Evaluation of outcome prediction and disease extension by quantitative 2-deoxy-2-[18F] fluoro-d-glucose with positron emission tomography in patients with small cell lung cancer

The objective of this study is to determine whether 2-deoxy-2-[18F] fluoro-d-glucose with positron emission tomography (FDG-PET) imaging and quantitative PET parameters can predict outcome and differentiate patients with limited disease (LD) from extensive disease (ED) in patients with small cell lung cancer (SCLC). We retrospectively evaluated data from 25 patients who underwent either initial staging (Group A, n 12) or restaging (Group B, n 13) by conventional imaging methods and FDG-PET according to the simplified staging scheme developed by the Veterans Administration Lung Cancer Study Group-2. FDG-PET images were both visually and quantitatively evaluated with SUVmax, SUVave, total metabolic tumor volume (with SUVmax > %50 and SUVmax > 2.5), total lesion glycolysis (TLG) (with SUVmax > %50 and SUVmax > 2.5). The correlation between quantitative PET parameters, disease stages and survival were analyzed. By conventional methods 14 of 25 (56%) patients were reported to have LD and 11 of 25 (44%) had ED. FDG-PET scan upstaged 9 out of 25 (36%) and downstaged 2 out of 25 (%8) patients. Among the quantitative PET parameters, TLGs were the only PET parameters that differentiated between Group A and Group B patients. FDG-PET staging (p = 0.019) could predict significant survival difference between stages on contrary to conventional staging (p = 0.055). Moreover, TLG [SUVmax > %50] was the only quantitative PET parameter that could predict survival (p = 0.027). FDG-PET imaging is a valuable tool in the management of patients with SCLC for a more accurate staging. The use of quantitative PET parameters may have a role in prediction of stage and survival.