How can we Use PET/ CT More Accurately for Characterization of Asbestos-related Pleural Thickening?

Abstract

IntroductionThere is no consensus about standardized uptake value maximum (SUVmax) cut-off value to characterize pleural thickening worldwide. Sometimes, this causes unnecessary invasive diagnostic procedures. Our first aim is to determine a cut-off value for SUVmax. Secondly, we try to answer this question “If we use this cut-off value together with morphological parameters, can we differentiate benign thickening from Malignant pleural mesothelioma (MPM) more accurately”.Material and methodsThirty-seven patients with performed 2-deoxy-2-[18F]-fluoro-D-glucose ([18F]FDG-PET/CT) before pleural biopsy included the study. All of patients had histopathologically proven primary pleural disease. Their [18F]FDG-PET/CT imaging reports were re-assessed. If patient’s SUVmax or size of the thickening was not mentioned in report, we calculated them with their [18F]FDG-PET/CT.ResultsAge, pleural effusion, size, and SUVmax were found a relationship with MPM. We found the size>14 mm, and SUVmax>4.0 as cut-off values for MPM. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for size>14 mm were found as 86.4%, 85.2%, 82.6%, 88.5%, respectively. For SUVmax>4.0; sensitivity, specificity, PPV, NPV were 90.9%, 87.0%, 85.1%, 92.2%, respectively.ConclusionsIf a patient has SUVmax>4.0 and/or size>14 mm, the risk of MPM is high. These patients should be undergone biopsy. If patient’s SUVmax<4.0, size<14 mm and does not have pleural effusion, he/she has low risk for MPM. These patients can be undergone to the follow-up. If a patient's SUVmax<4, Size<14, and has pleural effusion MPM risk is approximately 4%. These patients can be undergone biopsy/cytology/follow-up. Novel studies are needed for these patients.