Literature review
Pancreatic head carcinoma accounts for approximately 70% of all pancreatic tumours, with only the slightest chance of long-term cure in the form of a surgical resection (pancreatoduodenectomy). However, during surgical exploration only 30-50% of pancreatic head carcinoma cases prove resectable. One of the major causes of unresectability is tumour invasion of the Superior Mesenteric Vein (SMV) or the Portal Vein (PV), as these 2 vessels lie in close proximity to the head of pancreas, so surgical separation of the tumour from the vessels proves impossible. Therefore, it is essential to image the pancreas and the peripancreatic vessels using CT as the imaging modality of choice, to provide evidence of tumour staging. Two articles investigate the accuracy of assessing CT images for different criteria as a means of evaluating the potential resectability of a patient with pancreatic head carcinoma. METHODOLOGY Article A examines the effectiveness of 5 CT criteria in evaluating resectability. 113 patients with suspected carcinoma of the pancreatic head were examined by spiral CT. Subsequently, only 65 of these patients required surgery for attempted resection. However, following surgery 15 patients were unable to be used in the study as the CT observations could not be related to surgery findings. Therefore, the remaining 50 patients with confirmed pancreatic head carcinoma could be analysed for venous invasion and hence the possibility of resection. Previous to surgery, each patient underwent a contrast-enhanced spiral CT of the pancreas. Each slice thickness was 5 mm, with 24 rotations at pitch 1:1, and at increments of 3 mm. The patients were injected at a rate of 2 ml s-1 with 130 ml contrast medium meglumineioxithalamath 300 mg ml-1 and with a time delay of 55 seconds.