FDG PET in the evaluation of malignant pleural mesothelioma

Abstract

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Objectives: The increasing incidence of malignant pleural mesothelioma (MPM) often caused by prior asbestos exposure has led to the development of new therapeutic approaches and a need for new diagnostic techniques to identify the extent of the disease at an early stage. FDG PET is being increasingly applied in the evaluation of chest tumors such as lung cancer. We have assessed the value of FDG PET in the evaluation of MPM.

Methods: Twenty-two patients with CT scan evidence of pleural thickening, or fluid, entered a study to evaluate the accuracy of FDG PET in diagnosing MPM. FDG PET imaging was performed at 1 hour post FDG injection. Image analysis was performed both with visual interpretation and using a semiquantitative method, standardized uptake values (SUV). The results of PET imaging were compared to histological data and/or clinical follow-up.

Results: Histology demonstrated the presence of MPM in 12 patients and histology amd/or clinical follow-up demonstrated benign processes in the remaining 10. Two patients had MPM in bilateral sides. PET assessment demonstrated significant FDG uptake in 13 of the 14 lesions with MPM. A false-negative result was observed in a patient with CT scan evidence of pleural fluid only. A benign pleural disease without significant uptake was correctly diagnosed in 9 patients. The uptake of FDG was significantly higher in malignant than in benign lesions (SUV=6.9±4.0 and SUV=1.3±0.5, respectively; p<0.0001). With a SUV cutoff of 2.0 to differentiate between malignant and benign disease, a sensitivity was 93% and a specificity was 90%.

Conclusions: FDG PET imaging was a sensitive method to identify MPM.