Endoscopic ultrasound (EUS) elastography-guided fine-needle aspiration cytology (FNAC) versus conventional EUS FNAC for solid pancreatic lesions: A pilot randomized trial

Background: Endoscopic ultrasound guided fine-needle aspiration (EUS FNA) is the first-line modality to diagnose suspected solid pancreatic malignant lesions. Elastography-guided FNA has been shown to improve the diagnostic yield of EUS FNA but prospective studies are limited. The aim of the study was to compare diagnostic accuracy, sensitivity and specificity of conventional and elastography-guided EUS FNA in patients with suspected malignant pancreatic solid masses.

Methods: Patients with suspected malignant solid pancreatic lesions presenting to our institute from July 2021 to January 2023 were recruited and randomized to conventional and elastography-guided EUS FNA using a 22-G EUS FNA needle. Diagnostic accuracy, sensitivity, specificity and positive and negative predictive values were calculated.

Results: Total 48 patients were initially screened for inclusion in the study, of which six were excluded and 42 patients underwent randomization. Finally, 20 patients in each group underwent the assigned intervention and were analyzed further. Baseline patient characteristics were similar in conventional FNA and elastography-guided FNA group with median age 52 (range 29-74) years and 51.8 (range 31-72) years, respectively, males being 70% and 75%, respectively. Median size of the lesion was 34 mm (range 14-48 mm) and 37 (range 18 to 50 mm), respectively, for both conventional and elastography arm. The average size of the lesion was 35.7 mm. Overall, the diagnosis of adenocarcinoma was made in 65% of cases. In the remaining cases, diagnoses were inflammatory mass, Castleman's disease, solid pseudopapillary epithelial neoplasm (SPEN), diffuse large B-cell lymphoma (DLBCL), pancreatic gastrointestinal stromal tumor (GIST) and metastasis. Conventional EUS FNA had diagnostic accuracy, sensitivity, specificity and positive and negative predictive values of 90%, 87.5%, 100%, 100% and 62.92%, respectively, and elastography-guided EUS FNA had diagnostic accuracy, sensitivity, specificity and positive and negative predictive values of 85%, 100%, 100% and 54.59%, respectively. No severe adverse events were noted.

Conclusion: There is no significant difference between conventional and elastography-guided EUS FNA in terms of diagnostic accuracy, sensitivity, specificity and positive and negative predictive values. Both techniques appear safe and effective for characterizing solid pancreatic masses and elastography did not score numerically over the conventional arm.