Endoscopic ultrasound (EUS) has a wide array of indications for diseases of the foregut. It can be used for staging, diagnosing, and even treating aspects of both benign and malignant processes of the esophagus, mediastinum, stomach, duodenum, pancreas, and additional extraintestinal organs. This chapter will focus on some of the most common indications for the use of EUS and particularly in ways in which management might be effected.
The TNM classification (Table 11-1) is currently used for the staging of esophageal cancer1,2 and accurate staging is critical for directing patients to appropriate treatment protocols. For instance, 5-year survival is >95% for stage 0 disease, 50–80% for stage I disease, and 10–40% for stage II disease.1-3 EUS has been demonstrated to be most reliable for locoregional staging, staging T3 and T4 lesions with accuracies of 89–94% and 88–100%, respectively.4,5 T1 and T2 lesions can be differentiated from T3 and T4 lesions with an accuracy of 87%.6 EUS is the most accurate modality for staging of regional lymph nodes compared to CT scan and PET.7 The overall accuracy of N staging is 75–80% compared to CT (51–74%).5 FNA improves the diagnostic performance of EUS by at least 13%.8 Unfortunately, EUS’s role for metastases (M) staging has been disappointing. PET scan and CT remain the most accurate methods for M staging. Small liver metastasis may be better detected by EUS.9
Table 11-1 TNM Staging of Esophageal Cancer |Favorite Table|Download (.pdf)
Table 11-1 TNM Staging of Esophageal Cancer
|Tumor (T) Stage of TNM Staging of Esophageal Adenocarcinoma|
|T0||No evidence of primary tumor|
|T1a||Tumor invades lamina propria or muscularis mucosae|
|T1b||Tumor invades submucosa|
|T2||Tumor invades muscularis propria|
|T3||Tumor invades adventitia|
|T4a||Resectable tumor that invades pleura, pericardium, or diaphragm|
|T4b||Unresectable tumor that invades other adjacent structures, ex aorta, trachea, vertebrae, etc|
Mediastinal Masses, Nodes, and Cysts
EUS is an excellent method of evaluating the posterior mediastinum. The role of EUS in the staging of lung cancer will ...