Diagnostic Performance of Endoscopic Ultrasound Elastography for Differential Diagnosis of Gallbladder Polyp

Background and aims: It is difficult to differentiate between neoplastic and non-neoplastic gallbladder (GB) polyps before surgery. Endoscopic ultrasound-elastography (EUS-EG) is a non-invasive complementary diagnostic method. The utility of EUS-EG in the differential diagnosis of GB polyps has not been investigated. We aimed to investigate the diagnostic performance of EUS-EG for the differential diagnosis of GB polyps.

Methods: Patients with GB polyps were prospectively enrolled from June 2020 until November 2022. EUS-EG and semi-quantitative evaluation of the strain ratio (SR) were performed for differential diagnosis of GB polyps. Fifty-three eligible patients were divided into two groups based on the final diagnosis after surgery. Patient demographics, EUS characteristics, and SR values were compared. Receiver-operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff SR value that discriminates between neoplastic and non-neoplastic GB polyps.

Results: The median SR value for neoplastic polyps (32.93 [interquartile range: 22.37-69.02]) was significantly higher than for non-neoplastic polyps (5.40 [2.36-14.44]; p<0.001). There were significant differences in SR values between non-neoplastic, benign neoplastic (23.38 [13.62-39.04]), and malignant polyps (49.25 [27.90-82.00]). The optimal cut-off SR value to differentiate between neoplastic and non-neoplastic polyps was 18.4. In multivariable logistic regression, SR value >18.4 (odds ratio 33.604, 95% confidence interval 2.588-436.292) was an independent predictor of neoplastic polyps.

Conclusions: EUS-EG and SR values can be used as a supplementary method for evaluating GB polyps.