Role of 18-FDG PET in evaluation of patients with cystic lesions of the pancreas

conversion to open required. Technical limitations were analyzed.Results LaparoscoplcRFA was completed successfully on lesions in segments 1,2,3,5,6,7 and 8. One patient was converted to open in order to address tumor extending into an adjacent segment of colon. Another patient underwent planned trans-diaphragmaticablation of a lesion in the dome of the liver during thoracotomy for a synchronous lung lesion. There were no immediate or late complications. After a mean follow-up of 6.4 months there were no recurrences. One port site metastasis occurred and one patient had 4 new lesions discovered eight months after surgery. Laparoscopiccryosurgery was completed on lesions in segments 2,3,4,6,7 and 8. Two patients required conversion from laparoscopy;one for dense adhesionsand the other for safe exposure of a segment 6 lesion abutting the stomach. Three Patients suffered complications from cryosurgery including two post-operativedeaths. After a mean follow-up of 9.3 months there was one recurrence. The average length of hospitalization (LOH) was greatest for those who underwent open surgery at 8.0 days. For cryosurgery performed laparoscopicallythe averageLOHwas 4.4 days,and for laparoscopicRFA1.8 days.Conclusions Every segment of the liver is accessible to laparoscopic tumor destruction. In experienced hands and under ultrasound guidance laparoscopic RFA can be performed with excellent results, short hospitalizationand minimal complicaions.

2450 Intraoperative Abdominal Ultrasonography-GuidedLarge Volume Ethanol Injection For Hepatocellular Carcinoma Ricardo J. Mondragon-Sanchez,Ana Lilia L. Gardo&o-Lopez, Hector Murrieta, Mauricio Frias-Mendivil, Rubi Espejo, Alejandro Mondragon-Sancbez,Rigoberto BemaI-Maldonado, Enst Nacional de Cancerologia,Mexico City Mexico BACKGROUND:Percutaneousethanol injection has been successfully used for small single HCClesions 5 cm or less in size. For bigger lesions the place of large volume ethanol injection has not been well explored. OBJECTIVE:To evaluatethe results of intraoperativeUS-guided large volume ethanol injection for HCC lesions greaterthan 4 cm in size. METHODS:Between June 1999 and June 2000, ten patients with unresectable HCCs were candidates for this treatment. A retrospective review of the clinical files was performed. During surgery a single session of absolute ethanol (99.5%) was instilled under US control. An average of 100 ml (range 80-120 ml) was administered. Follow-up evaluation included alpha-fetoprotein (AFP) levels and US or computed tomography (CT). Morbidity and mortality ware analyzed.Survival was determined by Kaplan Meier method. RESULTS:There were four men and six women with a median age of 62 years (range 56-80 years), The median size of the lesions was 8 cm (range 4-15 cm). Sevenpatients had concomitant hepatitis C liver cirrhosis, two patients had hepatitis B and C liver cirrhosis, and one case was not associated to a chronic liver disease. A significant reduction of AFP levels after treatment was observed (Initial median AFP: 966 ng/dl, post treatment levels: 42 ng/dl) US and CT scan showed a variable reduction in size. Postoperativecomplications included: pleural effusion, GI bleeding,fever and transient hypotension (morbidity 40%), No mortality was recorded. The 1 year survival rate after treatment was 60%. CONCLUSION:Intraoperative US-guidedlarge volume ethanol injection is a safe palliativetherapy for patients with HCC lesions greaterthan 4 cm in size. We believe that this procedure could increasethe survival in cirrhotics patients with unresectableHCC. However, prospective and randomizedstudies are neededto demonstratethis observation.

