ABSTRACT
Objective The aims were to investigate the value of 18F-fluorodeoxyglucose (FDG) PET/CT in the diagnosis of bronehioloalveolar carcinoma (BAC) and its metabolic and anatomic features in differentiating from non-BAC adenocareinoma (non-BAC AC ). Methods This was a retrospective 18F-FDG PET/CT study on a consecutive series of 87 patients (32 BAC, 55 non-BAC AC) with 110 pathology-proven lesions. The maximum standardized uptake value ( SUVmax) was calculated for all lesions. Tumor's location, morphology and margins, internal structures were analyzed on CT. Statistical analysis compared the mean SUVmax between the two groups, analysed the relationship between tumor subtype and features on CT and compared the diagnostie aeeuraeies with PET alone, CT alone and PET/CT. The t-test, McNemar test, Fisher exact test were used to analyze the data using SPSS 12.0. Results Significant differences were found between mean SUVmax in a total of 47 lesions with BAC and 63 lesions with non-BAC AC (1.51±0.17 vs 6.28± 3.04, t=-10.374, P <0.0001 ). Pure ground glass density, which was foued in BAC, was the most significant CT feature in distinguishing tumor types ( Fisher exact test, P<0.0001 ). Diagnos-tic accuracies were 88% (28/32) with PET/CT, 47% (15/32) with PET and 66% (21/32) with CT. Differences in aeeuraeies between PET and PET/CT and between CT and PET/CT were statistically signifi-cant (P= 0.001,0.039 ). Conclusions Diagnostie accuracy can be higher by understanding the function-al eharaeteristies on PET and anatomical features on CT. The presence of persistent ground glass in a lesion on CT is a significant feature for BAC and should raise the suspicion of this tumor type even in cases of low 18F-FDG activity.