PET scan in the staging of non-small cell lung cancer

Imaging techniques play an essential role in the diagnosis, staging, and follow-up of patients with lung cancer. Positron emission tomography (PET) has become an important innovation in lung cancer imaging. In this report, a comprehensive overview is given of the important number of prospective performance studies, looking at the value of PET in locoregional and distant staging of NSCLC, and at its potential impact on patient management. In the assessment of locoregional lymph node spread, PET has a high negative predictive value in the exclusion of N2 or N3 disease, so that mediastinoscopy can be omitted in most patients with negative mediastinal PET-images. False negative mediastinat PET findings may occur in patients with minimal N2 disease. Because of possible false positive findings in patients with inflammatory nodes or granulomatous disorders, confirmation and lymph node mapping by mediastinoscopy remains mandatory in these situations. In the extrathoracic staging, PET is a useful adjunct to conventional imaging, because it is able to detect unexpected metastatic lesions. An isolated positive finding that determines the possibility for radical treatment requires pathological verification, because of the possibility of a false positive result. PET is also able to exclude malignancy in equivocal lesions, but caution is needed in case of small lesions. There are currently insufficient data to state that PET could replace standard imaging. The use of PET as described in the performance studies, now undergoes further validation in large-scale randomised patient outcome studies. In the meanwhile, a current recommendation for the use of PET in contemporary lung cancer staging is provided. (C) 2003 Elsevier Ireland Ltd. All rights reserved.