Significance of 18F-fluorodeoxyglucose PET/computed tomography in the initial staging of malignant peritoneal mesothelioma.

Abstract

Objective: This study was aimed at evaluating the significance of 18F-fluorodeoxyglucose PET/computed tomography (FDG PET/CT) in the staging and differentiation of malignant peritoneal mesothelioma (MPeM).

Materials and methods: We retrospectively analyzed clinical and imaging data of 21 women and 21 men with MPeM who underwent 18F-FDG PET/CT, and reviewed and analyzed 18F-FDG PET/CT characteristics of the patients. Standardized uptake values (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG = MTV × SUVmean) were determined for peritoneal lesions at the highest glycolysis point. Two experienced readers assessed tumor-node-metastasis (TNM) staging and peritoneal cancer index according to Peritoneal Surface Oncology Group International diagnostic requirements.

Results: The SUVmax and MTV values were significantly lower for the epithelial cases than for the nonepithelioid cases, with the difference being significant (P < 0.05). The mean TLG value was significantly lower for the epithelial cases than for the nonepithelioid cases; however, the difference was NS (P > 0.05). Exploratory laparotomy was performed in 18 patients, the 18F-FDG PET/CT diagnostic accuracy for the T stage was 72.2%, and the TNM stage diagnostic accuracy was 94.4%. However, lymph node metastasis was more common in the biphasic type group, and metastasis was more often seen in the sarcomatoid type group.

Conclusion: Using a previously suggested novel approach for TNM staging in 18F-FDG PET/CT assessment of MPeM may improve the accuracy of staging; however, SUVmax values showed slight variations depending on the pathology type. 18F-FDG PET/CT can improve the accuracy of TNM staging, and SUVmax values vary slightly depending on the pathology type. Furthermore, 18F-FDG PET/CT can afford simultaneous visualization of lesions throughout the body, which can help develop a treatment strategy.