Relationship between primary lesion FDG uptake and clinical stage in different histologic subtypes of lung cancer

Despite the major advances in prevention and treatment of lung cancer, it is still the leading cause of cancer related death throughout the world. Current staging systems not only guide the steps of treatment but also provide information about the prognosis. Positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) is a powerful diagnostic tool used in staging of lung cancer.The aim of the study is to investigate the relationship of FDG PET derived parameters like maximum standart uptake value (SUVmax), total lesion glycolysis (TLG) and biologic tumor volume (TV) with the clinical stage and different histological subtypes of lung cancer.The study included the patients diagnosed as lung cancer and referred to the Nuclear Medicine Department of Gazi University for primary staging purposes.PET/CT scans and pathology reports of 168 patients were assessed. Significant differences between the diameter, SUVmax, TLG and TV were observed between different T stages and stage groups in NSCLC patients and also in adenocarcinoma (AC) patients. In patients with squamous lung cancer (SCC) significant differences between the diameter, TLG and TV in different T stages were found.Primary lesion SUVmax correlated significantly with tumor diameter and metastatic lesion SUVmax.In conclusion, metabolic parameters obtained in FDG PET scan significantly differ in T stages and stage groups in NSCLC patients especially for adenocarcinomas. Primary lesion SUVmax correlates with tumor diameter and metastatic lesions metabolic activity in lung cancer patients.Key words: Lung cancer, FDG PET, SUVmax