Imaging description

Talc pleurodesis is performed to obliterate the pleural space to prevent recurrent pleural effusion or spontaneous pneumothorax. All pleural fluid present is drained and talc is insufflated at thoracoscopy or instilled as a slurry by chest tube. Talc is a chemical irritant causing an intense inflammatory response. The leukocytes in this inflammatory response accumulate FDG avidly, outlining the talc-treated pleural. After months, the inflammation often becomes irregular along the pleural surface. This activity on PET lasts for years and possibly over a decade. The intense pleural activity mimics that seen in mesothelioma and pleural metastasis (Figure 79.1). The increased attenuation of talc can best be seen in the pleural reflections on CT [1, 2].

Importance

Incorrect interpretation of increased FDG accumulation along the pleura due to talc pleurodesis could have significant adverse consequences. The intense pleural uptake of FDG on PET/CT secondary to talc pleurodesis can be misinterpreted as recurrent or metastatic malignancy. The pleural activity from talc can obscure the evaluation of pleural disease and mesothelioma [3].