Pancreatic EUS-FNA Research Articles

A deep learning model using hyperspectral image for EUS-FNA cytology diagnosis in pancreatic ductal adenocarcinoma.

Endoscopic ultrasonography-guided fine-needle aspiration/biopsy (EUS-FNA/B) is considered to be a first-line procedure for the pathological diagnosis of pancreatic cancer owing to its high accuracy and low complication rate. The number of new cases of pancreatic ductal adenocarcinoma (PDAC) is increasing, and its accurate pathological diagnosis poses a challenge for cytopathologists. Our aim was to develop a hyperspectral imaging (HSI)-based convolution neural network (CNN) algorithm to aid in the diagnosis of pancreatic EUS-FNA cytology specimens. HSI images were captured of pancreatic EUS-FNA cytological specimens from benign pancreatic tissues (n = 33) and PDAC (n = 39) prepared using a liquid-based cytology method. A CNN was established to test the diagnostic performance, and Attribution Guided Factorization Visualization (AGF-Visualization) was used to visualize the regions of important classification features identified by the model. A total of 1913 HSI images were obtained. Our ResNet18-SimSiam model achieved an accuracy of 0.9204, sensitivity of 0.9310 and specificity of 0.9123 (area under the curve of 0.9625) when trained on HSI images for the differentiation of PDAC cytological specimens from benign pancreatic cells. AGF-Visualization confirmed that the diagnoses were based on the features of tumor cell nuclei. An HSI-based model was developed to diagnose cytological PDAC specimens obtained using EUS-guided sampling. Under the supervision of experienced cytopathologists, we performed multi-staged consecutive in-depth learning of the model. Its superior diagnostic performance could be of value for cytologists when diagnosing PDAC.

Avoid non-diagnostic EUS-FNA: a DNN model as a possible gatekeeper to distinguish pancreatic lesions prone to inconclusive biopsy.

This work aimed to explore the utility of CT radiomics with machine learning for distinguishing the pancreatic lesions prone to non-diagnostic ultrasound-guided fine-needle aspiration (EUS-FNA). 498 patients with pancreatic EUS-FNA were retrospectively reviewed [Development cohort: 147 pancreatic ductal adenocarcinoma (PDAC); Validation cohort: 37 PDAC]. Pancreatic lesions not PDAC were also tested exploratively. Radiomics extracted from contrast-enhanced CT was integrated with deep neural networks (DNN) after dimension reduction. The receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were performed for model evaluation. And, the explainability of the DNN model was analyzed by integrated gradients. The DNN model was effective in distinguishing PDAC lesions prone to non-diagnostic EUS-FNA (Development cohort: AUC = 0.821, 95% CI: 0.742-0.900; Validation cohort: AUC = 0.745, 95% CI: 0.534-0.956). In all cohorts, the DNN model showed better utility than the logistic model based on traditional lesion characteristics with NRI >0 (p < 0.05). And, the DNN model had net benefits of 21.6% at the risk threshold of 0.60 in the validation cohort. As for the model explainability, gray-level co-occurrence matrix (GLCM) features contributed the most averagely and the first-order features were the most important in the sum attribution. The CT radiomics-based DNN model can be a useful auxiliary tool for distinguishing the pancreatic lesions prone to nondiagnostic EUS-FNA and provide alerts for endoscopists preoperatively to reduce unnecessary EUS-FNA. This is the first investigation into the utility of CT radiomics-based machine learning in avoiding non-diagnostic EUS-FNA for patients with pancreatic masses and providing potential pre-operative assistance for endoscopists.

Splitting or Lumping of Pancreatic EUS FNA and Core Needle Biopsy Specimens? A Comparison of Different Practices at an Academic Center

Splitting or Lumping of Pancreatic EUS FNA and Core Needle Biopsy Specimens? A Comparison of Different Practices at an Academic Center

Endoscopic ultrasonographic diagnosis of pancreatic tuberculosis in immunocompetent patients—A case series from eastern India

Tubercular involvement of pancreas is rare. It presents as a focal lesion of pancreas on cross sectional imaging. Endosonography with fine-needle aspiration (EUS-FNA) is crucial for a timely presurgical diagnosis. A retrospective review was conducted on 117 cases of pancreatic focal mass undergoing EUS-FNA at our institution over a period of 3 years, and 5 cases with pancreatic tuberculosis (TB) were detected. The clinical presentation varied from obstructive jaundice, recurrent acute pancreatitis to incidentaloma of pancreas. All patients received antitubercular therapy and were followed up for at least 6 months. In conclusion, pancreatic tuberculosis is a differential of a pancreatic focal lesion and EUS-FNA is the method for diagnosis ofthis conditionthat may obviate surgical exploration.

