OBJECTIVE. A potential source of false-positive FDG PET interpretations in oncologic imaging is FDG uptake in brown fat. The purpose of this study was to determine the prevalence, location, and appearance of hypermetabolic brown fat in the mediastinum.MATERIALS AND METHODS. All PET/CT scans obtained at our cancer institution from August to October 2003 were retrospectively reviewed for increased FDG uptake in the mediastinum localized to fat on CT. The following features were recorded: location, appearance, maximal standard uptake value (SUVmax) of hypermetabolic mediastinal brown fat, and presence of extramediastinal brown fat.RESULTS. PET/CT scans were obtained in 845 oncologic patients. Fifteen patients (1.8%) with focal hypermetabolic mediastinal brown fat were identified: nine women and two men (age range, 27–79; mean, 55.1 years) and four children (age range, 5–16 years; mean, 10 years). Hypermetabolic mediastinal brown fat (mean SUVmax, 5.7) was more common in children (4/8) than in adults (11/837)...

Positron emission tomography (PET)/computed tomographic scanning, using 18F-2-deoxy-D-glucose, complements conventional imaging evaluation of patients with lung cancer. The strength of PET scanning lies in the detection of nodal and extrathoracic metastases. PET scanning is also currently being studied in the assessment of prognosis and therapeutic response and has the potential to alter management of oncologic patients. This review will discuss the role of PET/computed tomographic scanning in the diagnosis, staging, and evaluation of prognosis and treatment response in patients with lung cancer.

Malignant pleural mesothelioma (MPM) is an uncommon neoplasm arising from mesothelial cells of the pleura. The prognosis is poor with a median survival of 8 to 18 months after diagnosis. Multimodality regimens combining chemotherapy, radiotherapy, immunotherapy, and surgery are being used more frequently in patient management. Extrapleural pneumonectomy is the surgical treatment of choice in 10% to 15% of patients who present with resectable disease and is reported to prolong survival. Accurate staging is important to distinguish patients who are resectable from those requiring palliative therapy. Integrated computed tomography-positron emission tomography (CT-PET) increases the accuracy of overall staging in patients with MPM and significantly improves the selection of patients for curative surgical resection. Specifically, CT-PET detects more extensive disease involvement than that shown by other imaging modalities and is particularly useful in identifying occult distant metastases. This article reviews aspects of imaging performed in the initial staging of patients with MPM according to the International Mesothelioma Interest Group staging system and will emphasize the appropriate role of CT-PET imaging in determining the T, N, and M descriptors.