Comparison of endoscopic ultrasound guided fine needle aspiration and PET/CT in preoperative diagnosis of pancreatic adenocarcinoma.

BACKGROUND Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) is the procedure of choice to investigate and sample pancreatic masses for the preoperative diagnosis of pancreatic ductal adenocarcinoma (PDAC). The role of 18fluoro-deoxyglucose positron emission tomography/computed tomography (PET/CT) in PDAC is debated. This study evaluates the role of EUS-FNA as compared to PET/CT in the preoperative evaluation of PDAC. METHODS Preoperative evaluation by PET/CT and EUS-FNA was performed on 25 patients with pancreatic solid lesions, who underwent a subsequent Whipple procedure or partial pancreatic resection. RESULTS This series included 19 PDACs and 6 non-PDACs including 1 metastatic breast ductal adenocarcinoma, 2 low grade neuroendocrine tumors, 2 chronic pancreatitis and 1 gastrointestinal tumor abutting the pancreas. EUS-FNA correctly diagnosed 18 of 19 PDACs, 1 metastatic breast ductal adenocarcinoma and all 5 of the other non-PDAC cases. One case of well differentiated PDAC was negative on EUS-FNA. PET/CT provided excellent size and was positive in 14 of 19 PDACs and the metastatic breast ductal adenocarcinoma. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for EUS-FNA in diagnosis of selected pancreatic tumors were 91%, 100%, 100%, 50% and 92%, respectively, while they were 65%, 100%, 100%, 20% and 68% for PET/CT, respectively. CONCLUSIONS Compared to PET/CT, EUS-FNA has a higher sensitivity and accuracy for preoperative diagnosis of PDAC. However, PET/CT provides excellent size, volume and stage information. A combination of both PET/CT and EUS will better help guide diagnosis and treatment of pancreatic adenocarcinoma.