Diagnostic value of digital droplet polymerase chain reaction and digital multiplexed detection of single-nucleotide variants in pancreatic cytology specimens collected by EUS-guided FNA

EUS-guided FNA is recommended as a first-line procedure for the histopathologic diagnosis of pancreatic cancer. Molecular analysis of EUS-FNA samples might be used as an auxiliary tool to strengthen the diagnosis. The current study aimed to evaluate the diagnostic performances of K-ras testing using droplet digital polymerase chain reaction (ddPCR) and a novel single-nucleotide variant (SNV) assay performed on pancreatic EUS-FNA samples. EUS-FNA specimens from 31 patients with pancreatic masses (22 pancreatic ductal adenocarcinomas, 7 chronic pancreatitis, and 2 pancreatic neuroendocrine tumors) were included in the study. K-ras testing was initially performed by ddPCR. In addition, mutational status was evaluated using an SNV assay by NanoString technology, using digital enumeration of unique barcoded probes to detect 97 SNVs from 24 genes of clinical significance. The overall specificity and sensitivity of cytologic examination were 100% and 63%, respectively. K-ras mutation testing was performed using ddPCR, and the sensitivity increased to 87% with specificity 90%. The SNV assay detected at least 1 variant in 90% of pancreatic ductal adenocarcinoma samples; the test was able to detect 2 K-ras codon 61 mutations in 2 cases of pancreatic ductal adenocarcinoma, which were missed by ddPCR. The overall diagnostic accuracy of the cytologic examination alone was 74%, and it increased to 91% when the results of both molecular tests were considered for the cases with negative and inconclusive results. The current study illustrated that integration of K-ras analysis with cytologic evaluation, especially in inconclusive cases, can enhance the diagnostic accuracy of EUS-FNA for pancreatic lesions.

The Risk Factors for Acute Pancreatitis after Endoscopic Ultrasound Guided Biopsy.

The risk of developing pancreatitis induced by endoscopic ultrasound-guided fine needle aspiration (EUS FNA) is relatively small. However, patients undergoing sampling through the normal pancreatic parenchyma or the pancreatic duct may have a higher rate of pancreatitis. Here, we determine the factors associated with increased risk of acute pancreatitis in patients undergoing FNA through normal pancreatic parenchyma/pancreatic duct. In this prospective study at a tertiary cancer center, patients undergoing sampling through the pancreatic duct or ≥5 mm of the normal parenchyma between December 2013 and September 2017 were included. Post-EUS induced pancreatitis was diagnosed by the presence of abdominal pain with an amylase or lipase level higher than three times normal value. A total of 712 patients underwent pancreatic EUS FNA. A total of 163 patients were included in the high-risk group. Mean age was 63 years, 82 females, mean number of needle-passes was 3.3 (range, 1-7). Fifteen patients (15/163, 9.2%) developed pancreatitis after EUS FNA through the pancreatic parenchyma compared with only one case among the control group (＜5 mm of normal parenchyma) (0.18%, 1/549, p＜0.0001). Several factors appeared to be associated with pancreatitis, including young age, solid lesion, and a recent history of acute pancreatitis. By logistic regression, a prior history of recent pancreatitis was the only statistically significant factor associated with post-EUS-guided biopsy pancreatitis (p=0.008). Patients with a recent history of acute pancreatitis undergoing EUS FNA through 5 mm or more of the normal pancreatic parenchyma are at a much greater risk of acute pancreatitis.

P.06.5: Impact of Routine Cell-Block Preparation on Results of Pancreatic Solid Lesions EUS-FNA

P.06.5: Impact of Routine Cell-Block Preparation on Results of Pancreatic Solid Lesions EUS-FNA

Comparison of two different size needles in endoscopic ultrasound-guided fine-needle aspiration for diagnosing solid pancreatic lesions: A meta-analysis of prospective controlled trials.

