Prognostic importance of 18F-fluorodeoxyglucose uptake by positron emission tomography for stage III non-small cell lung cancer treated with definitive chemoradiotherapy

Abstract Objectives Survival heterogeneity exists among patients with non-small cell lung cancer (NSCLC), even within the same stage. We aimed to evaluate the prognostic role of pre-treatment maximum standardized uptake value (SUV max ) in patients treated with definitive concurrent chemoradiotherapy for stage III NSCLC. Materials and methods Between 2010 and 2017, 103 patients with stage III NSCLC who underwent 18 F-FDG PET/CT at the time of diagnosis were included in the study. Results Higher tumor stages were correlated with higher pre-treatment SUV max of lymph nodes (LNs) ( p  = 0.005) but were not correlated with higher SUV max of primary tumor (PT) ( p  = 0.2). The median SUV max of LNs was 2.84, 8.06, and 11.11 in stage IIIa, IIIb and IIIc, respectively. Higher nodal stage was also correlated with higher SUV max of LNs ( p  = 0.01). According to ROC analysis, there was no significant cut-off value of SUV max observed for PT, therefore continuous variables were used for survival analyses. The best SUV max cut-off was ‘3.5’ for the LNs, therefore the SUV max of LNs was evaluated as both a dichotomous and a continuous variable. Pre-treatment SUV max of PT did not predict survival outcomes but both the continuous and dichotomous variables of SUV max of LNs predicted RFS and OS. Nodal stage (N0–2 vs N3) and AJCC stage (IIIa vs IIIb vs IIIc) were the other prognostic factors. Conclusions Pre-treatment SUV max of LNs had prognostic value in patients treated with definitive concurrent chemoradiotherapy for stage III NSCLC. In future trials, pre-treatment SUV max of the LNs would serve as a guide for patients who might benefit from more aggressive treatments.