• Lung cancer
• non-small cell lung cancer
• small cell lung cancer
• COPD mechanisms
• asthma
• asthma mechanisms
• COPD exacerbations
• cough/mechanisms/pharmacology

We thank Drs Paredes and Mehta for their comments on our work on positron emission tomography (PET)–CT in the staging of lung cancer.1 As correctly pointed out by Drs Paredes and Mehta, there is a discrepancy in the number of patients undergoing endoscopic ultrasonography (EUS) in the two reports from our institution.2 3 Although both reports concern the staging of patients with non-small cell lung cancer, they address different aspects of the disease. The paper published in the New England Journal of Medicine2 was an intention-to-treat analysis with PET–CT as the only intervention and with the number of futile thoracotomies as the final end point. We have meticulously tried to assemble and report complete and accurate data on all included patients in both papers. Unfortunately, this was done twice, giving rise to a minor discrepancy in the number of patients undergoing PET–CT and EUS reported in the two studies. When performing the analysis previously published in Thorax,3 we focused on information regarding the specific N-stage of each patient. In order to confirm the N-status of each patient, we compared the initial database2 with (A) the database from a study on EUS performed in parallel with the study on PET–CT (as mentioned in both our previous reports) and (B) the nationwide pathology register. By doing this, we found an additional five patients in each group who had undergone an EUS examination. In four and five patients, respectively, of the additional five patients found in each of the two groups, a fine-needle aspiration (FNA) was done during the same procedure. There was still no significant difference in the frequency of either EUS or EUS–FNA between the two groups and it had no impact on the reported results. Our findings confirm that PET–CT is an important part of preoperative staging of patients with non-small cell lung cancer, but it also underscores, as stated by Drs Paredes and Mehta and in the Discussion section of our paper, the need for a complimentary well-considered use of invasive mediastinal staging. Finally, we would be happy to welcome both Drs Paredes and Mehta to our department for a discussion of our data.