Evaluation of elastosonography and fine-needle aspiration biopsy results in the diagnosis of thyroid nodules

Objective
The aim of our study is to investigate the importance of strain sonoelastography (SSE) in the diagnosis of thyroid nodules and in the selection of indications for fine-needle aspiration biopsy (FNAB).
Materials and methods
We included 481 patients who visited our clinic between 2019–2022 with thyroid nodules in the study and used a stepwise diagnostic approach to choose patients to perform surgery on and follow-up. All patients were ranked into 2 groups: Group 1 included 135 (28,1%) patients were assessed as SSE along with traditional examinations. The 2nd group included 346 (71.9%) patients who underwent ultrasound examination using SE, only the hard nodule or hard regions of the nodule detected by SSE were obtained with FNAB. We followed up on nodules with benign FNAB results, and nodules with suspicious or malignant results underwent thyroidectomy. Histopathology results of surgically removed nodules were compared with SSE and FNAB results. AUROC was the primary, while sensitivity, specificity, PPV and NPV were the secondary outcome.
Results
Out of 481 patients, 420 (87.3%) were female, 61 (12.7%) were male, and the age range was 17–83 (CI=45.57±25.9). The mean nodule size was 23.33±16.7 mm. After evaluating elastography results, FNAB was performed on 346 (71.9%) nodules. Surgical treatment was performed in 114 (group 1) (84.4%) of 135 patients, benign tumors were diagnosed in 107 (93.8%), and malignant tumors in 7 (6.2%). Surgical treatment in group 2 was performed in 146 (42.2%) of 346 patients, benign tumors were detected in 105 (71.9%) patients, and malignant in 41 (28.9%). The combined use of the sonoelastography and fine-needle aspiration biopsy contributed to a significant increase in the frequency of detection of thyroid nodules of malignant structure, which amounted to 28.9% in patients of the main group (versus 6.2% in patients of the control group) and a decrease in the frequency of surgical interventions by more than 2 times in patients of the second group. The area of the ROC curve for SSE was S=0.851±0.029; 95% CI (0.794 to 0.908); =0.000. It is a statistically significant marker in the diagnosis of thyroid nodules. The most important marker in the diagnosis of thyroid nodules was the FNAB test: S=0.874±0.034; 95% CI (0.807 to 0.940); =0.000. Sensitivity, specificity, PPV, and NPV of elastosonography of the I group were 42.9±18.7%, 96.3±1.8%, 42.9%, 96.3; of II group 68.3±7.3%, 87.6±3.2%, 68.3%, 87.6%; FNAB 90.2±4.6%, 90.5±2.9%, 76.2%, 91.3%, respectively.
Conclusion
Combined use of SE and Bethesda system was able to detect malignancy in the early stages and to reduce the number of operations.