An evaluation of the role of dual phase helical CT for the assessment of resectability of carcinoma of the gall bladder

Full text: The aim of this study was to assess the ability of dual phase helical CT to predict resectability of carcinoma of the gall bladder (CaGB). 32 consecutive patients suspected to have CaGB on clinical examination and sonography presented to a tertiary care centre over a 10 month period. Of these 32 patients, 15 (10 females, 5 males; age range 33- 72 years; mean age 48.4 years) were included in this prospective study based on the following inclusion criteria: presence of mass in gall bladder fossa on sonography, dual phase helical CT, confirmation at surgical resection or palliation and histopathologic examination. Axial sections of 2mm were obtained (collimation 3mm, table speed 4.5mm/sec) for arterial phase (scan delay 20 secs; craniocaudal progression) followed by venous phase (scan delay 60 secs; caudocranial progression) using the same protocol, on a subsecond helical scanner. The criteria used for unresectability was presence of distant metastatic spread (liver, peritoneum, lymph nodes), extensive local contiguous organ spread, involvement of secondary biliary confluence of both lobes of liver, tumoral invasion of main portal vein or proper hepatic artery or simultaneous invasion of one side of the hepatic artery and the other side of the portal vein. Surgical and histopathologic confirmation was done in all cases and CT findings related to unresectability were correlated with surgical findings. Of the 10 patients considered unresectable on the basis of CT findings 9 had tumors that were unresectable at surgery (sensitivity 100%, positive predictive value, 90%). 5 patients had more than one reason for being unresectable and 4 had one reason alone for being unresectable (lymphadenopathy (n=3), hepatic metastasis (n=1), and vascular invasion (n=1)). All five patients considered resectable based on CT findings had resectable tumors at surgery (negative predictive value 100%).The overall accuracy of CT was 93.3%. Dual phase helical CT as a single imaging modality comprehensively evaluates CaGB and may be a useful tool in preoperative staging of this tumor in determining resectability. Copyright (2002) Blackwell Science Pty Ltd