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

OBJECTIVE

This study was aimed at evaluating the significance of 18 F-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 18 F-FDG PET/CT, and reviewed and analyzed 18 F-FDG PET/CT characteristics of the patients. Standardized uptake values (SUV max ), metabolic tumor volume (MTV), and total lesion glycolysis (TLG = MTV × SUV mean ) 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 SUV max 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 18 F-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 18 F-FDG PET/CT assessment of MPeM may improve the accuracy of staging; however, SUV max values showed slight variations depending on the pathology type. 18 F-FDG PET/CT can improve the accuracy of TNM staging, and SUV max values vary slightly depending on the pathology type. Furthermore, 18 F-FDG PET/CT can afford simultaneous visualization of lesions throughout the body, which can help develop a treatment strategy.