Prognostic Value of the Quantitative Metabolic Volumetric Measurement on 18F-FDG PET/CT in Stage IV Nonsurgical Small-cell Lung Cancer

Rationale and Objectives: Stage IV non-small-cell lung cancer (NSCLC) consists of a heterogeneous group of patients with different prognoses. We assessed the prognostic value of baseline whole body tumor burden as measured by metabolic tumor volume (MTV), total mean, lesion glycolysis (TLG), and standardized uptake values (SUVmax and SUVmean) of all tumors in nonsurgical patients with Stage IV NSCLC. Materials and Methods: Ninety-two consecutive patients with newly diagnosed Stage IV NSCLC who had a pretreatment F-18 fludeoxyglucose positron emission tomography/computed tomography scan were retrospectively reviewed. The MN, TLG, SUVmean and SUVmax of whole-body (WB) tumors were measured with the MIMvista workstation with manual adjustment. Results: There was a statistically significant association between overall survival (OS) and In(MTV)/In(TLG) at the level of WB tumor burden (MTVWB) and of primary tumor (MTVT). The hazard ratio (HR) for a 1-unit increase of In(MTVWB) and In(MTVT) before and after adjusting for age and gender was 1.48/1.48 (both P < .001) and 1.25/1.25 (P = .006, .007), respectively. The HR for a 1-unit increase of In(TLG(WB)) and In(TLG(T)) before and after adjusting for age and gender was 1.37/1.37 (both P = .001) and 1.19/1.19 (P = .001,.017), respectively. There was no statistically significant association between OS and In(SUVmax) and In(SUVmean) at WB tumor burden, primary tumor, nodal metastasis, or distant metastasis (P > .05). There was low interobserver variability beween two two radiologists with concordance correlation coefficients of 0.90 for In(MTVWB) and greater than 0.90 for SUVmaxWB SUVmeanWB, and In(TLG(WB)) Conclusion: Baseline WB metabolic tumor burden, as measured with MN and TLG, is a prognostic measurement in patients within Stage IV NSCLC with low interobserver variability. This study also suggests pretreatment MN and TLG measurements may be used to further stratify patients with Stage IV NSCLC and are better prognostic measures than SUVmax and SUVmean measurements.