Comparison of Diagnostic Performance of Preoperative PET-CT for Patients with and without Neoadjuvant Therapy in Non-Small Cell Lung Cancer: Does Induction Therapy Affect the Preoperative PET-CT Results?

PET-CT has been widely used for restaging after induction therapy in patients with non-small cell lung carcinoma. We aimed to as- sess the role of preoperative PET-CT in patients receiving induction therapy and compare with those without induction therapy. Pa- tients treated with surgery for non-small cell lung carcinoma were included. There were two subgroups according to the presence of preoperative induction therapy. The results of preoperative PET-CT in these two groups were compared. There were 217 pati- ents, 58 in neoadjuvant group and 159 in control (without preoperative induction therapy) group. In N2 lymph nodes, the positive predictive value (PPV) was significantly higher in the neoadjuvant group than in the control group (p=0.01), where the negative pre- dictive value (NPV) (p=0.0001) and accuracy (p=0.03) were significantly lower. In aorticopulmonary lymph nodes, the NPV was sig- nificantly higher in the control group (p=0.002). In lower N2 lymph nodes, the PPV was higher (p=0.007) and the NPV was lower (p=0.003) in the neoadjuvant group. In N1 lymph nodes, the specificity was found to be lower in the neoadjuvant group (p=0.01). The sensitivity, PPV and accuracy for mass was lower in the neoadjuvant group (p=0.002, p=0.0003, and p=0.001, respectively). The negative predictive value and accuracy of PET-CT were slightly decreased in patients with non-small cell lung carcinoma rece- ived induction therapy before surgical resection. PET-CT appears to be beneficial for the assessment of patients those are planned to be treated surgically for lung cancer whether they have received induction therapy or not.