Efficacy of procalcitonin measurement in patients after total thyroidectomy due to medullary thyroid carcinoma.

Procalcitonin (PCT) is a protein synthetized by the thyroid C cells, inside which it is cut into calcitonin (CT) and catacalcin. It remains undetectable in serum in normal conditions. Its level increases during inflammation and in small cell lung cancer. There have been studies suggesting that the PCT level increases in medullary thyroid carcinoma (MTC). So far there have been no reports that would assess the usefulness of PCT detection in MTC. Our aim was to evaluate the usefulness of serum PCT assays in patients with MTC. We investigated 24 patients at 17-78 years of age, all after total thyroidectomy due to MTC. All patients had serum CT concentrations measured by radioimmune assay. The upper limit of the CT level was 60 pg/ml. The serum PCT was evaluated with an immunochromatographic kit. The reaction was considered positive when the PCT level exceeded 0.5 ng/ml. In all cases the C-reactive protein (CRP) serum level was measured. The statistical analysis was performed with Statistica 5.1G. The CT levels in all patients varied from 0 to 1410, mean 603.8 pg/ml. In 8 patients the CT level was within normal range, in 6 patients it was marginally, and in 10 patients markedly elevated. The PCT test was considered positive in 16 patients. There was correlation among serum PCT and CT concentrations (Spearman test, p<0.0001). The PCT levels varied considerably among patients with normal, marginally and markedly elevated CT levels (Kruskal-Wallis test, p=0.0013). All patients had normal CRP values. Fisher's exact test revealed a correlation between serum PCT and CT increase (p=0.04). Further studies on a larger group of patients should be considered; thus, the PCT assay can be considered useful in cases of unclear CT concentration.

[Usefulness of isotope diagnosis, ultrasound neck investigation and thyroglobulin assays in quantification of patients operated on for differentiated thyroid cancer and prepared for radioiodine treatment]. / Przydatnosc diagnostyki izotopowej, ultrasonografii szyi oraz oznaczen tyreoglobuliny w kwalifikacji chorych operowanych z powodu raka zróznicowanego tarczycy przygotowywanych do leczenia radiojodem (doswiadczenie wlasne).

UNLABELLED: The aim of the study was to assess the efficacy of surgical treatment of patients operated on differentiated thyroid carcinoma, using Tg serum assays and 131-I whole body scintigraphy. We investigated 208 patients aged from 15 to 78 yr. (mean 43.52, S.S. 16.37) including 182 females and 26 males. 183 cases of papillary cancer and 25 cases of follicular cancer were confirmed by pathologist. All the patients were investigated 6-8 weeks after thyreoidectomy. The following procedures were performed in all the patients: 1. ultrasound imaging. 2. 131 iodine uptake test, 24 hours after administration. 3. 131-I whole body scintigraphy (dose per patient 3 mCi, device Varicam). 4. TSH and Tg serum assay using FIA method. Moreover, all the tissue fragments obtained during surgery underwent histopathological assessment. RESULTS: The mean volume of the post-surgery thyroid tissue remains was 2.91 cc varying from 0 to 40. Volume was counted with Gutekunt's formula. Oncologically suspected lymph nodes were found in 8 cases. The mean TSH serum level was 79.31 (SD 59.59). The mean Tg serum level was 51.73 (SD 179). The mean value of an iodine uptake test was 6.96% (SD 6.69). Whole body scintigraphy discovered solitary thyroid site iodine uptake areas in 199 patients (95.7%). Additional uptake areas were observed in 4.3% 2 (0.9%) cases in cervical lymph nodes, 4 (1.9%) cases in lungs, 3 (1.5%) in bones. The correlation between investigations both laboratory and isotopic, and clinical state was observed in 207 cases (99.5%). The presence of high Tg serum level despite of absence of extracervical iodine uptake areas was observed in one case. We presume that the situation can be caused by the presence of multiple lung metastases not having possibility of iodine uptake. Ultrasound imaging, 131-I scintigraphy and Tg serum assays are essential methods in diagnosing and treatment process in the patients with differentiated thyroid carcinoma.