Background:This meta-analysis aimed to provide a pooled analysis of prospective controlled trials comparing the diagnostic accuracy of 22-G and 25-G needles on endoscopic ultrasonography (EUS-FNA) of the solid pancreatic mass.Methods:We established a rigorous study protocol according to Cochrane Collaboration recommendations. We systematically searched the PubMed and Embase databases to identify articles to include in the meta-analysis. Sensitivity, specificity, and corresponding 95% confidence intervals were calculated for 22-G and 25-G needles of individual studies from the contingency tables.Results:Eleven prospective controlled trials included a total of 837 patients (412 with 22-G vs 425 with 25-G). Our outcomes revealed that 25-G needles (92% [95% CI, 89%–95%]) have higher sensitivity than 22-G needles (88% [95% CI, 84%–91%]) on solid pancreatic mass EUS-FNA (P = 0.046). However, there were no significant differences between the 2 groups in overall diagnostic specificity (P = 0.842). The pooled positive and negative likelihood ratio of the 22-G needle were 12.61 (95% CI, 5.65–28.14) and 0.16 (95% CI, 0.12–0.21), respectively. The pooled positive likelihood ratio was 12.61 (95% CI, 5.65–28.14), and the negative likelihood ratio was 0.16 (95% CI, 0.12–0.21) for the 22-G needle. The pooled positive likelihood ratio was 8.44 (95% CI, 3.87–18.42), and the negative likelihood ratio was 0.13 (95% CI, 0.09–0.18) for the 25-G needle. The area under the summary receiver operating characteristic curve was 0.97 for the 22-G needle and 0.96 for the 25-G needle.Conclusion:Compared to the study of 22-G EUS-FNA needles, our study showed that 25-G needles have superior sensitivity in the evaluation of solid pancreatic lesions by EUS–FNA.

Interobserver Agreement in the Classification of Pancreatic Cysts With Needle-Based Confocal Laser Endomicroscopy

Introduction: Needle-based confocal laser endomicroscopy (nCLE) may serve as an accurate and clinically relevant adjunct in classifying pancreatic cysts. The question remains whether clinician interpretation of nCLE images is consistent enough to render nCLE a precise tool. The aim of this study was to determine our institutional interobserver agreement for interpretation of nCLE images of pancreatic cysts. Methods: All pancreatic cyst EUS-FNA cases with nCLE from 3/2014-4/2015 at a large tertiary medical center were included. 3 interventional endoscopists who independently had performed the cases reviewed all nCLE images in a blinded manner and classified each case as serous cystadenoma (SCA), intraductal papillary mucinous neoplasm (IPMN), neuroendocrine tumor (NET), or other. Each clinician designated diagnostic certainty (certain/uncertain) and image quality (poor/fair/good). The primary outcome was interobserver agreement in pancreatic cyst classification, as calculated by the Fleiss kappa in SAS 9.3. Secondary outcomes were accuracy of individual and group diagnosis, as compared to overall cyst clinical impression as previously determined by the performing endoscopist, based upon radiology studies, EUS, nCLE, CEA/amylase, cytology and surgical pathology.Table 1: Interobserver Agreement in Pancreatic Cyst Evaluation with nCLEResults: 14 cases were included. Interobserver agreement was “fair to good” (kappa=0.65, p=0.003). nCLE diagnosis by the performing endoscopist was accurate in 11/14 cases. Blinded accuracy was 43%, 50%, and 57%, respectively. Majority consensus, with at least 2 of 3 clinicians independently achieving the same diagnosis, occurred in 12/14 cases. Consensus accuracy was 58% and increased to 67% in cases of unanimous agreement. There was little correlation between consensus diagnostic accuracy and certainty. In all instances of unanimous agreement, regardless of diagnostic accuracy, there was high level of certainty. Image quality appeared to have limited impact on achieving consensus or the accuracy of consensus diagnosis. Conclusion: Our prior work has shown that nCLE enhances accuracy in classifying pancreatic cysts and is clinically relevant in preventing referral for surgical resection. Interobserver agreement is high demonstrating the reliability of this tool, yet both individual and group diagnostic accuracy fell short of that of the performing endoscopist, indicating that clinical context is vital to nCLE's utility. Clinicians would benefit from greater training with nCLE to improve the yield of this new technology.

Development of a device for detecting target specimens from EUS-guided FNA samples.

