The comparison PET/CT findings with the known prognostic factors in lung cancer patients

Objective: Although advanced diagnostic and theraphautic development are achieved, lung cancer is the most leading cause of death in both gender around the world. The stage of tumor is still the most important factor in determining the prognosis of cancer. Since even at the same stage, survival rates are different, additional factors are needed for determining the prognosis. In this study, in order to determine the role of FDG-PET ([18F]-fluoro-2-deoxy-D-glucose Positron Emission Tomography) as a prognostic factor in lung cancer, the relationship between SUVmax (maximum Standardized Uptake Value) and histological, radiological, clinical findings of primary tumor was evaluated.Material and methods: The data of 97 lung cancer patients, pathologically diagnosed as stages I-IV either SCLC or NSCLC, admitted to the Department of Chest Diseases, School of Medicine, University of Çukurova between June 2006 and August 2009 were retrospectively analyzed.Results: The mean age of 8 (8.2 %) female and 89 (91.8 %) male patients was 57.3 years (range 32-81). Histological distribution of patients was as follows: 38 (39.2 %) adenocarcinoma, 33 (34 %) squamous carcinoma, 11 (11.3 %) SCLC, 15 (15.5 %) undetermined NSCLC. While 30 (30.9 %) patients were at stage I-IIIA, 67 (69.1 %) patients were at stage IIIB-IV. A weak positive correlation was observed between SUVmax and tumor size (r=0,255 p=0,012). SUVmax was signicantly higher in central tumors than peripheral tumors (p=0,047). According to the pulmonary function tests (PFT), SUVmax was significantly lower in patients with airway obstruction than in patients without airway obstruction (p=0,026). However no significant correlation was found between SUVmax and histological subtype, TNM stage, T, N, M categories, presence of atelectasis, radiological appearance of tumor, margin of tumor.Conclusion: In our study, no significant correlation was found between SUVmax with TNM stage and histological subtype in patients with lung cancer particularly at advanced stage. However a positive correlation was observed between SUVmax and tumor size. In our study, statistically significant correlation was observed between SUVmax and PFT findings, although no information about these findings in the English literature that we have searched was reached. Further prospective and multicentric studies with larger patients groups are needed to identify parameters effecting FDG uptake and the relation of SUV with prognosis in lung cancer.Key Words: Lung cancer, FDG PET, SUV, prognosis