Abstracts

receiving a novel neoadjuvant chemotherapeutic protocol. Methods: Study patientsreceived initial CT and EUS examinations for diagnosis and staging, followed byneoadjuvant chemotherapy consisting of gemcitabine, oxaliplatin, cetuximab perprotocol and subsequent restaging CT and EUS examinations within one month offollowing therapy. If sufficient radiologic response was attained to make the tumorresectable, surgical resection was performed and the CT/EUS stages were comparedto resected surgical pathology. Results: Fourteen patients were included in thepresent study. After completion of the neoadjuvant chemotherapy protocol, 6patients showed sufficient radiologic improvement on CT and/or EUS to allow forattempted surgical resection. Initial diagnostic pre-treatment EUS in all 6chemoresponsive patients demonstrated no greater than stage IIB.(see table) Duringexploratory laparotomy, all patients were deemed operable, and Whipple resectionswere performed. Post-treatment, EUS T staging was correct in 2 of these 6 patients.Incorrect T staging was primarily due to microscopic peripancreatic (non-vascular)invasion. EUS N staging was correct in 3 of 6 patients, all due to understaging. Of thesethree false negative N0 staging cases, nodal malignancy was diagnosedmicroscopically. CTscan correctly restaged (both Tand N) in 1 of 6 patients. In patientsfailing to respond to neoadjuvant chemotherapy (N Z 8), 6 of 8 were noted to beStage III. EUS and CTstaging were in agreement in all six of these cases. Conclusions:Preliminary evidence suggests that a restaging EUS can be an effective modality fordetermining surgical resectability in patients with locally advanced pancreatic cancerof stage IIB or less. EUS and CTshowed agreement in their findings of stage III disease,suggesting that EUS may be of limited additional benefit.

Pre-Tx Post-Tx Surgery

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CT STAGE EUS STAGE CT STAGE EUS STAGE PATH

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T3N0M0 IIA T3N1M0 IIB T3N0M0 IIA T3N0M0 IIA T3N1MX 9 T2N0M0 IB T3N0M0 IIA T1N1M0 IIB T2N1M0 IIB T3N1MX 11 T2N0M0 IB T3N0M0 IIA T1N0M0 IA T3N0M0 IIA T2N0MX 12 T3N1M0 IIB T2N0M0 IB T1N0M0 IA T2N0M0 IB T1N1MX 13 T3N1M0 IIB T3N0M0 IIA T1N1M0 IIB T3N0M0 IIA T3N0MX 15 T1N0M0 IA T2N0M0 IB T1N0M0 IA T1N0M0 IA T3N1MX

M1447

Temporal Trend in Utilization of Endoscopic Ultrasonography in

Patients with Pancreatic CancerFeng Li, Ying Zhou, Amitabh Chak, Gregory S. Cooper, Ananya DasEUS is an important modality for diagnostic evaluation in pancreatic cancer.Available information suggests that only a minority of patients with pancreaticcancer actually undergo the procedure, but whether the use of EUS has increasedover time is unknown. Objective: To study the trend in utilization of EUS inMedicare beneficiaries with pancreatic cancer using the SEER-Medicare database.Methods: We identified persons aged 66 years or older, who were recentlydiagnosed with pancreatic cancer, and were captured in both the SEER cancerregistry and the Medicare claims database between 1994 and 2002. Relevantdemographic, cancer specific information and EUS procedural information wasextracted. A logistic regression model was developed to study the independentassociation of year of diagnosis with EUS receipt after controlling for other relevantcovariates. Results: 10,716 patients with pancreatic cancer (59.2% with metastaticcancer) were diagnosed during the study period. Only 767 (7.2%) patients had EUSexamination for tumor evaluation and staging. The rate of EUS utilization in thesepatients increased from 0.6% in 1994 to 13.4% in 1999. (Figure) Adjusted for age atdiagnosis, race, gender, co-morbidity score, tumor stage, year of diagnosis wasa significant predictor of receipt of EUS. In the multivariate model, the odds ratiofor receiving EUS was much lower in patients diagnosed with pancreatic cancer inthe nineties compared to those diagnosed between 2000-2003 [OR, 95% CI, 0.14(0.11-0.19) for those diagnosed in 1994-1996 and 0.43 (0.35-0.53) for thosediagnosed in 1997-1999, respectively]. Conclusion: Although EUS evaluation is stillperformed in a minority of patients with pancreatic cancer, there is increasing trendin the utilization of EUS in these patients. This may reflect increasing availabilitywith dissemination of EUS technology from select academic centers to thecommunity.

M1448

Ultrasonographic Differential Diagnosis of Gallbladder PolypsJulia Orlova, Elena Bystrovskaya, Anatoly Ilchenko, Sergej G. KhomerikiThe aim: to determine the ultrasonographic diagnostic criterions of gallbladderpolyps with different histological structure. Materials and methods: The results oftrans-abdominal, endoscopic ultrasonography and color Doppler imaging (CDI)

