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.

BACKGROUND: Over the past 30-40 years, various carbon implant materials have become more interesting, because they are well accepted by the biological environment. The traditional carbon-based polymers give rise to many complications. The polymer complication may be eliminated through carbon fibres bound by pyrocarbon (carbon/carbon). The aim of this study is to present the long-term clinical results of carbon/carbon implants, and the results of the scanning electron microscope and energy dispersive spectrometer investigation of an implant retrieved from the human body after 8 years. METHODS: Mandibular reconstruction (8-10 years ago) was performed with pure (99.99 %) carbon implants in 16 patients (10 malignant tumours, 4 large cystic lesions and 2 augmentative processes). The long-term effect of the human body on the carbon/carbon implant was investigated by comparing the structure, the surface morphology and the composition of an implant retrieved after 8 years to a sterilized, but not implanted one. RESULTS: Of the 16 patients, the implants had to be removed earlier in 5 patients because of the defect that arose on the oral mucosa above the carbon plates. During the long-term follow-up, plate fracture, loosening of the screws, infection or inflammations around the carbon/carbon implants were not observed. The thickness of the carbon fibres constituting the implants did not change during the 8-year period, the surface of the implant retrieved was covered with a thin surface layer not present on the unimplanted implant. The composition of this layer is identical to the composition of the underlying carbon fibres. Residual soft tissue penetrating the bulk material between the carbon fibre bunches was found on the retrieved implant indicating the importance of the surface morphology in tissue growth and adhering implants. CONCLUSIONS: The surface morphology and the structure were not changed after 8 years. The two main components of the implant retrieved from the human body are still carbon and oxygen, but the amount of oxygen is 3-4 times higher than on the surface of the reference implant, which can be attributed to the oxidative effect of the human body, consequently in the integration and biocompatibility of the implant. The clinical conclusion is that if the soft part cover is appropriate, the carbon implants are cosmetically and functionally more suitable than titanium plates.
Carbon ; Follow-Up Studies ; Human Body ; Humans ; Inflammation ; Mandible ; Mandibular Reconstruction ; Mouth Mucosa ; Oxygen ; Polymers ; Titanium