Is Thyroid Stimulating-Hormone related to Functional Tumor Burden in Patients with Advanced Medullary Thyroid Cancer?

Objectives: To investigate the relation between thyroid-stimulating-hormone (TSH) and metabolic tumor volume (MTV) in patients with advanced medullary thyroid cancer. Methods: Ga-68-DOTA-TATE-PET/CT findings such whole-body somatostatin receptor-expressing metabolic tumor volume (SSR-E MTV) and total lesion volume (SSR-E TLV) were calculated, and correlation analysis was performed for TSH and whole-body SSR-E MTV and SSR-E TLV. Results: Totally twenty-eight patients were included in the study. The median TSH level was 2.90 mU/L and median free T4 was 2.70 ng/L. The median calcitonin level was 6671.6 pg/mL and the median carcinoembryonic antigen level was 202.8 ng/mL. Median whole-body SSR-E MTV was calculated as 37.2 cm3 and median SSR-E TLV was calculated 198.6 cm3. There was a significantly positive correlation between TSH and whole-body SSR-E MTV and SSR-E TLV (rho=0.739, p<0.001 and rho=0.595, p=0.006). In the linear regression analysis, only calcitonin was found as a significant factor in terms of correlated with for SSR-E MTV (p<0.001). there were found that calcitonin and TSH were statistically significant factors in terms of correlated with SSR-E TLV (p<0.001 and p=0.005, respectively). Conclusion: This is the first study shown that a positive correlation between TSH and SSR-E MTV in patients with advanced medullary thyroid cancer. [ABSTRACT FROM AUTHOR]