A Comprehensive Diagnostic Assessment of Thyroid Nodules Utilizing Scintigraphy and Telomere Lengths (T/S ratios)

Objectives: This study aims to evaluate the effectiveness and role of telomere length measurements in leukocytes, plasma free cell DNA (cfDNA), and biopsy cells, along with technetium-99m (Tc-99m) methoxyisobutylisonitrile (MIBI) scintigraphy, as non-invasive methods for diagnosing malignant thyroid lesions. Methods: Data from 128 patients, who underwent ultrasound, Tc-99m MIBI scintigraphy, and fine-needle biopsy with a preliminary diagnosis of malignant thyroid nodules, were analyzed. In 98 patients, telomere lengths in leukocytes (from blood), cfDNA (from plasma), and biopsy cells were measured using the quantitative polymerase chain reaction method, and the relative telomere/single copy gene (T/S) ratio was calculated. Based on cytological examination results, patients were categorized into three groups: malignant, benign, and suspicious. Group differences were analyzed using the Kruskal-Wallis and Chi-square tests, and correlations between variables were examined with Spearman correlation analysis. Results: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of Tc-99m MIBI scintigraphy for diagnosing malignant thyroid nodules were 64.70%, 79.16%, 29.72%, 83.51%, and 67.96%, respectively. While these results align with the literature, the positive predictive value was notably lower. No significant differences were observed in telomere lengths (T/S ratios) in leukocytes, plasma, or tissue between the groups. Conclusion: Tc-99m MIBI scintigraphy demonstrates reasonable diagnostic accuracy for identifying malignancy in thyroid nodules. Contrary to limited reports, telomere length measurements may not be a reliable method for predicting thyroid malignancy. Larger studies are needed to further explore these findings.