- Patients with a tracheo-oesophageal fistula or direct invasion of the tracheal mucosa or a major bronchi are not eligible. Bronchoscopy (with biopsy and cytology if lesion is seen) is required in order to rule out a fistula and/or direct invasion if the primary tumour is < than 30 cm from the incisors. Bronchoscopy is also required when the primary tumour is shown to be at or above the carina by an imaging study.