Study Of The Effective Factors And The Prognostic Value Of Primary Lesion Metabolic Tumor Volume Measured By¹⁸F-FDG PET/CT In Patients With NSCLC

Objective： To study the correlative factors of the primary lesion metabolic tumorvolume（MTV） on¹⁸F-FDG PET/CT in non-small cell lung cancer（NSCLC）priortreatment and observe the relationship between the primary lesion MTV of NSCLC andlymph node metastasis and/or distant metastasis.Meterials and Methods：Ninety-two patients with adenocarcinoma（AD） andforty-six patients with squamous cell carcinoma （SCC） in lung underwent¹⁸F-FDGwhole body PET/CT scans before treatment were reviewed from June2012toSeptember2013. All patients were confirmed by pathology. To measure the maximumstandardized uptake value（SUVmax）, metabolic tumor volume（MTV）, the lesion size,lesion density and other factors of the primary lesion, respectively; the metastatic stateswere confirmed by the pathology or the other imaging modality or following up. Thedifference between the two pathological types of AD group and SCC group wasanalyzed, The relationship between the primary lesion MTV and differentiation degree,age, lesion size, lesion density and T stages were evaluated in overall patients group,AD group and SCC group,respectively, statistical analysis was performed by one-wayANOVA, Pearson correlation and Spearman rank correlation; All patients were dividedinto four groups （AD without metastasis group, AD with metastasis group, SCC withoutmetastasis group, SCC with metastasis group）, the difference in the primary lesion size,SUVmax, MTV, T stages in the four groups were analyzed respectively, using one-wayANOVA; The relationship of pathological types, lesion size, SUVmax, MTV and Tstages of the primary lesion to metastasis were analyzed contrastly by Binary Logisticregression to correct interferential factors. The optimal threshold value and thediagnosis efficacy of AD group and SCC group were analyzed respectively by ReceiverOperating Characteristic Curve（ROC）analysis. Results：1. The primary lesion MTV is significantly different between AD group and SCCgroup （F=28.39, P<0.001）, the primary lesion MTV in SCC group X±s （36.47±33.49cm3） was significantly higher than that in AD group X±s（11.02±22.16cm3）.2. The primary lesion MTV was positively related with lesion size and Tstage（r=0.785,0.577in overall patients group,0.723,0.439in AD group,0.791,0.509in SCC group, P <0.01）, but no relationships were observed to age and the primarylesion density（r=-0.010、0.232in overall patients group，r=0.050、0.200in AD group,r=-0.149、0.246in SCC group, pï¹¥0.05）in overall patients group, AD group and SCCgroup. The primary lesion MTV was negatively related with differentiation degree bothin the overall patients group and AD group （r=-0.631in overall patients group,-0.751inAD, P <0.01） but there was no relationship in SCC group （r=-0.351, P <0.01）3. In the univariate analysis, the primary lesion size, SUVmax, MTV and T stagewere different in the four groups （AD without metastasis group, AD with metastasisgroup, SCC without metastasis group, SCC with metastasis group, F=15.439,15.348,11.745,13.267, respectively, P<0.001）.4. Only the primary lesion MTV was related with metastasis, and be incorporatedinto the regression equation in multivariate Logistic regression analysis （OR=1.096,P=0.000）.5. The area under the ROC curve that the primary lesion MTV prognoses lymphnode metastasis and/or distant metastasis was0.877in AD group,0.850in SCC group（P=0.000）.When Cutoff value was2.49cm3in AD group,¹⁸.49cm3in SCC group,sensitivity and specificity were89.1%（41/46）,78.3%（36/46）and81.3%（26/32）,78.6%（11/14） respectively.Conclusion：1. The primary lesion MTV of NSCLC patient in¹⁸F-FDG PET/CT maybeinfluenced by the lesion size and T stage, the primary lesion MTV is positively relatedwith lesion size and T stage; but no relationship are found between the primary lesionMTV and the age or the lesion density of the primary lesion. pathological types maybehave significant effect on the primary lesion MTV, the primary lesion MTV in SCC issignificantly higher than that in AD; The differentiation degree maybe have effect onthe primary lesion MTV in AD, the lower differentiation degree with the higher MTV inAD.2. The primary lesion MTV of NSCLC on¹⁸F-FDG PET/CT is an independent prognosis factor. The higher primary lesion MTV value means the higher metastasispotentiality. Use more than2.49cm3in AD and more than¹⁸.49cm3in SCC to do theideal diagnostic threshold value, the sensitivity, specificity of the primary lesion MTVwere both correspondingly high, so that more positive treatment should be adapted.