Accuracy of MDCT in preoperative definition of maximum tumor diameter in patients with gastric cancer

purpose: The maximum tumor diameter (Dmax) is a prognostic factor in patients with gastric cancer, considering its dependance on the depth of invasion. The aim of our work has been to evaluate the accuracy of MDCT in the preoperative definition of Dmax in patients with gastric cancer, assuming surgical specimen measurements as gold standard, in order to obtain a pre- surgery prognostic evaluation. material and methods: Pre-surgery CT examinations of 47 patients (mean age 53.5, range 48-71) with diagnosis of gastric cancer were evaluated retrospectively and in a blind fashion by a radiologist with expertise in the oncologic field. The Dmax measured was obtained through 2D multiplanar curved reconstruction (ADW 4.6 GE Healthcare). The results were compared with macroscopic data after surgery.results: The mean value of Dmax obtained by surgical specimen was 50 mm (range 30-60) versus 63 mm (range 46-92) of Dmax measured through MDCT. If the Dmax values were stratified in three groups (group 1 smaller than 40 mm, group 2 between 40 and 80 mm, group 3 bigger than 80 mm), a correlation with MDCT results of 25%, 62% and 71%, respectively, was found. Conclusion: MDCT is an accurate technique to obtain an appropriate preoperative definition of Dmax, within the limits of tumor bigger than 40 mm. The revaluation of each case with Dmax smaller than 40 mm will supply additional information about the discrepancy (retraction of the stomach following immersion into formalin, diffusion in the submucosal layer).