The examiner's learning effect and its influence on the quality of endoscopic ultrasonography in carcinoma of the esophagus and gastric cardia

Abstract

Background: The preoperative diagnosis of tumors of the esophagus and the gastric cardia is an important element in their stage-oriented therapy. The goal of the present study was to evaluate the accuracy of endosonographic ultrasound (EUS) and to test its usefulness in tumor staging and the assessment of operability.

Methods: A total of 139 tumors were scanned via EUS by one examiner ≤14 days prior to resection (TNM staging per UICC, 1987).

Results: The accuracy for completely traversable tumors was 60.8% for T1, 82.1% for T2, 77.5% for T3, and 33% for T4 stages. This accuracy was somewhat reduced in cases of nontraversable tumor stenosis (51.9%). In T staging, a significant case-dependent improvement in accuracy to 89.5% was found; this was regarded as a learning effect. In N staging, we considered only those tumors that were resected by the transthoracic approach with systematic node dissection and complete EUS (n= 80). N-stage accuracy (T1–T4) was 71.3%, and no improvement could be shown. To assess operability, discrimination between T1/T2 and T3/T4 tumors is crucial. Accuracy, sensitivity, and specifity can thus be improved significantly.

Conclusions: The quality of EUS depends on the experience of the examiner. Reliable results can be obtained after >75 examinations have been done. EUS is a valuable tool in tumor staging when it is performed by an experienced examiner or under the direct supervision of such a person.