2451 Peritoneal Washings Are Not Predictive Of Advanced Stage In Hilar Cholangiocarcinoma Robert C G Martin II, Yuman Fong, Memorial Sloan-KetteringCancer Ctr, New York, NY; Ronald P. Dematteo,Leslie H. Blumgart, MSKCC, New York, NY; William R. Jamagin, Memorial Sloan-KetteringCancer Ctr, New York, NY Introduction: Evaluation of peritoneal cytology during laparoscopic staging has been shown to provide valuablestaging information in patientswith gastric and pancreaticadenocarcinoma; however, no data exists regarding its utility in patients with hilar cholangiocarcinoma. The aim of our study was to prospectively evaluatethe presence of positive peritoneal cytology in MO and M1 diseaseand the influence of positive peritoneal cytology on survival. Methods: From 10/97 through 3/00, laparoscopic washings were obtained from 25 patients with hilar cholangiocarcinoma.Peritonealwashingswere obtainedfrom the right and left upper quadrants before any biopsies were taken. Cytological analysis was performed using the Papanicolau technique. Results: Eight females and 18 males were identified with a median age of 69 y/o (range 42-81). The most common presenting symptom was jaundice (n = 19). Prior stunting was performed in 22 of the patients with 8 undergoing percutaneousand 14 undergoing endoscopicdrainage. Metastaticdiseasewas suspectedpre-operativelyin 6 patients, 3 to the liver, 2 to the peritoneum and 1 to regional lymph nodes. Laparoscopyidentified 7 additional patients with unresectabledisease. Positive peritoneal cytology was seen in only 2 patients, and both had obvious peritoneal metastases. Sevenother patients had metastatic diseaseto distant sites, but none had positive cytology. Overall,6 patientswere found to have metastatic disease to the peritoneal cavity, none of whom had undergone prior percutaneousdrainage. The prevalenceof positive cytology by stage was as follows : 0% (0/4) in T2MO disease;0% (0/11) in TJMO disease; and 22% (2/9) in M1 disease.Conclusion: Peritoneal cytology was not predictive of advanced stage disease, even in the presence of macroscopic disease. Preoperative percutaneous drainage was not predictive of peritoneal disease. Laparoscopic staging identifies some patients with unresectablehilar cholangiocarcinomabut analysis of peritoneal cytology provides no additional information.

A-482

2452 Diagnostic Laparoscopy and Laparoscopic UltresooogrephyAre Essential for Staging Intraabdominai Neoplasms George J. Tsioulias, Thomas F. Wood, Mathew I-t. Chung, Donald L. Morton, Anton J. Bilchik, John Wayne Cancer Institute, Santa Monica, CA Background: Despite radiographic advances, disparities exist between preoperativeimaging studiesand intraoperetivefindings.Thisstudy comparedthe accuracyof diagnostic laparoscopy (DL) and ladaroscopicultrasonography(LUS) with that of spiral CT scan, MRI, uitrasonography and PET scan in assessing the extent and resectability of abdominal neoplasms. Methods: DI.A_US using a 7.5-Mhz ultrasound probe was undertaken in 70 consecutive patients with abdominal neoplasms. All patients had spiral CT scan with oral and IV contrast within 2 months of surgery.Additional imagingstudieswere obtainedif CTscanfindings wereequivocal. Results: The 43 males and 27 females had a mean age of 63 years (range, 35-87 years). The most frequent primary neoplasms were colerectal carcinoma (23), hepatoma (14), and melanoma (13). OL identified peritoneal metastatic implants not diagnosed by preoperative imaging in 12 cases (17%). In 22 cases (31%) there were discrepanciesbetween LUS and preoperativeimaging (vascular invasion in 1, size of metastsis in 3, number of metastasis in 6, location in 3, type of lesion in 4, and more than one variable in 5 cases). The findings of DL/LUS altered surgical treatment in 26 cases (37%). Conclusions:This is the largest reported series of DL/LUS for intreabdominal neoplasms. When compared with preoperativeimaging studies, the combinationof DL and LUS is more sensitiveand specific in staging intraabdominal neoplasms and effectively reducesthe number of unnencessarylaparotomies.DL/LUS should be routinely used in all patients with intraabdominal neoplasms who are candidates for surgical exploration.

