A comparison of endoscopic ultrasound guided biopsy and positron emission tomography with integrated computed tomography in lung cancer staging

Background and study aims: Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who had both procedures performed.

Patients and methods: 27 patients considered to be potential candidates for resection of NSCLC underwent PET/CT and EUS-FNA. Diagnoses were confirmed either by open thoracotomy, mediastinoscopy or clinical follow-up. Advanced lung cancer was defined as tumour-stage ≥ IIIA(N2), corresponding to T4- and/or N2-N3- and/or M1 disease. Diagnostic values of PET/CT and EUS-FNA, with regard to the diagnosis of advanced lung cancer, were assessed and compared.

Results: The sensitivity of PET/CT and EUS-FNA were respectively 60% and 60% for T4 disease, 56% versus 100% for N2-N3 disease (p=0.12) and 100% versus 33% for M1 disease (p=0.50). For diagnosing advanced lung cancer PET/CT had a sensitivity of 79%, specificity of 61%, positive predictive value (PPV) of 69%, negative predictive value (NPV) of 73%, and an accuracy of 70%. EUS-FNA had a sensitivity of 79%, specificity of 100%, PPV of 100%, NPV of 81%, and an accuracy of 89% for advanced lung cancer.

Conclusions: PET/CT and EUS-FNA had a comparable sensitivity and NPV for diagnosing advanced lung cancer, but EUS-FNA had superior specificity and PPV. The two methods seem to complement each other.