SWE Thresholds (kPa) for Thyroid Nodules: Opportunities and Limitations in Malignancy Risk Assessment
Why a Single SWE Threshold is Not Established
According to the EFSUMB Guidelines on Multiparametric Ultrasound Thyroid Nodule Evaluation (Cantisani et al., 2026), there is currently no consensus on the stiffness value ranges for distinguishing benign from malignant thyroid nodules, as these values differ between various ultrasound system manufacturers.
A meta-analysis including 14 studies and 2851 thyroid nodules suggested cut-off values ranging from 26.6 to 85.2 kPa. It was concluded that 2D-SWE has high diagnostic accuracy, with sensitivity and specificity rated as moderate (EFSUMB, 2026).
Quantitative Data on SWE (EFSUMB 2018)
According to the EFSUMB Guidelines for Non-Hepatic Applications (Săftoiu et al., 2019):
| Indicator | Value |
|---|---|
| Average stiffness of malignant nodules | 19.60–52.18 kPa |
| Declared cut-off values | 26.6–65 kPa |
| Average stiffness of benign nodules | 15.3–28 kPa |
| Sensitivity of SWE | 63.8–93.8 % |
| Specificity of SWE | 50–88.2 % |
The studies included nodules ranging from 2 to 71 mm in size, with the majority being papillary carcinomas. This is why the cut-off values have a wide range, and a single threshold cannot be established (EFSUMB, 2019).
Practical Conclusion
The most recent meta-analysis (14 studies, 2851 nodules) provides a cut-off range from 26.6 to 85.2 kPa (EFSUMB, 2019 and 2026). Given the dependence of absolute kPa values on the specific device, the SWE threshold cannot be used as a standalone universal criterion and should be interpreted in conjunction with B-mode and TI-RADS stratification.
It is recommended to clarify stiffness ranges for a specific device model according to the manufacturer's documentation [clarify].
Frequently asked questions
Is there a single SWE threshold in kPa for thyroid nodules?
No. According to EFSUMB (2026), there is no consensus on stiffness ranges for distinguishing benign from malignant nodules, as values vary between manufacturers.
What cut-off range does the meta-analysis provide?
The meta-analysis of 14 studies (2851 nodules) suggested a cut-off range from 26.6 to 85.2 kPa (EFSUMB, 2026).
What is the average stiffness of malignant and benign nodules?
According to EFSUMB (2019): malignant nodules — 19.60–52.18 kPa, benign nodules — 15.3–28 kPa.
What is the sensitivity and specificity of SWE?
Sensitivity is 63.8–93.8 %, specificity is 50–88.2 % (EFSUMB, 2019).
Why can't a single threshold be established?
Due to the wide range of nodule sizes (2–71 mm), the predominance of papillary carcinomas, and differences between devices (EFSUMB, 2019).