Background and study aims: Specimens collected by fine needle are microscopic and contain blood; therefore, the presence of a target specimen within a sample is often difficult to confirm. Although rapid on-site evaluation (ROSE) during endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) is beneficial, many health care facilities are unable to apply this technique due to a lack of cytopathologists. The aim of this study was to develop and validate a device that detects the target specimen within pancreatic tumor EUS-FNA samples. Patients and methods: Fifty-eight consecutive patients with solid pancreatic masses were studied for a preliminary case series at a tertiary-care university hospital (Tottori University Hospital, Yonago, Japan). The material collected was checked with a target sample check illuminator (TSCI) and was evaluated by one cytopathologist. Results: The agreement rate between the TSCI and histopathology was 93.7 %. Further testing procedures were not needed in 91.4 % of patients, and the mean number of needle punctures was 1.2 after a single pass using TSCI. No adverse events were encountered with the procedure. Conclusions: With the introduction of the TSCI in EUS-FNA, it became possible to both collect the minimum necessary target samples by EUS-FNA and to end further procedures, even without performing ROSE.

Tu1939 A Retrospective Single Center Analysis of Survival and Prognostic Factors of Adjuvant Gemcitabine Following Curative-Intended Surgery of Pancreatic Adenocarcinoma

G A A b st ra ct s were de-identified and evaluated by 4 blinded CyPs (3 experienced CyPs, 1 fellow). A modified validated scoring system was used to assess specimen quantity and quality and standardized among all CyPs (Table 1). Final cytologic diagnosis was categorized as: insufficient, benign, atypical, suspicious for malignancy or malignant and final clinical diagnosis as benign or malignant. IOV was calculated using multi-rater kappa (κ) statistics with 95% CI. Bivariate analyses were performed comparing cases with and without uniform agreement followed by logistic regression with backward selection to model the likelihood of uniform agreement. Assuming an overall κ of 0.8 amongst 4 CyPs, prevalence of malignancy of 0.6, and lower limit of 95% CI ≥ 0.7, a sample size of at least 72 cases was determined. RESULTS: 99 cases were included [49% males; mean age 64 yrs] of which 44% presented with weight loss and 28% jaundice. On EUS, mean lesion size was 25 mm, with distribution of lesions being: head/uncinate 56%, neck 8%, body 21% and tail 15%. EUS findings consistent with chronic pancreatitis were noted in 10% of cases. Final cytologic diagnosis revealed malignant diagnosis in 60% of cases, suspicious 4%, atypical 5%, benign 28% and inadequate 3%. IOV for overall final cytologic diagnosis was moderate (κ =0.45) with minimal improvement when combining suspicious + malignant diagnoses (κ=0.54). IOV was slight to fair (κ 0.040.32) for individual parameters (Table 1). Presenting symptom of jaundice (p<0.001), lesion size (p=0.04), number of nucleated/diagnostic cells (p<0.001), degree of GI contamination (p=0.03) and final cytologic (p=0.02) and clinical diagnosis (p=0.003) were significant factors on bivariate analysis (Table 2). On multivariate analysis the predictor for uniform agreement among CyPs was final clinical diagnosis of malignancy [OR 3.99 (CI 1.52-10.49)].CONCLUSIONS: Results of this study demonstrate significant IOV among CyPs for the final cytologic diagnosis and individual quantity and quality measures in the assessment of pancreatic EUSFNA specimens. The final clinical diagnosis of malignancy is the strongest predictor for agreement among CyP. Confirming these results and refinement of EUS-FNA scoring criteria in future multicenter studies is imperative. Table 1: Standardized scoring tool to assess individual EUS-FNA passes and final cytologic diagnosis and IOV of individual parameters

Sa1534 Predictors of Outcomes in Patients With Suspicious or Indeterminate Cytology on Pancreatic EUS-FNA

A diagnosis of “suspicious or indeterminate” on EUS-FNA cytology of pancreatic lesions may often become a management dilemma, requiring decisions on repeat FNA, surveillance, chemo-radiation or surgery.

