New positron emission tomography derived parameters as predictive factors for recurrence in resected stage i non-small cell lung cancer

Background The recurrence rate for stage I non-small cell lung cancer is high, with 20-40% of patients that relapse after surgery. The aim of this study was to evaluate new F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) derived parameters, such as standardized uptake value index (SUV _index), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), as predictive factors for recurrence in resected stage I non-small cell lung cancer. Methods We retrospectively reviewed 99 resected stage I non-small cell lung cancer patients that were grouped by SUV_index, TLG and MTV above or below their median value. Disease free survival was evaluated as primary end point. Results The 5-year overall survival and the 5-year disease free survival rates were 62% and 73%, respectively. The median SUV _index, MTL and TLG were 2.73, 2.95 and 9.61, respectively. Patients with low SUV_index, MTV and TLG were more likely to have smaller tumors (p ≤ 0.001). Univariate analysis demonstrated that SUV_index (p = 0.027), MTV (p = 0.014) and TLG (p = 0.006) were significantly related to recurrence showing a better predictive performance than SUV_max (p = 0.031). The 5-year disease free survival rates in patients with low and high SUV_index, MTV and TLG were 84% and 59%, 86% and 62% and 88% and 60%, respectively. The multivariate analysis showed that only TLG was an independent prognostic factor (p = 0.014) with a hazard ratio of 4.782. Conclusion Of the three PET-derived parameters evaluated, TLG seems to be the most accurate in stratifying surgically treated stage I non-small cell lung cancer patients according to their risk of recurrence.