Transoesophageal ultrasonography in the staging of lung cancer

In primary lung cancer, tumour extent is generally the most important determinant in the selection of therapy [6,42]. There is a growing tendency to stage this disease with the TNM classification, in which “T” means location and size of the primary lesion, “N”, lymph node involvement of the hilum and mediastinum, and “M”, the presence or absence of distant metastasis [6,35]. Epidemiological surveys based on the TNM classification show an excellent correlation between this staging and survival rate [20,35]. Most patients who have T4, N3 and/or Ml lesions are usually not considered surgical candidates [6,19]. With N2 lesions, it is reported that radical node dissection can cure a significant percentage of patients or prolong their survival rate [19,21,30,39]. T3 patients may be resectable, but surgical management of these lesions is controversial [19,25,30]. In summary, lung resection should not be performed in patients in whom the tumour cannot be completely removed; however, it is also essential not to preclude potentially curative surgery due to overstaging. Therefore the selection of the correct treatment in each patient depends on exact staging [ 13,421. High resolution and real-time sonographic scanning not only permits observation of relative movement of lesions and neighbouring structures, but also provides information about the characteristics of tissues such as differentiation of the vessels from solid masses [11,24,29,33,37,38]. However, the value of ultrasonography for the evaluation of the mediastinum is limited by bones and air. To solve this problem, transoesophageal endoscopic