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and morphologic study of 150 patients operated with polypoid lesions of thegallbladder were analyzed. Results: Ultrasonographic diagnostic criterions ofgallbladder polyps with different histological structure were determined byretrospective analyzing of the results of research and matching these data with theresults of morphologic study of operating material. As to small polypoid lesions,cholesterol polyp is commonly demonstrated as a pedunculated mass lesions withgranular configuration in contour and heterogeneous in internal texture, showinghigh-echo spots and is avascular. Their average size is 5.7 mm. In contrast, large-sized cholesterol polyps (of 10 mm or larger in size) are middlechogenic lesionswith smooth surface and homogeneous echo arrangement. Large-sized cholesterolpolyps may have central unechogenic area in internal texture. This artifact isdetermined by gall availability between the parts of polyp with clustered structure(foliage-shaped mass). Hyperechogenic inclusions in the stroma of polyp withreverberation and acoustic shade are also artifacts, specified by areas ofhaemorrhagia. Frequently vascularisation is found in large-sized polyps during CDI.Adenomatous polyps and polypoid form of focal adenomyomatosis have smoothand legible contour, middle echogeneous, homogeneous structure. The focaladenomyomatosis polyps have a wide basis (8,2 mm) and little height (2-3 mm).Fibrous polyps have smooth and legible contour, homogeneous structure, but theirechogeneous is notably higher. There can be met mixed cholesterol - adenomatouspolyps and fibroadenomatous polyps. Their echogeneous picture depends oncholesterol, fibrous or adenomatous component prevalence in the structure ofpolyp. This kind of polyps is characterized by larger size in comparison with otherpolyps, vascularisation, witch can be brought out with CDI. Conclusions: Duringstudy cholesterol polyps were brought out in 72,7% cases, cholesterol-adenomatous polyps were revealed in 8,7% cases, adenomatous polyps - in 8,7%cases, fibroadenomatous polyps were revealed in 2,0% patients, fibrous polyps in0,7% patients and polypoid form of focal adenomyomatosis was revealed in 1,3%patients. Cholesterol polyps in combination with adenomatous polyps were foundin 2,6% patients, cholesterol polyps in combination with cholesterol- adenomatouspolyps were found in 3,3% patients.

M1449

Diagnostic Accuracy of EUS/EUS-FNA for Pancreatic Cancer in

Patients with Or Without Associated Chronic PancreatitisBanke Agarwal, Amith V. Reddy, Jennifer L. Labundy, Naveen B. KrishnaBackground: Diagnosing pancreatic cancer (PaCa) in patients with associated chronicpancreatitis (CP) is often challenging even with EUS-FNA. CP can mimic morphologicfeatures of PaCa and also mask pancreatic tumors during EUS exam. Also, cytologically,CP can mimic well-differentiated PaCa making cytologic diagnosis of cancer difficult. Weexamined the performance characteristics of EUS-FNA for diagnosing PaCa in patientswith or without associated CP. Patients and Methods: This is a retrospective analysis ofour prospective database and included patients who had undergone EUS-FNA forsuspected PaCa at a university hospital from 2002-06. EUS-FNA was performed by anexperienced endosonographer and a cytopathology attending physician was presenton-site. Multiple FNA passes were made till the cytologist was convinced about thenature of the lesion. Cytology that was still reported as ‘atypical’ or ‘suspicious’ wasconsidered negative for malignancy. CP was diagnosed based on previously publishedEUS criteria. Final determination of malignancy was based on surgical pathology ora clinical follow-up of R12 months. Results: The mean age of 624 study patients (315male) was 64 � 14.5 years. There was EUS evidence of CP in 146 of 624 patients.Evaluation for PaCa with EUS-FNAwas prompted due to obstructive jaundice (n Z 268,including 45 patients with CP) or abnormal CT/MRI findings specifically: mass lesion inpancreas (n Z 228, 51 patients with CP), enlarged head of pancreas (n Z 71, 21 patientswith CP) and dilated PD� CBD (n Z 57, 29 patients with CP). A focal ‘mass’ lesion wasnoted by EUS in 61 of 146 patients (10 lesions malignant by cytology) with CP and 347 of478 patients (286 malignant by cytology) without CP. In five patients with CP, there wasno identifiable focal mass by EUS but FNA of the pancreas at the site of abrupt dilation ofPD identified malignancy. A final diagnosis of malignancy was made in 319 patients,including 21 of 146 patients with CP and 298 of 478 patients without it. The accuracy ofEUS-FNA for diagnosing PaCa in patients with vs those without associated CP was 95.2%vs 95.4%, with sensitivity 71.4% vs 94.3%, specificity 99.2% vs 97.2%, PPV 93.8% vs 98.3%and NPV 95.4% vs 91.1%. Summary and discussion: EUS-FNA is highly accurate fordiagnosing PaCa even in patients with associated CP, though with lower sensitivity (p !0.01). The higher NPVof EUS-FNA for PaCa in patients with associated CP seems ratherunexpected. This is likely artifactual due to lower prevalence of cancer in the CP group(14.4% vs 62.3% p ! 0.005) as the clinical/radiologic findings that prompt a search forPaCa can entirely be due to CP.

M1450

Clinical Significance of Dilated Common Bile Duct and

Pancreatic Duct in Patients with Or Without Obstructive

JaundiceBanke Agarwal, Amith V. Reddy, Jennifer L. Labundy, Naveen B. KrishnaBackground: Identification of a dilated common bile duct (CBD) and pancreaticduct (PD) (double duct sign) in patients with obstructive jaundice (ObJ) is veryhelpful clinically and is highly suggestive of a pancreatobiliary malignancy (PBM),though it can rarely be due to chronic pancreatitis or ampullary stenosis. Increasingly,

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