Tu1517 A Prospective Controlled Study on the EUS-CPN Bilateral Injection of 30 CC of Alcohol in Patients With Pancreatic Cancer Pain

A Prospective Controlled Study on the EUS-CPN Bilateral Injection of 30 CC of Alcohol in Patients With Pancreatic Cancer Pain Jose C. Ardengh*, Rafael Kemp, Eder R. Lima, Cristina G. Bertani, Gustavo A. Mota, Jose Sebastiao S. Dos Santos Anatomy and Surgery, Hosp. Clin. Fac. Med. Ribeirao Preto Universidade de Sao Paulo, Sao Paulo, Brazil; Endoscopy and Echoendoscopy, Hospital 9 de Julho, Sao Paulo, Brazil; Surgery, Hospital Federal dos Servidores do Estado do Rio de Janeiro, Rio de Janeiro, Brazil Introduction: Celiac plexus neurolysis (CPN) is currently used as a treatment option for morphine (resistant patients). The technique of alcohol injection during EUS-CPN for pancreatic cancer pain has not yet been standardized. The one or two injections, bilateral, or central techniques and drug combinations has been discussed. The aim of this study is to demonstrate the safety and efficacy of bilateral injection of absolute alcohol (30 cc) in patients with uncontrollable pain related to pancreatic cancer. Patients and methods: Patients who had a confirmed diagnosis and staging of unresectable pancreatic cancer, after surgery, EUS-FNA, US-FNA or CT-FNA became eligible for this study. We selected those with uncontrollable pain (score 9) and morphine-resistant. All patients received 30 cc of absolute alcohol using a 19G needle (15 cc per side), and were assessed by a questionnaire for pain intensity (0-no pain, 2-mild, 4-tolerable, 6-moderate, 8-severe, 9-incapacitating) before and 30, 60 and 90 days after EUS CPN. Results: Between January 2006 and January 2011, 208 patients became eligible. Seventy-eight were studied and controlled (mean age 63.8y, range 37-84y). EUSFNA-CPN at the same time was performed in 44 and EUS-CPN in 34 patients. The average size of tumors identified by EUS was 3.8 cm (1.5 6.2 cm). Immediately after the procedure, 25/78 (32%) had pain relief, lowering the score from 9 to 4 (10) and 6 (15). After 30 days evaluation revealed that 61/78 (78%) had pain score improved to 2 (7), 4 (32) and 6 (22), while after 60 and 90 days, pain relief occurred in 33/78 (42.3%) and 37/65 (57%). In this interval 13/78 (16.6%) died. There were mild complications (20.5%) after the procedure, all managed by conventional measures (severe diarrhea (6), postural hypotension (5), reversible (3) and irreversible (2) lower limb edema). The mean follow-up after EUS-CPN was 8.6 months (1-18 months). There was no effect on quality of life or survival. Conclusion: EUS-CPN reduces pain and can moderate morphine consumption in patients with pain related to inoperable pancreatic cancer. EUSCPN can be performed in all patients with pancreatic mass, during EUS for diagnosis and staging.

Direct histological processing of EUS biopsies enables rapid molecular biomarker analysis for interventional pancreatic cancer trials

ObjectiveCurrent practice to diagnose pancreatic cancer is accomplished by endoscopic ultrasound guided fine needle aspiration (EUS–FNA) using a cytological approach. This method is time consuming and often fails to provide suitable specimens for modern molecular analyses. Here, we compare the cytological approach with direct formalin fixation of pancreatic EUS–FNA micro-cores and evaluate the potential to perform molecular biomarker analysis on these specimen. Methods130 specimens obtained by EUS–FNA with a 22G needle were processed by the standard cytological approach and compared to a separate cohort of 130 specimens that were immediately formalin fixed to preserve micro-cores of tissue prior to routine histological processing. ResultsWe found that direct formalin fixation significantly shortened the time required for diagnosis from 3.6 days to 2.9 days (p < 0.05) by reducing the average time (140 vs 33 min/case) and number of slides (9.65 vs 4.67 slides/case) for histopathological processing. Specificity and sensitivity yielded comparable results between the two approaches (82.3% vs 77% and 90.9% vs 100%). Importantly, EUS–FNA histology preserved the tumour tissue architecture with neoplastic glands embedded in stroma in 67.89% of diagnostic cases compared to 27.55% with the standard cytological approach (p < 0.001). Furthermore, micro-core samples were suitable for molecular studies including the immunohistochemical detection of intranuclear Hes1 in malignant cells, and the laser-capture microdissection-mediated measurement of Gli-1 mRNA in tumour stromal myofibroblasts. ConclusionsDirect formalin fixation of pancreatic EUS–FNA micro-cores demonstrates superiority regarding diagnostic delay, costs, and specimen suitability for molecular studies. We advocate this approach for future investigational trials in pancreatic cancer patients.

