A combined approach of endobronchial and endoscopic ultrasound-guided needle aspiration in the radiologically normal mediastinum in non-small-cell lung cancer staging--a prospective trial

Abstract

Objectives: This prospective study aimed to assess the diagnostic yield of the combined approach - endobronchial (EBUS) and endoscopic (EUS) ultrasound-guided needle aspiration (combined ultrasound-needle aspiration (CUS-NA)) in the radiologically normal mediastinum in non-small-cell lung cancer (NSCLC) staging.

Methods: CUS-NA was performed simultaneously under local anaesthesia and sedation in consecutive NSCLC patients with mediastinal nodes that were not enlarged on CT (stage IA-IIB). All patients with negative CUS-NA subsequently underwent the transcervical extended bilateral mediastinal lymphadenectomy (TEMLA) as a confirmatory test.

Results: A total of 120 NSCLC patients underwent CUS-NA between 1 January 2008 and 31 December 2008. There were 318 mediastinal nodes biopsied (158 EBUS-NA - stations: 2R - 2, 2L - 1, 4R - 34, 4L - 33 and 7 - 88 and 160 EUS-NA - stations: 4L - 57, 7 - 101 and 9 - 2). CUS-NA revealed metastatic lymph node involvement in 19 of 120 patients (16%) and in 31 of 318 biopsies (10%). The prevalence was 22%. In 99 patients with negative CUS-NA, who underwent subsequent TEMLA, metastatic nodes were diagnosed in nine patients (8%) in 11 stations: 2R - 2, 4R - 4, 4L - 1, 5 - 3 and 7 - 1. In all but one patient there were 'minimal N2' only. Diagnostic sensitivity, specificity, total accuracy, positive predictive value (PPV) and negative predictive value (NPV) of CUS-NA for normal mediastinum was 68% (95% confidence interval (CI): 48-84), 98% (95% CI: 92-100), 91% (95% CI: 86-96), 91% (95% CI: 70-99) and 91% (95% CI: 83-96), respectively. The sensitivity of CUS-NA was significantly higher than with EBUS-NA alone (p=0.04) and higher, close to the level of significance than with EUS-NA alone (p=0.07). The NPV of all techniques was high and that of CUS-NA was significantly higher than EBUS-NA alone and EUS-NA alone (p=0.01, p=0.03). No complications of CUS-NA were observed.

Conclusions: In the radiologically normal mediastinum, CUS-NA is a highly effective and safe technique in NSCLC staging and, if negative, a surgical diagnostic exploration of the mediastinum may be omitted.