PET-CT in mediastinal staging of non-small cell lung cancer: analysis of false results.

Purpose: To analyse the risk and factors associated with false-negative (FN) and false-positive (FP) positron emission tomography-computed tomography (PET-CT) results in the mediastinal staging of non-small cell lung cancer.

Material and methods: This retrospective cohort study analysed data from a prospective database. It included patients with lung cancer who underwent preoperative staging with PET-CT, endobronchial ultrasound, and endoscopic ultrasound, followed by curative-intent anatomical lung resection with systematic lymph node dissection. Statistical analyses were performed to identify factors associated with FN and FP PET-CT results.

Results: Data from 781 patients were analysed. FN results were significantly associated with more advanced PET-CT-based stages and CT-based stage IIB. FP results were significantly associated with male sex, adenocarcinoma histology, CT-based disease stage, and SUV_max values of the primary tumour and lymph nodes.

Conclusions: False-negative PET-CT results in the diagnosis of mediastinal lymph node involvement were more likely to occur in PET-CT-based stages IB and IIB and less likely to occur in stage IIIA. FP results were more likely to be expected in men, with higher SUV_max values of the primary tumour and a more advanced CT-based stage of the disease.