ASSESSING THE DIAGNOSTIC PERFORMANCE OF ULTRASOUND ELASTOGRAPHY COMPARED TO FINE-NEEDLE ASPIRATION IN THYROID NODULE MALIGNANCY DETECTION

Background: Thyroid nodule evaluation demands precise diagnostic techniques to effectively distinguish benign from malignant lesions. Fine-needle aspiration cytology (FNAC) remains the gold standard for assessing thyroid nodules due to its established accuracy and reliability. However, ultrasound elastography is gaining attention as a non-invasive alternative, offering potential advantages in detecting malignancy through stiffness measurements. Despite promising results, limited data exist on its diagnostic utility in cases with single versus multinodular thyroid disease. This study seeks to address this gap by comparing the diagnostic accuracy of FNAC and ultrasound elastography in evaluating benign and malignant thyroid nodules in both solitary and multinodular glands. By exploring this comparison, we aim to provide deeper insights into the potential role of ultrasound elastography as a complementary or standalone diagnostic tool in routine clinical practice.

Objective: The primary aim of this study was to evaluate the diagnostic accuracy of ultrasound elastography in distinguishing between benign and malignant thyroid nodules. This assessment was conducted for both solitary and multinodular thyroid presentations, with findings compared directly against the established benchmark of fine-needle aspiration cytology (FNAC). By providing detailed analysis, this study aims to clarify the potential role of ultrasound elastography in routine thyroid nodule evaluation and its utility as an adjunct or alternative to FNAC in clinical practice.

Methodology: This prospective observational study was carried out at Ayub Teaching Hospital in Abbottabad, a 1,650-bed tertiary care government hospital serving the Khyber Pakhtunkhwa (KPK) region of Pakistan, from September 2022 to march 2023. We included adult patients aged 18 and older who presented with palpable or visible thyroid nodules. Exclusion criteria were applied to those with previous thyroid surgery, a confirmed cancer diagnosis, or patients who declined both diagnostic tests. Comprehensive demographic, clinical, and imaging data were collected from 340 participants to ensure a robust analysis. Ultrasound elastography’s sensitivity, specificity, and diagnostic accuracy were calculated, using FNAC as the reference standard. Receiver operating characteristic (ROC) curve analysis helped determine the optimal threshold for distinguishing between benign and malignant nodules. By situating this study within a major public hospital, we aimed to evaluate the practical utility of ultrasound elastography as a potential non-invasive diagnostic tool for thyroid nodules in Pakistani healthcare settings.

Results: This study included 340 participants, among whom 240 had benign thyroid nodules and 100 had malignant ones. Fine-needle aspiration cytology (FNAC) demonstrated a slightly higher diagnostic accuracy than ultrasound elastography, particularly for benign nodules, with a sensitivity of 92.00% and specificity of 85.33%. For malignant nodules, FNAC again outperformed ultrasound elastography, showing a specificity of 80.95% and sensitivity of 91.82%. Across all age groups, FNAC consistently provided more reliable results compared to ultrasound elastography. Overall, the accuracy rate of ultrasound elastography was found to be 81.94%, while FNAC achieved a higher accuracy of 85.47%. The optimal cutoff point for ultrasound elastography to differentiate benign from malignant nodules was identified as 4.2, yielding a sensitivity of 87.25% and specificity of 78.40%. These findings underscore the slightly superior diagnostic value of FNAC but also highlight the potential role of ultrasound elastography as a supportive, non-invasive tool in thyroid nodule assessment.

Conclusion: Ultrasound elastography demonstrates strong potential as a valuable, non-invasive, real-time tool that can complement fine-needle aspiration cytology (FNAC) in the diagnosis of thyroid nodules. While FNAC remains the benchmark for diagnostic accuracy, ultrasound elastography provides additional insights, especially in cases where a less invasive approach is preferred. This technology holds promise for broader application in settings where access to FNAC may be limited or where patients seek less invasive diagnostic options. Our findings support the role of ultrasound elastography as an adjunct to FNAC, paving the way for more accessible and reliable thyroid nodule evaluation, particularly in Pakistani clinical practice.