Integrated Positron Emission Tomography-Computed Tomography Does Not Accurately Stage Intrathoracic Disease of Patients Undergoing Trimodality Therapy for Malignant Pleural Mesothelioma

Department of Thoracic Surgery, Guy's Hospital, London, UK.
The Thoracic and Cardiovascular Surgeon (Impact Factor: 1.08). 06/2010; 58(4):215-9. DOI: 10.1055/s-0029-1241029
Source: PubMed

ABSTRACT The results of trimodality therapy for malignant pleural mesothelioma (MPM) are related to stage. Staging can be carried out by computed tomography (CT), magnetic resonance imaging and fluorodeoxyglucose positron emission tomography (FDG-PET), but all modalities suffer from limitations. We investigated whether integrated PET-CT improved the intrathoracic staging of patients undergoing trimodality therapy for MPM.
Twenty consecutive patients [18 male, median age 62 years (range 52-68)] who underwent 24 PET-CT scans prior to extrapleural pneumonectomy (EPP) as part of trimodality therapy for MPM were reviewed. The intrathoracic stage of MPM on PET-CT was compared with the pathological stage following examination of the resected specimen. Patients excluded from radical surgery due to metastatic disease were not studied here.
PET-CT was performed a median of 119 days (range 2-229) prior to EPP. 16 scans were performed after talc pleurodesis. Nine scans were performed following chemotherapy. PET-CT correctly identified the T stage in 3 patients, overstaged 4 and understaged 17. Six scans failed to identify disease that later proved to be pT4. Nine patients were found to have pN2 disease; PET-CT identified N2 disease with a sensitivity of 11.1 %, specificity of 93 % and accuracy of 66 %. Previous talc pleurodesis did not alter the accuracy of PET-CT staging.
In one of the few studies of integrated PET-CT in MPM that has complete pathological correlation we have shown that PET-CT does not accurately identify advanced tumor stage (T4) or mediastinal nodal disease (N2). The role of PET-CT staging prior to EPP lies outside the affected hemithorax.

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