Sa1557Conventional Versus Rosemont Endoscopic Ultrasound Criteriafor Chronic Pancreatitis: Interobserver Agreement in Same DayBack-to-Back ProceduresDavid Del Pozo*, Elvira Poves, Susana Tabernero, Mónica Villafruela,Ignacio Moral, Cecilia Sanz, Inmaculada Beceiro, Gloria BorregoAparato Digestivo, Hospital Principe de Asturias, Alcala de Henares,SpainBackground and study Aims: Endoscopic ultrasound (EUS) is a commonly usedand fairly sensitive method of assessing changes of chronic pancreatitis (CP)when routine noninvasive imaging has not shown overt features of CP. There areno studies comparing the interobserver agreement (IOA) of the classic criteriawith the Rosemont classification performed prospectively in the clinical practice.The aim of this study is to evaluate the IOA for the classic and the Rosemontcriteria for the diagnosis of chronic pancreatitis on the basis of clinical practice.Patients and Methods: Two experienced endosonographers evaluated in thesame day patients referred for EUS in a blinded fashion. All patients signed theconsent inform. Data from the sonographic criteria of both classic and Rosemontclassification were collected. Agreement was calculated using k statistics. Results:A total of 69 patients were evaluated. The study population included mainlypatients without pancreatic diseases, resulting in a low number of sonographicfindings. Table 1 shows the IOA and the frequency of the different findings inthe MST system and Table 2 in the Rosemont classification Agreement for thefinal diagnosis was moderate for both classification systems of chronicpancreatitis (k�0,53 for conventional and k�0.46 for Rosemont). Conclusions:Our study shows good agreement for the presence of cysts, main duct dilatationand lobularity, and moderate for the presence of hyperechoic foci, strands, ductwalls and the final diagnosis. The worst kappa value in this study is forhoneycombing lobularity, being this of great importance, because this is one ofthe overweighted features in the Rosemont classification. The interobserveragreement of EUS in the final diagnosis of CP is moderate. The concordancevalues obtained in clinical practice are similar to those obtained in multicenterstudies. The Rosemont classification has not improved the interobserveragreement.

Table 1. Interobserver agreement for classic criteria

kscore

Frequency of eachfeature by

endosonographerA(%)

Frequency of eachfeature by

endosonographerB(%) Agreement

Hyperechoic foci 0.48 30.4 36.2 ModerateStrands 0.55 42 40.6 ModerateLobularity 0.75 24.6 18.8 SubstantialCysts 0.66 1.4 2.9 SubstantialStones 1 1.4 1.4 Perfect*Duct dilatation 0.75 7.2 11.6 SubstantialDuct irregularity 1 1.4 1.4 Perfect*Hyperechoic duct

wall0.52 8.7 11.6 Moderate

Side branch 1 1.4 1.4 Perfect*Overall 0.53 NA NA Moderate�3 features NA 81.2 81.2 NA3-5 features NA 17.4 17.4 NA�5 features NA 1.4 1.4 NA

*Stones, irregular duct caliber, and dilated side branches n�2.

Table 2. Interobserver agreement for Rosemont criteria

kscore

Frequency of eachfeature by

endosonographerA(%)

Frequency of eachfeature by

endosonographerB(%) Agreement

Hyperechoic foci withshadowing

1 1.4 1.4 Perfect*

Lobularity withhoneycombing

0.31 5.8 10.1 Fair

Hyperechoic foci 0.48 30.4 36.2 ModerateLobularity 0.75 24.6 18.8 SubstancialCysts 0.66 1.4 2.9 SubstancialHyperechoic strands 0.55 42 40.6 ModerateDuct calculi 1 1.4 1.4 Perfect*Main pancreatic duct

dilatation0.75 7.2 11.6 Substancial

Irregular main pancreaticduct contour

1 1.4 1.4 Perfect*

Hyperechoic main pancreaticduct margin

0.52 8.7 11.6 Moderate

Dilated side branches 1 1.4 1.4 Perfect*Final diagnosis 0.46 NA NA ModerateNormal NA 79.7 79.7 NAIndeterminate NA 15.9 10.1 NASuggestive NA 2.9 8.7 NAConsistent NA 1.4 1.4 NA

*Stones, irregular duct caliber, and dilated side branches n�2.

Sa1558Clinical Utility of K-RAS Mutation Analysis With Washing FluidAfter EUS-FNA for Pancreatic Cancer DiagnosisYoon Jung Lee*1, Yoon-La Choi2, Kwang Hyuck Lee1, Jong Kyun Lee1,Kyu Taek Lee1, Woo IK Chang1, Jun Hee Lee1, Hye Yon Park1,Ja Ryong Jeon1

1Department of Medicine, Division of Gastroenterology, samsungmedical center, Seoul, Republic of Korea; 2Department of Pathology,samsung medical center, Seoul, Republic of KoreaBackground: Endosonography-guided fine needle aspiration (EUS-FNA) has beenused for the diagnosis of pancreatic cancer. Aspirated specimen obtained by thistechnique cannot be sufficient to make a cytopathological diagnosis. K-rasmutations are the most frequently acquired genetic alteration in pancreaticcancer and detecting this mutation from pancreatic tissue has been helpful in thediagnosis of pancreatic cancer. Aim: The combination of conventional cytologicaldiagnosis and K-ras mutation analysis with modified PCR technology wasinvestigated to improve the sensitivity of diagnosis. This technique can detectK-ras mutation using a tiny amount of specimen obtained by EUS-FNA. Methods:We enrolled 24 patients with suspicious solid masses in or around the pancreas(12 males, 12 females, 63.1�12.8 years). For the conventional cytologicaldiagnosis, 3 to 5 passes of FNA were performed in each patient. For the first 2attempts, the needle catheter was flushed with 2cc of saline and residualmaterials were collected for K-ras mutation analysis. The analysis was done withPNAClamp™ K-ras Mutation Detection Kit which is a modified PCR technologyby using optimized PNA probes. Results: Forty-eight EUS-FNA specimens wereobtained from twenty-four consecutive patients with pancreatic masses. Twenty-six specimens were obtained from thirteen patients with pancreatic cancer, andtwenty-two specimens from eleven patients with other pancreatic diseases. Forthe diagnosis of pancreatic cancer, sensitivity of conventional cytologicaldiagnosis alone, K-ras mutation analysis alone and the combination of the twomethods by EUS-FNA were 84.6% (22 of 26), 76.9% (20 of 26), and 92.3% (24 of26), respectively. Specificity was 100% in any tests. K-ras mutations weredetected in six specimens that were interpreted as inflammatory cells andatypical cells in the cytological diagnosis. Conclusion: A new K-ras mutationanalysis was helpful in diagnosing pancreatic cancer with EUS-FNA aspirates.This method detects K-ras mutation without additional hazards or efforts,because it can be performed only with the washing fluid of EUS-FNA needleafter puncture.

Sa1559Role of EUS in Patients With Elevated CA 19-9 and NegativeAbdominal CT FindingsMun Ki Choi*, Gwang HA Kim, Geun Am Song, Dong UK Kim,Bong Eun Lee, Hye Kyung JeonDepartment of Internal Medicine and Gastroenterology Division,Pusan National University School of Medicine, Busan, Republic ofKoreaBackground: Serum CA 19-9 is a tumor marker, used mainly for screening of

Abstracts

www.giejournal.org Volume 75, No. 4S : 2012 GASTROINTESTINAL ENDOSCOPY AB201