CT volumetry can potentially predict the local stage for gastric cancer after chemotherapy

Abstract

PURPOSE We aimed to evaluate the value of CT tumor volumetry for predicting and stages of gastric cancer after chemotherapy, with pathologic results as the reference standard. METHODS This study retrospectively evaluated 42 patients diagnosed with gastric cancer, who underwent chemotherapy followed by surgery. Pre— and post—treatment CT tumor volumes (VT) were measured in portal venous phase and volume reduction ratios were calculated. Correlations between pre— and post—treatment VV reduction ratio, and pathologic stages were analyzed. Receiver operator characteristic (ROC) analyses were also performed to assess diagnostic performance for prediction of downstaging to T0—2 stage and N0 stage. RESULTS Pretreatment VT, post—treatment VV and VT reduction ratio were significantly correlated with stage (r5:0.329, r5:0.546, r5: —0.422, respectively). Post—treatment VT and VT reduction ratio were significantly correlated with stage (r5=0.442 and rs: —0.376, respectively). Pretreatment VT, post—treatment V1, and VT reduction ratio were significantly different between T0—2 and T3,4 stage tumors (P 0.05, 0.001, and 0.002, respectively). The differences between N0 and 2N1 groups were also statistically significant (P 0.005 for post—treatment VT, 0.016 forVT reduction ratio, respectively).The area under the ROC curve (AUC) for identification ofT0—2 groups was 0.70 for pretreatment VT, 0.88 for post-treatment VT, and 0.82 for VT reduction ratio, respectively. AUC was 0.78 for post-treatment VT and 0.74 for VT reduction ratio for identification of N0 groups. CONCLUSION CT tumor volumetry, particularly post-treatment measurement of VT, is potentially valuable for predicting histopathologicT and stages after chemotherapy in patients with gastric cancer.