Non-small-cell lung cancer: detection of mediastinal lymph node metastases by endoscopic ultrasound and CT

In this prospective study endoscopic ultrasound (EUS) and computed tomography (CT) were evaluated to compare diagnostic accuracy of the two methods. They were performed for nodal staging in selected patients admitted to our institution for non-small-cell lung cancer (NSCLC). From February 1992 to July 1993, 45 patients were recruited for the study when N3 and N2 nodal involvement were excluded on standard chest X-ray. All the patients completed EUS and CT exams for staging before treatment. The results of sensitivity, specificity and accuracy were obtained in 30 patients who underwent surgical treatment with macroscopically radical resection of T and N, which allowed a complete surgical and histological comparison of CT and EUS findings. On a per-patient basis CT results were: sensitivity 63.6%, specificity 78.9% and accuracy of 73.3%; on a nodal station basis sensitivity, specificity and accuracy were 70.0%, 85.1% and 81.6%, respectively. The EUS evaluation showed, on a per-patient basis, values of sensitivity 45.5%, specificity 57.9% and overall diagnostic accuracy of 53.3%. On a nodal station basis the results were 50.0%, 86.6% and 78.2%, respectively. The results obtained in the 30 patients when both techniques were taken in association regarding sensitivity (90.9%), specificity (73.7%) and accuracy (80.0%) on a per-patient basis suggest that the association of EUS and CT offers the best approach for preoperative staging of NSCLC.