title: Qualitative elastography can replace thyroid nodule fine-needle aspiration in patients with soft thyroid nodules. A systematic review and meta-analysis.
abstract: BACKGROUND
  Only a minority of thyroid nodules is malignant; nevertheless, many invasive diagnostic procedures are performed to distinguish between benign and malignant nodules. Qualitative ultrasound elastography is a non-invasive technique to evaluate thyroid nodules.
  
  
  OBJECTIVE
  To investigate the diagnostic value of qualitative elastography in distinguishing benign from malignant thyroid nodules in patients referred for fine-needle aspiration (FNA).
  
  
  METHODS
  A systematic literature search (PubMed, Embase and Cochrane Library) was performed.
  
  
  METHODS
  Included studies reported thyroid nodule elastography color scores and the related cytologic or histologic findings in patients with a thyroid nodule referred for FNA.
  
  
  METHODS
  Two independent reviewers extracted study data and assessed study quality. Pooled sensitivities and specificities of different populations were calculated using a bivariate Bayesian framework.
  
  
  RESULTS
  Twenty studies including thyroid nodules were analyzed. Pooled results of elastography indicate a summary sensitivity of 85% (95% confidence interval [CI], 79-90%) and specificity of 80% (95% CI, 73-86%). The respective pooled negative predictive and positive predictive values were 97% (95% CI, 94-98%) and 40% (95% CI, 34-48%). The pretest probability of a benign nodule was 82%. Only 3.7% of the false-negative nodules was a follicular thyroid carcinoma. A pooled negative predictive value of 99% (95% CI, 97-100%) was found when only complete soft nodules (Asteria elastography 1) were classified as benign, which included 14% of the studied population.
  
  
  CONCLUSIONS
  Elastography has a fair specificity and sensitivity for diagnostic accuracy. Its major strength entails the detection of benignity, especially when only completely soft nodules are qualified as benign. The outcomes of our analysis show that FNA could safely be omitted in patients referred for analysis of their thyroid nodule when elastography shows it to be completely soft (Asteria elastography 1). This could prevent unnecessary invasive diagnostic procedures in a substantial portion of patients.
authors: Department of Surgery, University Medical Center Utrecht, The Netherlands.
authors: Sjoerd
authors: S
authors: Nell
authors: Department of Surgery, University Medical Center Utrecht, The Netherlands.
authors: Jakob W
authors: JW
authors: Kist
authors: Julius Center for Health Sciences and Primary Care Utrecht, The Netherlands.
authors: Thomas P A
authors: TP
authors: Debray
authors: Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, The Netherlands.
authors: Bart
authors: B
authors: de Keizer
authors: Department of Surgery, University Medical Center Utrecht, The Netherlands.
authors: Timotheus J
authors: TJ
authors: van Oostenbrugge
authors: Department of Surgery, University Medical Center Utrecht, The Netherlands.
authors: Inne H M
authors: IH
authors: Borel Rinkes
authors: Department of Endocrinology, University Medical Center Utrecht, The Netherlands.
authors: Gerlof D
authors: GD
authors: Valk
authors: Department of Surgery, University Medical Center Utrecht, The Netherlands. Electronic address: mvriens@umcutrecht.nl.
authors: Menno R
authors: MR
authors: Vriens
mesh_terms: D001499:Bayes Theorem; D044963:Biopsy, Fine-Needle / Q000379:methods; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006801:Humans; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: Elastography; Fine-needle aspiration; Malignancy; Meta-analysis; Review; Thyroid nodule; Ultrasound