Quantitative RT-PCR Analysis of MMR Genes on EUS-Guided FNA Samples From Focal Pancreatic Lesions

Pancreatic cancer is characterized by a variety of molecular alterations. Mismatch excision repair (MMR) is a DNA repair system that eliminates mismatched base pairs and it plays an important role in the maintaining of genomic integrity. The aim of the study was to assess the role of several MMR genes in the diagnosis of pancreatic cancer in samples collected by EUS-FNA procedure. The prospective study included 44 consecutive patients with pancreatic cancer (n=24) and chronic pseudotumoral pancreatitis (n=20). EUS-FNA was performed in all the patients. Gene analysis was performed by extracting the mRNA and by determining the expression of DNA repair genes (MLH1, MLH3, MSH6) using a standard algorithm. Total RNA was successfully isolated from all the EUS-FNA pancreatic samples. We analyzed ROC curves to assess the significance of determining the expression of analyzed genes in EUS-FNA samples, obtaining a cutoff value of 476621mRNA copies/mL for MSH6, and sensitivity and specificity of 75.0% and 100%, respectively. For MLH1 and MLH3, sensitivity and specificity were only satisfactory (64.65% and 76.11%, and 75.0% and 63.64%, respectively). The quality and amount of cellular sampling using pancreatic EUS-FNA allow the extraction of sufficient quantities of RNA to perform qRT-PCR analysis. The use of MMR genes for the differentiation between pseudotumoral chronic pancreatitis and pancreatic cancer using a minimally invasive sampling technique could be a promising technique.

Fluorescence In Situ Hybridization and K-ras Analyses Improve Diagnostic Yield of Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Solid Pancreatic Masses

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is the main diagnostic modality for pancreatic mass lesions. However, cytology is often indeterminate, leading to repeat FNAs and delay in care. Here, we evaluate whether combining routine cytology with fluorescence in situ hybridization (FISH) and K-ras/p53 analyses improves diagnostic yield of pancreatic EUS-FNA. Fifty EUS-FNAs of pancreatic masses in 46 patients were retrospectively analyzed. Mean follow-up was 68 months. Thirteen initial cytologic samples (26%) were benign, 23 malignant (46%), and 14 atypical (28%). We performed FISH for p16, p53, LPL, c-Myc, MALT1, topoisomerase 2/human epidermal growth factor receptor 2, and EGFR, as well as K-ras/p53 mutational analyses. On final diagnosis, 11 (79%) of atypical FNAs were malignant, and 3 benign (21%). Fluorescence in situ hybridization was negative in all benign and all atypical samples with final benign diagnosis. Fluorescence in situ hybridization plus K-ras analysis correctly identified 60% of atypical FNAs with final malignant diagnosis. Combination of routine cytology with positive FISH and K-ras analyses yielded 87.9% sensitivity, 93.8% specificity, 96.7% positive predictive value, 78.9% negative predictive value, and 89.8% accuracy. Combining routine cytology with FISH and K-ras analyses improves diagnostic yield of EUS-FNA of solid pancreatic masses. We propose to include these ancillary tests in the workup of atypical cytology from pancreatic EUS-FNA.

713 A New EUS Imaging Diagnosis for Pancreatic Cancer: A Pilot Study of Differential Diagnosis Between Chronic Pancreatitis and Pancreatic Cancer Based on the Quantitative Analysis With New Technology Using Raw Image

