Abstract:

Objective: 18-Fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) is one of the most valuable imaging types and tumor metabolic volume is another parameter that can be obtained from PET-CT. Our primary objective is to evaluate the effect of PET-CT metabolic parameters on survival in patients with malignant pleural mesothelioma (MPM). Methods: A total of 29 patients with MPM had been evaluated with 18F-FDG PET-CT between January 2016 and December 2017. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized uptake values (SUVmax) and TLG/liver SUVmean values were calculated. Also, effects of these parameters on survival rates were evaluated. Results: Histological subtypes of the disease were determined as epithelioid (n=24), biphasic (n=3), sarcomatoid (n=2). Median overall survival was 255 days (21-903). Median MTV was 225 cm³ (10-1879), median TLG was 1056 g/ml*cm³ (36-18927), median SUVmax was 7.7 (1.5-20) and TLG/liver SUVmean ratio was 561.2 (14.9-8113.7). Sensitivity and specificity for MTV 113 cut-off value were 86.4% and 85.7%, respectively. Determined cut-off value for TLG was 419.5, sensitivity and specificity of the value were 81.8% and 85.7%, respectively. Additionally, determined cut-off value for TLG/liver SUVmean ratio was 107.4, the rate of sensitivity and specificity for this value were 95.5% and 71.4%, respectively. The patients with higher MTV, TLG and TLG/liver SUVmean had worse survival rate. Conclusion: We confirmed significant association between MTV, TLG and TLG/liver SUVmean values and patients survival. These promising PET derived parameters can be used for evaluating treatment response and prognosis in MPM.

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