Potential Impact of Atelectasis and Primary Tumor Glycolysis on F-18 FDG PET/CT on Survival in Lung Cancer Patients

Background: Atelectasis is an important prognostic factor that can cause pleuritic chest pain, coughing ordyspnea, and even may be a cause of death. In this study, we aimed to investigate the potential impact of atelectasisand PET parameters on survival and the relation between atelectasis and PET parameters. Materials and
Methods: The study consisted of patients with lung cancer with or without atelectasis who underwent 18F-FDGPET/CT examination before receiving any treatment. 18F-FDG PET/CT derived parameters including tumorsize, SUVmax, SUVmean, MTV, total lesion glycosis (TLG), SUV mean of atelectasis area, atelectasis volume,and histological and TNM stage were considered as potential prognostic factors for overall survival.
Results:Fifty consecutive lung cancer patients (22 patients with atelectasis and 28 patients without atelectasis, medianage of 65 years) were evaluated in the present study. There was no relationship between tumor size and presenceor absence of atelectasis, nor between presence/absence of atelectasis and TLG of primary tumors. The overallone-year survival rate was 83% and median survival was 20 months (n=22) in the presence of atelectasis; theoverall one-year survival rate was 65.7% (n=28) and median survival was 16 months (p=0.138) in the absenceof atelectasis. With respect to PFS; the one-year survival rate of AT+ patients was 81.8% and median survivalwas 19 months; the one-year survival rate of AT- patients was 64.3% and median survival was 16 months(p=0.159). According to univariate analysis, MTV, TLG and tumor size were significant risk factors for PFS andOS (p<0.05). However, SUVmax was not a significant factor for PFS and OS (p>0.05).
Conclusions: The presentstudy suggested that total lesion glycolysis and metabolic tumor volume were important predictors of survivalin lung cancer patients, in contrast to SUVmax. In addition, having a segmental lung atelectasis seems not to bea significant factor on survival.