Quantitative elastography on par with fine-needle aspiration in evaluating pancreatic solid masses
It appears that quantitative elastography (QE) is as good as fine-needle aspiration (FNA) in the assessment of pancreatic solid masses (PSMs), but the former can be used as a potential alternative of the latter in cases where the new strain ratio (SR) cutoff-based classifications are applied, suggests a study.
A total of 134 patients (mean age, 53 years; 53 percent women) were included, with a median tumour size of 30 (10–78) mm. Of these, 69.4 percent were malignant and 30.6 percent were benign tumours (median SR, 19.5 vs 7.5; p=0.000), and 87 percent were pancreatic adenocarcinoma.
In both PSM types, parameters were comparable between QE with SR cutoff ≥10 and FNA (for malignant tumour: sensitivity, 94 percent in both; specificity, 85 percent vs 87 percent; positive predictive value, 93 percent vs 94 percent; negative predictive value, 87 percent in both; and accuracy, 92 percent; for benign tumour: sensitivity, 85 percent vs 87 percent; specificity, 94 percent in both; positive predictive value, 87 percent in both; negative predictive value, 93 percent vs 94 percent; accuracy, 92 percent).
The area under the curve was 0.96 (95 percent CI, 0.940–0.995; p<0.000). New classifications based on positive likelihood ratio were created: A ≤8.7 (benign tumour), B >8.7 to <15.5 (indeterminate), and C ≥15.5 (malignant tumour).
This prospective study was conducted between January and December 2016 and included patients with suspected PSM. Those with advanced disease and cystic components were excluded. Both QE and FNA were performed, and histologic information was obtained for the final diagnoses. The authors then calculated diagnostic tests and receiver-operating characteristic curve.
“[E]ndoscopic ultrasound with FNA enables tissue acquisition but has high false-negative rates, [while] QE predicts diagnosis on the basis of the SR,” the authors said.