Advanced Ultrasound Application – Impact on Presurgical Risk Stratification of the Thyroid Nodules

Abstract

Aim

Current major guidelines recommend risk stratification of the thyroid nodules, after each diagnostic evaluation, in order to focus attention on potentially risky nodules. The main aim of our study was to evaluate the performance of combined advanced ultrasound techniques in this process, compared with conventional stratification models, in order to reduce unnecessary fine-needle biopsies, respectively, surgery.

Material and Methods

We evaluated 261 cases (261 nodules) using conventional ultrasound (2B), real-time Doppler evaluation (4D) respectively, real-time elastography, using a linear multifrequency probe and a linear volumetric probe (Hitachi Prerius Machine, Hitachi Inc, Japan). All the nodules were classified using a risk stratification model comprising seven conventional US characteristics, two 4 D characteristics and a color map RTE aspect. The results were compared with the pathology results, considered the golden standard diagnosis.

Results

The prevalence of malignant nodules was 21.83% (57 cases). Conventional risk classification generated: 106 low-risk cases, 113 intermediate-risk and 42 high-risk cases. Our proposed risk classification changes the conventional risk classification with a risk upgrade in 27 cases and with a risk downgrade in 69 cases. The diagnostic quality of the combined risk stratification model was better, considering a low-risk category predictive for benignancy and a high category predictive for malignancy: Sensitivity: 80.88% versus 49.01%, respectively, Specificity: 91.22% versus 54.38. The diagnostic power differences were observed regardless of the nodule size.

Conclusion

Advanced ultrasound techniques did add diagnostic value in the presurgical risk assessment of the thyroid nodules.

Keywords:

• strain elastography
• volumetric Doppler
• complex ultrasound thyroid evaluation
• risk stratification

Abbreviations

2B, conventional ultrasound; RTE, real-time elastography; V, volumetric Doppler; Se, Sensitivity; Sp, Specificity; Acc, Accuracy; FNAC, Fine-needle aspiration cytology; PTC, papillary thyroid carcinoma; FTC, follicular thyroid carcinoma.

Author Contributions

DS, IS and VI performed the process of patients’ diagnostic and evaluation. IM conceived the study and performed the statistical analysis, while DNa and DNe participated in the design of the study and helped to draft the manuscript. VF performed the surgeries. All authors contributed to data analysis, drafting and revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

“This research was funded by a research grant: grant number: SMIS 45997/21.01.2014- “Cresterea calitatii actului medical prin valorificarea potentialului IT” funder: Guvernul Romaniei, Ministerul Comunicatiilor si societatii informationale, axa POS CCE.