The treatment of patients with asbestos-related pleural disease is challenging. Pleural manifestations of asbestos exposure include calcifications, plaques, benign effusion, and diffuse thickening. Diffuse pleural thickening can represent either a benign or a malignant process. In addition, many infectious disorders such as tuberculosis or empyema can cause fibrothorax, which cannot be easily differentiated from pleural malignancies. Cross-sectional imaging methods, such as CT or MRI, are helpful in identifying the location and extent of the involved areas. However, these modalities are frequently unable to discriminate between malignant disease and benign processes. Using morphologic criteria, the sensitivity and specificity of CT to predict the malignant nature of diffuse pleural lesions are 72% and 83%, respectively. Canadian health & care mall cialis professional 20 mg With MRI, low signal intensity on long repetition time images is associated with benign disease; sensitivity and specificity figures of 100% and 87%, respectively, have been reported with this technique to identify malignant disease. Radionuclide imaging with Gallium citrate has also been used for this purpose, with a sensitivity of 86% and a specificity of 81%. However, the resolution of imaging with gallium is poor, in the range of 1.5 to 2.0 cm, making it suboptimal for staging lymph node involvement and for the characterization of small pleural lesions. Because of these limitations, gallium scanning has not been accepted for routine evaluation of mesothelioma.
Positron emission tomography (PET) utilizing fluorodeoxyglucose (FDG) is a powerful diagnostic tool for the diagnosis and treatment of patients with cancer. FDG-PET has a proven utility in discriminating benign from malignant lung nodules. Similarly, FDG-PET could potentially differentiate benign from malignant pleural lesions, stage the extent of disease involvement, and help in the selection of biopsy sites by identifying the most metabolically active lesions.