Non-Marked Hypoechogenic Nodules: Multicenter Study on the Thyroid Malignancy Risk Stratification and Accuracy Based...

Area of Science:

• Radiology
• Oncology
• Endocrinology

Background:

• Thyroid nodules are common, and accurate malignancy risk stratification is crucial.
• The Thyroid Imaging Reporting and Data System (TIRADS) aids in classifying nodules based on ultrasound features.
• Evaluating specific ultrasound criteria, like non-marked hypoechogenicity, is key to refining diagnostic accuracy.

Purpose of the Study:

• To assess the predictive value of "non-marked hypoechogenicity" for thyroid nodule malignancy.
• To determine if classifying these nodules as TIRADS 3 enhances the modified TIRADS (M-TIRADS) score's accuracy.
• To evaluate the impact on reducing unnecessary fine needle aspiration (FNA) biopsies.

Main Methods:

• A retrospective analysis of 795 thyroid nodules from 767 patients undergoing ultrasonography and ultrasound-guided fine needle aspiration biopsy.
• Nodules were classified using Kwak TIRADS and a modified TIRADS (M-TIRADS) system based on suspicious ultrasound features.
• Histopathology and specific cytology results served as the reference standard for malignancy assessment.

Main Results:

• The M-TIRADS system demonstrated high sensitivity (93.02%) and specificity (81.31%) for malignancy detection.
• Classifying non-marked hypoechoic nodules as TIRADS 3 significantly improved M-TIRADS accuracy (78.26% vs. 48.11% for Kwak TIRADS).
• This classification strategy did not significantly alter malignancy risk in TIRADS 3, potentially reducing overdiagnosis and FNA procedures.

Conclusions:

• Non-marked hypoechoic nodules exhibit a low risk of malignancy.
• Classifying these nodules as TIRADS 3 enhances M-TIRADS predictive value and overall accuracy.
• The proposed M-TIRADS modification aids in reducing overdiagnosis and unnecessary FNA biopsies for thyroid nodules.