2453 Role of 18-FD6 PET in Evaluation of Patients with Cystic Lesions of the Pancreas. Cosimo Sperti, Claudio Pasquali, Semeiotica Chirurgica, Padova Italy; Giorgio Ferlin, PETCenter Nuclear Medicine, CestetfrancoV. Italy; Guido Liessi, Radiology, CastelfrancoV. Italy; Franca Chierichetti, PET-CenterNuclear Medicine, CastelfrancoV. Italy; Sergio Pedrazzoti,Semaiotica Chirorgica, Padova Italy The differential diagnosis betweenbenign and malignant cystic lesions of the pancreasbased on conventional imaging (CT or US-scan, MRI) is still unreliable in a number of patients. Aim of this study was to investigate the usefulness of 1B-FOG PET in the differential diagnosis between benign and malignant cystic lesions of the pancreas. METHODS:In a 4-year period, 56 patients with suspected cystic tumor of the pancreas underwent 18-FDG PET in addition to serum CA 19-9 assay, CTscan, and, in some cases, to MRI or endoscopic retrograde cholangiopancreatography(ERCP). The 18-FDG PET was analyzedvisually and semiquantitalively using the Standard Uptake Value (SUV). The accuracy of 16-FDG PET and CT were determined for evaluation of preoperativediagnosis of malignant cyst. RESULTS:Seventeen patients had a malignant tumor (Mucinous cystic tumor: 8; Adenocarcinoma with cystic degeneration or retention cyst: 5; Endocrine: 2; Solid-cystic tumor: 1; Intraductal papillary mucinous tumor: 1). FDG-PETcorrectly diagnosed a malignant lesion in 16 patients (94%) with a SUV range from 2.6 to 12.0. Twelve patients (70%) were correctly identified as having malignancyby CT-scanand/or CA 19-9 assay.Thirty-nine patients had benign tumors (Mucinous cystic tumor: 6; Serous cystic tumor: 11; Pseudocyst: 8; Congenital cyst: 2; Intraduntal papillary mucinous tumor: 8; Duodenalenterogenouscyst: 1; Mesenteric cyst: 1; Cystic lymphangioma:1; Endocrine:l). Only one Mucinous cystic tumor showed increased18FOG PET uptake(SIN 2.6). Five patientswith benign cysts showed CT findings o1malignancy. S e n s e , specificity, positive and negative predictive values of 18-FOG PET and CT-scan in detecting malignant cystic tumors were 94%, 97%, 94%, 97% and 65%, 87%, 69%, 85% respectively. CONCLUSIONS:18-FDG PET is more accurate than CT in the identification of malignant pancreatic cystic lesions and should be used, in combination with CT and tumor markers assay, in the evaluation of pancreatic cystic lesions. The positivity of 18-FDG PET strongly suggest malignancy and, therefore, a must of resection. The negativity of 18-FOG PET shows a benign tumor that may be treated with limited resection or, in selected highrisk cases, with biopsy and/or follow-up. 2454

The Role Of Prophylactic Gutric Bypass In Advanced Pancreatic Cancer Ari D. Brooks, Memorial Sloan-KetteringCancer Ctr, New York, NY; Paul S. Oudrick, Univ of Tennessee,Knoxville, TN; N Joseph Espat, Univ of Illinois, Chicago, IL; Murray F. Brennan, Kevin C. Conlon, Memorial Sloan-Kettering Cancer Ctr, New York, NY Background: Exploratory laparotomy has been advocatedfor patients with pancreatictumors on the assumptionthat if found unresectable,a surgical biliary bypassand prophylactic gastric bypass (PGB) are appropriate. However,the use of staging laparoscopy (SL) alone has been associated with a subsequent need for surgical bypass in only 3% of unresectable patients. A randomizedtrial comparing biliary bypass with PGB to biliary bypass alone has reported a 20% incidence of subsequentbypass in the latter group. We examinedour experiencewith open and laparoscopic managementapproaches.Methods: We identified 91 patients having PGB (82 biliary bypass) and 199 patients having SL only from a prospectivedatabaseof 1400 patients with adenocarcinomaof the pancreastreated between11/89 and 12/98. Symptomatic gastric outlet obstruction (GO0) was defined as failure to tolerate maintenancelevel caloric intake, delayed gastric emptying (DGE) was defined as over 10 days to regular diet. Post operative length of stay (LOS) is reported for the first hospitalization. Chi square, Mann Whitney U, and log rank analysiswere used for univariate comparisons. Results: The groups were comparablewith regard to sex and median age (66, range 39-87 years). PGB patients had increasedperioperativemorbidity and mortality. During follow up, 25% of PGB patients and 14% of SL patients had at least one readmission (p