Pancreatic solid masses (PSM) are difficult to assess; endoscopic ultrasound with fine-needle aspiration (FNA) enables tissue acquisition, but has high false-negative rates. Quantitative elastography (QE) predicts diagnosis on the basis of the strain ratio (SR). We aimed to compare both methods to evaluate PSM.
This prospective study, carried out between January and December 2016, included suspected PSM cases; those with advanced disease and cystic components were excluded. Both procedures were performed; histologic information was obtained for the final diagnoses. Diagnostic tests and receiver-operating characteristic curve were calculated. P<0.05 was considered statistically significant.
We included 134 patients (53% women; mean, 53±16.2 y). The median tumor size was 30 (10 to 78) mm, with 69.4% and 30.6% malignant and benign tumors (median SR: 19.5 vs. 7.5; P=0.000), respectively, and 87% were pancreatic adenocarcinoma. QE with SR cutoff ≥10 showed similar parameters to FNA in both PSM types: sensitivity, 94% in both; specificity, 85% versus 87%; positive predictive value, 93% versus 94%; negative predictive value, 87% in both; and accuracy, 92% for malignant and sensitivity, 85% versus 87%; specificity, 94% in both; positive predictive value, 87% in both; negative predictive value, 93% versus 94%; and accuracy, 92% for benign. The area under the curve was 0.96 (P<0.000; 95% confidence interval, 0.940-0.995). New classifications on the basis of positive likelihood ratio were grouped as follows: A ≤8.7 (benign tumor); B >8.7 to <15.5 (indeterminate); and C ≥15.5 (malignant).
QE has similar capacity to FNA in PSM evaluation. However, the former can be used potentially as a substitute of the latter in certain cases on the basis of these new SR cutoff-based classifications.
*Division of Endoscopy, Specialties Hospital, National Medical Center Century XXI
†Nanomedicine Multidisciplinary Laboratory and Cardiovascular Pharmacology, Research and Graduate Study Section, Medicine University, National Politechnic Institute
‡Training Center in Clinical Investigation, Coordination of Research in Health, National Medical Center Century XXI, Mexico City, Mexico
The authors declare that they have nothing to disclose.
Address correspondence to: Oscar V. Hernández Mondragón, MD, Department of Endoscopy, Specialties Hospital, National Medical Center Century XXI, Cuauhtémoc Avenue 330, Mexico City 06700, Mexico (e-mail: firstname.lastname@example.org).
Received September 6, 2017
Accepted January 24, 2018