Usefulness of endosonography and fine needle aspiration in preoperative evaluation of pancreatic cystic lesions

*4223 cOMPARISON OF MR CHOLANGIOPANCREATOGRAPHY (lVIRCP) WITH EUS AND INTRADUCTAL US (IDUS) IN [NTRADUCTAL PAPILLARY-MUCINOUS TUMOR (IPMT) OF THE PANCREAS Nobuyuki Yanagawa, Yusuke Mizukami, Sateshi Tanno, Atsuya Habiro, Keisuke Kimura, Takeshi Obara, Yutaka Kohgo, Asahikawa Medical Coil, Asahikawa Japan Background/Aim: EUS has been generally regarded as gold standard for the diagnosis of IPMTs. Recently, several studies showed that MRCP is comparable or superior to ERCP for the diagnosis of pancreaticobiliary diseases. The accurate diagnosis for the malignancy of IPMTs is critical to determine the management of patients with IPMTs, i.e., surgery or followup. The aim of this study was to evaluate the diagnostic potential of MRCP compared to EUS/IDUS in IPMTs. Methods: In addition to EUS/IDUS, MRCP images of 12 patients with IPMTs underwent surgical resection and 35 follow-up patients were retrospectively reviewed in a blinded fashion. Each nodular lesions detected by preoperative images were confirmed whether corresponding mural nodules were present or not in the resected specimens. We assessed the detectability of multiplicity of cyst, mural nodules, and whole image of main pancreatic duct (MPD) and major cystic lesion. Changes in size of the cystic lesions were examined at different periods in 19 follow-up cases. Results: Results are shown in Table. Detectability of the MPD and major cystic lesion in MRCP was significantly higher than that of EUS/IDUS. Accuracy of MRCP in detecting the multiplicity of cystic lesions was higher than that of EUS/IDUS. EUS/IDUS detected the mural nodules with higher sensitivity, however, there was a false positive associated with mucous clot. MRCP detected the nodules more than 6 mm in size, and the source image of sequential multislice studies was superior to maximum intensity projection image for the detection. Positive predictive value in diagnosing of mural nodule was higher in MRCP than in EUS/IDUS. In follow-up cases, the size of cystic lesions measured by MRCP showed high reproducibility compared to EUS/IDUS. Conclusions: MRCP is a useful modality to choose the appropriate management for the patients with IPMTs. It is likely that MRCP is more suitable than EUS/IDUS to evaluate the changes in size of the lesions and useful to detect new lesions during follow-up.

Detectability MPDIMaJorcyst Multiplicity of cyst Mural nodules

% of case mean No./case Sensilivily PPV

Reproducibility in cyst size

MRCP'

EUS

IDUS

91%/96% 64% 2.21±0,44 42 (74)% 89 (78)% 74%

64%/69% 45% 1.67±0.61 90% 68% 32%

57%/44% 27% 1.26±0,45 68% 52% ND

"' results of MIP reconstructionimage," parenthesis indicates the result of source image

:'4224 F-18-FLUORO DEOXYGLUCOSE SPECT (FDG)IPOSITRON COINCIDENCE D E T E C T I O N (PCD) AND E N D O S C O P I C ULTRASOUND (EUS) MAY BE AN IDEAL COMBINATION FOR F U R T H E R WORK-UP OF PANCREATIC ADENOCARCINOMA WHEN CONVENTIONAL IMAGING IS E I T H E R NEGATIVE OR EQUIVOCAL. C-irishMishra, Walt E. Drane, Suzanne T. Mastin, Stephen B. Vogel, Steven N. Hochwald, Manoop S. Bhutani, Univ of Florida, Gainesville,F L Background/Objectives: F D G imaging using a g a m m a camera with highenergy collimators (FDG SPECT) or positron coincidence detection (PCD) can be performed at a significantlylower cost than FDG-PET. Increased glucose uptake is highly suggestive for malignancy. Although F D G - P E T

