SPIRAL COMPUTED-TOMOGRAPHY AND OPERATIVE STAGING OF GASTRIC-CARCINOMA- A COMPARISON WITH HISTOPATHOLOGICAL STAGING

Background-Much controversy exists as to the value of computed tomogra phy (CT) in the preoperative staging of gastric cancer, because of its limited ability to identify correctly lymph node (LN) metastases, inv asion of adjacent organs, or hepatic and peritoneal metastases. Spinal CT scanners have a number of potential advantages over conventional s canners, including the absence of respiratory misregistration, image r econstruction smaller than scape collimation permitting overlapping sl ices and optimisation of intravenous contrast enhancement, Aim-To comp are the performance of spiral CT and operative assessment against form al (TNM) pathological staging. Patients and methods-A study of 105 con secutive patients who underwent bath spiral CT and operative staging w as performed. All CT scans were reviewed by a radiologist who commente d on tumour location and size, evidence of adjacent organ invasion, ly mph node metastases to both N1 and N2 nodes, and evidence of hepatic a nd peritoneal metastases. All patients underwent careful operative ass essment at the time of surgery, along the lines suggested by Rohde and colleagues. Results-Spiral CT remained poor at identifying LN metasta ses to bath NI and N2 lymph nodes, with sensitivity ranging from 24 to 43%; specificity, however, was 100%. Operative staging was superior, with sensitivities between 84 and 94%, but specificity was much lower (63-74%). Spiral CT correctly detected 13 of 17 cases of invasion of e ither the colon or the mesocolon (sensitivity 76%) compared with 16 of 17 cases at operative staging (sensitivity 94%). Spiral CT correctly identified three of six cases with invasion of the pancreas (sensitivi ty 50%) compared with six of six cases on operative staging (sensitivi ty 100%). Spiral GT correctly identified 12 of 17 cases of peritoneal metastases (sensitivity 71%) and four of seven cases of hepatic metast ases (sensitivity 57%).Conclusion-WhiIst spiral CT remains poor at ide ntifying lymph node metastases, it correctly identified most cases wit h invasion of either the colon or the mesocolon and half the cases of pancreatic invasion. Pt was of value in detecting peritoneal metastase s and some cases with hepatic metastases. At present, at Leeds General Infirmary spiral CT is performed routinely on all patients with gastr ic cancer and a selective staging laparoscopy policy is adapted in tho se patients he whom the status of the peritoneal cavity and liver is i n doubt.