Impact of MRI on the post-therapeutic diagnosis of T4 esophageal cancer

Background Opportunities for T4b esophageal cancer patients to receive curative surgery are increasing with the development of multidisciplinary treatments. However, the best modality to accurately diagnose infiltration to the organs surrounding T4b esophageal cancer is still unknown. The aim of this study was to determine the performance of CT and MRI in diagnosing T stage in T4b esophageal cancer, with reference to the pathological diagnosis. Methods A retrospective medical records review of patients with T4b esophageal cancer patients from January 2017 to December 2021 was conducted. Among 125 patients who were treated for cT4b esophageal cancer in Osaka University Hospital, 30 patients were diagnosed with cT4b esophageal cancer by CT, ycT staging with CT (contrast-enhanced images) and MRI (T2-FSE images), and curative R0 resection was performed. Preoperative MRI staging was independently performed by two experienced radiologists. The diagnostic performance of CT and MRI were examined using McNemar’s test. Results Nineteen and 12 patients were diagnosed with ycT4b by CT and MRI, respectively. Combined T4b organ resection was performed in 15 patients. A pathological diagnosis of ypT4b was made in 11 cases. In comparison to CT, MRI showed a higher diagnostic performance, specificity (47% vs. 89%, p = 0.013), and accuracy (60% vs. 90%, p = 0.015) for CT vs. MRI. Conclusions Our results—with reference to the pathological diagnosis—revealed that MRI had a superior diagnostic performance to CT for diagnosing T4b esophageal cancer invading the surrounding organs. An accurate diagnosis of T4b esophageal cancer may facilitate the implementation of appropriate treatment strategies.