FDG PET imaging of childhood sarcomas

Positron-emission tomography (PET) imaging using [(18)F]fluorodeoxyglucose (FDG) is useful for detection, staging, and monitoring a variety of malignancies, including lymphoma, in adults, but its utility in sarcomas, especially soft tissue sarcomas (STS), in children and young adults is not clear.

To evaluate the potential utility of FDG PET in the care of STS in children and young adults, we analyzed 46 PET scans in 25 patients acquired over 12 years. Scans were interpreted by two imaging physicians blinded to findings from other imaging studies and clinical information. Results were compared with computed tomography and magnetic resonance imaging, biopsy results, where available, and clinical follow-up of at least 12 months.

For a total of 46 scans in 25 patients, there were 25 true-positive scans, 3 false-positive scans, 12 true-negative scans, and 6 false-negative scans. The sensitivity of the PET scan was 86%, specificity was 80%, positive predictive value was 89%, and negative predictive value was 67%.

FDG PET may be a useful imaging modality in the management of children and young adults with STS, although prospective studies are needed to establish its true utility.