VOLUME 53, NO. 5, 2001

has been compared to EUS and CT scanning for evaluation of pancreatic adenocarcinoma,studies comparing EUS to FDG SPECT/PCD are limited. Questionable pancreatic masses seen by CT, common bile duct (CBD)or pancreatic duct (PD) strictures seen by either ERCP/MRCP, or an elevated CA 19-9 pose difficult clinical problems. We evaluate the clinical utility of F-18 SPECT/PCD as an adjunct to EUS in helping manage equivocal pancreatic adenocarcinoma. Methods: 52 pancreatic F-18-FDG SPECT/PCD cases were identified between July 1998, and December 2000.23 of these patients underwent EUS and had adequate clinical follow-up. Indications, CT findings, ERCP findings, EUS diagnosis prior to the FDG uptake results, CA 19-9 levels, operative reports, and clinic charts with at least 6 months follow-up were reviewed. Results: 13 females, and 10 males (Age 58.3± 14;range 27-84) comprised the study population. The indications for the EUS were as follows: 5-definite mass seen on CT, 18-equivocal for pancreatic adenocarcinoma. The 18 equivocal cases were as follows: 6-pancreatic head enlargement on CT, 6-CBD or PD abnormalities by either ERCP/MRCP/CT, 6-negative imaging but elevated CA19-9 and/or abdominal pain or weight loss. The sensitivity, specificity, PPV, and NPV for EUS were: 87.5%, 73%, 64%, 92%. The sensitivity,specificity, PPV,and NPV for FDG SPECT/PCD were: 87.5%, 80%, 70%, 92%. All 3 false positive FDG uptakes were in patients with severe chronic pancreatitis. 1 false negative was seen by both tests. 3 patients were found to have distant metastasis by FDG. Conclusions: EUS and FDG SPECT/PCD helped guide management in approximately 80% of patients referred for either equivocal imaging findings or abnormal CA 19-9 levels. EUS and FDG SPECT/PCD have nearly equal performance characteristics. EUS provides the ability for EUS guided FNA while FDG-SPECT/PCD is additionally useful for detecting distant metastasis. Thus, the combination of EUS and FDGSPECT/PCD may be ideal for further work-up of pancreatic adenocarcinoma when conventional imaging is either negative or equivocal.

*4225 U S E F U L N E S S OF ENDOSONOGRAPHY AND F I N E N E E D L E ASPIRATION IN PREOPERATIVE EVALUATION OF PANCREATIC CYSTIC LESIONS Robert E. Sedlack, Enrique Vazquez-Sequeiros, Aboud Affi, Ian D. Norton, Jonathan E. Claln, Maurits J. Wiersema, Mayo Clin, Rochester, MN Background: Preoperative differentiation of benign and malignant/potentially malignant (M/PM) pancreatic cystic lesions (PCL) is problematic. Limited data support the role of endosonography (EUS) and fine needle aspiration (FNA) in these settings. Aim: Assess the sensitivity, specificity and accuracy of EUS, cytology and cyst fluid analysis in PCL. Methods: 111 consecutive patients (54 males, mean age 59, range 18-79 ) from 7/97- 9/00 with known or suspected PCL based on CT or transabdominal ultrasound and confirmed by EUS were identified. Select patients underwent EUS guided FNA for cytology and CEA levels. A PCL was considered to be M/PM if one or more EUS criteria were met (wall thickness > 3ram, macroseptation, presence of mass or intramural growth, and cystic dilation of the main pancreatic duct). A CEA level greater than 50ng]ml was considered to suggest M/PM. Based on surgical pathology, cysts were classified as benign (simple cyst, pseudocyst, serous cystadenoma) or malignant, potentially malignant (M/PM) (mucinous cystadenoma, intraductal papillary mucinous tumor (IPMT), cystic islet cell tumor (ISLT), cystic adenocarcinoma (ACA)). Results: 34 patients unde~vent surgery and form the basis for our analysis. Cytology was performed in 18 of these patients and CEA levels were obtained in 11 patients. EUS was 100% sensitive in all 13 patients with ISLT, IPMT or ACA. Combining EUS, cytology and CEA results did not improve accuracy. There were no reported complications related to the EUS or EUS guided FNA. Conclusions: EUS alone is accurate in distinguishing benign from M/PM PCL. EUS has high sensitivity for detecting malignant PCL (especially in ISLT, IPMT, and ACA) and should be used when surgical therapy may not be undertaken. The addition of EUS FNA with cytology and CEA analysis, although safe, does not enhance diagnostic yield. Accuracy of EUS, Cytologyand CEA in Pancreatic Cystic Lesions

EUS Cytology CEA

Sensitivity

Specificity

Accuracy

91%*

60%

82%

27%' 28%

100% 25%

55% 27%

°p=O.01

G A S T R O I N T E S T I N A L ENDOSCOPY

AB175