Objective: To compare the N- and M-staging accuracy of PET vs CT, as per the American Joint Committee on Cancer (AJCC) eighth edition in patients with malignant pleural mesothelioma (MPM) being considered for multimodality therapy in a tertiary referral center. A secondary aim was to assess survival outcome of patients chosen for surgical management after PET.
Methods: A retrospective, single institution comparison of PET and CT was performed in patients with histologically proven MPM being considered for multimodality therapy. Performance of each modality in identifying nodal category and presence or absence of distant metastases was abstracted from electronic patient records. The standard of reference was surgical histopathology for nodal stage and histopathology or clinical and imaging follow-up of >3 months for distant metastases.
Results: There were 101 eligible patients with complete data sets; 82 males, 19 females with a mean age of 66.6 years (range: 39-85). Most patients (n = 68) had epithelioid histology. Surgery was performed in 61/101 patients (60.4%), most of whom had multimodality therapy. Nodal category was concordant to surgical histopathology in 38/60 patients (63.3%) on PET, compared to 27/60 (45%) on CT (p = 0.001). For detection of ≥N1 disease only, PET and CT correctly staged 15/37 patients (40.5%) and 8/37 (21.6%), respectively (p = 0.023). Distant metastases were identified uniquely on PET in eight patients and on CT only in one patient. Overall, PET and CT correctly identified 11/12 (91.6%) and 4/12 (33.3%) patients with distant metastases, respectively (p = 0.0391).
Conclusion: PET identifies significantly more patients with nodal or distant metastatic disease than CT and may contribute to more appropriate selection of patients with MPM for surgery or multimodality therapy. Advances in knowledge: In patients with MPM, fludeoxyglucose-PET/CT detects significantly more patients with distant metastases than CT. PET/CT can help in the selection of patients with MPM who would benefit from surgery or multimodality therapy.