title: Prospective cohort study comparing transient EUS guided elastography to EUS-FNA for the diagnosis of solid pancreatic mass lesions.
abstract: BACKGROUND
  Semiquantitative EUS-elastography has been introduced to distinguish between malignant and benign pancreatic lesions. This study investigated whether semiquantitative EUS-guided transient real time elastography increases the diagnostic accuracy for solid pancreatic lesions compared to EUS-FNA.
  
  
  METHODS
  This single centre prospective cohort study included all patients with solitary pancreatic lesions on EUS during one year. Patients underwent EUS-FNA and semiquantitative EUS-elastography during the same session. EUS and elastography results were compared with final diagnosis which was made on the basis of tissue samples and long-term outcome.
  
  
  RESULTS
  91 patients were recruited of which 68 had pancreatic malignancy, 17 showed benign disease and 6 had cystic lesions and were excluded from further analysis. Strain ratios from malignant lesions were significantly higher (24.00; 8.01-43.94 95% CI vs 44.00; 32.42-55.00 95% CI) and ROC analysis indicated optimal cut-off of 24.82 with resulting sensitivity, specificity and accuracy of 77%, 65% and 73% respectively. B-mode EUS and EUS-FNA had an accuracy for the correct diagnosis of malignant lesions of 87% and 85%. When lowering the cut-off strain ratio for elastography to 10 the sensitivity rose to 96% with specificity of 43% and accuracy of 84%, resulting in the least accurate EUS-based method. This was confirmed by pairwise comparison.
  
  
  CONCLUSIONS
  Semiquantitative EUS-elastography does not add substantial value to the EUS-based assessment of solid pancreatic lesions when compared to B-mode imaging.
authors.affiliation: Department of Medicine A, University Medicine Greifswald, Ernst-Moritz-Arndt-University Greifswald, Germany. Electronic address: mayerle@uni-greifswald.de.
authors.forename: J
authors.initials: J
authors.lastname: Mayerle
authors.affiliation: Department of Medicine A, University Medicine Greifswald, Ernst-Moritz-Arndt-University Greifswald, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Beyer
authors.affiliation: Department of Medicine A, University Medicine Greifswald, Ernst-Moritz-Arndt-University Greifswald, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Simon
authors.affiliation: Lister Department of Surgery, Glasgow Royal Infirmary, Glasgow, United Kingdom.
authors.forename: E J
authors.initials: EJ
authors.lastname: Dickson
authors.affiliation: Lister Department of Surgery, Glasgow Royal Infirmary, Glasgow, United Kingdom.
authors.forename: R C
authors.initials: RC
authors.lastname: Carter
authors.affiliation: Department of Pathology, Southern General Hospital, Glasgow, United Kingdom.
authors.forename: F
authors.initials: F
authors.lastname: Duthie
authors.affiliation: Department of Medicine A, University Medicine Greifswald, Ernst-Moritz-Arndt-University Greifswald, Germany.
authors.forename: M M
authors.initials: MM
authors.lastname: Lerch
authors.affiliation: Lister Department of Surgery, Glasgow Royal Infirmary, Glasgow, United Kingdom.
authors.forename: C J
authors.initials: CJ
authors.lastname: McKay
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle / Q000379:methods; D002277:Carcinoma; D015331:Cohort Studies; D003560:Cysts / Q000175:diagnosis / Q000473:pathology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D019160:Endosonography / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D012680:Sensitivity and Specificity
keywords: Chronic pancreatitis; Endosonography; Fine needle aspiration; Pancreatic mass; Strain ratio; Transient elastography