Clinical Application of Oral Contrast-Enhanced Ultrasound in Evaluating Preoperative T Staging of Gastric Cancer by Using AJCC 8th Staging Criteria

Abstract

Abstract Objective: To investigate the clinical application of Oral Contrast-Enhanced Ultrasound (OCEUS) in evaluating preoperative T staging of Gastric Cancer (GC). Methods: OCEUS was performed before the operation and standard ultrasound images were retained. The depth of infiltration of GC (T-stage) was evaluated according to the AJCC 8th TNM staging criteria. Finally, with the postoperative pathological staging as the gold standard reference, the sensitivity, specificity, negative predictive value, positive predictive value, and diagnostic value of OCEUS T staging were evaluated. Results: The diagnostic accuracy of OCEUS was T1a: 76.6%, T1b: 69.6%, T2:62.7%, T3:60.8%, T4a: 88.0%, T4b: 88.7%, and the total accuracy was 75.5%. The PPV of OCEUS were T1a: 76.6%, T1b: 69.6%, T2:62.7%, T3:60.8%, T4a: 88.0%, T4b: 88.7%. The sensitivity of ultrasonic T staging was higher than 62% except for T1b, which was 40.3%. The specificity of all ultrasonic T staging was higher than 91% except T3, which was 83.5%. The specificity of all ultrasonic T staging was higher than 91%, and the Youden index was higher than 60% except for T1b and T2. In T4b-stage tumors, OCEUS T staging was in good agreement with pathological T staging (kappa value > 0.75), whereas in T1a, T1b, T2, T3, and T4a tumors, it is in moderate agreement with pathological T staging (kappa value 0.40~0.75). The coincidence rate of OCEUS T staging was higher than 84%. Conclusion: OCEUS was effective, reliable, and accurate in diagnosing preoperative T staging of GC. Being a non-invasive diagnostic technique, OCEUS is worthy of clinical popularization.