ROLE OF SEMIQUANTITATIVE ELASTOGRAPHY BY STRAIN RATIO IN PREDICTING MALIGNANCY OF PANCREATIC MASSES

Aims:

Endoscopic ultrasound (EUS) is a very useful tool for diagnosing solid pancreatic masses (SPM). Add-on modules such as elastography or contrast-enhanced are used complementary for the evaluation of these lesions. Our aim was to assess the accuracy of semiquantitative elastography by strain ratio (SR) in predicting malignacy of pancreatic masses.

Methods:

We prospectively recruited patients who underwent EUS for evaluation of a SPM during a 12 months period and in whom elastography was also performed. EUS examinations were carried out using a Pentax Hitachi system. Semi-quantitative elastography results by SR were compared to the final diagnosis as made by results of fine needle aspiration (FNA), surgery or long-term outcome.

Results:

Altogether 58 patients were recruited, mean age was 65 ± 12, 57% male – of these, 45 (77.6%) were finally diagnosed with pancreatic adenocarcinoma (PADK), 4 (6.9%) with neuroendocrine tumors (NET), 6 (10.3%) with mass forming chronic pancreatitis, 2 (3.5%) with autoimmune pancreatitis (AIP) and 1 (1.7%) with metastasis. Mean SR was 22.7 in the PADK group, 63.5 for NETs, 2.52 for ChP, 24.9 for AIP and 4.35 for metastatis. SR had an AUROC of 0.790 (95% CI 0.613 – 0.968) in predicting malignancy; average SR was 8.92 in benign lesions and 26.4 in malignant ones. For a value over 20, SR had 81.8% specificity and 90.5% positive predictive value for malignacy.

Conclusions:

Semiquantitative elastography as done by SR measurement has good diagnostic performance for predicting malignancy of pancreatic masses and should be performed routinely during EUS examinations.