*Article* **Potential of FDG-PET as Prognostic Significance after anti-PD-1 Antibody against Patients with Previously Treated Non-Small Cell Lung Cancer**

**Kosuke Hashimoto 1, Kyoichi Kaira 1,\*, Ou Yamaguchi 1, Atsuto Mouri 1, Ayako Shiono 1, Yu Miura 1, Yoshitake Murayama 1, Kunihiko Kobayashi 1, Hiroshi Kagamu <sup>1</sup> and Ichiei Kuji <sup>2</sup>**


Received: 15 February 2020; Accepted: 4 March 2020; Published: 7 March 2020

**Abstract:** It remains unclear whether the accumulation of 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) before the initiation of anti-programmed death-1 (PD-1) antibody can predict the outcome after its treatment. The aim of this study is to retrospectively examine the prognostic significance of 18F-FDG uptake as a predictive marker of anti-PD-1 antibody. Eighty-five patients with previously treated non-small cell lung cancer (NSCLC) who underwent 18F-FDG-positron emission tomography (PET) just before administration of nivolumab or pembrolizumab monotherapy were eligible in our study, and metabolic tumor volume (MTV), total lesion glycolysis (TLG) and the maximum of standardized under value (SUVmax) on 18F-FDG uptake were assessed. Objective response rate, median progression-free survival and median overall survival were 36.6%, 161 days and 716 days, respectively. The frequency of any immune-related adverse events was significantly higher in patients with low 18F-FDG uptake on PET than in those with high uptake. By multivariate analysis, the tumor metabolic activity by TLG and MTV was identified as an independent prognostic factor for predicting outcome after anti-PD-1 antibody therapy, but not SUVmax, predominantly in patients with adenocarcinoma. Metabolic tumor indices as TLG and MTV on 18F-FDG uptake could predict the prognosis after anti-PD-1 antibodies in patients with previously treated NSCLC.

**Keywords:** FDG-PET; immune checkpoint inhibitor; PD-1; lung cancer; prognosis
