Mediastinal restaging: EUS-FNA offers a new perspective

Study objective: We hypothesized that transoesophageal endoscopic ultrasound guided fine needle aspiration (EUS-FNA) has the potential to be a valuable and accurate new diagnostic technique for mediastinal restaging in non-small cell lung cancer (NSCLC) after induction chemotherapy. The current restaging modalities either have a low diagnostic accuracy (computed tomography (CT) scan of the thorax) or they are invasive, can be technically difficult and are therefore not commonly performed (remediastinoscopy). Methods and patients: Nineteen consecutive patients with NSCLC and proven ipsilateral or subcarinal lymph node metastases (N2 disease) who had been treated with induction chemotherapy underwent mediastinal restaging by EUS-FNA. Patients had either a partial response ( n=14) or stable disease ( n=5) based on sequential CT scans of the thorax. Interventions: EUS-FNA was performed in an ambulatory setting with biopsy of mediastinal lymph nodes (LN). No complications occurred. When EUS-FNA restaged the mediastinum as no regional lymph node metastasis (N0), surgical resection of the tumour with lymph node sampling or dissection was performed. Results: The positive predictive value, negative predictive value, sensitivity, specificity and diagnostic accuracy of EUS-FNA in restaging mediastinal LN were 100, 67, 75, 100 and 83%, respectively. Conclusions and significance: EUS-FNA qualifies as an accurate, safe and minimally invasive diagnostic technique for the restaging of mediastinal lymph nodes after induction therapy in NSCLC. In the future EUS-FNA might play an important role in the mediastinal restaging in NSCLC, particularly to identify the subgroup of down staged patients who benefit most from further surgical treatment.