARY THYROID CANCER.

Purpose: To determine the effectiveness of the basal calcitonin (CTb) determination in the early postoperative period to predict the possible recurrence (persistence) of medullary thyroid cancer (MTC). Material and Methods: A retrospective study of the treatment results in 194 patients with MTC (148 (76.3%) primary - group 1 and 46 (23.8%) recurrent - group 2) according to the levels of CTb in the first week after surgery and one year later. All groups were analyzed by staging, the level of preoperative and postoperative basal calcitonin 5 days and 1 year after the primary surgery. Findings: Among all patients, women prevailed - 144 (74.2%), the average age was (48.7±15.2), the average follow-up period was 67.5 months. Basal calcitonin was studied in patients of all groups in the preoperative and serially in the postoperative periods: 5 days and 1 year after the most radical surgical volumes. To test the hypothesis about the possibility of using CTb indicators in the early postoperative period, the degree of compliance with normal calcitonin indicators (≤18 pg/mL) was assessed by observation groups 5 days and 1 year after surgery. Conclusions: 1. The CTb value 5 days after surgery is no less a reliable marker of the result of surgical treatment of MTC than the currently recommended CTb measurement 2-3 months after surgery. 2. The technique is applicable for both primary and reoperations used for recurrent forms of medullary thyroid cancer.