Prognostic importance of 18F-fluorodeoxyglucose uptake by positron emission tomography for stage III non-small cell lung cancer treated with definitive chemoradiotherapy. / Importancia pronóstica de la captación de 18F-Fluorodeoxiglucosa mediante tomografía de emisión de positrones para el cáncer de pulmón de células no pequeñas en estadio III tratado con quimio-radioterapia definitiva.

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 (SUVmax) 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 18F-FDG PET/CT at the time of diagnosis were included in the study. RESULTS: Higher tumor stages were correlated with higher pre-treatment SUVmax of lymph nodes (LNs) (p=0.005) but were not correlated with higher SUVmax of primary tumor (p=0.2). The median SUVmax 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 SUVmax of LNs (p=0.01). According to ROC analysis, there was no significant cut-off value of SUVmax observed for primary tumor, therefore continuous variables were used for survival analyses. The best SUVmax cut-off was 3.5 for the LNs, therefore the SUVmax of LNs was evaluated as both a dichotomous and a continuous variable. Pre-treatment SUVmax of primary tumor did not predict survival outcomes but both the continuous and dichotomous variables of SUVmax of LNs predicted recurrence free survival and overall survival. Nodal stage (N0-2 vs. N3) and AJCC stage (IIIa vs IIIb vs. IIIc) were the other prognostic factors. CONCLUSIONS: Pre-treatment SUVmax of LNs had prognostic value in patients treated with definitive concurrent chemoradiotherapy for stage III NSCLC. In future trials, pre-treatment SUVmax of the LNs would serve as a guide for patients who might benefit from more aggressive treatments.