title: Shear wave elastography in medullary thyroid carcinoma diagnostics.
abstract: Shear wave elastography (SWE) is a modern method for the assessment of tissue stiffness. There has been a growing interest in the use of this technique for characterizing thyroid focal lesions, including preoperative diagnostics.
  
  
  OBJECTIVE
  The aim of the study was to assess the clinical usefulness of SWE in medullary thyroid carcinoma (MTC) diagnostics.
  
  
  METHODS
  A total of 169 focal lesions were identified in the study group (139 patients), including 6 MTCs in 4 patients (mean age: 45 years). B-mode ultrasound and SWE were performed using Aixplorer (SuperSonic, Aix-en-Provence), with a 4-15 MHz linear probe. The ultrasound was performed to assess the echogenicity and echostructure of the lesions, their margin, the halo sign, the height/width ratio (H/W ratio), the presence of calcifications and the vascularization pattern. This was followed by an analysis of maximum and mean Young's (E) modulus values for MTC (EmaxLR, EmeanLR) and the surrounding thyroid tissues (EmaxSR, EmeanSR), as well as mean E-values (EmeanLRz) for 2 mm region of interest in the stiffest zone of the lesion. The lesions were subject to pathological and/or cytological evaluation.
  
  
  RESULTS
  The B-mode assessment showed that all MTCs were hypoechogenic, with no halo sign, and they contained micro- and/ or macrocalcifications. Ill-defined lesion margin were found in 4 out of 6 cancers; 4 out of 6 cancers had a H/W ratio > 1. Heterogeneous echostructure and type III vascularity were found in 5 out of 6 lesions. In the SWE, the mean value of EmaxLR for all of the MTCs was 89.5 kPa and (the mean value of EmaxSR for all surrounding tissues was) 39.7 kPa Mean values of EmeanLR and EmeanSR were 34.7 kPa and 24.4 kPa, respectively. The mean value of EmeanLRz was 49.2 kPa.
  
  
  CONCLUSIONS
  SWE showed MTCs as stiffer lesions compared to the surrounding tissues. The lesions were qualified for fine needle aspiration biopsy based on B-mode assessment. However, the diagnostic algorithm for MTC is based on the measurement of serum calcitonin levels, B-mode ultrasound and FNAB.
authors.affiliation: Department of Ultrasound, Institute of Fundamental Technological Research, Polish Academy of Science, Warsaw, Poland; Department of Radiology, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Dobruch-Sobczak
authors.affiliation: Department of Endocrine Oncology and Nuclear Medicine, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Gumińska
authors.affiliation: Department of Pathology, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland.
authors.forename: Elwira
authors.initials: E
authors.lastname: Bakuła-Zalewska
authors.affiliation: Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Mlosek
authors.affiliation: Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Rafał Z
authors.initials: RZ
authors.lastname: Słapa
authors.affiliation: Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Wareluk
authors.affiliation: Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Krauze
authors.affiliation: Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Ziemiecka
authors.affiliation: Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Migda
authors.affiliation: Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Wiesław
authors.initials: W
authors.lastname: Jakubowski
authors.affiliation: Department of Endocrine Oncology and Nuclear Medicine, Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Dedecjus
keywords: medullary thyroid carcinoma; shear wave elastography; thyroid; ultrasound