Role of Positron Emission Tomography in Staging Lymph Nodes in Non-small Cell Lung Cancer

Objective: Lung cancer is in the cancer group with high mortality, and early diagnosis and accurate staging prolongs survival. Positron emission tomography (PET) is routinely in use for staging of non-small cell lung cancer. Since there were still controversies, we aimed to investigate the reliability of PET especially in mediastinal lymph node (MLN) staging. Methods: A total of 141 surgical procedures were performed on 133 patients with non-small cell lung cancer clinically suitable for surgery. With PET, lymph nodes having a standart uptake value-SUVmax >2.5 were noted. With the results, the stations reached by mediastinal examination in 25 patients and direct thoracotomy in 8 patients were sampled. With the results, a total of 123 patients underwent resection, and 13 patients were referred to oncology clinics. In staging of MLN, tomography and PET were compared in terms of sensitivity and specificity, and also the relationship of PET with type, localization and size of tumor was investigated. Results: For mediastinal staging, sensitivity of PET in squamous cell lung cancer was 100%, while specificity 88%, positive predictivity 50%, negative predictivity 100%, and accuracy 89.5%. Hilar, intrapulmonary and mediastinal lymph nodes were analyzed and the same parameters were 64.5%, 80%, 80%, 64.5% and 74.4%, respectively. PET-SUVmax values were found to be statistically significantly associated with tumor size, central location, epidermoid histology and especially lymph node 7. The accuracy of PET in evaluating this lymph node station seemed to be higher. Conclusion: PET gives statistically significant results when we evaluate the MLN stations one by one. In addition, PET results should be confirmed, especially in the centrally located adenocarcinoma subgroup. If PET can provide more reliable results in staging with advancing technology in medicine, it will perhaps take its place as the gold standard in lung cancer as a non-invasive technique.