Computed Tomography, Positron Emission Tomography, Positron Emission Tomography/Computed Tomography, and Magnetic Resonance Imaging for Staging of Limited Pleural Mesothelioma: Initial Results

Investigative Radiology. 2008 Oct;43(10):737-44. [Link]

Plathow C, Staab A, Schmaehl A, Aschoff P, Zuna I, Pfannenberg C, Peter SH, Eschmann S, Klopp M.

Department of Diagnostic Radiology, University of Tuebingen, Tuebingen, Germany. christian.plathow@uniklinik-freiburg.de

Abstract

Objective: To evaluate and compare the role of computed tomography (CT), positron emission tomography (PET), PET/CT, and magnetic resonance imaging (MRI) in the correct staging of patients with limited malignant pleural mesothelioma (MPM).

Materials and Methods: Fifty-four patients with an epithelial MPM (34 men and 20 women) were included in this study. Patients were referred to our department for staging in a predicted resectable state (stage II/III). Within 3 days, PET/CT and MRI was performed in all patients. Images were evaluated by 3 specialists in the field of PET/CT and MRI. The subexaminations of PET/CT, PET, and CT were independently evaluated with respect to tumor stage. Subexaminations were compared with each other, with MRI and PET/CT. N-stage was verified by mediastinoscopy. Afterward, consensus reading was performed.

In 52 patients, surgery served as gold standard. In 2 patients, follow-up control served as gold standard as an inoperable situation with distant metastases was found. Additionally, interobserver variability ([kappa] value) was calculated.

Results: In stage II, accuracy was 0.77 (CT), 0.86 (PET), 0.8 (MRI), 1.0 (PET/CT), and in stage III 0.75, 0.83, 0.9, 1.0. PET/CT was significantly more accurate (P < 0.05) in stages II and III compared with all other techniques. CT and MRI were not able to detect distant metastases in 2 patients, which changed therapy (operable vs. inoperable). Interobserver variability was 0.7, 0.9, 0.8, 1.0 in stage II and 0.9, 0.9, 0.9, 1.0 in stage III.

Conclusion: PET/CT makes it possible to stage patients with limited MPM with high accuracy and low interobserver variability.