Published online May 16, 2022. doi: 10.4253/wjge.v14.i5.320
Peer-review started: December 4, 2021
First decision: January 8, 2022
Revised: February 11, 2022
Accepted: April 3, 2022
Article in press: April 3, 2022
Published online: May 16, 2022
Processing time: 162 Days and 23.8 Hours
The diagnosis of endoscopic ultrasound (EUS) for esophageal cancer after neoadjuvant therapy is controversial. In addition, it is unclear whether the echogenic lesions detected using EUS are indeed residual tumors and how they appear on ultrasound.
There are few studies that contrast echographic and pathologic images of esophageal cancer after neoadjuvant therapy. In our clinical experience, we have observed that the esophageal muscle layer can be clearly visualized using EUS in patients with a good response to neoadjuvant therapy.
To investigate the ultrasound imaging features of residual tumors and identify the limitations and potential of EUS.
Twenty-three patients receiving esophagectomy after neoadjuvant therapy [15 patients after neoadjuvant chemotherapy (NAC) and 8 patients after chemoradiotherapy (CRT)] were studied. We diagnosed the T stage and compared ultrasound images with pathological findings using ultrasound for surgical specimens. Furthermore, the rate of reduction for the muscle layer defect was evaluated using EUS images obtained before and after neoadjuvant therapy.
The accuracy of T stage rate was 61%, which worsened after CRT (38%) than after NAC (73%). Moreover, pT0 could not be diagnosed in all cases. The detection rate of residual tumor for specimens using ultrasound retrospectively was 75%. Tumor borders were irregular and echogenicity was mixed type after CRT. There was a correlation between the pT stage and the rate of muscle layer defect reduction measured by EUS.
Some tumors are undetectable on ultrasound when compared to pathological images. However, focusing on the esophageal muscle layer may improve the accuracy of T stage diagnosis of residual tumors.
If EUS helps diagnose T stage of residual tumors in patients after neoadjuvant therapy by focusing on the muscle layer, the clinical treatment options can be expanded significantly.