Positron emission tomography - Computed tomography for staging of mediastinal lymph nodes in patients with non-small cell lung cancer.

BACKGROUND: The tumor involvement of lymph nodes (LN) in N2 station is a very important factor for the further therapy decision and the prognosis of lung cancer patients. Today, integrated positron emission tomography-computed tomography (PET-CT) is considered to be the new standard in the staging of bronchial carcinoma. The aim of this study is to investigate the correctness of the clinical staging of the mediastinal LNs in operated patients and to investigate the sensitivity and specificity of the PET-CT examination for mediastinal LNs.

SUBJECTS AND METHODS: In the years 2010-2014, 359 patients underwent surgery for bronchial carcinoma. The histological examination of all mediastinal and hilar LNs was used as a reference to the data from the PET-CT examinations. The correctness of the PET staging, overestimation, and underestimation for the N stage was analyzed. In addition, the "sensitivity," "specificity," and "overall accuracy" of the PET-CT examination with regard to the N2 LNs were calculated.

RESULTS: It was found that in 8.9% the staging of the mediastinal N2/N3 LN stations was rated too high by the PET and in 11.2% too low. The study showed a sensitivity of 47.37%, a specificity of 90.07%, and an accuracy of 81.01% for the mediastinal LNs.

CONCLUSION: Our study confirms the limited ability of integrated PET-CT in staging the mediastinal LNs. We, therefore, recommend a histological examination of the LNs in patients with PET-positive N2 LNs to avoid false-positive results and to initiate correct therapy.