The Study On The Diagnostic Value Of ¹⁸F-FDG Metabolic Parameters Combined With MSCT For Solitary Ground-glass Lung Adenocarcinoma

Objective The MSCT signs and metabolic characteristics of ¹⁸F-FDG PET/CT in invasive lung adenocarcinoma?IAC?,preinvasive lesion?PL?and microinvasive adenocarcinoma?MIA?with ground glass components of pulmonary nodules were analyzed and compared to investigate the differential diagnosis value of MSCT and¹⁸F-FDG PET/CT in MIA and PL,MIA and IAC,IAC low risk-group and IAC high-risk group.Materials and Methods Retrospective analysis was performed on 197 patients with solitary pulmonary nodules containing ground glass components who underwent ¹⁸F-FDG PET/CT examination and underwent surgical resection including 20 cases of PL,34 cases of MIA and 143 cases of IAC.The largest diameter of nodules measured by CT images was all less than or equal to 30 mm.Among them,143 cases of IAC lung nodules according to the adenocarcinoma growth pattern is further divided into two groups.The lesions with only LPA and/or APA and/or PPA growth were assigned to the low-risk group,and the lesions with SPA and/or MPA were classified into the high-risk group.Comparative analysis was conducted in three groups:MIA and PL group,MIA and IAC group,IAC low-risk group and high-risk group.The record contents included gender,age,lesion location,size?average diameter?,density,maximum standard uptake value(SUV_max),mean standard uptake value(SUV_mean),retention index?RI?,maximum tumor uptake ratio?T/N?,based on the SUV_max tumor with a normal contralateral lung background the ratio of the rate of change(?T/N_max),lobulation sign,spiculation sign,vocule sign,air bronchgram,pleural indentation and vascular convergence sign?the internal and peripheral bronchovascular bundles of PL and MIA were included?.T test was used to investigate the difference of continuous data,and chi-square test was used to investigate the correlation of grouping imaging features.Multivariate Logistic regression analysis was used to test the correlation factors with statistical differences before treatment.ROC analysis was performed according to the Logistic regression analysis results,and Z test was used to compare the AUC results in pairs.P<0.05 was considered statistically significant.Results?1?The results were compared between MIA and PL groups:The differences of lesion density and vascular convergence sign between the two groups were statistically significant,and they were independent influencing factors to differentiate the two.When the density was-445.5 Hu,the area under the ROC curve was 0.701,and the sensitivity of the two was 52.9%,and the specificity was 85.0%.Gender,lesion location,lesion size,SUV_max,SUV_mean,T/N value,lobulation sign,spiculation sign,vocule sign,air bronchgram,pleural indentation,the number of lesions traversing the bronchovascular bundles,RI,delayed imaging SUV_max,delayed imaging T/N,?T/N_max had no statistical significance between the two groups.?2?The results were compared between MIA and IAC groups:There were statistically significant differences in the lesion size,SUV_max,SUV_mean,T/N,delayed imaging SUV_max,delayed imaging T/N,lobulation sign,vocule sign,air bronchgram,and pleural indentation between the two groups.Among them,T/N,vocule sign and air bronchgram were the independent influencing factors to differentiate the two.When the value of T/N was 1.410,the area under the ROC curve was 0.826,and the sensitivity and specificity of the two were 83.7%and 76.5%respectively.The combination of T/N,vocule sign and air bronchgram was the most effective.There was no significant difference in gender,lesion location,lesion density,spiculation sign,vascular convergence sign,RI,?T/N_max between the two groups.?3?Results of comparative analysis of IAC high-risk group and low-risk group:There were statistically significant differences in lesion size,SUV_max,SUV_mean,RI,delayed imaging SUV_max,delayed imaging SUV_mean,delayed imaging T/N,lobulation,and pleural indentation between the two groups.Among them,SUV_mean,size and pleural indentation were the independent influencing factors to differentiate the two.When the value of SUV_max was 1.625,the area under the ROC curve was 0.699.The sensitivity and specificity of differentiating the two were 56.5%and 78.7%respectively.When the value of SUV_mean was 0.845,the area under the ROC curve was 0.698.The sensitivity and specificity of differentiating the two were 82.6%and 44.0%respectively.When the average diameter was 13.765 mm,the area under the ROC curve was 0.716,and the sensitivity and specificity of differentiating the two were 82.6%and 45.3%respectively.The combined diagnosis of SUV_max,SUV_mean,lesion size,pleural indentation,and lobulation sign was effective in differentiating the two.Gender,lesion location,lesion density,T/N,spiculation sign,vocule sign,air bronchgram,vascular convergence sign,and?T/N_max had no statistical significance between the two groups.Conclusion?1?In the pulmonary nodules of MIA and PL,the density was greater than-445.5 Hu, and the changes in the peribronchial vascular bundle suggested that MIA was more likely.?2?In MIA and IAC nodules containing ground glass components,the value of T/N was greater than 1.410,combined with vocule sign and air bronchogram,are more supportive of IAC.?3?For IAC ground glass nodules,the value of SUV_max was greater than 1.625,the value of SUV_mean was greater than 0.845,combined with the average diameter of the lesion was greater than 13.765 mm,and the lobulation sign and the pleural indentation were helpful to suggest the IAC high-risk group.