The Difference Between EUS & CT Scan in Diagnosing and Staging Peri Ampullary Tumours: An evidence-based approach

Abstract

Periampullary carcinoma has a better prognosis than pancreatic adenocarcinoma. Hence accurate pre – operative staging is essential for avoiding surgical exploration for unresectable tumours. At the same time, operable cases should not be denied curative surgery based on false positive imaging. Hence it is essential that the imaging should have a high positive predictive value. This article makes a case for the utility of EUS in the accurate diagnosis of periampullary cancer, the detection of lymph node metastases and invasion of the Portal/Superior Mesenteric vein as compared to CT scanning. Electronic search of the PubMed, Embase and Cochrane Central Register of Controlled Trials databases was performed from 1982 to May 2009 to identify relevant studies. Articles meeting the criteria were retrieved and studied according to a standard proforma. Data were extracted from the articles into an Excel database and compared. The search revealed 211 published articles. Twenty-one papers matched the selection criteria. Sixteen articles were prospective and five retrospective. The data compared included local staging of the tumour, lymph node and venous involvement. CT scanning remains the initial investigation of choice in the diagnosis and staging of periampullary tumours but EUS might be superior for overall detection of lesions, especially those smaller than 2 cm. Although CT remains the investigation of choice, it is essential that EUS is performed by experienced operators and used when the clinical suspicion is high and CT fails to demonstrate a mass. This could increase the number of early lesions detected and improve the overall prognosis.