The F-18 FDG PET/CT and CT evaluation of pleural plaques.

Introduction: Pleural plaques have the possibility of bearing malignancy thus investigation of this entity is important and the most important indicator of malignancy in general is fluorodeoxyglucose (FDG) accumulation in radiological appearance. However there is discrepancy between results of previous studies in the literature about this subject. The aim of this study is to analyze the standardized uptake value of pleural plaques and the cut off levels for malignancy in comparison with computed tomography (CT).

Materials And Methods: Seventy one patients were included in the study (27F, 44M; mean: 59.9 ± 13.1 years). Oncologic F-18 FDG positron emission tomography/computed tomography (PET/CT) was performed to all the subjects for a different primary tumor. Pleural plaques were identified in all patients in CT component of PET/CT examination. Contrast enhanced and nonenhanced CT images were evaluated by a Radiology Physician independently according to the gold standard pathology.

Result: The diagnostic sensitivity, specificity of CT was; 39%, 79% respectively and if the cut-off SUVmax level was accepted "4.8" the diagnostic sensitivity and specificity of PET was 71%, and 63% respectively.

Conclusions: According to the results and ROC curves determined in the study the cut-off level for evaluation of pleural plaques in PET examination was "4.8". The sensitivity and accuracy of PET was higher compared to CT with this cut-off value.