Clinical utility of 18F-FDG positron emission tomography in malignant peritoneal mesothelioma.

BACKGROUND The purpose of this study was to determine the utility of 18F-FDG-PET for evaluating the presence and the extent of malignant peritoneal mesothelioma (MPM), for disease surveillance/recurrence detection and for evaluating response to therapy. METHODS We retrospectively analyzed clinical and imaging data of 60 MPM patients (34 women and 26 men, mean age 53.6 y, range 18-80 y) who had multiple 18F-FDG-PET/CT or PET scans (18F-FDG scans) at various stages of the disease. RESULTS Eleven patients had baseline pretreatment scans and all 11 scans showed 18F-FDG avid diffuse, nodular or mixed disease distribution patterns characteristic of MPM. Four patients out of eleven had an early post-treatment 18F-FDG scan (<6 months) and all scans were accurate in determining response to treatment. Forty-nine patients with a history of treated MPM without baseline scans had multiple disease surveillance 18F-FDG scans. Their initial 18F-FDG scans had an accuracy of 82% and positive predictive value of 83% and negative predictive value of 80% for the detection of disease presence and disease-free state, respectively. For fifteen patients with a true negative 18F-FDG scan, a second follow-up scan accurately detected disease recurrence or absence of recurrence in all cases. Metastatic or remote nodal disease was more common in the biphasic histopathologic subtype group while pleural disease was predominantly seen in the epithelial MPM group. No relationship was found between the uptake pattern and the histopathologic subtype. CONCLUSION 18F-FDG-PET is a valuable imaging modality in the pre-surgical evaluation and management of MPM and further prospective studies are warranted.