Use of PET/CT in Diagnosis and Staging of Malignant Pleural Mesothelioma

Background The pleural space is formed by two pleural membranes: the parietal pleura and the visceral pleura. Each is comprised of a single layer of mesothelial cells, a basement membrane, and a layer of connective tissue which contains blood vessels and lymphatics. Various benign, malignant, and tumor-like conditions can involve the pleura. Malignant neoplasms are more common than benign neoplasms. Pleural tumors can have a varied imaging spectrum – may be unilateral or bilateral, calcified, or noncalcified, and focal or diffuse. Aim of the Work To elucidate the role of PET/CT in diagnosing and staging of malignant pleural mesothelioma (MPM) patients. Patients and Methods A cross sectional analysis of all cases of malignant mesothelioma referred to Elmaadi Military hospital during the period from Nov. 2020 to Jun. 2021 for assessment of the role of F18-FDG PET/CT in staging, restaging and monitor of therapy response compared to CT. The total number of patients with mesothelioma was 30 patients, 20 males and 10 females. Results In the present study, 27 patients out of 30 patients evaluated with PET/CT showed positive findings at primary sites in pleura and accurately localized tumor sites in them. Also 9 patients of them had local lesions in pleura only with 6 patients had loco-regional lesions. Furthermore 12 patients had loco-regional and metastatic lesions. We demonstrate that PET/CT has high sensitivity than CT in detecting MPM lesions specially intrathoracic lymph node and extrathoracic metastasis as (37% vs. 18 %) of PET/CT and CT respectively. Conclusion FDG PET/CT increases the accuracy of overall staging in patients with MPM and significantly improves the selection of patients for curative surgical resection. Specifically, FDG PET/CT is particularly useful in identifying mediastinal lymph node involvement and detection of distant metastases.