Background: Several studies have already addressed the potential role of an increased fluorine 18 fluorodeoxyglucose (18F FDG) uptake in identification of pleural malignancy. In this pilot study, we investigate the role of 18F-FDG positron emission tomography/computed tomography (PET/CT) for differentiating asbestos-related benign pleural disease from malignant mesothelioma.
Materials and methods: The study population comprised 31 consecutive patients (17 malignant mesotheliomas, nine benign asbestos pleurisies, and five diffuse pleural fibrosis) with a mean age of 61 years between January 2006 and December 2008. Thoracoscopy or image-guided pleural needle biopsy were systematically performed to reveal pathologic diagnosis and/or clinical follow-up for at least 3 years for presence or absence of malignant pleural effusion. ROCs analyses for standardized uptake value (SUV) adjusted to body weight were calculated between benign and malignant pleural diseases.
Results: 18F-FDG PET/CT imaging correctly detected the presence of malignancies in 15 of 17 patients with malignant mesothelioma for sensitivity, specificity, and overall accuracy of 88.2%, 92.9%, and 90.3%, respectively. 18F-FDG PET/CT imaging correctly identified 13 of 14 cases of benign pleural disease. The mean SUV values were 6.5 +/- 3.4 for malignant mesothelioma cases and 0.8 +/- 0.6 for benign pleural diseases (p < 0.001). When we compared the two groups of pleural disease, a cut-off value of 2.2 for SUV gave the best accuracy with 94.1%, 100%, 100%, and 93.3% for sensitivity, specificity, positive predictive value, and negative predictive value, respectively.
Conclusion: Preliminary results of this trial provide evidence that 18F-FDG PET/CT imaging is a highly accurate and reliable noninvasive test to decide for further investigation of differentiating malignant mesothelioma from benign pleural disease.