Distinguish Thyroid Malignant from Benign Alterations Using X-Ray Fluorescence Analysis of Trace Element Contents in Nodular Tissue

Introduction: Thyroid benign (TBN) and malignant (TMN) nodules are a common thyroid lesion. The differentiation of TMN often remains a clinical challenge and further improvements of TMN diagnostic accuracy are warranted. Objective: The aim of present study was to evaluate possibilities of using differences in trace elements (TEs) contents in nodular tissue for diagnosis of thyroid malignancy. Methods: Contents of TEs such as bromine (Br), copper (Cu), iron (Fe), iodine (I), rubidium (Rb), strontium (Sr), and zinc (Zn) were prospectively evaluated in nodular tissue of thyroids with TBN (79 patients) and to TMN (41 patients). Measurements were performed using energy-dispersive X-ray fluorescent analysis. Results: It was observed that in TMN tissue the mass fractions of Br, I and Zn were approximately 2.9, 20, and 1.3 times, respectively, lower while the mass fraction of Rb 41% higher than in TBN tissue. Contents of Cu, Fe, and Sr found in the TBN and TMN groups of nodular tissue samples were similar. Conclusions: It was proposed to use the I mass fraction and I/Rb mass fraction ratio in a needle-biopsy of thyroid nodules as a potential tool to diagnose thyroid malignancy. Further studies on larger number of samples are required to confirm our findings and proposals.