A New EUS Imaging Diagnosis for Pancreatic Cancer: A Pilot Study of Differential Diagnosis Between Chronic Pancreatitis and Pancreatic Cancer Based on the Quantitative Analysis With New Technology Using Raw Image Atsushi Irisawa, Tadayuki Takagi, Tsunehiko Ikeda, Rei Suzuki, AI Sato, Goro Shibukawa, Takuto Hikichi, Masaki Sato, Katsutoshi Obara, Hiromasa Ohira Gastroenterology, Fukushima Medical University Aizu Medical Center, Fukushima, Japan; Gadteroenterology and Rheumatology, Fukushima Medical University, Fukushima, Japan; Endoscopy, Fukushima Medical University Hospital, Fukushima, Japan (Background and Aim) Reportedly, patients with chronic pancreatitis (CP) are 16 times more likely to develop pancreatic cancer (PC) than normal individuals. Strong evidence exists for the association of hereditary CP and PC. Although EUS enables detection of subtle pancreatic abnormalities and EUS-FNA is highly useful for diagnosing PC, it is frequently hard to detect the small cancer that invades slowly into the rough pancreatic parenchyma due to CP. The aim of this study is to develop a new EUS imaging diagnosis for PC using quantitative analysis with new technology. This method will be strongly help to excavate the small cancer in patients with CP. (Patients and Methods) Twenty-eight patients were enrolled in this study (CP in 10, PC in 28). The final diagnosis was established for all patients by various methods including EUS, EUS-FNA, surgery and long-term follow up more than 6 months. The ultrasound images were recorded in each case with using the EUS center (EU-ME1, Olympus Medical Systems Corp., Tokyo, Japan) and the curved linear-arrayed echoendoscope (GFUC240P-AL5 or GF-UCT240-AL5, Olympus Medical Systems Corp., Tokyo, Japan) as a raw image format (RAW image). The RAW image contains minimally processed data from the image sensor. It is not yet processed and therefore is not ready to be printed or edited with a graphics editor. The captured RAW image were quantitatively analyzed with a new technology (developed by Olympus Medical Systems Corp.), and attempted to create an image for the analysis of CP and PC. The image was described using two parameters on each RAW image: 1) mid-band fit and 2) intercept, which are both obtained from the spectrum intensity on the regression line of frequency spectrum available from the RAW imaging data. The quantitative analyses were performed by measuring the average value of intercepts and the average of mid-band fits. The results of the quantitative analyses were compared with the EUS/EUS-FNA diagnosis. (Results) There were significant differences between CP and PC in either 2 parameters (the average value of intercepts; 56 /-2.8 dB CP vs. 62 /-4.6 dB in PC, p 0.001. the average of mid-band fits; 47 / 2.3 dB in CP vs. 54 / 3.4 dB in PC, p 0.001). PC was clearly distinguished using 2 parameters from CP (figure) (Conclusion) It was considered that EUS examination with this new quantitative analysis using RAW imaging data would be useful for excavation and diagnosis the small cancer in patients with CP.

T1392 Immunohistochemistry of Pancreatic EUS-FNA Samples for the Differential Diagnosis of Solid Pancreatic Tumors

T1392 Immunohistochemistry of Pancreatic EUS-FNA Samples for the Differential Diagnosis of Solid Pancreatic Tumors

T1470: Stylet Use Does Not Affect Adequacy of Specimen of Pancreatic EUS FNA: A Prospective, Single Blinded, Randomized, Control Trial

Endoscopic ultrasound fine needle aspiration (EUS FNA) is routinely performed with the stylet in place during puncture. The removal of the stylet has been shown to increase cellularity of the aspirate. There are no prospective, randomized, controlled data looking at whether stylet use or lack of, affects the adequacy of EUS FNA.

A Prospective Comparison of EUS-Guided FNA Using 25-Gauge and 22-Gauge Needles

Background and Aims. There are limited data on the differences in diagnostic yield between 25-gauge and 22-gauge EUS-FNA needles. This prospective study compared the difference in diagnostic yield between a 22-gauge and a 25-gauge needle when performing EUS-FNA. Methods. Forty-three patients with intraluminal or extraluminal mass lesions and/or lymphadenopathy were enrolled prospectively. EUS-FNA was performed for each mass lesion using both 25- and 22-gauge needles. The differences in accuracy rate, scoring of needle visibility, ease of puncture and quantity of obtained specimen were evaluated. Results. The overall accuracy of 22- and 25-gauge needle was similar at 81% and 76% respectively (N.S). Likewise the visibility scores of both needles were also similar. Overall the quantity of specimen obtained higher with the 22-gauge needle (score: 1.64 vs. P < .001). However the 25-gauge needle was significantly superior to the 22-gauge needle in terms of ease of puncture (score: 1.9 vs. 1.29, P < .001) and in the quantity of specimen in the context of pancreatic mass EUS-FNA (score: 1.8 vs. 1.58, P < .05). Conclusion. The 22-gauge and 25-gauge needles have similar overall diagnostic yield. The 25-gauge needle appeared superior in the subset of patients with hard lesions and pancreatic masses.