18F-fluorodeoxyglucose positron emission tomography is correlated with the pathological necrosis and decreased microvessel density in lung adenocarcinomas

ObjectiveWe explored the relationship between preoperative F-18-FDG-PET parameters, tumor necrosis, and microvessel density (MVD) in patients with pulmonary adenocarcinomas.MethodsA total of 164 patients, who underwent surgical resection for lung adenocarcinoma, were reviewed retrospectively. The maximum standardized uptake value (SUVmax), peak SUV corrected for lean body mass (SULpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) values were measured by preoperative F-18-FDG-PET. The extent of tumor necrosis was examined and CD31 expression was evaluated to count the MVD.ResultsThe SUVmax, SULpeak, MTV, and TLG levels were significantly lower in patients exhibiting no necrosis compared to those with necrosis. When we divided the patients into two groups based on high vs. low PET parameter values, elevated SUVmax, SULpeak, MTV, and TLG values were significantly more associated with partial or diffuse necrosis than were lower values (p<0.001). A negative correlation was evident between the MVD and SUVmax, MVD and SULpeak, MVD and MTV, and MVD and TLG. Tumor necrosis was correlated with a shorter overall survival (OS) (p=0.007) and recur-free survival (RFS) (p<0.001). However, multivariate analysis revealed that necrosis was not of prognostic significance. The SUVmax, MTV and TLG were associated with inferior OS or RFS rates in univariate analysis, however, not in multivariate analysis.ConclusionHigh-level FDG accumulation is correlated with tumor necrosis in lung adenocarcinoma.