Clinical impact of EUS elastography followed by contrast-enhanced EUS in patients with focal pancreatic masses and negative EUS-guided FNA

Abstract

Aim: It is well known that endoscopic ultrasound guided fine needle aspiration (EUS-FNA) has a high sensitivity (over 85%) and specificity (100%) for diagnosis of pancreatic cancer. The aim of the study was to establish a EUS based clinical diagnostic algorithm in patients with pancreatic masses and negative cytopathology after EUS-FNA, based on previously published results and cut-offs of real-time elastographic (RTE) EUS and contrast-enhanced harmonic (CEH) EUS. Material and methods: We included in the study a subgroup of 50 consecutive patients with focal pancreatic masses which underwent EUS examinations with negative EUS-FNA. RTE-EUS and CEH-EUS were performed sequentially in all patients. The sensitivity, specificity and accuracy of these methods were calculated separately. A clinical decision algorithm based on elastography followed by CEH was established. Results: For the diagnosis of possible malignancy, the sensitivity, specificity and accuracy of RTE-EUS were: 97.7%, 77.4%, and 84% respectively. CEH-EUS had similar results: 89.5%, 80.7%, and 84%, respectively. In 25 patients with soft/mixed appearance during elastography,sequential assessment using contrast-enhanced EUSwas performed. The specificity of CEH-EUS for detection of chronic pancreatitis in this sub-set of patients was excellent (100%). In other 25 patients with hard appearance in elastography (low strain) CEH-EUS had an excellent specificity (100%) and accuracy (93%) in the detection of pancreatic cancer. Conclusions: The proposed algorithm with sequential use of elastography followed by CEH could be a good clinical tool in the set of patients with negative EUS-FNA results for the differentiation between benign and malignant focal pancreatic masses.

Diagnostic utility of endoscopic ultrasonography-elastography in the evaluation of solid pancreatic masses: a meta-analysis and systematic review

“…Their cut-off values were decided by using previous published studies, or the one with the highest accuracy rate based on the receiver operator characteristic (ROC) curves. Four studies also evaluated CE-EUS [4,19,20,22], and 4 studies evaluated EUS-FNA [7,8,19,22].…”

“…Characteristics of the selected studies are shown in Table I. Six studies used SH as the diagnostic standard [4,9,22,[26][27][28], 7 studies used SR [7][8][9]16,19,23,27,30], 3 studies used color pattern [20,23,24],and 3 studies used elastic score [21,25,29]. For those using SH, the cut-off values ranged from 62 to 80, and for those using SR, the cut-off values varied from 3.05 to 24.82.…”

“…Seventeen studies were finally selected [4,[7][8][9]16,[19][20][21][22][23][24][25][26][27][28][29][30] ( figure 1 shows the flow chart of the selection process). Only one was a conference abstract [27], the others were all full-texts.…”

“…We took male ratio, disease coverage, malignant proportion into consideration, while it still could not show the sources of heterogeneity. Three studies [4,22,26] used the same cut-off value, and their pooled sensitivity (fixed-effect model) and specificity (fixed-effect model) were 0.90 (95%CI, 0.81-0.95) and 0.81 (95%CI, 0.71-0.89), respectively. The heterogeneity disappeared (I 2 =0%), suggesting that differ-ent cut-off values might be the sources of heterogeneity.…”

“…Clinical information, biochemical tests, and imaging techniques diagnosis and elastic score, the latter include strain histograms (SH) and strain ratio (SR). The accuracy of EUS-EG in distinguishing solid pancreatic masses has varied greatly in different studies [4,[7][8][9], and several meta-analysis have been published on this issue [10][11][12][13][14][15]. However, the newly added data since 2013 have not been updated [4,[7][8][9]16], and the results should be pooled separately based on each different measurement.…”